NRC-PSEG Public Meeting on Hydrology Storm Surge Analysis

DRAFT August 12, 2014

PSEG Letter ND-2014-00XX, dated August 22, 2014

ENCLOSURE 1

Response to RAI No. 67

Question Nos. 02.04.05-12 02.04.05-13 02.04.05-14 02.04.05-15 02.04.05-16 02.04.05-17

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Response to RAI No. 67, Question 02.04.05-12:

In Reference 2, the NRC staff asked PSEG for information regarding the Probable Maximum Surge and Seiche Flooding, as described in Subsection 2.4.5 of the Site Safety Analysis Report. The specific request for Question 02.04.05-12 was:

Supplement to RAI 39, Question 2.4.5-6:

To show compliance with 10 CFR 52.17, PSEG should evaluate the storm surge induced by the PMH at the site as recommended by Regulatory Guide 1.59 and supplemented by current best practices. NUREG-0800, Standard Review Plan (SRP), Chapter 2.4.5, ‘Probable Maximum Surge and Seiche Flooding,’ establishes criteria that the NRC staff applies to evaluate whether PSEG meets the NRC's regulations. SSAR Sections 2.4.5.2.2.2 and 2.4.5.2.2.3 discuss application of the SLOSH storm surge model to develop the surge at the mouth of Delaware Bay and at the proposed project site.

In response to RAI 39, Question 2.4.5-6 (ML11349A356), PSEG provides information on the PMH storm parameters as referenced and some additional information on SLOSH storms applied in comparison. Since SLOSH applies MOM (maximum of maximums) analysis, NRC staff is unable to completely determine individual storm characteristics that produced the SLOSH results presented in the ESP application (Revision 1). The PSEG response to RAI 39, Question 2.4.5-6 also states that maximum SLOSH water level at the project site equals 22.8 ft-NAVD (SSAR page 2.4-77) which is still below the PMH surge estimates (Bodine/HEC-RAS/Wind Setup) after adding the 10% high tide (SSAR page 2.4-77). No additional SLOSH runs have been conducted by PSEG since the site safety audit.

Through independent confirmatory analysis, NRC staff determined that application of PMH storm parameters as input in the SLOSH model produces water surface elevations that exceed the publicly available SLOSH Display Program (V. 1.61g) data for Category 4 storms in the PSEG Site area. In order to show compliance with the requirements of 10 CFR 52.17 and evaluate the methods applied, NRC staff requests that PSEG provide an analysis of the PMH events using a conservative, current practice approach such as those predicted by a two-dimensional storm surge model (e.g., ADCIRC, FVCOM, SLOSH, other) with input from appropriate PMH scenarios and with resolution that captures the nuances of the bathymetry and topography near the project site. Note that, to account for wave-induced water level effects (wave setup), PSEG will likely need to couple a nearshore wave transformation model to a hydrodynamics model.

PSEG Response to NRC RAI:

PSEG has performed a confirmatory analysis of the PMH storm parameters presented in SSAR Subsection 2.4.5.2 using the ADCIRC+SWAN modeling platform. Enclosure 2

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includes a revision to SSAR Subsection 2.4.5, in which the confirmatory analysis is presented. A description of the modeling system, PMH simulations performed, and a comparison of the results are provided. The confirmatory PMH simulations used the same input parameters applied to the ADCIRC+SWAN modeling system as the existing Bodine, Kamphuis and HEC-RAS modeling approach used to determine the design basis storm surge water surface elevation (WSEL). The results show that the Bodine, Kamphuis and HEC-RAS model produces conservative WSELs at the PSEG Site when compared to the ADCIRC+SWAN model. A summary of the ADCIRC+SWAN results for modeling the PMH storm, including still water level (SWL), wave runup, 10 percent exceedance high tide, 100 year projected sea level rise and total water level (TWL) is provided below. The input parameters to each PMH simulation are provided in SSAR Table 2.4.5-4 (see Enclosure 2). When simulated using the existing Bodine, Kaphuis and HEC-RAS modeling approach, the maximum WSEL due to the PMH event is 42.4 ft. NAVD.

The antecedent water level in the ADCIRC+SWAN model is adjusted through the sea surface height adjustment parameter, and by doing so, raises the water level throughout the entire model domain by that amount. For example, adjusting the initial conditions to account for both sea level rise and the 10 percent exceedance high tide raises the initial water level by 5.85 ft throughout the entire model domain (e.g., the Western North Atlantic Ocean, Gulf of Mexico, and Caribbean Sea). Although this may be appropriate for the potential sea level rise, which would be a widespread effect, tides are localized increases and coincident decreases in sea level that don’t represent a net increase in water volume. Artificially raising water levels throughout the entire model domain in this manner will likely lead to conservative results at the site given the geometry of Delaware Bay and the funneling effect that the geometry causes with water being pushed up the bay. That is, the added volume of water that is artificially introduced into the model will most likely be pushed up into the bay during the PMH simulation leading to artificially higher flood levels at the PSEG Site.

The first simulation set the antecedent water level at 0 ft. NAVD and subsequently added potential sea level rise and 10 percent exceedance high tide to the maximum total WSEL determined. The below table provides the results at the PSEG Site.

Flooding Source Value

Maximum SWL (ft, NAVD)a 18.63

Runup (ft)a 7.51

Maximum SWL + Runup (ft, NAVD) 26.14

10% Exceedance High Tide (ft, NAVD) 4.50

100-yr Projected Sea Level Rise (ft) 1.35

Total WSEL (ft, NAVD) 31.99

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a) Indicates the individual SWL and Runup values that produce the maximum total WSEL combination when the time series values are added together.

The second simulation set the antecedent water level equal to the estimated potential sea level rise (see SSAR Subsection 2.4.5.4) at 1.35 ft. NAVD and subsequently added 10 percent exceedance high tide to the maximum total WSEL determined. The below table provides the results at the PSEG Site.

Flooding Source Value

Maximum SWL (ft, NAVD)a 20.16

Runup (ft)a 7.43

Maximum SWL + Runup (ft, NAVD) 27.59

10% Exceedance High Tide (ft, NAVD) 4.50

Total Flood Level (ft, NAVD) 32.09

a) Indicates the individual SWL and Runup values that produce maximum total WSEL combination when the time series values are added together.

The third simulation set the antecedent water level equal to the estimated potential sea level rise and 10 percent exceedance high tide at 5.85 ft. NAVD to determine the maximum total WSEL. The below table provides the results at the PSEG Site.

Flooding Source Value

Maximum SWL (ft, NAVD88)a 25.27

Runup (ft)a 7.74

Maximum SWL + Runup (ft, NAVD88) 33.01

Total Flood Level (ft, NAVD88) 33.01

a) Indicates the individual SWL and Runup values that produce the maximum total WSEL combination when the time series values are added together.

The confirmatory PMH simulations in the ADCIRC+SWAN modeling system produce maximum WSELs approximately 10 ft. below the equivalent maximum WSEL of the Bodine, Kaphuis and HEC-RAS modeling approach. Varying the antecedent water levels of the model simulations from 0 ft. NAVD to 5.85 ft. NAVD to conservatively account for potential sea level rise and the 10 percent exceedance high tide results in an approximate 1 ft. difference in maximum WSEL at the PSEG Site.

Based on the confirmatory PMH simulations performed in the ADCIRC+SWAN modeling system, it is shown the Bodine, Kaphuis and HEC-RAS modeling approach

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produces conservative resultant WSELs at the PSEG Site when the same input parameters are applied.

Associated PSEG Site ESP Application Revisions:

Enclosure 2 contains proposed revisions to SSAR Subsection 2.4.5. Figures 2.4.5-8 through 2.4.5-11, and Table 2.4.5-4 are provided in Enclosure 2 and added to the SSAR based on the response to this question.

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Response to RAI No. 67, Question 02.04.05-13:

Supplement to RAI 39, Question 2.4.5-8:

To show compliance with 10 CFR 52.17, PSEG should evaluate the storm surge induced by the PMH at the site as recommended by Regulatory Guide 1.59 and supplemented by current best practices. NUREG-0800, Standard Review Plan (SRP), Chapter 2.4.5, ‘Probable Maximum Surge and Seiche Flooding,’ establishes criteria that the NRC staff applies to evaluate whether PSEG meets the NRC's regulations. SSAR Section 2.4.5.2.2.3 discusses application of the Kamphuis wind setup model to estimate wind-induced water level changes from the mouth of Delaware Bay (developed by the Bodine model) to the project site approximately 80 km (50 miles) inland.

In response to RAI 39, Question 2.4.5-8 (ML11349A356), PSEG provides equations and details of the analysis for the SSAR wind setup calculation. PSEG states that fetch development applies the longest possible fetch (53+ miles) and that the wind setup files are located in Enclosure 3. PSEG also discusses that the shape of bay/estuary is known to alter tide, surge propagation and height, and that the combined HEC-RAS/Wind Setup model results show amplification of surge (also indicated by a historical storm data). Finally, PSEG provides a comparison to SLOSH amplification that shows that the SLOSH model produces a similar (5.5 ft versus 6 ft) increase in storm surge from the bay mouth to the project site. However, the PSEG response to RAI 39, Question 2.4.5-8 does not provide a direct method for wind setup that includes shape of bay.

In order to show compliance with the requirements of 10 CFR 52.17 and evaluate the methods applied, NRC staff requests that PSEG provide:

(1) a discussion of depth values applied by the wind setup method. The PSEG response to RAI 39, Question 2.4.5-8 states that bathymetry along the fetch line is applied in the wind setup model, but the bathymetry values necessary to calculate the total water depth are not clearly provided. The wind setup calculation depends on the total water depth and the bathymetric location applied in the wind setup calculation is important (but not clearly demonstrated). The bathymetry across Delaware Bay varies significantly so the depth value can vary widely depending on where the value is chosen.

(2) a discussion of what wind speed averaging was applied to develop the wind speeds applied in the wind setup calculations. The PSEG response to RAI 39, Question 2.4.5-8 does not clearly describe the wind field

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averaging method applied in the application of the wind speeds within the wind setup calculation.

Note, using a conservative, current practice approach, such as those predicted by an execution of a two-dimensional storm surge model (e.g., SLOSH) with input from appropriate PMH scenarios, will account for the shape of the bay when developing wind-induced water level changes from the mouth of Delaware Bay to the project site approximately 80 km (50 miles) inland. This methodology will negate the need for combining multiple models and methods.

PSEG Response to NRC RAI:

(1) Bathymetric data for the Delaware Bay was obtained from NOAA’s National Ocean Service Estuarine Bathymetry Data Set (SSAR Reference 2.4.3-11), as described in SSAR Subsection 2.4.5.2.2.3. A bathymetric profile along the wind setup fetch is generated from this data to provide the elevation of the bottom of the bay at 10- meter intervals along the 85.4 kilometer (53.1 mi.) fetch. Wind setup is calculated in a step-wise manner at every 10 meters along the fetch, starting at the midpoint of the fetch and stepping toward the site. The initial depth of water is measured below the water surface elevation (WSEL) representing the surge plus tide that is calculated using HEC-RAS at the midpoint of the fetch, River Mile 24.92. The WSEL calculated using HEC-RAS at the midpoint of the fetch is conservatively applied along the entire length of the fetch. The total water depth used in the wind setup calculations for each 10-meter interval is equal to the initial depth of water plus the cumulative water level rise due to wind setup calculated along the fetch from the previous interval. This fetch accounts for a varied bathymetric contour along the Delaware Bay, ranging from the shallow areas near the shorelines to the deeper areas near the navigational channel.

The response to RAI No. 67, Question No. 02.04.05-12 presents a confirmatory analysis of the PMH storm surge event using the ADCRIC+SWAN modeling system. While there may be certain limitations associated with the ability of the Kamphuis wind setup methodology to capture the nuances of the bathymetry and variable hurricane wind directions across the Delaware Bay, the overall combination of models and methods produces a conservative estimate of the maximum WSEL associated with the PMH storm surge event when compared to ADCRIC+SWAN results.

(2) There is no wind speed averaging applied to the wind speeds used within the wind setup calculation. As described in the response to RAI 39, Question 2.4.5-8 (Reference 3), the wind speed and direction are calculated at the midpoint of the fetch line during the PMH simulation in accordance with NOAA NWS 23 (SSAR Reference 2.4.5-19). The wind speed and direction calculated at the fetch midpoint are applied to the entire length of the fetch without any averaging. This procedure is repeated for the wind setup calculations for each time step.

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Associated PSEG Site ESP Application Revisions:

None.

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Response to RAI No. 67, Question 02.04.05-14:

Supplement to RAI 39, Question 2.4.5-9:

To show compliance with 10 CFR 52.17, PSEG should evaluate the storm surge induced by the PMH at the site as recommended by Regulatory Guide 1.59 and supplemented by current best practices. NUREG-0800, Standard Review Plan (SRP), Chapter 2.4.5, ‘Probable Maximum Surge and Seiche Flooding,’ establishes criteria that the NRC staff applies to evaluate whether PSEG meets the NRC's regulations. SSAR Section 2.4.5.3.1 discusses the development of the wave runup at the PSEG Site.

In order to show compliance with the requirements of 10 CFR 52.17 and evaluate the methods applied, NRC staff requests that PSEG provide the following:

(1) Clarification on the time of maximum still water level provided in response to RAI 39, Question 2.4.5-9. In the PSEG response to RAI 39 (ML11349A356), Question 2.4.5-9, the simulation time of maximum still water level (21.0 hours) does not match the maximum still water level in Table 2.4.5.1 in the SSAR (Revision 1) and Table RAI 39-9-2 (20.5 hours). PSEG also states the design flooding condition occurs at simulation time 21.5 hours when Table 2.4.5.1 in the SSAR and Table RAI 39-9-2 indicate 21.0 hours.

(2) The relationship between the two wind speeds listed in PSEG response to RAI 39, Question 2.4.5-9, Table 39-9-1 (Column 2 and Column 4).

PSEG Response to NRC RAI:

(1) A typographical error was identified in the response text of RAI No. 39 Question No. 02.0.4.05-9 (Reference 3) regarding the reported simulation time for maximum still water level (SWL) and the time of the design flooding condition when SWL plus wave runup reaches its maximum elevation. The correct simulation time of maximum SWL is 20.5 hours. Similarly, the correct simulation time of the design flooding condition when SWL plus wave runup reaches its maximum elevation is 21.0 hours. These values are consistent with SSAR Table 2.4.5-1 and Table RAI 39-9-2.

(2) The wind speed in Column 4 of Table 39-9-1 in PSEG’s response to RAI No. 39 Question No. 02.0.4.05-9 (Reference 3) is the average of the wind speeds in Column 2 for the averaging period shown in Column 6., Table RAI 67-14-1, which includes additional columns with notes describing the procedure used to average the

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wind speed values and directions is provided to clarify the relationship between the two wind speeds in Table RAI 39-9-1.

Associated PSEG Site ESP Application Revisions:

None.

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Table RAI 67-14-1 Wind Speed and Direction Information Used to Calculate Wave Runup Sheet 1 of 2

Resultant Component of Average Average of Resultant Wind Angle (θ) Component Direction Angle for Resultant Wind W Averaging of W W Wind Speed Simulation Speed from of W along T N from Runup Direction Direction perpendicular Time along perpendicular (R) for Time (hr) (W) Traverse traverse Traverse (β) =318.24 for (From) to traverse Period traverse to traverse Runup (mph) (Degree) (W ) (mph) for Runup - β Runup T (W ) (mph) (mph) (mph) (mph) N (Degree) Note (1) Note (2) Note (3) Note (4) Note (5) Note (6) Note (7) Note (9) 1 2 3 4 5 6 7 8 9 10 11 12 13 17.5 73.2 NE 97.43 -9.46 72.57 N/A8 N/A8 N/A8 N/A8 N/A8 N/A8 N/A8

8 8 8 8 8 8 8 DRAFT DRAFT 18.0 83.6 NE 94.97 -7.25 83.28 N/A N/A N/A N/A N/A N/A N/A 18.5 91.0 NE 90.31 -0.49 90.95 N/A8 N/A8 N/A8 N/A8 N/A8 N/A8 N/A8 August August 19.0 100.6 NE 82.92 12.40 99.8 17.5-19.0 -1.20 86.65 86.66 90.79 227.45 NE 12, 12, 19.5 112.4 ENE 71.47 35.73 106.61 18.0-19.5 10.10 95.16 95.69 83.94 234.30 ENE 2014 2014 20.0 123.2 E 54.49 71.55 100.29 19.0-20.0 39.89 102.23 109.74 68.68 249.56 ENE 20.5 132.4 ESE 32.43 111.77 71.01 19.5-20.5 73.02 92.64 117.95 51.75 266.49 E 21.0 134.4 SE 9.49 132.52 22.16 20.0-21.0 105.28 64.49 123.46 31.49 286.75 ESE 21.5 128.9 SE 352.50 127.76 -16.81 20.0-21.5 110.90 44.16 119.37 21.71 296.53 ESE 22.0 118.6 SSE 342.38 113.03 -35.89 20.0-22.0 111.32 28.15 114.83 14.19 304.05 ESE 22.5 108.2 SSE 335.53 98.50 -44.82 19.5-22.5 98.69 28.94 102.85 16.34 301.90 ESE 23.0 97.0 SSE 329.80 83.83 -48.79 19.0-23.0 87.45 28.17 91.88 17.86 300.38 ESE 23.5 87.8 S 326.34 73.10 -48.69 18.5-23.5 78.15 26.89 82.65 18.99 299.25 ESE 24.0 78.9 S 322.15 62.28 -48.39 22.5-24.0 79.43 -47.67 92.64 -30.97 349.21 S

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Table RAI 67-14-1 Wind Speed and Direction Information Used to Calculate Wave Runup Sheet 2 of 2

Notes: 1) Direction of traverse 318.24 degree

2) WT=W x cos(θ)

3) WN=W x sin (θ) 4) Values from Column 5 are averaged over the time period identified in Column 7 5) Values from Column 6 are averaged over the time period identified in Column 7 DRAFT DRAFT 2 2 0.5 6) R = (WT + WN ) August August 7) For WN >0 and WT >0, β = tan-1 (WN/WT)

For WN >0 and WT < 0, β = 180 + tan-1 (WN/WT) 12, 12, For W <0 and W > 0, β = tan-1 (W /W ) 2014 2014 N T N T

For WN <0 and WT < 0 ; N/A therefore not specified 8) The averaging period begins at hour 19.0 using the previous 1.5 hrs of data. 9) The resultant direction for wave runup is the closest fetch applied to the time step based on the value computed in Column 12.

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Response to RAI No. 67, Question 02.04.05-15:

Supplement to RAI 39, Question 2.4.5-10:

To show compliance with 10 CFR 52.17, PSEG should evaluate the wind- induced wave runup under PMH or PMWS winds with runup estimates based on USACE Coastal Engineering Manual equations and supplemented by current best practices. NUREG-0800, Standard Review Plan (SRP), Chapter 2.4.5, ‘Probable Maximum Surge and Seiche Flooding,’ establishes criteria that the NRC staff applies to evaluate whether the applicant meets the NRC's regulations. SSAR (Revision 1) Section 2.4.5.3.2 discusses the development of the wave runup estimate for the project site.

The PSEG response to RAI 39, Question 2.4.5-10 (ML11349A356), provides equations and discussion on the methods applied to develop wave runup at site. The discussion details wave height calculation (CEM), fetch calculation, wind speed adjustment (NWS 23), and runup calculation. However, the discussion provides only limited details of values applied in analysis; no table to show different scenarios, fetch directions, wind speeds, etc. The discussion ends with a final runup equation (D’Angremond and van Roode) with the addition of surface roughness coefficient (0.5 for rip-rap).

The NRC staff has concerns that fall within two different areas:

1. Overall, the wave height calculation methodology appears satisfactory. However, the PSEG response to RAI 39, Question 2.4.5-10 (Enclosure 1, Page 27, paragraph 2) indicates that the maximum wave height = 1.67Hmo and also equates the significant wave height with Hmo.

i. Hmo is not equivalent to the significant wave height (H1/3); however, the approximation Hmo = H1/3 is common and acceptable.

ii. CEM Equation II-1-132 (SSAR Reference 2.4.5-27, page II-1-74) gives the following relationships: H1/100 = 1.67 H1/3 Hmax = 1.86 H1/3

The relationship between maximum wave height and significant wave height on Enclosure 1, Page 27, appears inaccurate; however, designing to H1/100 (the 1% wave height) versus Hmax is generally acceptable.

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In order to show compliance with the requirements of 10 CFR 52.17 and evaluate the methods applied, NRC staff requests that PSEG provide a reference to the Hmax = 1.67H1/3 relationship or update the SSAR to indicate the H1/100 design.

2. Based on the NRC staff review of the PSEG response to RAI 39, Question 2.4.5-10, the runup equation (RAI 39-10-11) is derived from CEM Section II-4-4- a(1). The PSEG RAI response shows the runup estimates apply a roughness coefficient equal to 0.5 to this equation.

i. The CEM equation applied calculates runup on beaches, while the estimate at the project site requires a calculation for runup on a rubble structure. CEM Section VI-5-2 discusses more appropriate equations and calculations for runup on structures.

ii. The roughness coefficient listed in the PSEG response to RAI 39, Question 2.4.5-10 does not apply to equation RAI 39-10-11. The roughness coefficient and method of application relates to formulas in CEM Section VI-5-2. The equations listed in CEM Section VI-5-2 have additional parameters when compared to the runup equation applied in the PSEG response to RAI 39, Question 2.4.5-10 (equations derived from CEM Section II-4-4-a(1)). The additional parameters may result in higher runup estimates, even when applied in combination with the roughness coefficient.

iii. The equation/discussion in the PSEG response to RAI 39, Question 2.4.5-10 does not indicate the exceedance level of the runup (e.g. 0.1 %, 2%, etc.). As listed in the PSEG response, the application of the roughness coefficient and the CEM Section II-4-4-a(1) formula would appear to give an exceedance level of 50% (i.e. 50% of incident waves will produce a higher runup).

In order to show compliance with the requirements of 10 CFR 52.17 and evaluate the methods applied, NRC staff requests that PSEG provide additional justification for the equation applied to develop the runup (i.e., justification for the use of a roughness coefficient with the CEM section II-4-4-a(1) equation). In addition, NRC staff requests that PSEG provide a discussion on the exceedance level of the runup estimate developed and the appropriateness of that exceedance level.

PSEG Response to NRC RAI:

The wave runup methodology described in SSAR Subsection 2.4.5.3 has been revised to use the methodology presented in USACE Coastal Engineering Manual (CEM), Chapter VI-5. Enclosure 2 provides a revised SSAR Subsection 2.4.5.3 which details the methodology used, input parameters at critical time steps and resulting wave runup

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values. The revised methodology increases the maximum WSEL due to the PMH event to 42.4 ft. NAVD.

Associated PSEG Site ESP Application Revisions:

Enclosure 2 contains proposed revisions to SSAR Subsection 2.4.5.3, Table 2.4.5-1, and Figure 2.4.5-7. Table 2.4.5-5 is added to the SSAR based on the response to this question.

Enclosure 2 contains proposed revisions to other SSAR Chapter 2 Subsections to reflect the results presented in SSAR Subsection 2.4.5. SSAR Figure 2.4.2-7 has been revised.

Enclosure 2 contains proposed revisions to ER Subsection 2.3.1 to reflect the results presented in SSAR Subsection 2.4.5.

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Response to RAI No. 67, Question 02.04.05-16:

Supplemental Question To show compliance with 10 CFR 52.17, PSEG should evaluate the storm surge induced by the PMH at the site as recommended by Regulatory Guide 1.59 and supplemented by current best practices. NUREG-0800, Standard Review Plan (SRP), Chapter 2.4.5, “Probable Maximum Surge and Seiche Flooding,” establishes criteria that the staff applies to evaluate whether PSEG meets the NRC regulations. SSAR (Revision 1) Sections 2.4.5.2.1 and 2.4.5.2.2 discuss application of the HEC-RAS model to propagate the storm surge at the mouth of Delaware Bay (developed by the Bodine model) to the project site approximately 80 km (50 mi) inland.

In response to RAI 25 (ML11179A080, June 23, 2011, and ML11195A163 (Supplemental), July 7, 2011), PSEG provided four DVDs with HEC-RAS related files, data, and a user's guide for data. Review of data indicates that some questions still remain.

After reviewing the Surface Water Digital Files User’s Guide (referenced in PSEG's Supplemental Response to RAI 25, dated July 7, 2011 (ML11195A163)), the NRC staff has the following comments and observations:

An NRC staff review of the HEC-RAS geometry file and model setup (i.e., MASTER.g01) shows the roadways leading to the two bridges are not included in the model. The surge flow could have been partially blocked by the roadways. PSEG possibly used an ineffective flow scheme (HEC-RAS model ineffective flow area method) instead. In order to show compliance with the requirements of 10 CFR 52.17 and evaluate the methods applied, the NRC staff requests that PSEG provide a discussion and justification for the model setup applied.

An NRC staff review of the unsteady HEC-RAS model (Delaware_River_Hydraulic_Model) surge calibration run (Plan: Surge_calibration_1933) provides the following comments and observations:

An NRC staff review of a PSEG animation of the longitudinal water surface profile appears to indicate model numerical instability during the simulation. The numerical instability occurs to a degree that could affect calibration and model prediction values. In order to show compliance with the requirements of 10 CFR 52.17 and evaluate the methods applied, the NRC staff requests that PSEG describe any steps taken steps to minimize

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the model instabilities. If steps were taken to reduce model instabilities, please describe how these steps affected the model calibration.

An NRC staff review of the unsteady HEC-RAS model (Delaware_River_Hydraulic_Model) Probable Maximum Hurricane (PMH) surge run (Plan: PMH_R28_T26_25YR_FLD_DYNAMIC) provides the following comments and observations:

The PSEG animation of the longitudinal water surface profile appears to indicate model numerical instability during the simulation. The instability appears very pronounced just before the passing of the peak surge wave for the PMH surge run (as presented in the HEC-RAS Model run screen shots pasted below). In order to show compliance with the requirements of 10 CFR 52.17 and evaluate the methods applied, the NRC staff requests that PSEG describe any steps taken steps to minimize the model instabilities. If steps were taken to reduce model instabilities, please describe how these steps affected the model results.

PSEG Response to NRC RAI:

Question No. 02.04.05-16 presents two major questions (1) clarification of the modeling technique used for bridge approach embankments in HEC-RAS, and (2) further discussion of model oscillations, which appear to indicate model instabilities. Response to these two questions is provided below.

Bridge Approach Embankments

Question No. 02.02.05-16 request clarification regarding the HEC-RAS modeling technique used for the bridge approach embankments for the Delaware Memorial Bridge (I-295, approximately 17.5 miles upstream of the PSEG Site) and the Commodore Barry Bridge (US-322, approximately 30 miles upstream of the PSEG Site). Figure RAI 67-16-1 shows the model profile provided in Reference 2 and the location of the two bridges represented in the HEC-RAS model. The current HEC-RAS model uses an ineffective-flow-area methodology to represent the approach embankments, but it does not explicitly key in the embankment on either side of the bridge into the data editor. To assess the effects of this modeling technique, the HEC- RAS model is modified to include approximations of the bridge approach embankments in order to gauge the sensitivity of the current modeling results versus the modified modeling results.

The HEC-RAS model geometry file is modified to include the approximate bridge roadway approaches using estimates based on available information. The PMH simulation is re-run in HEC-RAS and the resultant water surface elevations (WSELs) at the PSEG Site are computed. The difference between the current and modified modeling method of representing the bridge approaches were then compared.

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Table RAI 67-16-1 presents the resulting peak WSEL and peak flow (Q) resulting at the three river stations (River Miles 52, 50.8, and 50.36) that cross through the PSEG Site. From this table it can be seen that there is a very slight increase (0.01 ft.) in the maximum WSEL at the PSEG Site. This slight increase is most likely because the bridge approach embankments act as a slightly more effective barrier to upstream movement of the storm surge and therefore produce a slightly greater backwater effect at the PSEG Site. There are also small and insignificant differences in the flow past the site. These results show the current HEC-RAS approach to modeling the bridge embankments at the Delaware Memorial Bridge and Commodore Barry Bridge are appropriate for the PMH storm surge event, and no changes to the HEC-RAS model or resultant water surface elevations are required.

Table RAI 67-16-1 Effects of Adding Approximate Bridge Approaches to Model

Model Results Difference Q River Mile Plan Q Total WSEL Total WSEL. (cfs) (ft NAVD) (%) (%) Current HEC-RAS model -2859915 16.19 52 0.22 0.06 Modified for Bridge Embankment -2853571 16.20

Current HEC-RAS model -2886137 16.16 50.8 0.18 0.06 Modified for Bridge Embankment -2880970 16.17

Current HEC-RAS model -3134544 16.13 50.36 0.10 0.06 Modified for Bridge Embankment -3131386 16.14

Model Instabilities

Question 02.02.05-16 also inquires about the model oscillations, which appear to indicate model instabilities. These oscillations in the WSEL can be seen in the figures provided with RAI No. 02.04.05-16 (Reference 2). As an example, the oscillations in the WSEL at time 19:00 can be seen on Figure RAI 67-16-1 (reproduced from Reference 2). As noted in Reference RAI 67-16-1, stability issues are not uncommon when performing unsteady flow analyses. A sensitivity analysis was performed in order to assess the potential significance of the perceived numerical instability suggested by an oscillating water surface profile for the PMH surge run (between 29JUN2006 17:30 to 29JUN2006 19:30).

The model is modified by varying a number of parameters recommended by the USACE Hydraulic Engineering Center (HEC) (Reference RAI 67-16-1) to minimize potential instability problems. The effect of varying these parameters is assessed to determine the relation between the observed oscillations and a level of instability that could affect model results. Four model runs are made to evaluate the sensitivity of the resulting

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maximum WSEL to different modeling techniques that might be used to smooth out perceived numerical instabilities generated by HEC-RAS. These modeling scenarios are based on the HEC-RAS plan modeling run called “PMH_R28_T26_25YR_FLD_DYNAMIC.”

The following four sensitivity runs are made: 1) Adjust computational time step from 30 seconds to 5 seconds 2) Set Theta coefficient = 1.0, (changed from 0.6 in PMH run). The Theta coefficient is a weighting factor applied in the model finite difference calculations. 3) Adjusted Options and Tolerances, including keeping Theta = 1.0,increasing maximum number of warm up time steps from 20 to 40, and adjusting Theta during the warm up period from 0.6 to 1.0. 4) Add interpolated cross sections every 2,000 feet from river mile (RM) 56.8 to the most upstream cross section.

The oscillations at the model’s downstream boundary from RM 0 to approximately RM 2 (0 to 10,000 ft.) are consistently observed during the rapid increase in the boundary condition elevation. As noted in Reference RAI 67-16-1, oscillations of this type are not uncommon during periods of sharp changes in flow that occur at the model boundary as the surge hydrograph is introduced to the model domain.

Figure RAI 67-12-2 illustrates the resulting water surface profile at time step 26JUN2006 18:30 hr for the PMH run and the sensitivity runs listed above. This figure addresses the perceived instabilities at approximately RM 64 (340,000 ft.). The base or PMH run with no adjustments is shown with the dark dashed line. It was found that run 3, adding warm up modifications to run 2, was not significantly different from run 2. Accordingly, the two runs are labeled as one line (Theta=1 + Warm Up). From Figure RAI-67-2, it can be seen the sensitivity run “Interpolated Cross Sections” oscillates less than the PMH run. Additionally, the sensitivity run “Theta=1+Warm Up” oscillates less than the PMH run. Shortening the computational time step from 30 to 5 seconds slightly increases the oscillations.

Figure RAI 67-16-3 illustrates the resulting water surface profile at time step 26JUN2006 19:00 hr for the PMH run and the sensitivity runs listed above. This figure addresses the perceived instabilities at approximately RM 85 (450,000 ft.). From Figure RAI 67-16-3, it can be seen that the sensitivity run results are similar to the previous time step provided in Figure RAI 67-16-2 and discussed above.

The resulting maximum WSEL at the PSEG Site for each run are summarized in Table RAI 67-16-2. These results are presented to show the effect that might be realized at the PSEG Site if potential modeling improvements were made to reduce the perceived numerical instability suggested by the oscillations. From Table RAI 67-16-2, it can be seen that the current PMH run in the unchanged HEC-RAS model generally produces the most conservative estimate, with the exception that the sensitivity run using a 5- second time step, which has the effect of increasing oscillations rather than decreasing, is 0.01 foot higher at RMs 50.36 and 52.

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Table RAI 67-16-2 Effects of Numerical Instability Runs at the PSEG Site

Current PMH HEC-RAS Sensitivity Model Run Model Run Interpolated Time Step = Adjust Calc Options Cross Sections 5 Sec Theta = 1.0 and Tolerances WSEL WSEL WSEL WSEL WSEL River Mile (ft. NAVD) (ft. NAVD) (ft. NAVD) (ft. NAVD) (ft. NAVD)

52 16.19 16.05 16.20 16.15 16.15

50.8 16.16 16.04 16.16 16.16 16.16

50.36 16.13 16.00 16.14 16.11 16.11

The results of this sensitivity analysis show that there is a negligible difference in the resulting water surface elevation at the PSEG Site as a result of addressing the modeling instabilities that occurred several miles upstream of the site and well before the peak surge period. These results show the current HEC-RAS model is appropriate for the PMH storm surge event, and no changes to the HEC-RAS model or resultant water surface elevations are required.

References:

RAI 67-16-1 Brunner, G.W. Common Model Stability Problems When Performing an Unsteady Flow Analysis. USACE Hydrologic Engineering Center., http://www.nws.noaa.gov/oh/hrl/modelcalibration/6.%20%20Hydraulic%20 Model%20Calibration/4.1%20L- 11%20CommonModelStabilityProblemsInUnsteady%20FlowAnalysis.pdf, accessed June 25, 2014.

Associated PSEG Site ESP Application Revisions:

None.

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DRAFT August 12, 2014

Figure RAI 67-16-1 Water Surface Profile for Time Step 26JUN2006 19:00 Showing Bridge Locations and Water Level Oscillations DRAFT DRAFT August August 12, 12, 2014 2014

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Figure RAI 67-16-2 Sensitivity Runs for Oscillations at Time Step 26JUN2006 18:30 DRAFT DRAFT August August 12, 12, 2014 2014

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Figure RAI 67-16-3 Sensitivity Runs for Oscillations at Time Step 26JUN2006 19:00 DRAFT DRAFT August August 12, 12, 2014 2014

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Response to RAI No. 67, Question 02.04.05-17:

Supplement to RAI 39, Question 2.4.5-7:

To show compliance with 10 CFR 52.17, PSEG should evaluate the storm surge induced by the PMH at the site as recommended by Regulatory Guide 1.59 and supplemented by current best practices. NUREG-0800, Standard Review Plan (SRP), Chapter 2.4.5, ‘Probable Maximum Surge and Seiche Flooding,’ establishes criteria that the NRC staff applies to evaluate whether PSEG meets the NRC's regulations. SSAR Section 2.4.5.2.2.3 discuss application of the HEC- RAS model to propagate the storm surge at the mouth of Delaware Bay (developed by the Bodine model) to the PSEG project site approximately 80 km (50 miles) inland.

The PSEG response to RAI 39, Question 2.4.5-7 (ML11329A069) lists HEC-RAS model upgrades in V4.1 not found in V4.0 (applied in the SSAR analysis). The PSEG response also states that only two model corrections in V4.1 could affect results for analysis (related to bridge crossings). Comparison of output for bridge crossing data developed with V4.1 and V4.0 versions of code indicate identical curves. PSEG did not conduct model results comparison between more recent HEC-RAS versions and the model used for the SSAR. Instead, PSEG relied on the development of bridge curves with each model version and on documented differences between the versions.

In order to show compliance with the requirements of 10 CFR 52.17 and evaluate the methods applied, NRC staff requests that PSEG provide a discussion of their V4.0 HEC-RAS model compared to the latest HEC-RAS model version to confirm that there is no effect to any of the HEC-RAS model results from recent software updates.

PSEG Response to NRC RAI:

The PMH model run is compared between HEC-RAS Version 4.0 and 4.1. The PMH model files are run in both model versions V4.0 and V4.1, and the modeling results are then compared so as to confirm that there are no significant differences between the two model versions. The results are presented in Table RAI 67-17-1.

As can be seen from Table RAI 67-17-1 there are very slight differences in river flow and there are no differences in the WSEL at the PSEG Site. It is therefore concluded that there is no significant difference between the results generated by the two HEC- RAS model versions for the PMH analysis at the PSEG Site.

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Table RAI 67-17-1 Water Surface Elevation Comparison between HEC-RAS V4.0 and V4.1

Q Total WSEL Model Version River Mile (cfs) % Difference (ft. NAVD) Version 4.0 50.36 -3134544 < 0.0001% 16.13 Version 4.1 -3134545 16.13

Version 4.0 -2886137 16.16 50.8 < 0.0001% Version 4.1 -2886136 16.16

Version 4.0 -2859915 16.19 52 < 0.0001% Version 4.1 -2859914 16.19

Associated PSEG Site ESP Application Revisions:

None.

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PSEG Letter ND-2014-00XX, dated August 22, 2014

ENCLOSURE 2

Optical Media containing the following:

 Proposed Revisions Part 2 – Site Safety Analysis Report, Subsection 2.4.5 - Probable Maximum Surge and Seiche Flooding  Proposed Revisions Part 2 – Site Safety Analysis Report, Chapter 2 – Site Characteristics  Proposed Revisions Part 3 – Environmental Report, Subsection 2.3.1 – Hydrology

DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report

2.4.5 PROBABLE MAXIMUM SURGE AND SEICHE FLOODING

In this subsection, the hydrometeorological design basis is developed to ensure that potential hazards to the safety-related structures, systems and components (SSC) at the new plant location, due to the effects of probable maximum hurricane (PMH) surge and seiche, are considered in the design of the new plant. The new plant is located on the eastern shore of the Delaware River estuary. The existing topography at the new plant location ranges from 5 to 15 feet (ft.) NAVD (Reference 2.4.5-11). Consequently, the new plant may be affected by hurricane storm surge.

The approach used to determine the PMH surge, seiche flooding, and wave runup are presented. The methodologies used to determine storm surge from the PMH are in accordance with American National Standards Institute/American Nuclear Society (ANSI/ANS)-2.8-1992 (Reference 2.4.5-1) and RG 1.59.

Methods used to determine maximum surge and seiche flooding include:

 Bodine storm surge model (Reference 2.4.5-2), coupled with the HEC-RAS model (Reference 2.4.5-28) and the wind setup model of Kamphuis (Reference 2.4.5-10)  NOAA, Sea, Lake, and Overland Surges from Hurricanes (SLOSH) model (References 2.4.5-22 and 2.4.5-23)  RG 1.59

The results in this subsection are conservatively based on the Bodine storm surge model, which is used to determine the storm surge from the PMH in combination with HEC-RAS and the Kamphuis wind setup model. The Bodine model calculates storm surge at the open coast. HEC-RAS determines the PMH surge water level as the surge propagates through Delaware Bay to the new plant location. The Kamphuis method calculates additional effects on water levels at the new plant caused by wind blowing over the Delaware Bay. The alternative methods listed above (SLOSH and RG 1.59) are investigated, and results are discussed in this subsection, but the alternative methods are determined to have limitations for determining the PMH surge at the site. Those limitations are discussed in Subsection 2.4.5.2.

The overall approach and sequence of steps are as follows. Subsection 2.4.5.1 documents that the PMH, as defined by NOAA’s Meteorological Criteria for Standard Project Hurricane and Probable Maximum Hurricane Windfields National Weather Service Technical Report NWS 23 (NWS 23)(Reference 2.4.5-18), represents the Probable Maximum Wind Storm (PMWS) at the new plant location. As defined by NOAA, the PMH may exhibit a range of meteorological characteristics, so preliminary screening level calculations are performed that identify the PMH characteristics that produce the PMH surge at the new plant location. The PMH with these specific characteristics is used to specify the PMWS.

Determination of the maximum SWL (SWL) of the PMH surge is presented in Subsection 2.4.5.2. The analysis commences with the effects of the hurricane over the continental shelf, producing a surge at the mouth of Delaware Bay, which is determined using the Bodine model. The surge is superimposed on a coincident 10% exceedance high tide.

Rev. 3 2.4-67 DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report

Outputs of the Bodine model are used as input to HEC-RAS, defining the surge at the mouth of the bay as a stage boundary condition. The upstream boundary of HEC-RAS is the head of tide at Trenton, NJ, where the discharge hydrograph reflects the effects of hurricane-associated precipitation. The additional effects of wind blowing over Delaware Bay, not simulated by HEC-RAS, are calculated using a formula for wind setup in semi- enclosed bodies of water as presented by Kamphuis (Reference 2.4.5-10).

Wave heights and wave runup coincident with the maximum SWL are determined in Subsection 2.4.5.3, using the hurricane wind field specified by NWS 23. Wave runup is calculated in accordance with USACE’s Coastal Engineering Manual (Reference 2.4.5- 27). Wave runup is added to the maximum SWL of the PMH surge.

In Subsection 2.4.5.4, the potential future effects of sea level rise are evaluated and added to the maximum WSEL from the PMH surge, which includes coincident wind wave activity, to determine the future maximum WSEL through the projected life of the new plant in Subsection 2.4.5.5.

Subsection 2.4.5.6 presents a confirmatory analysis of the PMH surge using a conservative, current practice approach predicted by a two-dimensional storm surge model. The results of this confirmatory analysis demonstrate the conservative nature of the maximum WSEL determined using the methodologies presented in Subsections 2.4.5.2 through 2.4.5.5.

Subsection 2.4.5.7 addresses sediment erosion and deposition associated with the PMH and their potential effects on the safety-related intake structure. Subsection 2.4.5.8 demonstrates that Delaware Bay does not resonate with meteorological or seismic forcing, providing further confirmation that the PMH surge as calculated in this section represents the most severe flooding that could occur at the new plant.

2.4.5.1 Probable Maximum Winds (PMW) and Associated Meteorological Parameters

This subsection identifies the meteorological characteristics of the PMH that causes the PMH surge and demonstrates that the PMH wind field represents the PMWS at the new plant location. The basic meteorological parameters that define the PMH are varied within limits given by NOAA (Reference 2.4.5-18) to determine the most severe combination that results. The detailed analysis of surge (in Subsection 2.4.5.2) is based on the most severe combination of these parameters.

The meteorological parameters associated with the PMH at the mouth of Delaware Bay are based on NWS 23. The mouth of Delaware Bay is defined as a point bisecting the line from Cape May, New Jersey (NJ) to Cape Henlopen, Delaware (DE), at latitude 3851’30”N, longitude 7501’30”W. At this location, NOAA provides the following meteorological parameters for the PMH:

 Central pressure, p0 = 26.65 inches of mercury [in. of Mercury (Hg)].  Pressure drop, p = 3.5 in. of Hg.  Radius of maximum winds, R = from 11 to 28 nautical miles (NM).  Forward speed, T = from 26 to 42 knots (kt).

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 Coefficient related to density of air, K = 68 (when parameters are in units of in. of Hg and kt)  Track direction, from 138 degrees (moving northwest).

The northwest track direction is perpendicular to bathymetric contours of the continental shelf offshore of the mouth of Delaware Bay (Reference 2.4.5-20). The track of this storm is illustrated in Figure 2.4.5-1. This track direction is within the range of directions that NOAA specifies for the PMH at the mouth of Delaware Bay. The inflow angle, which varies with distance from the storm center, is as specified by NOAA (Reference 2.4.5- 18). From these parameters, the maximum winds range from 128 to 135 kt, as shown in Table 2.4.5-2. Thus, the PMH is a relatively strong Category 4 hurricane by the Saffir- Simpson hurricane scale. Category 4 hurricanes have maximum sustained winds ranging from 114 to 135 kt.

NOAA specifies that the PMH may occur within a range of radius of maximum winds (R) and forward speed (T) (Reference 2.4.5-18). The method described in Subsection 2.4.5.2.2.2 is used to calculate the maximum storm surge at the open coast for nine possible combinations of R (11, 20, and 28 NM) with T (26, 34, and 42 kt) spanning the ranges of these parameters specified by NOAA. This analysis follows methodology described in ANSI/ANS-2.8-1992 Section 7.2.1.4. In these preliminary simulations, designed to identify the PMH producing the maximum storm surge, a static high tide condition is specified. This tide condition differs from the dynamic tidal input used in Subsection 2.4.5.2.2. These preliminary screening level analyses (presented in Table 2.4.5-3) show that the surge at the mouth of Delaware Bay increases with R and T, with a maximum surge at the mouth of the bay when both R and T are high, specifically for the PMH with R = 28 NM, and T = 42 kt. This result is consistent with modeling performed in support of RG 1.59, which determined that the maximum surge at the coast consistently resulted from the PMH with high R and T.

The hurricane producing the maximum surge at the open coast may not produce maximum WSEL in bays and estuaries. A storm that progresses at approximately the same speed as the tide propagates is expected to produce maximum surges within Delaware Bay (Reference 2.4.5-3). The speed of propagation of the tide in Delaware Bay is approximately 14 kt (References 2.4.5-3 and 2.4.5-8). Therefore, it may be expected that a PMH with a high forward speed (42 kt) may not produce the highest storm surge at the new plant location, even though it produces the highest surge at the mouth of Delaware Bay. A fast-moving storm moves ahead of the storm surge wave, while a slower moving storm tends to reinforce the surge. Since the surge at the mouth of Delaware Bay is strongly dependent on the radius of maximum winds, R, but weakly dependent on the forward speed, (T), the three storms with R = 28 are further investigated using HEC-RAS and the Kamphuis wind setup method to determine the potential effects of these storms on SWLs at the new plant location. This analysis (presented in Table 2.4.5-3) shows that the PMH with R = 28 NM, and T = 26 kt produces the maximum surge at the new plant location consistent with Bretschneider’s evaluation.

A PMH with R = 28 NM, and T = 26 kt produces the PMH surge at the new plant location. The PMH with R = 28 NM and T = 26 kt, is simulated in more detail in Subsections 2.4.5.2 and 2.4.5.3. Specifically, the storm is simulated with a fluctuating

Rev. 3 2.4-69 DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report tide at the mouth of Delaware Bay, which produces the 10 percent exceedance high tide at the new plant location. The phase of the tide is established in relation to the development of the storm surge such that the 10 percent exceedance high tide coincides with the peak storm surge at the new plant location.

The pressure distribution and wind field associated with this storm are determined as specified by NOAA (Reference 2.4.5-18) for a PMH. Wind speed and direction at any point depend on p, T and R; the distance and angular orientation of the specified point relative to the center of the storm and the direction of storm movement. Wind speed varies with time at a point as the storm moves along its track relative to that point. Latitude and the density of air also affect the wind speed calculations. The maximum sustained winds over the ocean are calculated to be 128 kt; while the maximum winds over Delaware Bay are 126 kt, and maximum winds at the new plant location are 116 kt.

The HEC-RAS hydraulic simulation does not account for wind stress acting on water within Delaware Bay, therefore, the effect of wind stress within the bay is determined using the steady state wind setup method described by Kamphuis (Reference 2.4.5-10). Wind setup refers to the response of water surface elevations in enclosed or semi- enclosed bodies of water to winds blowing across the water surface. The method presented by Kamphuis assumes wind setup in Delaware Bay to be a steady state response to steady, uniform wind over the bay. This simplification is appropriate because Delaware Bay is less extensive in area than the continental shelf, and winds are more uniform. The assumption that the bay exhibits a steady state response to winds that change with time is a conservative assumption (Reference 2.4.5-4) because the bay would not reach a steady state condition instantaneously.

ANSI/ANS-2.8-1992 (Reference 2.4.5-1), recommends use of the parameterization of the wind stress, k, as discussed in Bodine (Reference 2.4.5-2), unless other values can be justified using better observational data. Recent research shows that the Bodine parameterization overestimates the wind stress coefficient at hurricane force winds. Recent observations of the wind stress coefficient at hurricane force winds have been made possible by the development of observational devices not available in 1971 when the Bodine technical memorandum was published (References 2.4.5-26 and 2.4.5-7). Observations, utilizing advanced devices, have determined k values at hurricane force winds ranging from 1.4 x 10-6 to 3.0 x 10-6 (References 2.4.5-4, 2.4.5-26, and 2.4.5-7). Above the threshold of hurricane force winds, k does not increase with wind speed (Reference 2.4.5-7). Therefore, the Bodine relationship for the wind stress coefficient is modified at high wind speeds so that the wind stress coefficient does not exceed 3.0 x 10-6, the highest observed value reported at hurricane force winds (References 2.4.5-4, 2.4.5-26, and 2.4.5-7). Use of a maximum value of k of 3.0 x 10-6 is conservative based on measured values at hurricane force winds.

2.4.5.1.1 Probable Maximum Wind Storm (PMWS)

The PMH represents the PMWS that could cause flooding at the new plant location. A 31-year record (1978 through 2008) of wind speed and direction data from Dover, DE (11 miles west of the center of Delaware Bay) was analyzed. The Dover weather station is the closest to the center of Delaware Bay, and thus the most appropriate location for evaluating winds over the bay that could cause wind setup or seiche activity. Setup of Delaware Bay has been observed when strong winds parallel to its long axis (i.e.,

Rev. 3 2.4-70 DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report northwest-southeast) persist for durations of 2 to 12 hours (Subsection 2.4.11). Winds at Dover were averaged over 4 hours, a sufficient duration to cause wind setup of Delaware Bay, based on the observations summarized in Subsection 2.4.11. The analysis shows that 4 hour average winds parallel to the long axis of Delaware Bay did not exceed 35 mph (30 kt) at Dover. Overwater winds are expected to be 50 kt when overland winds are 30kt (Reference 2.4.5-18). Therefore winds of sufficient duration to cause wind setup or seiche did not exceed 50 kt over Delaware Bay during the period 1978 through 2008. By comparison, the wind speeds associated with the PMH exceed 125 kt over Delaware Bay. Therefore, the PMH represents the PMWS for the new plant location.

2.4.5.1.2 Appropriateness of PMH Determination

The probable maximum storm surge water level estimation described in Subsection 2.4.5.5 uses the PMH parameters defined by NWS 23 for coastal locations on the United States (U.S.) Gulf and East coasts. NWS 23 is recognized as a reliable source of information to characterize the PMH (Reference 2.4.5-1). The PMH parameters in NWS 23 are based on historical data for hurricanes making landfall on the U.S. coasts between 1851 and 1975. Comparisons of hurricane climatology during the period evaluated in NWS 23 with hurricanes making landfall after 1975 indicate that the NWS 23 parameters for the PMH are still applicable.

NOAA (Reference 2.4.5-15) has summarized variations in the frequency of major hurricanes that relate to variations in climatologic conditions. The Atlantic Multi-decadal Oscillation, which refers to cyclic fluctuations in oceanic surface temperature over periods that last as long as several decades, appears to affect the frequency of hurricanes; resulting in periods of 20 years or more with a high frequency of major hurricanes, which may be followed by a similar period with lower hurricane frequency. Atlantic Ocean hurricanes were significantly more active from 1995 to 2005 than in the previous two decades (1970 to 1985). Prior to that, the period 1945 through 1970 was relatively active, as active as the 1995 to 2005 period. NOAA published a technical memorandum (Reference 2.4.5-24) analyzing the number and strength of hurricane strikes by decade and location in the U.S. According to this publication, on average, a Category 4 or stronger hurricane hits the U.S. once every 7 years. However, in the 35 years from 1970 to 2005, only three Category 4 or larger hurricanes have reached the U.S., which is less than the expected number of 5 in 35 years. Based on this information, it is reasonable to conclude that the number and strength of hurricanes since NWS 23 was published are not greater than hurricanes prior to 1975. The NWS 23 climatological data set includes the relatively active period of 1945 through 1970. Therefore, meteorological criteria for hurricanes affecting the gulf and east coasts of the U.S., described in NWS 23, are conservative even considering potential future climatic variability.

2.4.5.2 Surge and Seiche Water Levels

Determination of the maximum SWL of the PMH surge is presented in this subsection. The most severe hurricane storm surges historically reported for the site and surrounding area are characterized in Subsection 2.4.5.2.1. The PMH surge SWL calculations are presented in Subsection 2.4.5.2.2. Analysis of the PMH surge begins with the effects of the hurricane as it moves over the continental shelf, producing a surge

Rev. 3 2.4-71 DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report at the mouth of Delaware Bay, determined using the Bodine model. The surge is superimposed on a coincident 10% exceedance high tide. Outputs of the Bodine model are used as input to HEC-RAS, defining the surge at the mouth of the bay as a stage boundary condition. The upstream boundary of HEC-RAS is the head of tide at Trenton, NJ, where the discharge reflects a historical rainfall event that conservatively represents the effects of hurricane-associated precipitation. The additional effects of wind blowing over the Delaware Bay are calculated using a formula for wind setup in semi-enclosed bodies of water as presented by Kamphuis (Reference 2.4.5-10).

Results are compared with results from alternative methods. The methodology used to determine the PMH surge SWL are validated by reproducing the storm surge observed in Delaware Bay from one of the historical hurricanes summarized in Subsection 2.4.5.2.1.

2.4.5.2.1 Historical Surges

Delaware, New Jersey, and Pennsylvania did not experience a direct hit from a major hurricane during the period 1851-2006 (Reference 2.4.5-24). Although storms that create substantial surges in Delaware Bay are rare, the bathymetry and shape of Delaware Bay can produce storm surge in response to hurricanes that make landfall to the west of the bay while traveling in a northward direction. Hurricanes producing severe storm surge at Philadelphia, PA (on the Delaware River estuary 30 miles northeast of the PSEG Site) include the Chesapeake-Potomac hurricane (1933), Hazel (1954), Connie (1955), Floyd (1999), and Isabel (2003). Tracks of these storms are shown in Figure 2.4.5-2, based on data accessed from NOAA’s Coastal Services Center (Reference 2.4.5-12). This list of storms is assembled from published descriptions of hurricanes producing significant surges in Delaware Bay and from review of hurricane tracks passing within 100 NM of the new plant location, while making landfall to the west of the mouth of Delaware Bay.

The Chesapeake-Potomac hurricane made landfall as a Category 1 hurricane near Currituck, North Carolina (NC). Traveling northwest, its track paralleled the western shore of Chesapeake Bay. It then turned northeasterly, bringing the storm center within 80 NM of the new plant location (Reference 2.4.5-12). It produced a maximum storm surge of 3.8 ft. near the mouth of Delaware Bay; 7.7 ft. at Reedy Point, DE (nearest tidal gage to the new plant location), and 7.1 ft. at Philadelphia (Reference 2.4.5-3).

Hazel made landfall as a Category 4 hurricane near the border of NC and South Carolina (SC). It moved north, with Category 1 status at its nearest approach to the new plant location, when the storm center was 98 NM west of the new plant location (Reference 2.4.5-12). Hazel produced a maximum storm surge at Philadelphia of 9.4 ft. (Reference 2.4.5-31).

Connie made landfall near Cape Charles, Virginia, as a tropical storm, and its inland track generally followed the eastern shore of Chesapeake Bay. At its nearest point, the storm center was within 43 NM of the new plant location (Reference 2.4.5-12). It produced a maximum surge at Philadelphia of 5.0 ft. (Reference 2.4.5-31).

The storm center of Floyd bypassed Delaware Bay to the south and east, 70 NM from the new plant location, moving northeast as a Category 1 hurricane (Reference 2.4.5-

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12). It produced a storm surge (after correcting for astronomical tide) of 3.0 ft. at Cape May, NJ (mouth of Delaware Bay); 2.9 ft. at Reedy Point; and 4.0 ft. at Philadelphia (Reference 2.4.5-13).

Traveling northwest, Isabel made landfall as a Category 1 hurricane near Beaufort, NC. The storm center was closest to the new plant location at 163 NM to the southwest. At this point, it was a tropical storm (Reference 2.4.5-12). Isabel produced a storm surge of 3.1 ft. at Lewes, DE; 5.0 ft. at Reedy Point; and 5.4 ft. at Philadelphia (Reference 2.4.5- 14).

Hurricane Hazel and the Chesapeake-Potomac hurricane produced the maximum historical storm surges recorded in Delaware Bay. Of these, the Chesapeake-Potomac hurricane storm center passed closer to the new plant location, exhibiting a northwesterly track most similar to the hypothetical storm track of the PMH (References 2.4.5-18 and 2.4.5-17). Based on the storm track and adequate available data related to this storm, the Chesapeake-Potomac hurricane of August 1933 is selected to validate the storm surge model used to determine the PMH surge.

2.4.5.2.2 Estimation of Probable Maximum Storm Surge

In order to satisfy the combined events criteria specified in Section 9.2.2 of ANSI/ANS- 2.8-1992, (Reference 2.4.5-1) storm surge at the new plant is evaluated combining probable maximum surge and seiche with wind wave activity concurrent with the 10 percent exceedance high tide, and effects of hurricane-associated precipitation. This subsection outlines the sequence of steps taken to calculate the maximum surge SWL due to PMH. Subsequent subsections describe wave runup and sea level rise estimates.

Surge at the open coast results from meteorological and oceanographic processes occurring offshore over a scale of 500 NM. Between the mouth of the bay and the new plant location, a distance of 50 NM, the propagation of the surge is controlled by the geometry and hydraulics of the estuary. Water levels further increase due to wind blowing directly over the bay. Wave runup addresses processes occurring upwind of the new plant location on spatial scales (fetch lines) of less than 10 NM which are discussed in Subsection 2.4.5.3. The analysis proceeds from the large, offshore spatial scales to smaller spatial scales proximal to the new plant location near the head of Delaware Bay. Details of the storm surge analysis are presented in the remainder of this subsection.

The PMH surge SWL is determined by combining the effects of surge at the open Atlantic coast coincident with the 10 percent exceedance high tide. That surge plus tide is propagated through Delaware Bay to the new plant location; and the effects of wind setup resulting from wind stress over Delaware Bay are superimposed, by addition, on the propagated surge. The overall approach uses:

 Bodine method to determine storm surge at the open coast  HEC-RAS analysis to propagate that surge through Delaware Bay to the site  Kamphuis method to determine wind setup at the site caused by winds blowing over the Delaware Bay

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The storm surge water levels determined by the Bodine method are used as a stage boundary condition at the mouth of Delaware Bay for the HEC-RAS simulation within the Delaware River estuary. The upstream boundary conditions input into the HEC-RAS model, consisting of discharge of the Delaware River at Trenton, and discharge of tributaries downstream of Trenton, are based on a 2006 event to account for hurricane- related precipitation. The water levels determined by HEC-RAS, and winds defined by NOAA (Reference 2.4.5-18) for the PMH, are used to determine wind setup at the new plant location. The combination of HEC-RAS surge, which includes the 10 percent exceedance high tide, and Kamphuis wind setup determines the PMH surge SWL at the new plant location.

The Bodine model was used by the NRC to develop default storm surge estimates at the open coast in support of RG 1.59 and is cited as an acceptable methodology for such analyses by ANSI/ANS-2.8-1992 (Reference 2.4.5-1).

HEC-RAS is a widely accepted model for dynamic flood routing in rivers developed by the U.S. Army Corps of Engineers. It incorporates the ability to simulate hydraulics of estuaries by using a stage hydrograph as a downstream (tailwater) boundary condition. According to ANSI/ANS 2.8-1992, Section 7.3.2.1, a transient one-dimensional model can be used to compute resonance effects for a narrow body of water with a bay entrance. HEC-RAS is one-dimensional, and does not account for flow perpendicular to the primary longitudinal axis of the Delaware Bay and estuary. This model simplification does not have a significant effect on HEC-RAS ability to simulate either the tide or storm surge at the new plant.

Flow in Delaware Bay and near the new plant is predominantly longitudinal (References 2.4.5-36 and 2.4.5-37). Bretschneider determined that cross-wind effects on storm surge are virtually negligible (less than 3 percent) upstream of the head of Delaware Bay (upstream of RM 48), and reduces surge on the east side of the estuary at the new plant location (Reference 2.4.5-3), therefore neglecting cross-wind effects is conservative at the new plant location. The wind setup algorithm of Kamphuis is a steady-state analytical solution of the fundamental equations governing hydrodynamics, which can be found in reference texts (References 2.4.5-27 and 2.4.5-4). Its primary assumption, that water levels exhibit a steady state response to varying winds, is conservative because the bay does not respond to the winds instantaneously. The combination of these methods is demonstrated to be valid by reproducing the storm surge of an actual historical hurricane as described in the remaining paragraphs of this subsection.

These methods are validated by reproducing the surge observed during the Chesapeake-Potomac hurricane of 1933. The pressure distribution and winds associated with this storm are specified as described by Bretschneider (Reference 2.4.5- 3) and NOAA (Reference 2.4.5-18). Bretschneider reports a pressure drop of 0.85 in. of Hg. This value is used with NOAA (Reference 2.4.5-18) formulas for the Standard Project Hurricane to determine the pressure distribution and wind field throughout the storm. Bretschneider reports maximum sustained winds over the ocean of 58 mph (50 kt), and maximum sustained winds over Delaware Bay of 50 mph (43 kt). The simulated storm exhibits maximum winds of 64 mph (56 kt) over the ocean, and 47 mph (41 kt) over Delaware Bay, similar to the wind speeds reported for the Chesapeake-Potomac hurricane.

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Coincident astronomical tides are specified at the mouth of Delaware Bay. Comparison of model results with the actual response to the Chesapeake-Potomac hurricane is expressed as storm surge, the difference between actual water levels and the predicted astronomical tide level. The storm surge calculated at the mouth of Delaware Bay, using the Bodine method, reproduces the observed surge as described by Bretschneider (Reference 2.4.5-3). Comparison of observed and simulated surge at the mouth of the bay is illustrated in Figure 2.4.5-3. The peak storm surge at Reedy Point, DE, is calculated to be 7.9 ft., while the observed surge at Reedy Point was 7.7 ft. Water surface elevations (surge plus tide) at Reedy Point are illustrated in Figure 2.4.5-4. The Delaware Bay storm surge model described here is demonstrated to be conservative. The margin of error is consistent with comparable models, such as NOAA’s SLOSH model which has a stated margin of error of +/- 20 percent (Reference 2.4.5-23).

2.4.5.2.2.1 Estimation of 10 Percent Exceedance High Tide

Maximum monthly high tide values from 1987 through 2008 are analyzed at NOAA tidal gage stations upstream and downstream from the new plant location to determine the 10 percent exceedance high tide at the site (Reference 2.4.5-16). This analysis calculates a 10 percent exceedance high tide of 4.2 ft. NAVD at the Lewes, DE, NOAA tidal gage (8557380) at river mile (RM) 0, and 4.6 ft. NAVD for the Reedy Point, DE, NOAA tidal gage (8551910) at RM 59 as illustrated in Figure 2.4.5-5. Based on these values, the 10 percent exceedance high tide at the new plant location at RM 52 is determined by linear interpolation to be 4.5 ft. NAVD.

This approach for estimating 10 percent exceedance high tide, based on recorded tides, intrinsically includes the effects of sea level anomaly (also known as initial rise). ANSI/ANS-2.8-1992, Section 7.3.1.1.2, concludes sea level anomaly need not be included when 10-percent exceedance high tide is based on recorded tides. Sea level anomaly is not included in this analysis because recorded tide data is used to calculate the 10-percent exceedance high tide.

2.4.5.2.2.2 Storm Surge at the Open Coast

Calculations presented by Bodine are verified by reproducing a sample problem provided by Bodine (Reference 2.4.5-2). The model reproduced Bodine’s results for maximum surge to four significant figures.

Inputting the PMH identified in Subsection 2.4.5.1 into the Bodine calculations, a maximum surge elevation of 20.9 ft. NAVD is calculated at the mouth of Delaware Bay. This value includes a fluctuating tide at the mouth of the bay that generates the 10 percent exceedance high tide at the new plant coincident with the peak storm surge (Figure 2.4.5-6).

As a point of comparison, other methodologies available from NOAA and NRC to determine storm surge at the open coast are NOAA’s SLOSH program and RG 1.59 Appendix C. SLOSH results are accessed using the SLOSH Display Program v. 1.61g (Reference 2.4.5-22) and adjusted to account for the 10 percent exceedance high tide and NAVD datum. NOAA uses SLOSH to determine hurricane surge levels for a large number of potential hurricanes and provides access to the results via the SLOSH Display Program. The storms presented in the Display Program include a Category 4

Rev. 3 2.4-75 DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report storm on the Saffir-Simpson scale, but the Delaware Basin v3 SLOSH dataset does not include a storm with the same parameters as the PMH determined for the PSEG Site. Using the SLOSH Display Program, the highest surge elevation at the mouth of Delaware Bay is 17.6 ft. NAVD. Accounting for the 10 percent exceedance high tide indicates a Category 4 storm elevation of 19.8 ft. NAVD.

RG 1.59 is applicable to determine PMH surge levels on open coast sites on the Atlantic Ocean and Gulf of Mexico. Therefore, it is appropriate to use this methodology for estimating storm surge up to the mouth of Delaware Bay, but it is not appropriate to use it beyond the area where a hurricane makes initial landfall. As such, it is not an acceptable method for estimating surge at the new plant. RG 1.59, Appendix C, results for the mouth of Delaware Bay are based on interpolating results from Atlantic City, NJ, and Ocean City, MD, and then adjusting to NAVD. Including the 10 percent exceedance high tide, RG 1.59 estimates a maximum storm surge of 21.7 ft., NAVD at the mouth of the Delaware Bay.

While the three methods do not compare the exact same hurricane parameters, the three models produce similar storm surge estimates at the mouth of Delaware Bay for Category 4 hurricanes. The Delaware Basin v3 SLOSH dataset does not include a storm with the same parameters as the PMH determined for the PSEG Site. Therefore, SLOSH is not used to determine the peak surge at the mouth of the Bay. RG 1.59 cannot be used to determine surge at the new plant location, and cannot be used as a substitute for the Bodine method because it does not provide a stage hydrograph for the simulated hurricane to input into HEC-RAS. Further, RG 1.59 does not simulate the PMH as defined by NWS 23 (References 2.4.5-32 and 2.4.5-18). The Bodine method produces a more conservative result than SLOSH, and can specifically simulate the response to the PMH. Therefore, the Bodine model is selected as the basis for determining the PMH surge. The stage hydrograph, including the peak surge at the mouth of the bay calculated using the Bodine method, is input to the HEC-RAS model which propagates the storm surge through Delaware Bay.

2.4.5.2.2.3 Propagation of Surge through Delaware Bay

The propagation of surge through Delaware Bay is calculated using the HEC-RAS computer program. The HEC-RAS model is developed using channel geometry and floodplain elevations for the Delaware River between Trenton, NJ, and the head of Delaware Bay determined from the Triangular Irregular Network (TIN) terrain model developed from the U.S. Geological Survey (USGS) National Elevation Dataset (NED) (Reference 2.4.5-30) digital elevation model (DEM), and the NOAA Estuarine Bathymetry DEM (Reference 2.4.5-19). The HEC-RAS model is calibrated using observed tidal data. The calibrated model is then used to simulate the propagation of the surge from the mouth of Delaware Bay to the new plant.

In order to simulate the propagation of the PMH surge, the surge hydrograph generated by the Bodine calculations for the PMH is used as the stage boundary condition at RM 0. Discharge hydrographs generated by the Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) for the Delaware River at Trenton and its major tributaries downstream of Trenton are used to simulate flow conditions in the Delaware River resulting from a historical rainfall event that conservatively represents the effects of hurricane-associated precipitation. Specifically, the HEC-RAS model uses a historical

Rev. 3 2.4-76 DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report rainfall event that occurred in June 2006 that produced a basin average rainfall of 6 inches in the Delaware River Basin.

A discharge boundary condition at Trenton, defined by the HEC-HMS model response to the June 2006 rainfall event is input into the HEC-RAS model (Reference 2.4.5-29). Discharges from tributaries downstream of Trenton are also based on the HEC-HMS hydrographs for the June 2006 event, representing hurricane-associated precipitation. The output from the Bodine method describing the surge at the open coast is specified as the stage boundary condition at RM 0.

The effect of winds blowing over Delaware Bay, referred to as wind setup, is calculated using a standard method presented by Kamphuis (Reference 2.4.5-10), and is added to the HEC-RAS simulated water levels. Wind setup depends on wind speed and direction over the center of Delaware Bay; a coefficient accounting for wind and bottom stress; and water depth. The winds over the center of Delaware Bay at model time step 20.5 hours are 120 kt from the south-southeast, determined in accordance with NWS 23 (Reference 2.4.5-18). The stress coefficient is 3.3 x 10-6 (Reference 2.4.5-3). The cross- section average depth of water varies with RM and time, and is determined from the HEC-RAS water levels and channel geometry. The calculated wind setup at time 20.5 hours is 14.0 ft. at the new plant location. The wind setup is added to the HEC-RAS water level to determine the SWL, 26.86 ft. at t = 20.5 hours (Table 2.4.5-1).

Using the methods described in this subsection, the PMH surge SWL at the new plant location is 26.9 ft. NAVD (Table 2.4.5-1 and Figure 2.4.5-6). This maximum still water surface elevation combines the coincident effects of the 10 percent exceedance high tide, the propagation of the open coast surge through Delaware Bay, hurricane- associated precipitation, and the effect of winds over Delaware Bay.

The maximum SWL may be compared with maximum surge levels calculated by the NOAA SLOSH model, accessed using the SLOSH Display Program v. 1.61g (Reference 2.4.5-22). However, the Delaware Basin v3 SLOSH dataset does not include a storm with the same parameters as the PMH determined for the PSEG Site, nor do results include the 10 percent exceedance high tide, or effects of river flow. The maximum surge level reported by the SLOSH Display Program at the new plant location is 22.8 ft. NAVD. Adjusting to include the 10 percent exceedance high tide indicates a Category 4 storm elevation of 25.3 ft. NAVD using the SLOSH Display Program.

Based on the analyses described in Subsection 2.4.5.2, the PMH surge SWL at the new plant location is 26.9 ft. NAVD. The maximum WSEL, including wave runup, occurs one- half hour later, when the SWL is 26.7 ft. NAVD (Subsection 2.4.5.5 and Table 2.4.5-1).

2.4.5.3 Coincident Wave Runup

Subsection 2.4.5.3.1 presents the methodology used to determine wave runup coincident with the PMH surge. Results of the analysis are provided in Subsection 2.4.5.3.2. The resultant wave runup is added to the maximum SWL.

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2.4.5.3.1 Methodology

Coincident wave runup, in association with the PMH surge, is determined using the approach described by USACE (Reference 2.4.5-27). Winds are estimated at the new plant location in accordance with NOAA (Reference 2.4.5-18). Water depth is determined from the TIN terrain model, using coincident water levels determined by the Delaware Bay storm surge model, as defined in Subsection 2.4.5.2. The wave field is fetch- and duration-limited, as defined by USACE. Wind vectors are averaged over time consistent with the fetch and duration limitations, as specified by USACE. The significant wave height and period are calculated using the straight line fetch and the friction velocity. A check is made to validate the use of deep water equations, comparing the calculated significant wave period with the limiting spectral peak period. If the calculated period is less than the limiting spectral peak period, then the deep water equations are valid. Otherwise, the wave heights are limited by breaking. The maximum breaker height is determined using the Miche criterion (Reference 2.4.5-27).

The still WSEL and wave data (significant wave height, period and direction) over the course of the PMH storm surge event are shown in Table 2.4.5-5. The wave runup calculations described below are performed at each half hour interval.

Wave runup calculations for the new plant are based upon the latest design guidance found in the USACE Coastal Engineering Manual (CEM), Chapter VI-5 (Reference 2.4.5- 27). The new plant’s powerblock will be constructed on engineered fill with riprap protection, with facing slopes of 3:1 (horizontal:vertical), as shown on Figure 2.5.4.5-2.

Although the CEM prescribes the use of significant wave height to calculate wave runup, one alteration from the methodology presented in the CEM is the use of the lesser of (a) the maximum wave height, or (b) the “breaker height” (0.78 times depth of water) for computation of wave runup as required by Reference 2.4.5-1. Per Reference 2.4.5-1, the maximum wave height, Hmax, is defined as the 1 percent wave, H1%, and for deep water waves, Hmax = 1.67 times the significant wave height, Hs. CEM Equation II-1-132 also defines H1% as 1.67 times Hs (Reference 2.4.5-27). Consequently, Hs, is replaced by Hmax (Hs times 1.67) in the CEM equations for both the surf similarity parameter and the wave runup for the PSEG Site. This alteration essentially yields the highest runup of any single wave running up the embankment.

CEM Equation VI-5-3 provides a general form for the wave runup equation for structures as (Reference 2.4.5-27):

Rui% / Hs = (A ξ + C) γr γb γh γβ (Equation 2.4.5-1)

where: Rui% runup level exceeded by i percent of the incident waves Hs significant wave height of incident waves at the toe of the structure, in this case the maximum wave height (Hmax = 1.67Hs) ξ surf similarity parameter, ξom or ξop (defined below) A, C coefficients dependent on ξ and i but related to the reference case of a smooth, straight impermeable slope, long-crested head-on waves and Rayleigh-distributed wave heights γr reduction factor for influence of surface roughness

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γb reduction factor for influence of a berm (γb = 1 for non-bermed profiles) γh reduction factor for influence of shallow-water conditions where the wave height distribution deviates from the Rayleigh distribution (γr = 1 for Rayleigh distributed waves) γβ factor for influence of angle of incidence β of the waves (γβ = 1 for head- on long-crested waves, i.e., β = 0o). The influence of directional spreading in short-crested waves is included in γβ as well.

The surf similarity parameter for random waves is defined as:

tan tan om  or op  (Equation 2.4.5-2) som sop

where:

2 H s som  2 g Tm

2 H s sop  2 g Tp

tan α is the structure slope Tm is the mean wave period Tp is the spectral peak wave period.

For the new plant an i value of 2 percent is adopted. This establishes values for A and C in Equation 2.4.5-1 depending on the surf similarity parameter as provided by CEM Equation VI-5-6:

A=1.5 ξop ; C=0 for 0.5< ξop≤ 2

A=0.0 ; C=3.0 for 2< ξop≤ 3-4

In establishing the γ parameters to be used in the calculation of wave runup at the new plant, the berm factor γb is set equal to 1.0 because there is no berm in the design cross- section. The shallow water reduction factor is conservatively set to 1.0 as there will be storm surge conditions where the waves impinging on the new plant’s slope will be non- breaking (i.e., Rayleigh distributed). The roughness factor γr as provided by Table VI-5-3 of the CEM is between 0.5 and 0.6, dependent upon the number of layers of rock to be placed on the slope. As this design detail has yet to be determined, the least restrictive value of 0.6 is selected for conservatism. Finally, it is assumed that the waves are head- on; i.e., normally-incident to the slope, so that γβ is set equal to 1.0.

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2.4.5.3.2 Wave Runup at the New Plant Location

Wave runup is determined at a time coinciding with the maximum PMH surge SWL at the new plant location, as well as half-hour intervals immediately before and after that time. Calculations during the extended time are performed to ensure that the maximum PMH flood level, consisting of the SWL plus wave runup, is identified. Coincident wave runup in association with the PMH is determined using the methodology described in Subsection 2.4.5.3.1. Winds coincident with the maximum surge are determined at the new plant location using the methodology described by NOAA (Reference 2.4.5-18).

At the time when SWL plus wave runup peaks, the wind speed is 104 kt from the east- southeast. Due to the flood levels associated with the PMH surge, the inundated fetch line upwind to the east-southeast is 8.3 mi. The wave field reaches steady state along this fetch line if winds blow steadily along the fetch line for 1.5 hours (hr.). Therefore, wind speed is averaged over the prior 1.5 hr. to determine an appropriate wind speed and direction.

The significant deep water wave height is 14.7 ft., and its period is 5.6 seconds. The maximum wave height is 24.5 ft.; however, the average depth along the fetch line is 22.0 ft. Thus, the deepwater equations are not valid: waves of this height would break. The maximum breaker height is 14.5 ft. Wave runup is estimated from the maximum wave height or the maximum breaker height, whichever is less; in this case the maximum breaker height. The wave runup is calculated to be 14.3 ft. using the procedure described in Subsection 2.4.5.3.1. Table 2.4.5-5 presents the wave runup results at each time step calculated.

2.4.5.4 Potential Sea Level Rise

NOAA has evaluated the trend of sea level at the NOAA Reedy Point tidal gage station. Measurements at any given tide station include both global sea level rise and vertical land motion, such as subsidence, glacial rebound, or large-scale tectonic motion. The monthly sea level trend based on monthly mean sea level data from 1956 through 2006 is 1.14 ft./century, with an upper 95 percent confidence limit of 1.35 ft./century (Reference 2.4.5-21). The maximum flood level determined at the new plant location includes 1.35 ft. to conservatively account for sea level rise over the projected 60 year life of the new plant.

2.4.5.5 Maximum Water Surface Elevation Associated with the PMH

The PMH, defined in Subsection 2.4.5.1, is determined to produce the PMH surge, as defined in NRC RG 1.59. Specifically, the storm used to determine maximum WSEL is the PMH that causes the PMH surge as it approaches the site along a critical path at an optimum rate of movement. At the time when water levels including wave runup peak, the SWL at the new plant location is calculated to be 26.7 ft. NAVD. The addition of wave runup, 14.3 ft., creates a water surface elevation of 41.0 ft. NAVD. Future sea level rise of 1.35 ft. per century is added to the effects of storm surge and wave runup for a maximum water surface elevation that could occur during the projected life of the new plant of 42.4 ft. NAVD at the new plant location. This result is illustrated in Figure 2.4.5- 7, and water elevations from the combined events are presented in Table 2.4.5-1, which

Rev. 3 2.4-80 DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report discusses rounding the result to tenths of ft. The PMH maximum WSEL of 42.4 ft. NAVD using this alternative represents the design basis flood for the new plant location.

Maximum wave runup does not occur simultaneously with maximum SWL (Table 2.4.5- 1). When the SWL reaches its maximum at 26.9 ft. NAVD, wave runup is 12.8 ft, which combines to an elevation of 39.7 ft. NAVD. One half-hour later, SWL drops to 26.7 ft. NAVD and wave runup increases to 14.3 ft., which combines to 41.0 ft. NAVD (Figure 2.4.5-7), 0.3 ft. higher than the previous time step.

2.4.5.6 PMH Confirmatory Analysis

In order to further demonstrate the conservative nature of the maximum WSEL described in Subsection 2.4.5.5, a confirmatory analysis is performed using a current day two-dimensional storm surge modeling system. This subsection presents information on the development of the modeling system, the PMH cases run in the model and conclusions regarding the WSELs determined at the PSEG Site.

2.4.5.6.1 Modeling System

The modeling system used for the confirmatory analysis of the PMH surge at the PSEG Site uses a suite of state-of-the-art numerical wind, wave, and surge models and methods to compute surge still and total WSELs at the points of interest. The model suite consists of the Oceanweather Planetary Boundary Layer (PBL) wind model for tropical storms, the wave-field model Simulating Waves Nearshore (SWAN), and the storm surge and tidal model ADCIRC. This wind, wave and surge modeling approach is very similar to the recent FEMA-sponsored Region III floodplain-mapping project (Reference 2.4.5-44). In addition to the numerical models, estimation of wave runup at the points of interest to establish a maximum total WSEL is determined using the approach described by USACE (Reference 2.4.5-27). The input to the modeling system is a series of parameters that represent the synthetic storm (i.e., storm track, which consists of time, position, central pressure, Holland B parameter [which controls the shape of the pressure and wind fields], radius to maximum winds, and peripheral pressure). The output from the modeling system is the maximum still WSEL and total WSEL for the PSEG Site associated with each individual storm modeled.

2.4.5.6.1.1 Wind Model

The Oceanweather PBL model is used to develop wind and pressure fields for the synthetic storms (Reference 2.4.5-40). For each storm, defined by a track and time- varying wind field parameters, the Oceanweather PBL model is applied to construct wind and atmospheric pressure fields every 15 minutes for driving surge and wave models. Oceanweather generates wind and pressure fields with a highly refined meso-scale moving vortex formulation developed originally by Chow (Reference 2.4.5-39) and modified by Cardone et al. (Reference 2.4.5-38). The model is based on the equation of horizontal motion, vertically averaged through the depth of the planetary boundary layer.

2.4.5.6.1.2 ADCIRC+SWAN Model

Storm surge simulations are performed using the tightly coupled ADCIRC+SWAN state- of-the-art coastal circulation and wave model. ADCIRC is based on the two-dimensional,

Rev. 3 2.4-81 DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report vertically-integrated shallow water equations that are solved in Generalized Wave Continuity Equation form (Reference 2.4.5-41). The equations are solved over complicated bathymetry encompassed by irregular seashore boundaries using an unstructured finite-element method. This algorithm allows for flexible spatial discretizations over the entire computational domain. The advantage of this flexibility in developing a computational mesh is that larger elements can be used in open-ocean regions where coarser resolution is needed, whereas smaller elements can be applied in the nearshore and estuary areas where finer resolution is required to resolve hydrodynamic details and more accurately simulate storm surge propagation onto a complex coastal landscape. (Reference 2.4.5-45)

The recent FEMA Region III storm surge study developed a high-resolution ADCIRC mesh that covers the entire Delaware Bay and PSEG Site region (see Figure 2.4.5-8). The ADCIRC mesh is comprised of a high-resolution grid covering FEMA Region III that was appended to a previously developed grid of the western North Atlantic, the Gulf of Mexico and the Caribbean Sea. Specifically, the grid covers the area from the 60 degrees west meridian to the US mainland. Within FEMA Region III, the grid extends inland to the 49.2 ft. NAVD (15 m) contour to allow for inland storm surge flooding. In this region, the grid was designed to resolve major bathymetric and topographic features such as: inlets; dunes; and river courses, as identifiable on the detailed FEMA digital elevation model (DEM), satellite images, and National Oceanic and Atmospheric Administration (NOAA) charts. (References 2.4.5-42 and 2.4.5-43)

After confirming the FEMA developed ADCIRC mesh was operating correctly on the project computing platform, the mesh is refined in the vicinity of the PSEG Site to more accurately represent the topographic features of the site. To properly describe the topographic features important to the hydrodynamic and wave characteristics at the PSEG Site, high resolution, site-specific topographic data including the controlling vertical features important to surge conveyance and wave propagation were incorporated into the finite element mesh. The refined mesh for the PSEG Site area is shown on Figure 2.4.5-9. The refined PSEG Site mesh is inserted into the overall FEMA Region III mesh and the model is re-validated using the same Hurricane Isabel and Nor’easter Ida test storm input files as the FEMA Model validation report prepared by USACE (Reference 2.4.5-44). A graphical comparison of water levels from the Hurricane Isabel storm simulation on the refined PSEG Site mesh and unmodified FEMA Region III at locations around the PSEG Site is shown in Figure 2.4.5-10. This process confirms that the refined mesh produces results that are essentially the same as the unmodified FEMA Region III mesh in the vicinity of the PSEG Site.

2.4.5.6.1.3 Wave Runup Estimation

The ADCIRC+SWAN simulations of each storm produce still WSEL and wave data (significant wave height, period and direction) over the course of each storm surge event. Wave field data on each of the four sides of the site (see Figure 2.4.5-11) are provided at 15-minute intervals. The data is analyzed and captured for the subsequent wave runup calculations. The wave runup calculations described below are performed at each time step and at each of the four locations around the site. After the calculations are performed, the maximum total WSEL value, defined as the still WSEL plus wave runup, at any of the four points is captured as the maximum value for that storm event.

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Wave runup calculations for the new plant are based upon the latest design guidance found in the USACE Coastal Engineering Manual (CEM), Chapter VI-5 (Reference 2.4.5- 29). The new plant’s powerblock will be constructed on engineered fill with riprap protection, with facing slopes of 3:1 (horizontal:vertical), as shown on Figure 2.5.4.5-2. The wave runup equations described in Subsection 2.4.5.3.1 are used for the confirmatory analysis. Additionally, the angle of incidence factor is considered variable in this analysis because more detailed waver direction information is available from the ADCRIC+SWAN model.

Based upon Equation VI-5-11 from the CEM and the expectation that waves impinging on the slope will be short-crested, the angle reduction factor is given by:

γβ = 1 – 0.0022 β (Equation 2.4.5-3)

where: β (in degrees) is computed based upon the mean wave direction produced by SWAN and the orientation of the new plant’s embankment.

The angle, β, is oriented such that it is zero when the incident wave direction is normal to a particular side of the new plant’s embankment and is valid up to +/- 90° from due perpendicular. For example, at the Western point of interest (see Figure 2.4.5-11) a wave would need to have an easterly direction component to be impinging on the site. If the wave is traveling due East, then the angle β is zero and no reduction factor for wave direction is included in the wave runup calculation. If the wave is traveling in an easterly direction with some north/south component to it, then the wave runup is reduced according to the factor determined using Equation 2.4.5-3. This reduction factor is conservatively set to be very small and is only 20 percent when the wave is parallel to the shore (i.e., +/- 90 degrees).

2.4.5.6.2 PMH Storm Simulations

Using the modeling system described in Subsection 2.4.5.6.1, three PMH storm simulations are run with differing antecedent water level conditions to compare the sensitivity of the resultant WSEL at the PSEG Site to the effects of potential sea level rise and 10 percent exceedance high tides. The PMH parameters described in Subsection 2.4.5.2 are used as an input to the modeling system. Table 2.4.5-4 provides the input parameters for each confirmatory PMH model simulation.

One additional parameter not identified by NOAA (Reference 2.4.5-18), but required by the Oceanweather PBL wind field model is the Holland B parameter. A Holland B parameter of 1.1 is selected for these simulations, as this represents the mean value for the region.

As described in Subsection 2.4.5.2.2, the combined events criteria specified in Section 9.2.2 of ANSI/ANS-2.8-1992, (Reference 2.4.5-1) for determining the storm surge at the new plant is evaluated by combining probable maximum surge and seiche with wind wave activity concurrent with the 10 percent exceedance high tide, and effects of hurricane-associated precipitation. The modeling system developed for the PMH confirmatory analysis accounts for the surge with wind wave activity concurrent with the

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10 percent exceedance high tide through the use of antecedent water levels. The effects of hurricane-associated precipitation are not included in the confirmatory analysis.

Analysis of the effects of precipitation based flooding in the Delaware River Basin is discussed in Subsections 2.4.3 and 2.4.4. These subsections estimate the resultant WSEL at the PSEG Site from the 500 year flood and various probable maximum precipitation events. While the ANSI/ANS-2.8-1992 combined events criteria only requires assessment of hurricane-associated precipitation, even these extreme precipitation events do not significantly increase the WSEL at the PSEG Site due to the size of the Delaware River at this location. Based on the limited response in WSEL at the PSEG Site to extreme precipitation events and the significantly lower WSEL when the PMH storm is modeled in the ADCIRC+SWAN modeling system, effects of hurricane-associated precipitation are not included in the confirmatory analysis.

2.4.5.6.3 Confirmatory Analysis Comparisons and Conclusions

The confirmatory PMH simulations in the ADCIRC+SWAN modeling system produce maximum WSELs approximately 10 ft. below the equivalent maximum WSEL of the Bodine, Kaphuis and HEC-RAS modeling approach. Table 2.4.5-4 presents the resulting maximum WSEL’s at the PSEG Site for each PMH event modeled. The only difference between each of the ADCIRC+SWAN simulations of the PMH is the antecedent water levels. Varying the antecedent water levels of the model simulations from 0 ft. NAVD to 5.85 ft. NAVD to conservatively account for potential sea level rise and the 10 percent exceedance high tide results in an approximate 1 ft. difference in maximum WSEL at the PSEG Site.

Based on the confirmatory PMH simulations performed in the ADCIRC+SWAN modeling system, it is shown the Bodine, Kaphuis and HEC-RAS modeling approach produces conservative resultant WSELs at the PSEG Site when the same input parameters are applied.

2.4.5.7 Sediment Erosion and Deposition Associated with the PMH Surge

Tidal current velocities normally range from 2 to 3 ft/sec. Velocities determined by the HEC-RAS model’s simulation of the PMH surge show that velocities throughout Delaware Bay exceed 4.9 ft/sec; while velocities in the river channel near the new plant exceed 8 ft/sec. These calculated current velocities are sufficient to cause resuspension of natural sediments and cause erosion (Reference 2.4.5-5). Safety-related SSC will be protected against erosion that could affect the integrity of those facilities. Gross deposition is determined by conservatively assuming that all total suspended solids in the water column are deposited within a few days after passage of the hurricane. Observations of total suspended solids concentrations (TSS) in other bays and estuaries shortly after passage of hurricanes indicate that TSS increase approximately tenfold more than normal pre-storm levels (References 2.4.5-9, 2.4.5-34, and 2.4.5-35). TSS levels near the bottom of the Delaware Bay normally range between 450 and 525 mg/L during the flood and ebb periods in the tidal cycle (Reference 2.4.5- 5). Therefore, TSS levels immediately after the storm could reach 5000 mg/L, ten times greater than the normal level of approximately 500 mg/L. Since current velocities are higher in the river channel near the new plant than would generally occur throughout

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Delaware Bay, net erosion is more likely to occur than net deposition. Since the intake structure would be protected from erosion, net deposition could occur immediately around the intake structure. Calculations based on the assumption that 5000 mg/L of total suspended solids deposit shortly after the passage of the hurricane indicate that deposition is not expected to exceed 2 in. of sediment.

The effect of the PMH surge on sediment deposition and erosion is not expected to adversely affect operation of safety-related SSC.

2.4.5.8 Seiche and Resonance

Seiche is an extreme sloshing of an enclosed or partially enclosed body of water excited by meteorological causes (e.g., barometric fluctuations, storm surges, and variable winds), interaction of wave trains with geometry and bathymetry of the water body (e.g., from tsunamis), and seismic causes (e.g., a local seismic displacement resulting in sloshing of the water body).

Seiche motion can be complex in water bodies with variable width and depth. The simplest seiche motion in an estuary like Delaware Bay causes the largest water level fluctuations at the head of tide (near Trenton, NJ) while water levels are relatively constant at the mouth of the bay. This type of seiche is called the fundamental mode (Reference 2.4.5-27). The free oscillation period of the fundamental mode seiche propagating along the length of the Delaware Estuary from its mouth at RM 0 to the head of tide at Trenton (RM 134) is 31 hrs.

Shorter length seiche waves (with shorter oscillation periods) are possible. The effect of winds blowing along the axis of Delaware Bay (northwest-southeast) may excite a seiche within Delaware Bay, but with little effect on the upper estuary, due to the change in orientation of the river in the upper estuary (more nearly northeast-southwest) and less surface area for the wind to act on. Therefore, winds from the northwest tend to excite a shorter length wave with greater effect in Delaware Bay and less effect in the upper estuary. Fluctuations in the strength of northwest winds could generate seiche waves of the second mode, which have a period of 10 hrs. (Reference 2.4.5-27).

Researchers have observed water level fluctuations in Delaware Bay that have lower frequency than tides, which are semidiurnal (indicating 12-hour periods). Water level fluctuations that have lower frequency than tides are referred to as subtidal. The magnitude of such subtidal oscillations observed by these researchers at the new plant location was less than 2 ft. Researchers further determined that these water level fluctuations are associated with wind forces of two types. The first type is direct wind stress on the surface of Delaware Bay, while the second is an indirect forcing associated with wind stress fluctuations over the Atlantic Ocean. The fluctuations in wind stress are associated with fluctuations in water levels in the Delaware Bay at periods of more than 3 days. Together, these direct and indirect wind stress fluctuations are associated with nearly all subtidal fluctuations of water surface elevations observed at Reedy Point, DE, 7 mi. from the new plant location. (References 2.4.5-36 and 2.4.5-37)

From the observations reported, it can be seen that the atmospheric forcing, associated with seiche motion in Delaware Bay, occurs with longer periods (more than 3 days) than the natural period of oscillation of the Delaware Estuary (30 hrs. or less). Therefore,

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Delaware Bay does not resonate with the meteorologically-induced wave periods. This lack of resonance contributes to the relatively small magnitude of seiche motion in Delaware Bay.

The Delaware Bay also would not resonate with seismic activity. Seismic waves have a period of 1 hr. or less (Reference 2.4.5-25). Subsection 2.4.6 documents the effect of tsunami-induced seiche motion in Delaware Bay, showing that the magnitudes of water level fluctuations are too small to affect safety-related SSC.

Due to the lack of resonance with identified forcing functions, as well as observational evidence of the relatively small magnitude of seiche motions, potential seiche waves produce much smaller flood levels than the PMH surge.

2.4.5.9 References

2.4.5-1 American National Standards Institute/American Nuclear Society, “Determining Design Basis Flooding at Power Reactor Sites,” ANSI/ANS- 2.8-1992, p. 1, 20, 32, 1992.

2.4.5-2 Bodine, B.R. 1971, “Storm Surge on the Open Coast Fundamental and Simplified Prediction,” U.S. Army Corps of Engineers, Coastal Engineering Research Center Technical Memorandum No. 35, 1971.

2.4.5-3 Bretschneider, C.L, “Hurricane Surge Predictions for Delaware Bay and River,” Department of the Army Corps of Engineers, Beach Erosion Board, Miscellaneous Paper No. 4-59, 1959.

2.4.5-4 Bretschneider, C.L, “Engineering Aspects of Hurricane Surge,” Estuary and Coastline Dynamics, A.T. Ippen, ed., McGraw-Hill, New York, p. 231 – 256, 1966.

2.4.5-5 Cook, T.L., C.K. Sommerfield and K. Wong, “Observations of Tidal and Springtime Sediment Transport in the Upper Delaware Estuary,” Estuarine Coastal and Shelf Science, 72: p. 235 – 246, 2007.

2.4.5-6 d’Angremond, K. and F.C. van Roode, “Breakwaters and Closure Dams,” Taylor and Francis, London, p. 148, 2004.

2.4.5-7 Donelan, M.A., B.K. Haus, N. Reul, W.J. Plant, M. Stiassnie, H.C. Graber, O.B. Brown and E.S. Saltzman, “On the Limiting Aerodynamic Roughness of the Ocean in Very Strong Winds,” Geophysical Research Letters, 31:L18306(5 pp.), 2004.

2.4.5-8 Harleman, D.R.F, “Tidal Dynamics in Estuaries, Part II: Real Estuaries,” Estuary and Coastline Hydrodynamics, A.T. Ippen, ed., McGraw-Hill, New York, 1966.

2.4.5-9 Jones, S.H., et al., “Transport and Fate of Microbial Contaminants and Suspended Sediments in the Great Bay: Effects on Water Quality and

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Management Implications,” Technical Completion Report #59 (USGS Grant), 1992.

2.4.5-10 Kamphuis, J.W., “Introduction to Coastal Engineering and Management,” World Scientific Publishing Co., River Edge, New Jersey, 2000.

2.4.5-11 MASER Consulting, PA ALTA/ACSM Land Title Survey for PSEG Nuclear LLC of Block 26, Lots 4, 4.01, 5 and 5.01, Job Number 05001694D, Index Number HASU023453, dated June 13, 2008.

2.4.5-12 National Oceanic and Atmospheric Administration, Coastal Services Center, “Historical Storm Tracks,” Website, http://csc-s-maps- q.csc.noaa.gov/hurricanes/download.jsp, accessed April 1 – April 9, 2009.

2.4.5-13 National Oceanic and Atmospheric Administration, “Effects of Hurricane Floyd on Water Levels Data Report,” NOAA Technical Report NOS CO- OPS 027, 2000.

2.4.5-14 National Oceanic and Atmospheric Administration, “Effects of Hurricane Isabel on Water Levels Data Report,” NOAA Technical Report NOS CO- OPS 040, 2004.

2.4.5-15 National Oceanic and Atmospheric Administration, “FAQ / State of the Science: Atlantic Hurricanes and Climate,” 2 pp., 2006.

2.4.5-16 National Oceanic and Atmospheric Administration, “Historic Tide Data,” Website, http://tidesandcurrents.noaa.gov/station_retrieve.shtml?type=Historic%20 Tide%20Data&state=Delaware&id1=855, accessed April 7, 2009.

2.4.5-17 National Oceanic and Atmospheric Administration, “Hurricane Climatology for the Atlantic and Gulf Coasts of the United States,” NOAA Technical Report NWS 38, 1987.

2.4.5-18 National Oceanic and Atmospheric Administration, “Meteorological Criteria for Standard Project Hurricane and Probable Maximum Hurricane Windfields, Gulf and East Coasts of the United States,” NOAA Technical Report NWS 23, 1979.

2.4.5-19 National Oceanic and Atmospheric Administration, “NOS Estuarine Bathymetry: Delaware Bay DE/NJ (M090),” Website http://egisws01.nos.noaa.gov/servlet/BuildPage?template=bathy.txt&parm 1=M090&B1=Submit, accessed January, 28,2009.

2.4.5-20 National Oceanic and Atmospheric Administration, “Outer Continental Shelf Resource Management Map – Bathymetric Map, Salisbury,” NOS NJ 18-5 (OCS), 1975. 2.4.5-21 National Oceanic and Atmospheric Administration, “Sea Level Trends Online, 8551910 Reedy Point, Delaware,” Website,

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http://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=85 51910, accessed April 27, 2009.

2.4.5-22 National Oceanic and Atmospheric Administration, “SLOSH Display Program v. 1.61g,” October 20, 2009.

2.4.5-23 National Oceanic and Atmospheric Administration, “SLOSH: Sea, Lake, and Overland Surges from Hurricanes,” NOAA Technical Report NWS 48, 1992.

2.4.5-24 National Oceanic and Atmospheric Administration, “The Deadliest, Costliest, and Most Intense United States Tropical Cyclones from 1851 to 2006 (and Other Frequently Requested Hurricane Facts),” NOAA Technical Memorandum NWS TPC-5, 2007.

2.4.5-25 Oliver, J., “A Summary of Observed Seismic Surface Wave Dispersion,” Bulletin of the Seismological Society of America, 52: p. 81 – 86, 1962.

2.4.5-26 Powell, M.D., P.J. Vicker and T.A. Reinhold, “Reduced Drag Coefficient for High Wind Speeds in Tropical Cyclones,” Nature 422: p. 279 – 283, 2003.

2.4.5-27 U.S. Army Corps of Engineers, “Coastal Engineering Manual,” Engineer Manual 1110-2-1100, United States Army Corps of Engineers, Washington, D.C. (in 6 volumes), 2002.

2.4.5-28 U.S. Army Corps of Engineers, “HEC-RAS 4.0 Software,” Website, http://www.hec.usace.army.mil/software/hec-ras/hecras-download.html, accessed February 23, 2009.

2.4.5-29 U.S. Geological Survey, “Flood Magnitude and Frequency of the Delaware River in New Jersey, New York, and Pennsylvania,” USGS Open File Report 2008-1203, 2008.

2.4.5-30 U.S. Geological Survey, “National Elevation Dataset”, Website, http://seamless.usgs.gov/index.php, accessed February 2, 2009.

2.4.5-31 U.S Navy, “Hurricane Havens Handbook for the North Atlantic Ocean,” Websites, http://www.nrlmry.navy.mil/~cannon/tr8203nc/0start.htm and , accessed April 9, 2009.

2.4.5-32 Not Used

2.4.5-33 Not Used

2.4.5-34 Walker, Nan, “Tropical Storm and Hurricane Wind Effects on Water Level, Salinity, and Sediment Transport in the River-Influenced Atchafalaya- Vermilion Bay System, Louisiana, USA,” Estuaries 24(4): p. 498 – 506, 2001.

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2.4.5-35 Wilber, D.H., et al, “Suspended Sediment Concentrations Associated with a Beach Nourishment Project on the Northern Coast of New Jersey,” Journal of Coastal Research 22(5): p. 1035 – 1042, 2006.

2.4.5-36 Wong, K. and J.E. Moses-Hall, “On the Relative Importance of the Remote and Local Wind Effects to the Subtidal Variability in a Coastal Plain Estuary,” Journal of Geophysical Research, 103: p. 18,393 – 404, 1998.

2.4.5-37 Wong, K. and R.W. Garvine, “Observations of Wind-Induced, Subtidal Variability in the Delaware Estuary,” Journal of Geophysical Research 89: p. 10,589 – 597, 1984.

2.4.5-38 Cardone, V.J., C.V. Greenwood, and J.A. Greenwood, 1992. Unified program for the specification of hurricane boundary layer winds over surfaces of specified roughness. Final Report. Contract Report CERC-92- 1. Dept. of the Army,Waterways Experiment Station, Vicksburg, MS.

2.4.5-39 Chow, S. H., 1971. A study of the wind field in the planetary boundary layer of a moving tropical cyclone. Master of Science Thesis in Meteorology, School of Engineering and Science, New York University, New York, N.Y.

2.4.5-40 Thompson, E. F. and V. J. Cardone, 1996. “Practical modeling of hurricane surface wind fields,” ASCE Journal of Waterway, Port, Coastal and Ocean Engineering. 122, 4, 195-205.

2.4.5-41 University of North Carolina, “Introduction – ADCIRC,” Website, http://adcirc.org/home/documentation/users-manual-v50/introduction/, accessed October 14, 2013.

2.4.5-42 U.S. Army Corps of Engineers, “FEMA Region III Storm Surge Study, Coastal Storm Surge Analysis System Digital Elevation Model,” ERDC/CHL TR-11-1, Report 1, 2011.

2.4.5-43 U.S. Army Corps of Engineers, “FEMA Region III Storm Surge Study, Coastal Storm Surge Analysis: Computational System,” ERDC/CHL TR- 11-1, Report 2, 2011.

2.4.5-44 U.S. Army Corps of Engineers, “FEMA Region III Storm Surge Study, Coastal Storm Surge Analysis: Modeling System Validation,” ERDC/CHL TR-11-1, Report 4, 2013.

2.4.5-45 U.S. Nuclear Regulatory Commission, “The Estimation of Very-Low Probability Hurricane Storm Surges for Design and Licensing of Nuclear Power Plants in Coastal Areas,” NUREG/CR-7134, October 2012.

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Table 2.4.5-1 Resulting Water Elevations at the PSEG Site (RM 52)(a)(b)(c)

PMH Surge Hurricane Hurricane Maximum Surge Surge with Water Model Time Stillwater Wave Wave Sea Level Surface Step Level Runup Runup Rise Elevation (hr.) (ft. NAVD) (ft.) (ft. NAVD) (ft.) (ft. NAVD) 20.5 26.9 12.8 39.7 1.35 41.1 21.0 26.7 14.3 41.0 1.35 42.4 a) PMH surge results include coincident 10 percent exceedance high tide. b) PMH surge SWL occurs one-half hour earlier than the PMH surge maximum water surface elevation, and is equal to 26.9 ft. NAVD. c) Calculations are performed using more significant figures than shown in the Table, and the result is rounded to tenths of a ft. If intermediate results were rounded prior to addition the result would not be correct.

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Table 2.4.5-2 Maximum Sustained Wind Speed (kt) for Multiple PMH Scenarios(a)

Radius of Maximum Winds, R (NM)

11 20 28 42 135 133 132 Forward Speed, T (kt) 34 133 131 130 26 131 129 128

a) Each PMH evaluated in the above table exhibited a central pressure, p0 = 26.65 inches of mercury; pressure drop, Δp = 3.5 inches of mercury; and track direction from 138 degrees (moving northwest). These parameters, and the ranges considered, represent the PMH that can affect the project site according to NOAA (Reference 2.4.5-18).

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Table 2.4.5-3 Maximum Surge (ft. NAVD) for Multiple PMH Scenarios from Screening Simulations(a)

Radius of Maximum Winds, R (NM)

11 20 28 28 At Mouth of Delaware Bay (RM 0) At the Site (RM 52) 42 18.5 21.7 22.7 23.4 Forward Speed, T (kt) 34 18.4 21.2 22.1 25.3 26 18.1 21.2 22.1 27.8

a) Each PMH evaluated in the above table exhibited a central pressure, p0 = 26.65 inches of mercury; pressure drop, Δp = 3.5 inches of mercury; and track direction from 138 degrees (moving northwest). The tide is specified as static at the 10% exceedance high tide at the mouth of the Delaware Bay. Consequently these results cannot be compared with results presented in table 2.4.5-1 where a dynamic tide input is specified.

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Table 2.4.5-4 PMH Storm Parameters and Maximum Total Water Surface Elevation

Confirmatory Confirmatory Confirmatory Storm Description PMH Storm Run #1 Run #2 Run #3 Bodine and Modeling System ADCIRC ADCIRC ADCIRC HEC-RAS Central Pressure (mb) 902 902 902 902 Peripheral Pressure (mb) 1021 1021 1021 1021 Radius to Maximum 28 28 28 28 Winds (NM) Forward Speed (kt) 26 26 26 26 Storm Track Heading 42 42 42 42 (deg. West of North) Holland B Parameter N/Aa 1.1 1.1 1.1 Dynamic 10% Antecedent Water Levelb Exceedance 0 1.35 5.85 (ft. NAVD) High Tide Maximum Total Water Surface Elevationc 42.4 32.0 32.1 33.0 (ft. NAVD)

a) The NOAA wind field model (Reference 2.4.5-18) does not use the Holland B parameter. b) HEC-RAS is used to dynamically model the 10 percent exceedance high tide coincident with the PMH surge; whereas, the ADCIRC+SWAN model uses a static initial water surface elevation set to the elevations indicated in the table. c) These values include wave runup and potential sea level rise.

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Table 2.4.5-5 Wave Runup Parameters and Results

Model Wave Surf Wave Fetch Still WSEL Hmax Time Step Hs (ft.) Period Similarity Runup Direction (ft. NAVD) (ft.) (hr.) (sec) Parameter (ft.) 19.0 NE 9.3 7.2 4.0 4.6 1.40 5.8 19.5 ENE 15.4 9.5 4.7 7.9 1.25 8.8 20.0 ENE 23.3 11.7 5.1 11.8 1.11 11.7 20.5 E 26.9 13.1 5.3 12.8 1.11 12.8 21.0 ESE 26.7 14.7 5.6 14.4 1.10 14.3 21.5 ESE 25.7 14.0 5.5 14.1 1.10 13.9 22.0 ESE 24.4 13.3 5.4 13.1 1.12 13.2 22.5 ESE 22.9 11.5 5.1 12.1 1.11 12.1 23.0 ESE 21.5 9.9 4.9 11.2 1.10 11.1 23.5 ESE 19.5 8.6 4.7 9.8 1.12 9.9 24.0 S 17.0 9.0 4.5 12.8 0.95 11.0

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With Sea Level Rise = 42.4 ft. NAVD With Wave Runup = 41.0 ft. NAVD 40

35 at T = 21.0 hours

PMHS = 26.7 ft. NAVD 25

10 Probable Maximum Hurricane Surge (feet NAVD*)

-5 0 5 10 15 20 25 Time (hours)

*NAVD - North American Vertical Datum 1988 **PMHS (Probable Maximum Hurricane Surge) includes 10% exceednace high tide

PSEG Power, LLC Legend PSEG Site ESPA Part 2, Site Safety Analysis Report New Plant** With Coincident Wave Runup** Probable Maximum Hurricane Surge With Sea Level Rise Plus Additional Effects of Wave Runup and Potential Sea Level Rise

FIGURE 2.4.5-7 Rev. 1

DRAFT August 12, 2014 DRAFT August 12, 2014 N

. '. . W• . . E

Legend PSEG Power, LLC PSEG Site ESPA * PSEG Site Part 2, Site Safety Analysis Report FEMA Region III ADCI RC Mesh FIGURE 2.4.5-8 Rev. 0 DRAFT August 12, 2014 DRAFT August 12, 2014

Legend PSEG Power, LLC PSEG Site ESPA * PSEG Site Power Block Part 2, Site Safety Analysis Report ADCIRC Mesh Refinement at PSEG Site FIGURE 2.4.5-9 Rev. 0 DRAFT August 12, 2014 DRAFT August 12, 2014 Water Level Comparison for Hurricane Isabel (Tides+Surge+Waves) at One Mile North of Site

••••••• Revised Grid -- FEMAGrid

4 g 3 ~ ~ 2 Qj > ~ ! 0 ~

-2

-3 9/12/03 9/13/03 9/14/03 9/15/03 9/16/03 9/17/03 9/18/03 9/19/03 9/20/03

Date Water Level Comparison for Hurricane Isabel (Tides+Surge+Waves) at One Mile South of Site

Water Level Comparison for Hurricane Isabel ••••••• Revised Grid FEMAGrid (Tides+Surge+Waves) at One Mile West of Site 6 5 ------••••••• Rev ised Grid FEMAGrid L 4 6 c ---,------~ 3 5 L------r- z --. -- --_. 4 ~ 2 -.-. Qj c ~ 1 ~ 3 .... z ~ ------'---'-il---\-t--l-;/:l _J::\ 0 _ -0 __ ~ 0 ~ 2 3: ~ -1 "---- ~ -2 ~ 0 3: -1 "---- ~ 9/12/03 9/13/03 9/14/03 9/15/03 9/16/ 03 9/17/03 9/18/03 9/19/03 9/20/03 -2 Date -3 ~I------~----~----~------~----~------~----~----~ 9/12/03 9/ 13/03 9/14/03 9/15/03 9/16/03 9/17/03 9/18/ 03 9/19/03 9/20/03 PSEG Power, LLC PSEG Site ESPA Date Part 2, Site Safety Analysis Report Legend Comparison of Refined PSEG Site Mesh Locations One Mile Around Site 6. versus Unmodified FEMA Region III * PSEG Site Power Block FIGURE 2.4.5-10 Rev. 0 DRAFT August 12, 2014 DRAFT August 12, 2014

PSEG Power, LLC PSEG Site ESPA Part 2, Site Safety Analysis Report Legend Wave Runup Computation Locations around the Power Block PSEG Site Power Block FIGURE 2.4.5-11 Rev. 0 DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report

LIST OF TABLES (CONTINUED) ADD Insert A per RAI No. 67. Number Title

2.4.3-2 HEC-RAS Simulation Results of PMP Events

2.4.3-3 Worst Historical Storm Surge

2.4.3-4 Resulting PMF at the PSEG Site (RM 52) From Alternative I of ANSI/ANS-2.8- 1992 Section 9.2.2.2

2.4.3-5 Resulting PMF at the PSEG Site (RM 52) From Alternative II of ANSI/ANS-2.8- 1992, Section 9.2.2.2

2.4.4-1 Delaware River Basin Selected Water Control Structures

2.4.4-2 Summary of Tributary Dam Failure Input Parameters

2.4.4-3 Summary of Tributary Dam Failure Output Data Excluding Tidal Effects

2.4.4-4 Summary of Reservoir Sedimentation Rates

2.4.4-5 Resulting Maximum Water Surface Elevation at the PSEG Site (RM 52) From Dam Failure (Combined Events Alternative II of ANS)

2.4.5-1 Resulting Water Elevations at the PSEG Site (RM 52)

2.4.5-2 Maximum Sustained Wind Speed (kt) for Multiple PMH Scenarios

2.4.5-3 Maximum Surge (ft. NAVD) for Multiple PMH Scenarios from Screening Simulations

2.4.6-1 Historical Record of Tsunamis Affecting the U.S. East Coast

2.4.6-2 Parameters for Seven Individual Okada Sources Which Make Up the Composite Hispaniola Trench Source

2.4.6-3 Grids A, B, and C for Currituck Landslide Case

2.4.6-4 Grids A, B and C for La Palma, Canary Island Landslide Case

2.4.6-5 Grids A, B, and C for the Hispaniola Trench Earthquake Case

2.4.6-6 Summary of Maximum Runup and Drawdown Values at PSEG Salem Site for Each Case

2.4.7-1 Historic Ice Jam Events on the Delaware River and Tributaries

Rev. 3 2-xx

DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report

LIST OF FIGURES (CONTINUED) ADD Insert B per RAI No. 67.

Number Title

2.4.3-8 PMF Plot for the PSEG Site per Approximate Method from RG 1.59

2.4.3-9 Individual Components of the Combined Event Alternative I of ANSI/ANS-2.8- 1992, Section 9.2.2.2 Stage Hydrograph at the PSEG Site

2.4.3-10 Individual Components of the Combined Event Alternative II of ANSI/ANS-2.8- 1992, Section 9.2.2.2 Stage Hydrograph at the PSEG Site

2.4.4-1 Delaware River Basin Dams

2.4.4-2 Minimum Settled Particle Diameter at PSEG Intake Structure

2.4.4-3 Water Surface Elevations at the New Plant Location Following Failure of the Cannonsville and Pepacton Dams

2.4.4-4 Flow Rates at the New Plant Location Following Failure of the Pepacton and Cannonsville Dams

2.4.5-1 PMH Track

2.4.5-2 Hurricanes Producing Significant Storm Surges in Delaware Bay

2.4.5-3 Comparison of Bodine Method and Observed WSEL in Delaware Bay for the Chesapeake-Potomac Hurricane

2.4.5-4 Comparison of Calculated and Observed Surge at Reedy Point, DE

2.4.5-5 Determination of 10% Exceedance High Tide at Lewes and Reedy Point, DE

2.4.5-6 Probable Maximum Hurricane Surge Still Water Level at the New Plant Location

2.4.5-7 Probable Maximum Hurricane Surge Plus Additional Effects of Wave Runup and Potential Sea Level Rise

2.4.6-1 Slope at the Site Using Grid C

2.4.6-2 Comparison of Water Surface Elevation Generated by the Currituck Slide With and Without Friction

2.4.6-3 Current Speeds Generated by the Currituck Slide

2.4.6-4 Nested Model Grids for Currituck Landslide Case

2.4.6-5 Nested Model Grids for the La Palma, Canary Islands Landslide Case Rev. 3 2-xxxi

DRAFT August 12, 2014 REPLACE with "14.3 ft. 42.4 ft. NAVD" REPLACE with PSEG Site per RAI No. 67. "runup" ESP Application per RAI No. 67. Part 2, Site Safety Analysis Report

Table 2.0-1 (Sheet 7 of 9) PSEG Site Characteristics

SSAR Site Characteristic PSEG Site Value Definition Section Annual Average Undepleted/No The maximum annual average farm undepleted/no decay Decay /Q Value @ Nearest 1.10 x10-7 s/m3 Table 2.3-34 atmospheric dispersion factor (/Q) value for use in determining Farm, northwest, 4.9 mile gaseous pathway doses to the maximally exposed individual. Annual Average The maximum annual average farm undepleted/2.26-day decay /Q Undepleted/2.26-day Decay -7 3 1.10 x10 s/m Table 2.3-34 value for use in determining gaseous pathway doses to the /Q Value @ Nearest Farm, DRAFT DRAFT maximally exposed individual. northwest, 4.9 mile August August Annual Average Depleted/8.00- The maximum annual average farm depleted/8.00-day decay /Q day Decay /Q Value @ -8 3 8.20 x10 s/m Table 2.3-34 value for use in determining gaseous pathway doses to the Nearest Farm, northwest, 4.9 12, 12, maximally exposed individual. mile 2014 2014 Annual Average D/Q Value @ The maximum annual average farm relative deposition factor (D/Q) Nearest Farm, northwest, 4.9 3.50 x10-10 1/m2 Table 2.3-34 value for use in determining gaseous pathway doses to the mile maximally exposed individual. Hydrology Figure 1.2-3 presents the proposed Proposed Facility Boundaries 2.1 PSEG Site boundary map. facility boundary.

Maximum Ground Water 10 ft. NAVD 2.4.12.5 The maximum elevation of groundwater at the PSEG Site.

Maximum Stillwater Flood The stillwater elevation, without accounting for wind induced waves 26.9 ft. NAVD Table 2.4.5-1 Elevation that the water surface reaches during a flood event. The height of water reached by wind-induced waves running up on Wave Run-up 7.9 ft. Table 2.4.5-1 the site. The water surface elevation at the point in time where the Combined Effects Maximum 35.9 ft. NAVD Table 2.4.5-1 combination of the still water level and wave run-up is at its Flood Elevation maximum.

Rev. 3 REPLACE with "Runup" 2.0-8 per RAI No. 67. DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report

Salem Generating Station (SGS) and Hope Creek Generating Station (HCGS) are located in the western portion of the PSEG Site. SGS has two Westinghouse pressurized water reactors (PWRs) with once-through condenser cooling systems. Units 1 and 2 entered commercial service in June 1977 and October 1981, respectively. Each unit is licensed for 3459 megawatts thermal (MWt). The nuclear steam supply system for each unit includes a PWR, reactor coolant system, and associated auxiliary fluid systems. SGS is located in an area of engineered backfill at a grade elevation of 9.7 ft. NAVD (Reference 2.4.1-14).

HCGS is a single-unit plant utilizing a General Electric boiling water reactor (BWR) with a natural draft cooling tower; the unit is currently licensed for 3840 MWt. HCGS entered commercial service in December 1986. The nuclear steam supply system includes a BWR, reactor coolant system, and associated auxiliary fluid systems. The Hope Creek plant is located in an area of engineered backfill at an elevation of 11.7 ft. NAVD. The Turbine and Auxiliary Building ground floor levels are at a grade elevation of 12.2 ft. NAVD. (Reference 2.4.1-13)

The new plant location is to the north of the HCGS. Most of the area for the new plant lies within the current property boundary. However, PSEG is developing an agreement in principle with the U.S. Army Corps of Engineers (USACE) to acquire an additional 85 acres immediately to the north of the HCGS. A specific reactor technology has not been selected for construction at the PSEG Site. Designs under consideration are: REPLACE with "42.4 Single Unit U.S. Evolutionary Power Reactor (U.S. EPR) ft." per RAI No. 67. Single Unit Advanced Boiling Water Reactor (ABWR) Single Unit U.S. Advanced Pressurized-Water Reactor (US-APWR) REPLACE with Insert C Dual Unit Advanced Passive 1000 (AP1000) per RAI No.67.

The circulating water system (CWS) for the new plant includes cooling tower(s). The Delaware River is used for makeup water for the CWS and the turbine plant cooling systems. In addition to the circulating water cooling tower, service water cooling tower(s) are included in the new plant design.

The design basis flood (DBF) is 35.9 ft. NAVD as calculated in Subsection 2.4.5. Floor elevations for safety-related structures, systems and components (SSC) for the new plant, other than the intake structure, will be established to maintain one foot of clearance above the DBF, as required by Tier 1 of the design control document (DCD) for the technology selected. The area surrounding the safety-related SSC will be graded such that the runoff from probable maximum precipitation (PMP) on the site drains away from the SSC into a system of swales and pipes that carry runoff to the Delaware River.

The design basis low water level at the ultimate heat sink (UHS) makeup water intake is -15.9 ft. NAVD as discussed in Subsection 2.4.11 and shown on Figure 2.4.2-7.

Elevations reported in Section 2.4 are in NAVD. Some components of hydrologic events, such as storm surge and wave height, are customarily expressed in feet, which are not tied to a datum.

Rev. 3 2.4-2

DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report

(References 2.4.2-13 and 2.4.2-17). This is approximately 30 times greater than the mean freshwater discharge of the Delaware River near the site. Tides within the Delaware Estuary are semidiurnal (Reference 2.4.2-10). The nearest tidal gage station to the PSEG Site is NOAA’s Reedy Point, DE, tidal station, located upstream at RM 59. Mean tidal range at the Reedy Point tidal station is 5.34 ft. (Reference 2.4.2-11). Seasonal variations in the tidal cycle at Reedy Point (Reference 2.4.2-11) show higher msl elevations from April through October, as compared to November through March (Table 2.4.2-3).

Mean sea level trends at Reedy Point are evaluated by NOAA. The upper 95 percent confidence interval for sea level rise, based on monthly msl data, is estimated to be 1.35 feet/century (Reference 2.4.2-12). Flood elevations at the PSEG Site are affected by the regional tidal influences. Tidal variations are addressed in applicable modeling scenarios for determination of the design basis flood (DBF).

The DBF for the PSEG Site is determined by selecting the maximum flood elevation on the Delaware River adjacent to the site. This determination is obtained by considering possible flooding scenarios, singular and in combination, as applicable to the site. Flooding scenarios investigated for the site include: REPLACE with "42.4 Flooding due to PMP on the site (Subsection 2.4.2) ft." per RAI No. 67. PMF on rivers and streams (Subsection 2.4.3) Potential dam failures (Subsection 2.4.4) Maximum surge and seiche flooding (Subsection 2.4.5) REPLACE with Insert C Probable maximum tsunami (PMT) (Subsection 2.4.6) per RAI No.67. Ice effect flooding (Subsection 2.4.7) Channel diversions (Subsection 2.4.9)

Flooding due to underwater landslides is evaluated with the PMT and detailed in Subsection 2.4.6. Each of these flooding scenarios is evaluated in conjunction with other flooding and meteorological events, such as wind-generated waves and/or 10 percent exceedance high tide, in accordance with guidelines provided in Regulatory Guide (RG) 1.59, Design Basis Floods for Nuclear Power Plants, 1977 and American National Standards Institute/American Nuclear Society (ANSI/ANS)-2.8-1992, Determining Design Basis Flooding at Power Reactor Sites (Reference 2.4.2-1), as detailed in Subsections 2.4.2 through 2.4.7.

Evaluation of the above-referenced flooding scenarios indicates that the DBF for the new plant is the probable maximum surge and seiche associated with the probable maximum hurricane (PMH). As described in Subsection 2.4.5, the DBF includes still water level, 10 percent exceedance high tide, wind setup, and wave runup. The DBF flood level derived from storm surge associated with the PMH, including sea level rise, is elevation 35.9 ft. NAVD. A summary of the types of floods considered and their associated flood levels is presented in Table 2.4.2-4. Results of select flooding events and other relevant elevations are shown on Figure 2.4.2-7. Sea level rise is only added to the worst case flooding scenario to develop a conservative design basis flood.

Floor elevations for safety-related SSC for the new plant will be established to maintain clearance above the DBF, as required by Tier 1 of the DCD for the technology selected. The area surrounding the safety-related SSCs will be graded such that the runoff from the PMP on the site drains away from the structures. Rev. 3 2.4-25

DRAFT August 12, 2014 DRAFT August 12, 2014 REPLACE with "42.4 PSEG Site ft." per RAI No. 67. ESP Application Part 2, Site Safety Analysis Report

Table 2.4.2-4 PMF Determination in Accordance with ANSI/ANS-2.8-1992 “Determining Design Basis Flooding at Power Reactor Sites”

Max. WSEL Type of Flooding SSAR Subsection (ft. NAVD) Local PMP 2.4.2 (a) PMF on Streams and Rivers 2.4.3 21.0 Potential Dam Failures 2.4.4 9.4 PMS and Seiche Flooding 2.4.5 35.9 Probable Maximum Tsunami 2.4.6 5.7 Ice Effects 2.4.7 8.1 Channel Diversions 2.4.9 n.a.(b) a) WSEL depends on the stormwater drainage system design for the new plant and cannot be evaluated until the reactor technology is selected and the site grading plan, which is dependent of the selected technology, is developed. b) n.a. = not applicable

Rev. 3 2.4-32

DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report

2.4.3 PROBABLE MAXIMUM FLOOD ON STREAMS AND RIVERS

In this subsection, the hydrometeorological design basis is developed to determine the extent of flood protection required for those safety-related SSC necessary to ensure the capability to shut down the reactor and maintain it in a safe shutdown condition. The PMF on streams and rivers is investigated to determine peak WSEL in the Delaware River near the new plant location. The PMF on streams and rivers is the hypothetical flood “that is considered to be the most severe reasonably possible, based on comprehensive hydrometeorological application of PMP and other hydrologic factors favorable for maximum flood runoff such as sequential storms and snowmelt” (Reference 2.4.3-1). REPLACE with Insert C per RAI No.67. This subsection presents the calculated maximum WSEL at the PSEG Site based on the PMF. The methods used to determine the PMF follow ANSI/ANS-2.8-1992 (Reference 2.4.3-1); and NRC RG 1.59.

The Delaware River Basin drains to the Atlantic Ocean and is located in portions of five states: Pennsylvania (PA), New York (NY), New Jersey (NJ), Maryland (MD), and Delaware (DE). The basin is 13,600 square miles (sq. mi.) (Reference 2.4.3-4). The river is tidally influenced up to the U.S. Geological Survey (USGS) Gage Station 01463500, at Trenton, NJ, located at river mile (RM) 134 (Reference 2.4.3-16).

The new plant location is at RM 52, north of the existing HCGS, on the PSEG Site. The new plant is located on the shoreline of the Delaware River, where tidal fluctuations have a dominant effect on water levels under normal meteorological conditions, but severe precipitation in the basin and hurricanes can also affect water levels. The overall Delaware River Basin watershed is depicted in Figure 2.4.3-1. Floor elevations for safety-related SSC for the new plant will be established to maintain clearance above the design basis flood, as required by Tier 1 of the design control document for the technology selected. The area surrounding the safety-related SSC will be graded such that the runoff from the PMP on the site drains away from the structures.

2.4.3.1 Design Bases for Flooding in Streams and Rivers

This subsection presents the simulation details and results of the PMF analysis. Three different methods are used to determine the PMF. Two of the methods simulate river flood levels resulting from two different PMP events. The third method determines the PMF flood level using the Approximate Method from NRC RG 1.59. The resulting PMF water levels are then combined with other flood-producing events which may occur simultaneously. The highest water level at the plant location resulting from these three methods is considered the PMF.

Two potential PMP events are developed using NOAA HMR Number (No.) 51 and No. 52 (References 2.4.3-8 and 2.4.3-9). The first of the two potential PMP events evaluated is designed to yield maximum rainfall throughout the Delaware River Basin. The second potential PMP event is designed to yield more intense rainfall in the portion of the basin near and upstream of the new plant location.

Flooding is simulated for PMP of a 15,000 sq. mi. storm centered over Doylestown, PA, oriented to produce maximum total rainfall within the Delaware River Basin (Reference 2.4.3-1). Rev. 3 2.4-36

DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report entered into the HEC-RAS simulation as lateral inflow hydrographs. The combination of the downstream boundary condition of 10 percent exceedance high tide (4.5 ft. NAVD) and the PMF lateral inflows produce a maximum WSEL at the new plant of 7.3 ft. NAVD. Combining the inflow and downstream boundary condition in HEC-RAS changes the magnitude of the PMF at the site.

The 25-year surge and seiche is determined using the Chesapeake-Potomac hurricane of 1933. The 1933 hurricane is described in detail by Bretschneider (Reference 2.4.3-2). Its maximum water surface elevation, 8.3 ft. NAVD (Figure 2.4.5-4) surge exceeds the estimated 25-year recurrence interval surge and seiche of 5.7 ft. NAVD, at Reedy Point, DE, near the new plant location (Reference 2.4.3-15). For a conservative approach, the 1933 hurricane surge plus 10 percent exceedance high tide is used as the downstream boundary condition in the HEC-RAS model. This 1933 hurricane is described in greater detail in Subsection 2.4.5.2.1. The HEC-RAS simulation of the PMF and 10 percent exceedance high tide plus the 25-year surge and seiche produces a maximum WSEL at the new plant of 13 ft. NAVD. Coincident wave runup on a 3 (horizontal):1 (vertical) slope or flatter with riprap, in association with the 25-year surge and seiche, is determined to be 3.1 ft. Coincident wave runup is calculated using the methodology described in Subsection 2.4.3.1.2.

This combination of events, defined by Alternative II, produces a maximum WSEL at the PSEG Site of 16.1 ft. NAVD (Table 2.4.3-5). The simulated components of this total are 4.5 ft. from the 10 percent exceedance high tide, plus an additional 2.8 ft. from the simulated PMF, plus 5.7 ft. from the simulation of the surge and wind setup from the 25-year hurricane. The coincident wave runup, 3.1 ft., is added to the HEC-RAS modeled output. The stage hydrograph at the new plant for the combined events of the Alternative II simulation with each component illustrated is presented in Figure 2.4.3-10. REPLACE with "36.9

ft. NAVD" per RAI 2.4.3.2 Design Basis for Site Drainage No. 67.

The existing topography in the vicinity of the new plant location is low and flat, with an elevation ranging from 5 to 15 ft. NAVD (Reference 2.4.3-6). The maximum WSEL determined in this subsection is 21.0 ft. NAVD (Table 2.4.3-4). The grade elevation for the new plant will be set at a level that provides for clearance above the DBF, as required by Tier 1 of the DCD for the selected technology. The new plant location will be graded to ensure that runoff drains away from safety-related SSC via overland flow to outfalls that discharge to the Delaware River. At the new plant elevation, debris and waterborne projectiles are not expected to come into contact with safety-related SSC other than the intake structure. The intake structure will be designed to protect it from debris resulting from the PMF.

2.4.3.3 Effects of Sediment Erosion and Deposition

Water velocities determined by the HEC-RAS model simulation of the PMF may exceed 7 feet per second (ft/sec) in Delaware Bay. Normal tidal velocities approach 3 ft/sec. Suspended sediment concentrations in Delaware Bay were observed by Cook (Reference 2.4.3-3). These values routinely range from 450 to 525 milligrams per liter (mg/L) near the bottom of the water column during flood and ebb periods in the tidal cycle. The value of the critical velocity (resuspension velocity) for the bay was estimated to be 30 centimeters per second (cm/s) +/- 8 cm/s (0.98 ft/sec +/- 0.23 ft/sec). Therefore, at typical water velocities in the bay, resuspension

Rev. 3 2.4-42

DRAFT August 12, 2014 DRAFT August 12, 2014 REPLACE with Insert C PSEG Site per RAI No.67. ESP Application Part 2, Site Safety Analysis Report

The flood elevations determined in this subsection are less than the maximum WSEL from the storm surge associated with the PMH evaluated in Subsection 2.4.5. The grade elevation for the new plant will be set at a level that provides for clearance above the DBF, as required by Tier 1 of the DCD for the technology selected. In addition, sedimentation and erosion associated with the PMF do not represent a significant threat to operation of any safety-related SSC.

Subsection 2.4.10 addresses flooding protection requirements for the new plant location and considers the most severe flooding condition identified in this and other subsections of this report.

2.4.3.5 References

2.4.3-1 American National Standards Institute/American Nuclear Society, “Determining Design Basis Flooding at Power Reactor Sites,” ANSI/ANS-2.8-1992, (historical), p. 1, 32, 1992.

2.4.3-2 Bretschneider, C.L. Hurricane Surge Predictions for Delaware Bay and River, Department of the Army Corps of Engineers Beach Erosion Board, Miscellaneous Paper No. 4-59, 1959.

2.4.3-3 Cook, T.L, “Observations of Sediment Transport in the Delaware Estuary During Spring Runoff Conditions,” University of Delaware, Master of Science in Marine Studies Thesis, 2004, http://www.geo.umass.edu/grads/cook/tcook_thesis.pdf, accessed July 21, 2009.

2.4.3-4 Delaware River Basin Commission, “State of the Basin Report,” Cover and Introduction, Website http://www.state.nj.us/drbc/SOTB/index.htm, p. 6, accessed June 16, 2009.

2.4.3-5 Delaware River Basin Commission 2007b, “Stream River Mileage July 2007,” Website, http://www.state.nj.us/drbc/StreamMileageJuly2007.pdf, p. 11, accessed February 16, 2009.

2.4.3-6 MASER Consulting, PA ALTA/ACSM Land Title Survey for PSEG Nuclear LLC of Block 26, Lots 4, 4.01, 5 and 5.01, Job Number 05001694D, Index Number HASU023453 dated June 13, 2008.

2.4.3-7 National Oceanic and Atmospheric Administration, “Historic Tide Data,” Website http://tidesandcurrents.noaa.gov/station_retrieve.shtml?type=Historic%20Tide%2 0Data&state=Delaware&id1=855, accessed April 7, 2009.

2.4.3-8 National Oceanic and Atmospheric Administration, HMR-51 1978, “Hydrometeorological Report No. 51, Probable Maximum Precipitation Estimates, United States East of the 105th Meridian,” U.S. Department of Commerce, p. 2; 48, 1978.

2.4.3-9 National Oceanic and Atmospheric Administration, HMR-52 1982, “Hydrometeorological Report No. 52, Application of Probable Maximum

Rev. 3 2.4-44

DRAFT August 12, 2014 DRAFT August 12, 2014 REPLACE with PSEG Site "2.4.3.1.2" per RAI ESP Application No. 67. Part 2, Site Safety Analysis Report maximum flood elevations, as presented in ANSI/ANS-2.8-1992, Section 9.2.1.2. Wave runup is determined using 2-year annual extreme wind speed of 50 mph, as shown in Section 9.1.4 of ANSI/ANS-2.8-1992 (Reference 2.4.4-1). Wind speeds are adjusted for duration in accordance with the Coastal Engineering Manual (Reference 2.4.4-7). Fetch directions are evaluated in 22.5 degree increments and the fetch direction that yields the highest wave runup is presented. Wave conditions are limited by fetch for the critical direction, which is wind blowing from the west across a flooded fetch of 4 miles. The flooded fetch is calculated at elevation 6.8 ft. NAVD, as discussed in Subsection 2.4.4.3, for a total length of 4 miles. The smaller of the maximum wave height or the maximum breaker height is used to determine runup, as described in Sections 7.4.3 and 7.4.4.5 of ANSI/ANS-2.8-1992 (Reference 2.4.4-1). The maximum wave height of 5.6 ft. is controlling. Subsection 2.4.5 provides a detailed discussion of the methods used to determine wave runup and wind setup.

The plant facilities are assumed to be constructed on fill at a 3 (horizontal):1 (vertical) or flatter slope with the slope protected by riprap.

Water Level at the New Plant Location

The inflow hydrographs from the 500-year flood calculations are incorporated into the HEC-RAS model along with discharge hydrographs from the selected tributaries for the four dam break scenarios. The maximum WSEL at the new plant location due to dam failure under any of the modeled scenarios is 9.4 ft. NAVD.

2.4.4.3 Water Level at the New Plant Location

HEC-HMS and HEC-RAS modeling show that maximum WSELs at the new plant location result from the simultaneous failure of the Pepacton and Cannonsville dams, excluding the influence of tides (Table 2.4.4-3). Conservative parameters used in this analysis include the combination of multiple dam failures timed to reach the new plant location simultaneously, the reservoirs being full at the time they are breached and the dam failures occurring instantaneously due to seismic activity. The maximum WSEL at the new plant location resulting from this scenario, including the influence of tides, is 6.8 ft. NAVD (Figure 2.4.4-3). Figure 2.4.4-4 illustrates the maximum flow rates for this scenario.

In accordance with ANSI/ANS-2.8-1992 standards (Reference 2.4.4-1), maximum wave height and wave runup are simulated coincident with dam failure flood levels through the Delaware River. The combined effect of dam failure with 10 percent exceedance high tide, the 500-year frequency flood, and the 2-year wind-wave runup, produces a maximum WSEL at the new plant location of 9.4 ft. NAVD (Figure 2.4.4-3 and Table 2.4.4-5).

2.4.4.4 Effects of Sediment Deposition and Erosion

The settling of particles carried downstream from the Marsh Creek and Hoopes Reservoir dam breaks are calculated to address the potential for suspended sediments from dam failures that may adversely affect the operation of the intake structure at the new plant. These two reservoirs are chosen because they are the closest reservoirs to the PSEG Site and represent the highest potential for sediment deposition at the PSEG Site due to dam failure. Both are located on the Christina River, a tributary entering the Delaware River at RM 71. The Hoopes Reservoir is located 37 RM upstream from the PSEG Site and Marsh Creek Reservoir is located 53 RM Rev. 3 2.4-57

DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site REPLACE with Insert C ESP Application per RAI No.67. Part 2, Site Safety Analysis Report confluence of the Christina and Delaware rivers, with less deposition occurring at the intake structure. Therefore, dam breaks of the Marsh Creek and Hoopes reservoirs do not represent a significant buildup of sedimentation at the intake structure.

2.4.4.5 Dynamic Effects of Dam Failure-Induced Flood Waves on Structures, Systems and Components

The maximum WSEL caused by dam-failure induced flood waves is 9.4 ft. NAVD. This is lower than the DBF elevation caused by probable maximum storm surge, described in Subsection 2.4.5. Floor elevations for safety-related structures, systems and components (SSC) for the new plant, other than the intake structure, will be established to maintain one foot of clearance above the DBF, as required by Tier 1 of the DCD for the technology selected. With the exception of the intake structure, no safety-related SSC will be subject to dynamic forces associated with the flood wave caused by dam failures in the Delaware River Basin. The intake structure of the new plant will be designed to protect it from dynamic effects associated with dam-failure induced flood waves.

2.4.4.6 Conclusions

There are no dams in series to model a domino-type failure. Combinations of failure of large dams on tributaries to the Delaware River are modeled to determine worst case flooding elevations due to dam failures at the new plant location. Based on the settling velocity of soils and distance to the site, deposition of sediment due to dam breach is not significant at the intake structure. Low water as a result of dam breach is not considered because there are no dams on-site or downstream that affect the availability of safety-related water supply to the new plant.

Flood elevations determined by these dam failure analyses are developed using conservative assumptions through modeling procedures that include:

Addition of the downstream stage boundary condition of 10 percent exceedance of the high tide Multiple dam failures peak flows reaching the site at high tide Dams are considered full at the time of the breach Failures occur instantaneously due to seismic activity

Of the four seismic dam breach scenarios modeled, the scenario producing the maximum WSEL at the new plant location is the combined failure of the Pepacton and Cannonsville dams. This breach scenario results in a flood elevation of 9.4 ft. NAVD at the PSEG Site (Table 2.4.4- 5) and includes the following components: the 10 percent exceedance high tide at 4.5 ft. NAVD, coincident with the 500-year frequency storm event of 2.0 ft., the combined Pepacton and Cannonsville dam breaches of 0.3 ft., and the 2-year wind speed applied in the critical direction of 2.6 ft. However, the maximum WSEL resulting from potential dam failures is exceeded by the maximum storm surge associated with the PMH, as described in Subsection 2.4.5.

Rev. 3 2.4-59

DRAFT August 12, 2014 PSEG Site REPLACE with ESP Application "2.4.3.1.2" per RAI Part 2, Site Safety Analysis Report No. 67.

Table 2.4.4-5 Resulting Maximum Water Surface Elevation at the PSEG Site (RM 52) From Dam Failure (Combined Events Alternative II of ANS)

Failure of Wave Runup from 2- 10% Exceedance Cannonsville and Year Wind Speed in Maximum Water High Tide 500-Year Flood Pepacton Reservoirs the Critical Direction Surface Elevation (ft. NAVD) (ft.) (ft.) (ft.)(a) (ft. NAVD) 4.5 2.0 0.3 2.6 9.4

a) Coincident wave runup is described in detail in Subsection 2.4.5

DRAFT DRAFT August August 12, 12, 2014 2014

Rev. 3 2.4-66 DELETE per RAI No. DRAFT August 12, 2014 67. PSEG Site ESP Application REPLACE with " of Part 2, Site Safety Analysis Report 36.9 ft." per RAI No. 67. 2.4.6.4.8 Summary of Tsunami Amplitudes at PSEG Site

Runup values calculated during simulations are relative to 10 percent exceedance high tide, which serves as the static initial water level in the simulations. Maximum runup values are reported in Table 2.4.6-6 relative to the 10 percent exceedance high tide elevation. Drawdown values are reported in Table 2.4.6-6 relative to the 90 percent exceedance low tide elevation. The 10 percent exceedance high tide is 4.5 ft. NAVD and 90 percent exceedance low tide is -5.08 ft. NAVD based on values from the NOAA tidal gage at Reedy Point (Reference 2.4.6-13). This provides an approximation for extreme water levels reached for wave runup events arriving coincident with high astronomical tide, or for drawdown events arriving coincident with low astronomical tide. The PMT at the PSEG Site is caused by the Currituck Landslide. In the most conservative model without bottom friction, maximum runup at the PSEG Site is 5.65 ft. NAVD and maximum drawdown is -6.16 ft. NAVD.

These results indicate that a landslide tsunami on the U.S. East Coast continental shelf margin represents the PMT case.

2.4.6.5 Effects of Runup on Safety-Related Facilities

The new plant grade will be established at an elevation at least 1 ft. above the DBF of 35.9 ft. NAVD. As indicated in Table 2.4.6-6, none of the maximum predicted runup elevations obtained in this study overtop this elevation. Therefore, PMT events do not constitute a limiting design basis for the new plant nor do hydrodynamic and hydrostatic forces impact any safety- related structures. The DBF caused by storm surge and associated wave runup caused by the PMH, described in Subsection 2.4.5, governs the design to protect safety-related structures from wave runup. 2.4.6.6 Consideration of Debris and Waterborne Projectiles

The grade elevation for the new plant will be established at a level providing for clearance above the DBF, as required by Tier 1 of the DCD for the selected technology. Therefore, debris and waterborne projectiles do not come into contact with safety-related structures. The intake structure at the new plant will be designed to protect it from impacts of waves and waterborne projectiles.

2.4.6.7 Effects of Sediment Erosion and Deposition

Strong water currents associated with tsunami wave activity can cause erosion and deposition, rapidly changing the morphology of an impacted area. In order to examine whether this mechanism is likely to have an impact at the new plant location, the speed of current at the site for the Currituck cases, both with and without friction, is considered. Figure 2.4.6-3 shows that water current speeds for the case without friction are significantly higher than for the case with friction, but each value falls within the range of normal tidal current activity in the bay (Reference 2.4.6-29). A rapid morphological response to tsunami activity at the site is not expected.

2.4.6.8 Consideration of Other Site-Related Evaluation Criteria

Three tsunami sources are selected to analyze the PMT at the new plant location. Two tsunami sources (Currituck and Canary Islands) are assumed to generate the tsunami due to submarine landslides, which are not necessarily tied to strong seismic activity. The Currituck landslide is Rev. 3 2.4-96 REPLACE with " PMT related debris" per RAI No. 67. DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report freezing temperature). Conditions that lead to supercooling include air temperatures of 21°F (-6 C) and below, open water, and clear nights (Reference 2.4.7-14).

As discussed in Subsection 2.4.7.1, surface ice has been observed on the Delaware River at the PSEG Site, primarily during the months of January and February (Reference 2.4.7-4). This is consistent with the U.S. Coast Guard (USCG) Ice Guide (Reference 2.4.7-22). Table 2.4.7-2 summarizes the thickness and concentration of ice reported near the PSEG Site during the period of record from the 1998/1999 winter to the 2004/2005 winter. The concentration of ice is defined as the fraction of an area that is covered by sea ice. The National Ice Center reports this concentration data in tenths (Reference 2.4.7-8). A review of the National Ice Center data shows the thickest ice in the vicinity of the new plant was reported as code 741 on January 31, 2000. Using the World Meteorology Organization’s ice chart symbology, this translates to a thickness of 12 to 28 in. for the most mature portions of ice on the Delaware River, 4 to 6 in. for newer portions of formed ice, and 0 to 4 in. for the most recently formed ice. The highest concentration of ice reported during this period of record is 9-tenths to 10-tenths in the mid- to upper-Delaware Bay, occurring during the week of January 26, 2004 (Reference 2.4.7-4). This means that the ice formed in the mid and upper portions of Delaware Bay was concentrated enough to allow formation of a solid sheet of ice, but was not concentrated enough to be considered fast ice (ice anchored to the shoreline). The new plant is located at the transition from the Delaware Bay to the Delaware River. Table 2.4.7-2 summarizes the thickness and concentration of ice reported near the PSEG Site during this period of record. REPLACE with In accordance with ANS 2.8, Section 8.3, the "protectedintake structure from theat the new plant location will be designed with protective measures to mitigateeffects potential of theeffects DBF." from frazil ice, surface ice, and other dynamic forces associated with ice effects.per RAI No. 67.

2.4.7.5 Conclusions

The new plant design will ensure that all above-grade safety-related SSC are situated one foot higher than the DBF elevation, as required by Tier 1 of the DCD for the technology selected . Based on review of historical ice jam information and model simulation of a major historic ice jam event, the flooding potential resulting from historic ice jam discharge is elevation 8.1 ft. NAVD. This is significantly lower than the DBF elevation of 35.9 ft. NAVD. The DBF is further discussed in Subsection 2.4.5. Surface ice has been observed at the site. Based on historic meteorological data, the potential for frazil ice exists at the PSEG Site (as discussed in Subsection 2.4.7.1). The new plant intake structure will be designed to address ice effects, including surface ice, frazil ice, and other dynamic forces and blockages associated with ice effects. The icing events presented in this subsection represent the worst case icing scenarios adjacent to and at the PSEG Site. REPLACE with "42.4 2.4.7.6 References ft. per RAI 67.

2.4.7-1 American National Standards Institute/American Nuclear Society, “Determining Design Basis Flooding at Power Reactor Sites,” ANSI/ANS-2.8-1992, (historical), p. 1; 32, 1992.

2.4.7-2 Delaware River Basin Commission 2007b, “Stream River Mileage July 2007,” Website, http://www.state.nj.us/drbc/StreamMileageJuly2007.pdf, p. 11, accessed February 16, 2009. Rev. 3 2.4-111

DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site REPLACE with Insert C ESP Application per RAI No.67. Part 2, Site Safety Analysis Report

2.4.10 FLOODING PROTECTION REQUIREMENTS

Maximum WSEL, including wave runup, is evaluated for different flood-producing events in Subsections 2.4.3 through 2.4.7. The results are summarized in Subsection 2.4.2 (specifically Table 2.4.2-4). The combined events evaluation for probable maximum surge and seiche flooding, presented in Subsection 2.4.5, represents the maximum flood level and, therefore, becomes the DBF at the new plant. That alternative includes the effects of the probable maximum hurricane surge associated with the PMH.

Floor elevations for safety-related SSC for the new plant, with the exception of the intake structure, will be established to maintain clearance above the DBF, as required by Tier 1 of the DCD for the selected technology. The area surrounding the safety-related SSC will be graded such that runoff from the PMP on the site drains away from new and existing structures to the Delaware River. To create the worst case scenario, the model assumes that all drainage structures (e.g. culverts, storm drains, and bridges) are blocked during the PMP event. Drainage systems for the new plant location will be designed so that the peak discharge from the local PMP does not produce WSEL that cause flooding of any safety-related SSC at the site.

The storm surge associated with the PMH is discussed in Subsection 2.4.5. This surge is calculated coincident with the 10 percent exceedance high tide. Wave runup is added to the storm surge to give the maximum WSEL at the site. The maximum WSEL combined with the potential sea level rise produces a water level of 35.9 ft. NAVD (Table 2.4.5-1). All safety-related SSC (with the exception of the intake structure) for the new plant will be constructed at least one foot higher than the DBF. The new plant site grade is established at 36.9 ft. NAVD. This meets the requirements of a dry site as defined in NRC RG 1.102. Riprap protection will be provided on the slopes of the site to provide protection from wave runup.

The maximum WSEL in the intake forebay is controlled by the PMH, as discussed in Subsection 2.4.5. Appropriate erosion control technology will be implemented, where applicable, to protect the intake structure from wind-induced waves, runup and associated erosion. Flood protection for the intake structure will be designed as part of the detailed design of the new plant. The intake structure will be designed to be protected from the effects of flooding and to withstand the applicable hydrodynamic forces, including wave forces, in accordance with RG 1.27, 1.59, and 1.102.

Procedures to address flooding protection requirements will be developed based on the detailed site design.

REPLACE with Insert D REPLACE with "42.4 per RAI No.67. ft. per RAI 67.

Rev. 3 2.4-124

DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 2, Site Safety Analysis Report

Following installation, the wells were developed using a submersible pump to remove fines from the well and filter pack, under the supervision of a NJ licensed well driller. During the development process, the pump was cycled on and off and/or lifted up and down to create a surge effect in the well. The wells were considered developed when the pumped water was relatively clear and visually free of suspended sediment, or after a maximum of two hours.

Following well development, field hydraulic conductivity tests (also referred to as "slug tests") were performed at each well using procedures described in Section 8 of ASTM D 4044 (Reference 2.5.4.3-1). A minimum of two rising head tests and two falling head tests were completed at each location. The results of the hydraulic conductivity tests are presented in Subsection 2.5.4.6. REPLACE with "2.4.10"

per RAI No.67. 2.5.4.3.2 Foundation Interfaces

Figures 2.5.4.3-3 and 2.5.4.3-4 show cross-sections along, and perpendicular to, the dip of the Coastal Plain deposits underlying the northern area at the PSEG Site. These cross-sections are constructed from the geotechnical boring logs and demonstrate the position of subsurface stratigraphy relative to the upper and lower bounds of embedment depths for safety-related structures within the plant parameter envelope (PPE) described in Subsection 1.3.3. Figure 2.5.4.3-2 shows the location of the cross-sections relative to the geotechnical borings performed during the course of the PSEG Site exploration.

As discussed in Subsection 2.4.5, the site grade of the new plant will be at elevation 36.9 ft. NAVD to achieve a grade at least 1 ft. above the design basis flood elevation of 35.9 ft. Between 25 and 30 ft. of fill will be required to achieve this site grade. The top of competent foundation materials, as evaluated in Subsection 2.5.4.5, occurs at approximate elevation -67 ft. NAVD at the new plant location. Table 1.3-1 lists the range of embedment depths for the four reactor technologies as 39 ft. to 84.3 ft. below the plant grade. Subtracting these depths from the site grade of elevation 36.9 ft, shows that the bottom of the foundations for the deepest base of the safety-related structures will lie at elevations -2.1 ft to -47.4 ft NAVD which corresponds to 20 to 65 ft. above the top of the competent foundation bearing material. Over-excavation of this unsuitable foundation support material and replacement with backfill material will be performed, as described in Subsections 2.5.4.5 and 2.5.4.10. DELETE per RAI No.67. 2.5.4.3.3 References

2.5.4.3-1 ASTM, 2008, “Standard Test Method (Field Procedure) for Instantaneous Change in Head (Slug) Tests for Determining Hydraulic Properties of Aquifers,” ASTM D 4044-08, 2008.

2.5.4.3-2 ASTM, 2005, “Standard Test Method for Energy Measurement for Dynamic Penetrometers,” ASTM D 4633-05, 2005.

2.5.4.3-3 ASTM, 2006a, “Standard Guide for Use of Direct Rotary Drilling with Water- Based Drilling Fluid for Geoenvironmental Exploration and the Installation of Subsurface Water-Quality Monitoring Devices,” ASTM D 5783-06, 2006.

2.5.4.3-4 ASTM, 2006b, “Standard Practice for Description and Identification of Soils (Visual-Manual Procedure),” ASTM D 2488-06, 2006.

Rev. 3 2.5-250

DRAFT August 12, 2014 DRAFT August 12, 2014

RAI No. 67 Response SSAR Markups

INSERT A (Chapter 2 - List of Tables)

2.4.5-4 PMH Storm Parameters and Maximum Total Water Surface Elevation 2.4.5-5 Wave Runup Parameters and Results

INSERT B (Chapter 2 - List of Figures)

2.4.5-8 FEMA Region III ADCIRC Mesh 2.4.5-9 ADCIRC Mesh Refinement at PSEG Site 2.4.5-10 Comparison of Refined PSEG Site Mesh versus Unmodified FEMA Region III Mesh 2.4.5-11 Wave Runup Computation Locations around the Power Block

INSERT C (Subsections 2.4.1.1, 2.4.2.2, 2.4.10)

Safety-related structures, systems and components (SSC) for the new plant will be designed with flood protection features to withstand the flood height of the DBF and its associated effects.

INSERT D (Subsection 2.4.10)

All safety-related SSC for the new plant will be designed with flood protection features to withstand the flood height of the DBF and its associated effects. The new plant site grade is established at 36.9 ft. NAVD.

DRAFT August 12, 2014 DRAFT August 12, 2014

NAVD PSEG 42.4 132.2 Probable Maximum Surge & Seiche

27.4’

21.0 110.8 Probable Maximum Flood (PMF) on Streams and Rivers 37.4’ 15.0 104.8 Maximum Existing Site Grade, New Plant Location

9.4 99.2 Potential Dam Failure 8.1 97.9 Ice Jam Breach

7.7 97.5 Historical High Water (November 1950)

5.7 95.5 Probable Maximum Tsunami 5.0 94.8 Minimum Existing Site Grade, New Plant Location 4.5 94.3 10% Exceedance High Tide

2.9 92.7 Mean Higher High Water (Reedy Point, DE)

0 89.8 North American Vertical Datum of 1988 ‐0.8 89.0 National Geodetic Vertical Datum of 1929

‐3.0 86.8 Mean Lower Low Water (Reedy Point, DE)

‐6.2 83.6 Maximum Drawdown, Tsunami

‐8.8 81.0 Historical Low Water (December 31, 1962)

‐15.9 73.9 Extreme Low Water Surface Elevation

Not to Scale PSEG Power, LLC PSEG Site ESPA Part 2, Site Safety Analysis Report Datum and Water Level Relationship FIGURE 2.4.2-7 Rev. 2 DRAFT August 12, 2014 DRAFT August 12, 2014 PSEG Site ESP Application Part 3, Environmental Report and is identified as more than 7 mi. in length along the Delaware Estuary. The calculated submarine groundwater discharge flux of 494 to 1024 cfs in that zone is similar in magnitude to the surface water discharge of the second and third largest tributary rivers of the Delaware Estuary. These preliminary findings suggest that estimates of freshwater discharge at various locations along the Delaware Estuary, based solely on upland drainage area and measured streamflows, may be underestimated, particularly during lower flow periods when groundwater discharges tend to be more sustained than surface flows.

2.3.1.1.4 Historic Flooding and Annual Peak Flood Frequencies

Riverine flood conditions are not a primary flooding concern at the PSEG Site because the flow conveyance capacity of the Delaware River at this location is large compared to riverine generated flow rates. Tidal storm surges generate higher water levels in the reach than do rainfall runoff events from the watershed. The Federal Emergency Management Agency (FEMA) has determined that for the 1 percent annual risk high water event, tidal storm surge water levels are higher than storm runoff generated water levels throughout the area surrounding the PSEG Site (Reference 2.3-27). Current FEMA floodplain information indicates that the 10-, 50-, 100-, and 500-yr return period flood elevations at RM 52 are 7.0, 8.2, 8.9, and 13.2 ft. National Geodetic Vertical Datum of 1929 (NGVD), respectively. FEMA refers to these as “stillwater” elevations. The area inundated by the 1 percent annual risk flood (100-yr flood), as indicated on FEMA’s Flood Insurance Rate Map for the area, is as shown on Figure 2.3-6. For context, the elevation of the terrain across the PSEG Site generally ranges from 5 to 15 ft. NAVD. Developed areas of the site are nominally 10 to 12 ft. NAVD. The site grade associated with the power block area of the new plant is set at an elevation of 36.9 ft. NAVD.

Based on over 100 yr of records, the largest peak instantaneous discharge on the Delaware River at Trenton, was an estimated 329,000 cfs on August 20, 1955. The next highest peak discharge was 295,000 cfs on October 11, 1903. By contrast, Harleman (Reference 2.3-31) estimated the maximum tidal flow rate in the Delaware River at RM 52 (PSEG Site) and at RM 38 to be 800,000 cfs and 1,350,000 cfs, respectively. The design basis flood level for the PSEG Site is the probable maximum flood (PMF) or probable maximum hurricane (PMH) surge, whichever is higher. PMF and PMH surge analyses for the SSAR conclude that the PMF elevation is 20.7 ft NAVD, and the PMH surge elevation is 35.9 ft NAVD.

Alloway Creek is the largest stream near the PSEG Site. While the stream is tidal beyond Hancocks Bridge, FEMA indicates that 100-year riverine flood flows for Alloway Creek are 5450 cfs at the confluence with the Delaware River and 4850 cfs at Hancocks Bridge (Table 2.3-7).

2.3.1.1.5 Delaware Estuary

The Delaware Estuary is a drowned river valley of the Delaware River (Reference 2.3-91). Geometrically, it is a relatively simple estuary, with a dominant freshwater input at the head of the estuary (Delaware River) and a single, funnel-shaped bay where mixing occurs. It has been stated that when Henry Hudson sailed into the bay in 1609, he found it too shallow to navigate (Reference 2.3-91). A navigation channel has been dredged routinely and is maintained by the USACE with an authorized depth of 40 ft. The USACE is currently planning to increase the navigation channel depth to 45 ft. (Section 2.8).

Rev. 3 2.3-8

DRAFT August 12, 2014