Document: NUREG-0800
Document ID: ebff6c02-bdd3-4751-9e36-9347caf05c8e
Document Type: srp
Title: and 2.4.6 are applicable to low water estimates due to the various phenomena discussed.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070258.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.5
CFR Part: 
CFR Title: 

Content:
apable of providing cooling water below the design temperature of 43.3 C (110 F) under normal operation or emergency 80 81 conditions. The applicants analyzed the pond's thermal performance assuming a loss-of-coolant accident in one unit, a simultaneous normal operation shutdown in the other, and 82 meteorological conditions of the severity specified in Regulatory Guide 1.27, "Ultimate Heat Sink for Nuclear Power Plants." The maximum pond temperature calculated was 42.9 C (109.3 F).83 WeThe staff independently modeled the thermal performance of the pond and conclude 84 that it is capable of providing cooling water below the design temperature of 43.3 C (110 F). WeThe staff conservatively estimated maximum water losses from the 85 86 pond, assuming meteorological conditions of the severity specified in Regulatory Guide 1.27, and conclude that the initial pond inventory will be sufficient to provide at least a 30-day cooling water supply without makeup. WeThe staff evaluated the potential effects of freezing events on the pond's capability 87 of providing emergency cooling water to the plant. Our analysis showed that the intake and discharge pipes will be below the maximum depth of pond freezing that could occur under meteorological conditions of the severity suggested in Regulatory Guide 1.27. In DRAFT Rev. 3 - April 1996 2.4.11-12 addition, to prevent freezing around the intake and discharge pipes, the intake pumphouse will be heated and the discharge piping will be buried below the frost line, heat traced or the discharge structure will be heated. We haveThe staff has evaluated the performance of the proposed cooling pond and 88 conclude that, under meteorological conditions of the severity described in Regulatory Guide 1.27, (1) the design will provide sufficient water in the pond to cool the plant for at least 30 days without any makeup and (2) the maximum temperature of the water supplied to the plant will be below the design temperature of 43.3 C (110 F).89