Document: NUREG-0800
Document ID: 9cdf4eb8-90c4-435e-84a4-d23c09056921
Document Type: srp
Title: STABILITY OF SUBSURFACE MATERIALS AND FOUNDATIONS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070268.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.5.4
CFR Part: 
CFR Title: 

Content:
f it is the staff's judgment that the applicant's investigations or testing are inappropriate or insufficient, additional investigations will be required. The final conclusion is based on professional judgment, considering the complexity of the site subsurface conditions. As part of the review, the staff must ascertain, often with the help of consultants, that state-of-the-art laboratory and field techniques and equipment are employed in determining the material properties. Subsection 2.5.4.3. Plot plans and profiles are reviewed by comparing the subsurface materials with the proposed locations (horizontal and vertical) of foundations and walls of all seismic Category I facilities. The profiles and plot plans are cross-checked in detail with the results of all subsurface investigations conducted at the site to ascertain that sufficient exploration has been carried out and to determine whether or not the interpretations made by the investigators are valid and the foundation design assumptions contain adequate margins of safety. Subsection 2.5.4.4. Staff evaluation consists of a detailed review of all geophysical explorations conducted at the site, including seismic refraction, reflection, and in-hole surveys and magnetic and gravity surveys. Consultant expertise regarding specific techniques may be drawn upon in this review. Logs of core borings, trenches, and test pits are reviewed and compared with data from the seismic surveys and other geophysical explorations. Results must be consistent or additional investigations are required, or the applicant must use the most conservative values. Following the PSAR review and during the FSAR review theThe staff compares conditions as 51 mapped in the open excavations with interpretations and assumptions derived during the investigation program. Subsection 2.5.4.5. Excavations, backfill, and earthwork are evaluated by the staff as follows: 1. The investigations for borrow material, including boring and test pit logs, and