PSEG RAI 61 Response
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PSEG Site ESP Application Part 2, Site Safety Analysis Report 2.5 GEOLOGY, SEISMOLOGY, AND GEOTECHNICAL INFORMATION This section provides information on the geology, seismology, and geotechnical characteristics of the PSEG Site. The section follows the standard format and content prescribed in Regulatory Guide (RG) 1.206, Combined License Applications for Nuclear Power Plants (LWR Edition), Revision 0, 2007. Further, the technical content complies with RG 1.208, A Performance-Based Approach to Define the Site-Specific Earthquake Ground Motion, Revision 0, 2007, for guidance respective to the level of investigation recommended at different distances from a proposed site for a nuclear facility. A particular focus is on data developed since the publication of the Updated Final Safety Analysis Report (UFSAR) for licensing Salem Generating Station (SGS) and the Hope Creek Generating Station (HCGS) in the same site area. The PSEG Site is located on the southern part of Artificial Island on the east bank of the Delaware River in Lower Alloways Creek Township, Salem County, New Jersey. The SGS and HCGS are adjacent to the planned new plant location. The site is relatively level with existing surface grades ranging nominally from elevation 5 to 15 feet (ft.), North American Vertical Datum 88 (NAVD). Investigations to obtain the data discussed in Section 2.5 were performed by MACTEC Engineering and Consulting, Inc. (with William Lettis Associates, Inc.) working under the overall direction of Sargent and Lundy, LLC. Field investigation work includes geologic mapping, geotechnical borings, surveying and geophysical testing as briefly described below. Laboratory testing of selected samples was performed. Subsection 2.5.1 describes basic geological and seismological data compiled through literature reviews as well as regional and site-specific studies. Much of the site-specific data was gathered as part of the geotechnical exploration program described in detail within Subsection 2.5.4, which also provides information for Subsection 2.5.2 as well as Subsection 2.5.3. Subsection 2.5.2 describes the vibratory ground motion at the site, including an updated seismicity catalog, description of seismic sources, and development of the Ground Motion Response Spectra (GMRS) and site-specific Safe Shutdown Earthquake (SSE). The site parameters to develop the GMRS and SSE are compiled from data acquired as part of the investigations described in Subsections 2.5.1 and 2.5.4. Subsection 2.5.3 describes the potential for surface faulting in the site area and presents the results of both regional and site-specific studies discussed in Subsections 2.5.1 and 2.5.4. Subsections 2.5.4 and 2.5.5 describe the stability of surface materials and slopes at the site. Included in Subsection 2.5.4 is a detailed discussion of site-specific investigations that provide supporting data for Subsections 2.5.1, 2.5.2, and 2.5.3. In summary, the geologic, seismologic, and geotechnical conditions for the PSEG Site are characterized from investigations conducted specifically for the early site permit application (ESPA) and are consistent with conditions noted for the existing SGS and HCGS. The geologic, seismic and geotechnical site characteristics meet the requirements for safe location and operation of a nuclear power plant as considered at the ESPA stage. Detailed discussions are provided in the following subsections. Rev. 2A 2.5-1 PSEG Site ESP Application Part 2, Site Safety Analysis Report 2.5.1 BASIC GEOLOGIC AND SEISMOLOGIC INFORMATION This subsection presents information on the geological, seismological, and geotechnical engineering properties of the PSEG Site. RG 1.208 provides guidance for the recommended level of investigation at different distances from a proposed site for a nuclear facility: • The site region is that area within 200 miles (mi.) of the new plant location. • The site vicinity is that area within 25 mi. of the new plant location. • The site area is that area within 5 mi. of the new plant location. • The site is that area within 0.6 mi. of the new plant location. These terms — site region, site vicinity, site area, and site — are used in Subsections 2.5.1 through Subsection 2.5.5 to describe these specific areas of investigation and are not applicable to other subsections of the Site Safety Analysis Report (SSAR). The geological and seismological information presented in this subsection is developed from a review of previous reports prepared for SGS and HCGS, published geologic literature, interpretation of aerial photography, subsurface investigations, geological mapping, and aerial reconnaissance conducted to support this ESPA. Previous site-specific reports reviewed include the HCGS UFSAR (Reference 2.5.1-176) and supporting referenced engineering reports and studies. A review of published geologic literature is used to supplement and update the existing geological and seismological information. This subsection of the SSAR is intended to demonstrate compliance with the requirements of 10 CFR 100, Reactor Site Criteria, Section 100.23, Geologic and seismic siting criteria, paragraph (c), Geological, seismological and engineering characteristics. 2.5.1.1 Regional Geology This subsection discusses the physiography, geologic history, stratigraphy, and tectonic setting within a 200-mi radius of the PSEG Site. The site region physiographic map (Figure 2.5.1-1) and regional geologic maps (Figures 2.5.1-2a, 2.5.1-2b, 2.5.1-3a, and 2.5.1-3b) show the physiography, geology, stratigraphy, and tectonic setting for the PSEG Site region. Summaries of the aspects of the regional geology are presented to provide the framework for evaluation of the geologic and seismologic hazards presented in the succeeding subsections. 2.5.1.1.1 Regional Physiography and Geomorphology The PSEG Site lies within the Coastal Plain physiographic province (Figure 2.5.1-1). The site region includes parts of several other physiographic provinces: the Continental Rise, Continental Slope, and Continental Shelf (from east to west), all located in the eastern portions of the site region, and (to the west) the Piedmont, New England, Blue Ridge, Valley and Ridge and Appalachian Plateau provinces. These physiographic provinces are discussed in the following subsections. Rev. 2A 2.5-2 PSEG Site ESP Application Part 2, Site Safety Analysis Report 2.5.1.1.1.1 Coastal Plain Physiographic Province The Coastal Plain physiographic province is the sub-aerial portion of the North American continental shelf. In the site region, the Coastal Plain province extends eastward from the fall line to the Atlantic Ocean along the length of the North American Atlantic margin (Figure 2.5.1- 1). The Coastal Plain province is characterized by low-lying, gently rolling terrain developed on sequences of deltaic, shallow, marine and continental shelf clastics consisting primarily of unconsolidated to semi-consolidated gravels, sands, silts, and clays that dip gently oceanward. The surface has been modified by erosional and depositional landforms associated with several transgressional and regressional marine cycles. In general, the Coastal Plain province exhibits lower topographic relief than the Piedmont province to the west. However, the land surface varies from flat to deeply incised. The mid-Atlantic Coastal Plain in the site region is traversed by major rivers and their associated valleys that are flooded to form estuaries, including Chesapeake Bay and Delaware Bay (Figures 2.5.1-1 and 2.5.1-4). The mid-Atlantic Coastal Plain has been subdivided into four major physiographic subprovinces (based on their characteristic geomorphology): Inner Coastal Plain, Middle Coastal Plain, Outer Coastal Plain, and Alluvial and Estuarine Valleys (Figure 2.5.1-5). The Inner Coastal Plain is further subdivided into two regions: the dissected outcrop belt, the area of the oldest and most incised coastal plain sediments, and the upland sands and gravels area (Figure 2.5.1-5). In the mid-Atlantic region, the upland sands and gravels occur largely as discontinuous bodies confined to hilltops. However, in and around the site vicinity in New Jersey (NJ) and the Delmarva Peninsula, this unit constitutes laterally continuous strata that dip to the southeast to form a rolling upland that is dissected by underfit streams. The land surface of the Inner Coastal Plain is at least 5 million years old (Reference 2.5.1-11 and Figure 2.5.1-5). The Middle Coastal Plain is a series of marine terraces and associated scarps developed in response to Pliocene and Early to Middle Pleistocene cyclic marine transgressions and regressions. These terraces have been exposed long enough to have well-developed drainages. In the site vicinity (Figure 2.5.1-6) and surrounding area, the Middle Coastal Plain occurs as a dissected upland with better-developed stream incision and drainages that were extended and entrenched during lowstands of sea level due to cyclic glaciations. The land surface of the Middle Coastal Plain is 200,000 – 3 million years old (Reference 2.5.1-11). In the site region, north of the Potomac River and in the site vicinity, the Coastal Plain has been located at a higher elevation since the late Pliocene and exposed longer than regions to the south (References 2.5.1-11 and 2.5.1-144). Consequently, deposition of Pleistocene marginal marine sequences is limited except for the Chesapeake and Delaware River valleys (Figures 2.5.1-5 and 2.5.1-6). In this region, the Middle Coastal Plain consists primarily of dissected uplands along with the terraces associated with the river valleys (Reference 2.5.1-11). The Outer Coastal Plain lowland area near the modern coastline is characterized by a land surface that is flat and poorly drained, with drainages predominately tidally influenced. In the Outer Coastal Plain, the water table is relatively close to the land surface. The drainage network in the Outer Coastal Plain is poorly developed since the land surface is younger than approximately 120,000 years (Reference 2.5.1-11).