Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 1 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

© Ontario Power Generation Inc., 2018. This document has been produced and distributed for Ontario Power Generation Inc. purposes only. No part of this document may be reproduced, published, converted, or stored in any data retrieval system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of Ontario Power Generation Inc.

Pickering Nuclear 2017 Impingement Monitoring Report

P-REP-07263-00011-R000 2018-04-16

Order Number: N/A Other Reference Number:

Internal Use Only

Prepared By: Jeff Wright Prepared By: Doug Brown Environmental Advisor Environmental Advisor Environment Programs Environment Programs

Reviewed By: Concurred By: Vanessa Tang Hon Yue Ali Esmaeily Section Manager Section Manager Environment Ops Support Environment Programs Pickering

Approved By: Raphael McCalla Director Environment Ops Support Nuclear

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 2 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

Table of Contents

Page

List of Tables and Figures ...... 3 Revision Summary ...... 4 Executive Summary ...... 5

1.0 INTRODUCTION ...... 6

2.0 THE FISH DIVERSION SYSTEM ...... 6 2.1 FDS Installation and Removal ...... 6 2.2 FDS Availability ...... 6

3.0 IMPINGEMENT MONITORING SAMPLING PROGRAM ...... 8

4.0 2017 FISH IMPINGEMENT ...... 9 4.1 Episodic Fish Impingement Event – November 16, 2017 ...... 9 4.2 Northern Pike ...... 13 4.3 Species at Risk...... 14

5.0 IMPINGEMENT AND ENTRAINMENT OFFSET PROJECTS ...... 14 5.1 Fisheries Act Authorization...... 14 5.2 Uncertainty ...... 14

6.0 CONCLUSION ...... 15

7.0 REFERENCES ...... 15 Appendix A: 17

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 3 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

List of Tables and Figures

Page

Figure 1 Annual Cumulative Biomass (kg) of Fish Impinged in 2010 - 2017 ...... 10

Table 1 Fraction of Time the Secondary Skirt is at the Surface ...... 7 Table 2 Frequency Distribution of Depth Logger Data ...... 8 Table 3 Comparison of Impingement Monitoring Effort ...... 8 Table 4 Biomass of Fish Impinged at Pickering NGS in 2017 ...... 11 Table 5 Number of Fish Impinged at Pickering NGS in 2017 ...... 12 Table 6 Flow Adjusted Rate of Biomass Impinged ...... 13 Table 7 Northern Pike Impingement ...... 13

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 4 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

Revision Summary

Revision Number Date Comments R000 2018-04-16 Initial issue.

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 5 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

Executive Summary

The Canadian Nuclear Safety Commission (CNSC) has accepted the Fish Diversion System (FDS) at the Pickering Nuclear Generating Station (PNGS) as the permanent solution to reduce fish impingement during operations. In order to provide assurance that the FDS maintains the expected level of performance, the CNSC requires OPG to monitor and report annually on the biomass of fish impinged. This document is the report for 2017.

The total biomass of all species and ages impinged in 2017 was 25,217 kg, which is equivalent to a rate of 4.99 kg/million m3 of station flow. The impingement reduction performance target was not met in 2017. The results in 2017 were heavily influenced by a single event starting on November 16 and lasting several days, which was reported to CNSC and DFO. During the event, a preliminary estimate of 24,000 kg of Alewife were impinged. In the absence of this event, impingement was 1,217 kg, the second lowest on record since assessment commenced in 2010.

In addition, to offset residual impingement impacts, the CNSC requested OPG implement a wetland improvement project of 3 hectares. To achieve this, OPG retained the Toronto and Region Conservation Authority (TRCA) to plan and upgrade a portion of the Duffins Creek wetland. The restoration project design phase was initiated in 2015 and was deemed to require an Authorization under Section 35(2)(b) of the Fisheries Act. OPG received this Authorization from Fisheries and Oceans Canada on January 17, 2018.

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 6 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

1.0 INTRODUCTION

In 2008, the Canadian Nuclear Safety Commission (CNSC) issued a directive to the Pickering Nuclear Generating Station (PNGS) to reduce fish impingement by 80% and entrainment by 60%. A fish diversion system (FDS) consisting of a barrier net was installed in front of the PNGS intake in 2009 and was studied in 2010 to 2011 to determine it’s capability to reduce impingement (Poulton, 2011, 2012a). Study results indicated that the FDS exceeded the 80% impingement reduction target in each year. As a result, in 2012, the CNSC accepted the FDS as the permanent solution to reduce fish impingement for all species during PNGS operations (CNSC 2012a), with the exception of Northern Pike, since this species in impinged in winter months when the FDS can not be deployed.

In order to provide assurance that the FDS maintained this level of performance, the CNSC required OPG to monitor and report annually on the biomass of fish impinged. This report documents observed impingement for 2017.

2.0 THE FISH DIVERSION SYSTEM

A complete description of the FDS system can be found in Kinectrics (2009) and Poulton (2011). A secondary skirt was added in 2011 to further reduce fish impingement in the event the main net and primary skirt became submerged (Poulton, 2012a). PNGS replaced the net in 2017, as the former net had reached its operational lifespan.

2.1 FDS Installation and Removal

In 2017, the FDS main net and the primary skirt installation were completed on May 11. Subsequent removal of the FDS was completed on November 13. No issues were reported during installation or removal of the FDS in 2017.

2.2 FDS Availability

Twenty four depth loggers, recording instantaneous depth at 15 minute intervals, were installed on the FDS in 2017 to monitor retention of the float lines at surface, and by extension FDS availability. All loggers were retrieved but the reading on three were irrational (South Main Net, East Main Net and West Second Skirt North). FDS performance is deemed acceptable when the loggers on the secondary skirt are submerged at depths ranging from 10 - 30 cm. Table 1 provides a weekly summary of the availability of each FDS aspect in 2017 and indicate the secondary skirt was at the surface for the majority of time the net was deployed.

As in previous years, daily visual observations of the secondary skirt by OPG security were conducted. The visual observations document if the float lines become submerged, and inform maintenance staff of net deficiencies requiring immediate corrective actions. Results of the visual observation show there were no periods in 2017 that the net was degraded.

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 7 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

Table 1 Fraction of Week that Each Aspect of the FDS Secondary Skirt was at the Surface (0-30 cm) While the FDS was Installed in 2017

Week Aspect Start End East South West 28-May-17 3-Jun-17 100% 100% 100% 4-Jun-17 10-Jun-17 100% 100% 100% 11-Jun-17 17-Jun-17 100% 100% 100% 18-Jun-17 24-Jun-17 100% 100% 100% 25-Jun-17 1-Jul-17 100% 100% 100% 2-Jul-17 8-Jul-17 100% 100% 100% 9-Jul-17 15-Jul-17 100% 100% 100% 16-Jul-17 22-Jul-17 100% 100% 100% 23-Jul-17 29-Jul-17 100% 100% 100% 30-Jul-17 5-Aug-17 100% 100% 99% 6-Aug-17 12-Aug-17 99% 100% 100% 13-Aug-17 19-Aug-17 98% 100% 100% 20-Aug-17 26-Aug-17 97% 100% 100% 27-Aug-17 2-Sep-17 99% 100% 100% 3-Sep-17 9-Sep-17 100% 100% 100% 10-Sep-17 16-Sep-17 100% 100% 100% 17-Sep-17 23-Sep-17 100% 100% 100% 24-Sep-17 30-Sep-17 99% 100% 100% 1-Oct-17 7-Oct-17 99% 100% 100% 8-Oct-17 14-Oct-17 98% 100% 100% 15-Oct-17 21-Oct-17 100% 100% 100% 22-Oct-17 28-Oct-17 99% 100% 100% 29-Oct-17 4-Nov-17 100% 100% 100% 5-Nov-17 11-Nov-17 100% 100% 100%

Table 2 provides a summary of the depth data as a frequency distribution. The secondary skirt was most frequently located within 30cm of the surface of the water (in the 0-30 cm range). Further, all three aspects (West, South and East) of the secondary skirt maintained a position within 50 cm of surface for 100% of the time the FDS was in service in 2017.

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 8 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

Table 2 Frequency Distribution of Depth Logger Data

Depth West South East Range 2nd 1st Main 2nd 1st Main 2nd 1st Main (cm Skirt Skirt Net Skirt Skirt Net Skirt Skirt Net below surface) 0-30 100 100 NA 100 97 NA 100 98 31 30 - 50 0 0 0 0 0 0 1 50 - 100 0 0 0 0 0 1 0 >100 0 0 0 1 0 1 68 Note: The south main net, east main net, and one west primary skirt loggers (1 of 3) had irrational data and could not be used.

3.0 IMPINGEMENT MONITORING SAMPLING PROGRAM

From 2010 to 2012, OPG undertook an extensive sampling program to demonstrate that the FDS was capable of meeting the CNSC impingement reduction targets. In 2012, the CNSC accepted that the FDS is capable of meeting the targets (CNSC 2012a). Subsequently, in 2013, the objective of the sampling program was changed from performance demonstration to compliance verification. Consequently, the bin sampling program was reduced from 4 events per week to 1 event per week in April 2013 (OPG 2013). Table 3 displays the sampling effort in 2017 and previous years.

Table 3 Comparison of Impingement Monitoring Effort

Period FDS Performance Pre-FDS FDS Compliance Verification* Evaluation Year 2003 - 2006 2010 2011 2012 2013 2014 2015 2016 2017 2004 # Bins 574 234 1,505 1,456 1,181 400 353 281 338 327 Sampled Total In- Service Bin 32,236 25,420 37,904 38,541 29,415 14,711 12,178 9,516 12,012 11,808 Hours sampled % of time sampled (based on full year of 46% 36% 54% 55% 42% 21% 17% 14% 17% 17% service for the 8 bin location) * In addition to the weekly sampling, OPG has committed to undertake event based sampling if a fish run occurred between the regularly scheduled sampling events.

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 9 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

4.0 2017 FISH IMPINGEMENT

The formula used to calculate and annualize fish impingement is provided in Appendix A. The quantity of fish impinged in 2017 is shown in Figure 1 and Tables 4 and 5.

The total biomass of all species and ages impinged in 2017 was 25,217 kg which is equivalent to a rate of 4.99 kg/million m3 of station flow. The results in 2017 were strongly influenced by a single event starting on November 16 which was reported to CNSC and DFO. During the event, an preliminary estimate of 24,000 kg of Alewife were impinged. In the absence of this event, impingement was 1,217 kg or 0.24 kg/million m3 of station flow, the second lowest impingement on record. Further, impingement rates during the period of time the FDS was not installed (January – April and November – December) were consistent with trajectories of years past during the same time frames (when the November event is excluded). However, because of this event the impingement reduction performance target was not met.

As observed since 2010, the FDS performance remains relatively consistent from year to year during the period when the barrier net is installed. Performance in the month of installation and removal (April, May and November) should be interpreted with caution as this is affected by the date of installation and removal. Impingement rates, especially when the FDS is removed, are also influenced by several uncontrolled variables affecting total fish biomass in the lake, weather, coastal processes, or sporadic impingement events. Trends in lake wide abundance of various fish species are monitored by the Ontario Ministry of Natural Resources Lake Ontario Management Unit and their annual report for 2017 is available online at http://glfc.org/lakecom/loc/mgmt_unit/.

4.1 Episodic Fish Impingement Event – November 16, 2017

As previously reported to the CNSC and DFO, a fish impingement event occurred at PNGS, starting on November 16 and continuing for several days. During this time, an preliminary estimate of 3 million Alewife with a biomass of 24,000 kg were impinged. The event occurred after the removal of the FDS was complete. It is a design requirement of the FDS to remove the barrier net in the fall to prevent damage from ice or late season storm events which could lead to catastrophic failure. The cause of the event is being investigated. For reporting purposes, the above estimates have been added to 2017 totals for impingement.

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 10 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

Figure 1 Annual Cumulative Biomass (kg) of Fish of All Species and Ages Impinged in 2010 - 2017

30,000 2010 See Note 2 2011 25,000 2012 2013 (kg) 20,000 2014 2015 2016 Biomass

15,000 2017

See Note 1 10,000 Cumulative 5,000

‐ Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Notes: 1. Starting May 28 2015, 6000 kg of Alewife were impinged at the P058 screen house. A breach in the net was found at a seam near the West Groyne. See P‐REP‐07263‐00009 . 2. An abnormal amount of Alewife were impinged starting November 16th and Pickering Nuclear declared this an impingement event. The preliminary estimate of biomass impinged was 24,000 kg.

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 11 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

Table 4: Biomass of Fish Impinged at Pickering NGS in 2017

Species Monthly biomass impinged for all species (g) Totals Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec (kg) Alewife 4,433 88,413 74,793 31,731 15,615 1,313 24,000,922 682 24,218 American Eel 29,157 14,556 12,060 5,583 41,321 97,172 200 Atlantic Salmon 3,984 4 Black Bullhead 639 112 1 Bluegill 200 0.2 Brown Bullhead 27 198 922 2,420 2,769 1,275 8 Brown Trout 9,199 9 Carp 46,908 44,116 4,959 96 Chinook Salmon 33 13,742 11,973 151 26 Emerald Shiner 130 455 30 114 23 108 1 Freshwater Drum 321 0.3 Gizzard Shad 30,367 34,387 33,457 34,576 30,965 24,563 188,584 377 Largemouth Bass 4,537 5 Logperch 211 145 0.4 Northern Pike 11,961 6,149 2,783 21 Pumpkinseed 143 103 85 0.3 Rainbow Smelt 240 328 1,243 24,204 11,508 15 115 38 Rainbow Trout 193 0.2 Rock Bass 405 0.4 Round Goby 957 7,398 6,275 3,878 34,539 29,517 10,826 6,828 4,722 2,753 1,914 3,785 113 Sea Lamprey 1,196 1,851 3 Silver Redhorse 1,290 1 Smallmouth Bass 8,923 106 2,908 2,755 15,638 30 Three-spine Stickleback 53 415 277 2,286 10,173 64 13 Unidentified 2,522 5,827 3,101 459 12 Walleye 47 0.05 White Bass 3,848 4 White Perch 140 970 1 White Sucker 614 243 1,560 13,743 7,586 24 Yellow Perch 1,798 1,259 2,848 4,736 462 115 206 11 Total Biomass (Kg) 94 74 79 132 175 114 43 23 5 35 24,125 319 25,217

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 12 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

Table 5 Number of Fish Impinged at Pickering NGS in 2017

Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals Alewife 119 8,163 24,495 10,687 6,197 431 3,013,459 336 3,063,887 American Eel 33 13 11 6 74 93 230 Atlantic Salmon 4 4 Black Bullhead 7 12 18 Bluegill 3 3 Brown Bullhead 6 4 10 12 19 5 57 Brown Trout 5 5 Carp 10 7 5 22 Chinook Salmon 4 12 5 21 41 Emerald Shiner 17 129 8 19 8 21 201 Freshwater Drum 4 4 Gizzard Shad 43 75 104 88 462 35 607 1,416 Largemouth Bass 4 4 Logperch 17 12 30 Northern Pike 8 17 8 33 Pumpkinseed 3 4 6 14 Rainbow Smelt 34 49 87 1,844 1,424 10 39 3,487 Rainbow Trout 6 6 Rock Bass 12 12 Round Goby 93 383 314 265 1,513 1,354 9,478 1,384 558 533 209 352 16,437 Sea Lamprey 3 5 9 Silver Redhorse 6 6 Smallmouth Bass 11 4 5 6 16 42 Three-spine 34 267 166 1,310 5,676 40 7,493 Stickleback Unidentified 13 8 16 10 46 Walleye 4 4 White Bass 5 5 White Perch 3 10 14 White Sucker 10 4 10 12 7 44 Yellow Perch 73 34 153 144 7 7 5 423 Total Number 424 1,051 787 3,716 17,012 25,930 20,172 7,602 558 1,434 3,013,848 1,461 3,093,997

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 13 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

Table 6 Flow Adjusted Rate of Biomass Impinged

2003/2004 2010 2011 2012 2013 2014 2015 2016 2017 Annual 18,214 4,617 4,012 1,706 2,926 3,953 8,553 1,035 25,217 Biomass (kg) Annual Station Flow 4.19 4.88 4.77 4.94 4.86 4.82 5.07 4.70 5.05 ( 109 m3) Annual Rate (kg/million 4.35 0.95 0.84 0.35 0.60 0.82 1.69 0.22 4.99 m3)

4.2 Northern Pike

In 2008, the CNSC requested that OPG implement measures to verify there is no population level impact on Northern Pike (P-CORR-00531-03269). Although effective while installed, the FDS was unable to achieve a reduction in Northern Pike impingement during the FDS performance validation period as impingement primarily occurred during the winter period when the FDS was not installed.

Table 7 provides a summary of Northern Pike impingement since 1974. The annualized estimate of impingement in 2017 was 33 individuals with an estimated biomass of 21 kg, the lowest biomass impinged in recent years.

Based on the data collected to date, it is unlikely that PNGS impingement is having a local or regional impact on northern pike populations.

Table 7 Northern Pike Impingement

Annual Number Annual Biomass Year (mean+ SD) (kg) (mean+ SD) 1974-1979 97 ± 46 207 ± 98 1980-1989 37 ± 19 83 ± 46 1990-1999 42 38 ± 31 2003-2004 38 67 2010 50 51 2011 46 120 2012 46 133 2013 58 188 2014 36 112 2015 27 70 2016 12 31 2017 33 21

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 14 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

4.3 Species at Risk

No fish species that are listed in Schedule 1 of the Species at Risk Act (SARA) were impinged in 2017. One species contained in the Species at Risk in Ontario List of the Endangered Species Act, namely American Eel was impinged in 2017. A total of 42 American Eel with a combined biomass of 40.9 kg were impinged, the majority of which were impinged during the net-free times of the year. After the database algorithms are applied, the extrapolated number of impinged American Eel in 2017 was approximately 230 individuals with an estimated biomass of 200 kg. OPG has stocked 4 million eels in Lake Ontario between 2006 and 2010, and increased impingement is expected due to this.

5.0 IMPINGEMENT AND ENTRAINMENT OFFSET PROJECTS

In 2013, the CNSC requested and OPG agreed to implement a wetland improvement project of 3 ha to offset the residual impacts of impingement on Northern Pike (CNSC, 2013). OPG undertook a review of potential projects and in February 2014 retained the Toronto and Region Conservation Authority (TRCA) to plan and upgrade a portion of Duffins Creek. This was communicated to the CNSC in P-CORR-00531-04382. The design phase for the Simcoe Point Wetland (SPW) restoration project, was initiated in 2015 and was deemed to require an Authorization under Section 35(2)(b) of the Fisheries Act. OPG received a Fisheries Act Authorization for SPW on January 17, 2018.

The project is on hold pending TRCA receipt of a Lakes and Rivers Improvement Act permit from MNRF.

5.1 Fisheries Act Authorization

In addition to authorizing construction impacts of the levee, fish gate and water control structure at SPW, the Fisheries Act Authorization of January 17, 2018 authorizes impingement and entrainment of fish due to water taking at PNGS during continued operations and stabilization phases. The serious harm to fish covered by the authorization includes the death of fish through impingement and entrainment resulting in loss of approximately 6,300 kg of Age 1 equivalents that does not include any aquatic species at risk listed under the Species at Risk Act and species listed in the Aquatic Invasive Species Regulation. The Authorization also accepts the use of the existing Big Island Wetland habitat bank that OPG constructed in the Bay of Quinte, and Atlantic Salmon stocking contributions in Duffins Creek, to offset residual impingement and entrainment impacts due to stations operations.

This additional mitigation measure required under the Authorization will offset all residual impingement and entrainment, resulting in a 100% reduction relative to the baseline in future years.

5.2 Uncertainty

The following is a summary of the uncertainty associated with the impingement estimates:

 There is uncertainty associated with the identification of fish sampled from the bins (physical counting, length/weight measurements, subsamples and identification). To mitigate this, sampling practices have been proceduralized and is undertaken by individuals who have completed the Royal Ontario Museum (ROM) fish identification course. Misidentification

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 15 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

may result in small errors associated with the individual species data reported in Tables 4 and 5, but will have no impact on the total biomass or total counts.

 There is uncertainty associated with missing or incomplete data from field forms. This has been minimized by quality checks and estimating missing values using descriptive statistics calculated or interpreted from available data.

 There is uncertainty in extrapolating data for non-sampled time periods. There is also high natural variability from season to season. This uncertainty has been reduced by extrapolating data within each month.

 There is high natural variability from day to day. The variability associated with this is real and cannot be reduced through increased sampling effort. However, Monte Carlo simulations on the 2011 data indicated that reducing the sampling frequency from 4 to 1 day per week would have minimal impact on the 95% confidence intervals.

6.0 CONCLUSION

(1) 2017 represents the highest annual biomass impingement rate observed since mitigation using the FDS began. This outcome, however, was solely the result of a single impingement event in mid-November which occurred after the FDS had been removed, consistent with procedure. When this outlier is removed from the data, impingement was the second lowest rate observed since 2010.

(2) OPG continued its efforts in partnership with the TRCA, towards completing a wetland improvement project to offset the residual impacts of impingement at Pickering NGS.

(3) Based on the reductions in impingement biomass of Northern Pike, it is unlikely that PNGS impingement is having a local or regional impact on Northern Pike populations.

(4) OPG received a Fisheries Act Authorization for Pickering Nuclear and the SPW which is effective January 17, 2018. Further dialogue between CNSC, DFO and OPG are proposed to discuss how the expectations for this report can be aligned with monitoring and reporting conditions of the Fisheries Act Authorization.

7.0 REFERENCES

Brown, D. 2014. Pickering Nuclear 2013 Impingement Monitoring Report. P-REP-07263-00007.

CNSC 2008. Letter, T.E. Schaubel to W.M. Elliot and P.F. Tremblay. Pickering NGS A and B: Mitigation Measures to Reduce Rates of Fish Mortality, New Action Item #2008-4-14. October 2, 2008. P-CORR-00531-03269

CNSC 2012a. Letter, M. Santini to G. Jager. Pickering NGS – Intake and Thermal Fish Mortality: Closure of Action Items 2008-4-13 (RIB # 2433), 2008-4-14 (RIB # 2434) and New Action Item 2012- 48-3489. August 13, 2012. e-Doc 3970429. P-CORR-00531-03773.

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 16 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

CNSC 2012b. Letter, M. Santini to G. Jager. Pickering NGS -Intake and Thermal Fish Mortality: Action Item 2012-48-3489. November 20, 2012. e-Docs 4025894 P-CORR-00531-01940.

CNSC 2013. Letter, M. Santini to G. Jager. Pickering NGS – Intake and Thermal Fish Mortality – Action Item 2012-48-3489. January 30, 2013. e-Doc 4072233 P-CORR-00531-04204.

DFO 2018. Letter, D. Nicholson to R. Lockwood. Paragraph 35(2)(b) Fisheries Act Authorization. January 17, 2018. P-CORR-00539.4-00003.

Gibson, D. 2015. Pickering Nuclear 2014 Impingement Monitoring Report. P-REP-07263-00008.

Kinectrics. 2009. Technical Validation Report: Fish Diversion System at Pickering Nuclear Generating Station OPG Project # 13-49280. OPG P-REP-23200-00016.

MNR 2013. Lake Ontario Fish Communities and Fisheries: 2012 Annual Report of the Lake Ontario Management Unit. Report ISSN 1201-8449.

OPG 2013. Letter, G. Jager to M. Santini. Long-Term Fish Impingement and Entrainment Monitoring Program, Action Notice 4 of Action item 2012-48-3489, June 13, 2013. P-CORR-00531-04216.

OPG 2015. Letter, B. McGee to M. Santini. Pickering NGS – Intake and Thermal Fish Mortality – Completion of Action Notice AN6 of CNSC Action Item 2012-48-3489 and Request for Closure of Action Item 2012-48-3489. March 6, 2015. P-CORR-00531-04382.

Poulton, S. 2011. Pickering Nuclear Generating Station 2010 Impingement Monitoring Report. P-REP-07263-00001.

Poulton, S. 2012a. Pickering Nuclear Generating Station 2011 Impingement Monitoring Report. P-REP-07263-00004.

Poulton, S. 2012b. Mitigation of Fish Entrainment at PNGS. P-REP-07262-00001.

Poulton, S. 2013. Pickering Nuclear Generating Station 2012 Impingement Monitoring Report. P-REP-07263-00006.

N-TMP-10010-R012 (Microsoft® 2007) Internal Use Only Document Number: Usage Classification: Report P-REP-07263-00011 N/A Sheet Number: Revision Number: Page: N/A R000 17 of 17 Title: PICKERING NUCLEAR 2017 IMPINGEMENT MONITORING REPORT

Appendix A:

The following formulas were used calculate monthly impinged biomass for each species:

Monthly annualized = ∗ biomass impinged for species x

Where: Fish = Record of individual fish in binj i = Total number of fish of species x in binj Bin = Record of bin sampled at a specific bin location j = Number of bins sampled at single bin location in one month Locn = one of 8 screenhouse bin locations Total Flow = Total monthly condenser cooling water and reactor building service water flow at the bin location # Days in Month = ∑Day 1 Hourly Flowday,locn * 24 hr Sampled Flow = Total flow at the bin location for the sampled time periods

= ∑bin 1j Hourly Flowday,locn * # Hours bin j was in Serviceday,locn

N-TMP-10010-R012 (Microsoft® 2007)