Document: NUREG-0800
Document ID: be033a97-be2a-4a23-91fe-52b123162b3b
Document Type: srp
Title: LOW WATER CONSIDERATIONS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070730439.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.11
CFR Part: 
CFR Title: 

Content:
ching in intake structures and surges in intake pipes) that could cause adverse effects are reviewed to ensure that the effects have been properly accounted for in the intake design. The potential for adverse hydrodynamic effects of a trip of the intake pumps is evaluated based on potential surges in intake sumps. 2.4.11-9 Revision 3 - March 2007 The potential for blockage of the intakes by littoral drift, sediment, debris, and ice is reviewed to ensure that the intakes are located and sized to prevent blockage which would preclude use of the safety-related water supply. Applicable literature describing historic sediment accumulations in the site region is reviewed to determine if mitigation measures are required to protect safety-related facilities. Independent estimates of “worst-case” buildups are made using statistical or deterministic techniques. The staff evaluates the applicant’s evidence as it relates to low water considerations. If the staff disagrees with the applicant’s conclusions, they will request additional information. The applicant should fully document and justify its estimates or accept the staff's estimates and redesign the SSC important to safety affected by low water levels. The staff should use the suggested criteria of Regulatory Guide 1.27 when the water supply comprises part of the ultimate heat sink. 3. Effect of Low Water on Safety-Related Water Supply: The staff reviews the adequacy of the ultimate heat sink to supply cooling water for conditions requiring safety-related cooling. In addition, the design basis of the intake system should be adequate to enable delivery of the necessary cooling water to the plant during adverse hydrological conditions. Where the specific design bases preclude plant operation during severe hydrologically-related events, availability of sufficient warning time should be demonstrated so that the plant may be shut down during or in advance of adverse events without causing potential damage to