Document: NUREG-0800
Document ID: c0d3006a-c4ee-4659-b650-837c0c94b143
Document Type: srp
Title: STABILITY OF SUBSURFACE MATERIALS AND FOUNDATIONS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340604.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.5.4
CFR Part: 
CFR Title: 

Content:
compacted granular backfill. If granular backfill is used, it will be compacted to at least 85 percent relative density or to 95 percent of the maximum density determined by the Modified Proctor test. These backfill criteria are acceptable criteria for soil pressures on foundations and buried pipes and are suitable and conservative for both static and dynamic conditions. Suitable borrow material for dikes, dams and impervious linings are available for the ultimate heat sink ponds. The applicant's tests on these materials and the construction criteria to be followed ensure that leakage, piping and cracking hazards of these vital earthworks are minimal. Filters, blanket drains, relief wells, piezometers and settlement monuments will assure the reliable performance of the ultimate heat sink water- retention facilities. The applicant has shown that the appropriate acceleration level on sound rock is 0.12g for the safe shutdown earthquake (SSE). The operating bases earthquake (OBE) value is taken as 0.06g. The applicant has performed a site-dependent analysis to estimate-the site amplification effects and found that the weathered rock or structural backfill would amplify the rock motion. An acceleration level of 0.17g for the SSE will be used for those structures founded on weathered rock or structural backfill over weathered rock. The time history used for seismic design of Category I earth dams and for liquefaction assessment envelopes the response spectra for the site and has a conservative duration. The staff concludes that information, including analysis and substantia- tion, presented by the applicant is sufficient to demonstrate that the properties and stability of all soils and rock, whose performance could adversely affect directly or indirectly safety-related structures of the nuclear plant or pose a hazard to the public, meet the requirements of the pertinent Commission's regulations (cite appropriate References 1 through 7). The applicant has met the