Document: NUREG-0800
Document ID: 9c59dff8-9325-43e2-8e81-843a0f6b4b2f
Document Type: srp
Title: and Regulatory Guide 1.189.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0327/ML032740044.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.5.1
CFR Part: 
CFR Title: 

Content:
BRN code to model fire propagation, provided that the shortcomings identified in NUREG/CR-5088, “Fire Risk Scoping Study,” developed by Sandia National Laboratory, are addressed. When the licensee assesses the effectiveness of manual fire fighting, it should use plant-specific data from fire brigade training to determine the response time of the fire fighters. The effectiveness of fire barriers should be assessed, and the use of separation in determining fire zones critically examined. The walkdown procedures should be specifically tailored to assess the remaining issues identified in the NUREG/CR-5088: (1) seismic/fire interactions, (2) effects of fire suppressants on safety equipment, and (3) control system interactions for severe accident vulnerabilities. Containment performance should be assessed to determine if vulnerabilities stemming from sequences that involve containment failure modes distinctly different from those obtained in the internal event analyses are predicted. Fire risk assessment submittals should contain the following information: • A description of the methodology and key assumptions used in performing the fire risk assessment. • A discussion of the criteria used to identify critical fire areas and a list of critical areas, including (a) single areas in which equipment failures represent a serious erosion of Revision 4 - October 2003 56 safety margin, and (b) same as (a), but for double or multiple areas sharing common barriers, penetration seals, HVAC ducting, etc. • A discussion of the criteria used for fire size and duration and the treatment of cross-zone fire spread and associated major assumptions. • A discussion of the fire initiation data base, including the plant-specific data base used. Describe the data handling method, including major assumptions, the role of expert judgment, and the identification and evaluation of sources of data uncertainties. A discussion of each case where the plant-specific data used is less