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:
al, these site parameters should be determined utilizing field and, if necessary, laboratory tests of materials representative of the entire area of influence of the expected draw- down of the system. Unless it can be substantiated that aquifer materials are essentially homogeneous, or that obviously conservative estimates have been used as design bases, provide preconstruction. pumping tests and other in-situ tests performed to estimate the pertinent hydrologic parameters' of the aquifer. Monitoring of pumping rates and flow patterns during dewatering for the construction excava- tion is also necessary to verify assumed design bases relating to such factors as permeability and aquifer continuity. In addition, the final design of the system should be based on construction dewatering data and related observations to assure that the values estimated from site exploration data are conservative. Lastly, the final design of the dewatering system and its hydrologic and geo- technical operational monitoring program should be confirmed by construction excavation and dewatering information. If such information fails to support the conservatism of design infor- mation previously reviewed by the staff, the changed information should be reviewed under 10 CFR Part 50, Subsections 35(b) and 55(e) (1)(iii). (c) Provide analyses and their bases for estimates of groundwater flow rates in the various parts of the permanent dewatering system, the area of influence of drawdown, and the shapes of phreatic surfaces to be expected during operation of the system. The extent of 2.4.12-15 Rev. 2 - July 1981 influence of the drawdown may be especially important if a natural or man-made water body affects, or is affected by, the dewatering systems. (d) Provide analyses, including their bases, to establish conservative estimates of the time available to mitigate the consequences of system degradation* that could cause groundwater levels to exceed design bases. Document the measures that will be