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:
se fluids within the radius of influence, the applicant concentrated his assessment on a large source of water, the condenser circulating water system, and on sources that could be accidently released directly into the wall drain. The applicant states that the failure of a circulating water system pipe inside the turbine building would cause water to be ponded to a depth of 13 feet above the turbine building floor. The wall of the adjacent auxiliary building facing the turbine building will be con- structed as a seismic Category I wall up to a level of 13 feet 6 inches above the turbine' floor to prevent flow of the ponded water in the turbine building into the auxiliary building. In addition, the appli- cant proposes to place a grout curtain under this wall to reduce seepage to the underdrain system and to extend seismic Category I retaining walls outward from the auxiliary building to retain a column of low permeability soil as a barrier to flow of water from the turbine building around to wall drains along the sides of the auxiliary building. The primary grout holes for the grout curtain below the auxiliary building substructure mat and the retaining wall will be spaced at 20-foot intervals. Secondary holes will split-space the primary grout holes. After the grout curtain is completed, with a maximum hole spacing of 10 feet center-to-center, four core holes will be drilled to verify the adequacy of the grout curtain. Along with visual inspection of the rock cores, the holes will be water tested to assure 2.4.12-6 Rev. 2 - July 1981 that the permeability of the grout curtain is less than the average permeability of continuous rock. The grout holes are to be split- spaced until the equality in permeability is attained. After comple- tion of the grouting and testing, the four test holes will be cased and maintained for observation and testing throughout the life of the plant. We conclude that the criteria for the design of retaining wall and placement of the grout