Document: NUREG-0800
Document ID: 91a12934-f0d9-4573-ad3b-553ab75dabc0
Document Type: srp
Title: FISSION PRODUCT CONTROL SYSTEMS AND STRUCTURES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0636/ML063600408.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.5.3
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CFR Title: 

Content:
in 10 CFR Part 100. III. REVIEW PROCEDURES The reviewer will select material from the procedures described below, as may be appropriate for a particular case. These review procedures are based on the identified SRP acceptance criteria. For deviations from these acceptance criteria, the staff should review the applicant’s evaluation of how the proposed alternatives provide an acceptable method of complying with the relevant NRC requirements identified in Subsection II. 1. Primary Containment Design A. The primary containment design is studied to familiarize the reviewer with the overall construction and anticipated performance capability of the primary containment. Certain parameters and design features, such as design leakage rate, purge/vent systems leakage rate prior to containment isolation, containment free volume, and internal fission product cleanup systems, should be noted for later use (see example of worksheet, Table 6.5.3-1). The performance capability of the internal fission product cleanup systems (if any) should be verified (see SAR Sections 6.5.1, 6.5.2, and 6.5.4). B. The transient response of the containment pressure following the accident should be studied. Historically, pressurized water reactor (PWR) containment design leakage rates have been reduced by a factor of two by one day into the accident (Regulatory Guide 1.4), whereas BWR containment design leakage rates were assumed to be constant for all time periods following the accident (Regulatory Guide 1.31). The reviewer should verify with the organization responsible for the review of reactor accident consequence assessment, specifically design basis containment and ventilation performance that these modeling assumptions are valid for each case reviewed. For those containments designed to reach subatmospheric pressure at some time less than 30 days after the accident, the same organization should verify the time necessary to reach subatmospheric pressure. 2. Secondary Containment Design A.