Document: NUREG-0800
Document ID: aa991707-7fa7-4f81-b272-8b2d0af4f5e9
Document Type: srp
Title: COOLING WATER CANALS AND RESERVOIRS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070250.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.8
CFR Part: 
CFR Title: 

Content:
bases for riprap 21 protection and the hydraulic design criteria for the two spillways. The applicant at ourthe staff's request, in Amendment No. 31 to the PSAR, provided criteria for the windwave 22 riprap protection based upon an empirical relationship for the median size stone to be placed in a blanket approximately two feet thick and indicated its specifications for stone gradation. A filter blanket approximately one foot thick is to be placed under the riprap to prevent piping (removal of smaller material) through the larger armor riprap cover layer. Criteria were provided for the filter gradation, angularity, durability of the riprap, and placement which provides assurance that erosive failure of safety-related embankments should not occur. An armor protection layer also is provided. WeThe staff finds these riprap design bases and spillway hydraulic design criteria to be 23 acceptable. 3. The staff concludes that the hydrologic aspects of the design of the reservoir system meets the requirements of General Design Criterion 44 and 10 CFR Part 100 and is therefore acceptable. This conclusion is based on the following evaluation. 4. Storage in the three reservoir system, runoff from the contributing drainage area, and diversion of A River flows to the main reservoir during periods of low runoff and high reservoir evaporation will constitute the water supply for the four-unit once-through cooling systems. 5. The applicant has provided analyses of the capability of the main and auxiliary reservoirs to supply water during emergency conditions requiring emergency shutdown and cooldown of one unit and the simultaneous normal shutdown and cooldown of the remaining three units as suggested in Regulatory Guide 1.27, "Ultimate Heat Sink for Nuclear Power Plants." In addition, the applicant has provided analyses of the operation of the plant and the main reservoir under historical and a synthesized 100-year drought condition. For the shutdown conditions, the applicant has