Document: NUREG-0800
Document ID: 48fb37ec-8e3e-4c2c-96c3-daa5e7da62f9
Document Type: srp
Title: of the applicant's SAR is reviewed to identify any missing data,
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340557.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.12
CFR Part: 
CFR Title: 

Content:
ions gathered during construction will be evaluated to deter- mine the applicability of the assumed CP design basis. If no CP groundwater review was undertaken, of the scope indicated above, this fact will be noted in the OL findings in addition-to the results of the current review. A sample CP statement follows: The proposed site lies within a groundwater region which is part of the Piedmont Groundwater Province. Groundwater in the area is derived entirely from local precipitation. The water is contained in the pores of the residual soils and in joints and cracks of the rock. There is a north-south groundwater ridge at the plant area, and ground- water flow is to the north, east, and west. The groundwater gradient in the plant area is about 6 to 7 feet per 100 feet.. Permeability is controlled by the extent and distribution of fractures in the bed- rock and by the size and distribution of pores in the overlying soil. The applicant has made laboratory and field permeability tests and has determined values ranging from zero to about 5000 feet per year. Measured depths from the existing ground surface to the groundwater table on the ridges range from about 40 to 80 feet. However, the proposed plant grade will.be at about existing groundwater level. The groundwater table is generally at or near the surface in valleys and draws near the site. In order to meet the requirements of General Design Criterion 2, 10 CFR Part 100, and 10 CFR Part 100, Appendix A with respect to ground- water levels and its effects on the plant, especially during postulated seismic events, the applicant proposes to permanently lower the ground- water levels in the vicinity of safety-related structures. This is to be accomplished by using a system of seismic Category I underdrains and exterior wall drains. 2.4.12-4 Rev. 2 - July 1981 The underdrains will consist of a series of interconnected flow channels spaced on 20-foot centers located under the foundation slabs. The exterior wall drains will