Document: NUREG-0800
Document ID: 087cef2c-a084-4143-84b9-9f1ba68e1851
Document Type: srp
Title: MASS AND ENERGY RELEASE ANALYSIS FOR POSTULATED SECONDARY SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340662.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.1.4
CFR Part: 
CFR Title: 

Content:
ures described below are followed for the review of the mass and energy release analysis of secondary coolant systems pipe breaks. The reviewer selects and emphasizes material from these procedures as may be appropriate for a particu- lar case. Portions of the review may be carried out on a generic basis or by applying the results of previous reviews of similar plants. The CSB reviews the secondary coolant system pipe breaks analysis assumptions to determine whether the "worst" pipe break accident case has been identified by the applicant, and whether the analysis was done in a conservative manner from the standpoint of containment pressure and temperature. This review involves the proposed methods and models used for blowdown analyses. The acceptability of the approach used by the applicant is evaluated based on the acceptance criteria in subsection II of this SRP section. The CSB also reviews analyses of postulated single failures of active components in the secondary systems, such as steam and feedwater line isolation valves and feedwater pumps, to determine whether the single failure has been selected which maximizes containment pressure and temperature. The CSB will request MEB to review the acceptability of nonsafety valves in limiting the mass and energy releases from the steam and feedwater systems. The CSB will request the ASB to review the rationale for determining the time 6.2.1.4-3 Rev. 1 - July 1981 at which operator action can be relied upon to terminate auxiliary feedwater flow to the affected steam generator. The CSB will review the applicant's calcu- lations for main feedwater flow into the affected steam generator to determine that the flow rate is conservatively maximized. If liquid entrainment is calculated in the applicant's steam line break model, the CSB will determine the validity of the experimental data provided to support the entrainment calculation. The CSB will also ascertain that the effect of steam separators located upstream from the