Document: NUREG-0800
Document ID: 6de5c1bb-88d0-4d17-8255-a248a8db304a
Document Type: srp
Title: SUBCOMPARTMENT ANALYSIS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070487.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.1.2
CFR Part: 
CFR Title: 

Content:
REVIEW RESPONSIBILITIES Primary - Containment Systems and Severe Accident Branch (SCSB) 1 Secondary - None I. AREAS OF REVIEW The SCSB reviews the information presented by the applicant in the safety analysis report 2 concerning the determination of the design differential pressure values for containment subcompartments. A subcompartment is defined as any fully or partially enclosed volume within the primary containment that houses high energy piping and would limit the flow of fluid to the main containment volume in the event of a postulated pipe rupture within the volume. A short-term pressure pulse would exist inside a containment subcompartment following a pipe rupture within the volume. This pressure transient produces a pressure differential across the walls of the subcompartment which reaches a maximum value generally within the first second after blowdown begins. The magnitude of the peak value is a function of several parameters, which include blowdown mass and energy release rates, subcompartment volume, vent area, and vent flow behavior. A transient differential pressure response analysis should be provided for each subcompartment or group of subcompartments that meets the above definition. The SCSB review includes the distribution of the mass and energy released into the break 3 compartment, nodalization of subcompartments, subcompartment vent flow behavior, and subcompartment design pressure margins. The SCSB review of the subcompartment model includes the basis for the nodalization within 4 each subcompartment, the initial thermodynamic conditions within each subcompartment, the DRAFT Rev. 3 - April 1996 6.2.1.2-2 nature of each vent flow path considered, and the extent of entrainment assumed in the vent flow mixture. The review may also include an analysis of the dynamic characteristics of components, such as doors, blowout panels, or sand plugs, that must open or be removed to provide a vent flow path, and the methods and results of components tests