Document: NUREG-0800
Document ID: a28650b3-fa03-428d-a2bd-4a27f583710b
Document Type: srp
Title: NUREG-0800
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070484.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6
CFR Part: 
CFR Title: 

Content:
increased over the life of a plant, this position includes requirements for leakage tests. The leakage tests include both periodic low-pressure leak tests and a preoperational high-pressure leak test (Mark II and Mark III containments). In addition, Mark I containments have been operating with a positive pressure differential between the drywell and wetwell which provides a mechanism for continuously monitoring the amount of bypass leakage. B. Position The system used to quench steam bypassing the suppression pool should be designed such that the steam bypass capability for small breaks satisfies the criteria described below. Any proposed alternative criteria must be suitably justified by the applicant and reviewed by the NRC staff. 1. Bypass Capability (Mark II and Mark III) The containment should have a steam bypass capability for small breaks of the order of: 46.5 cm (.05 ft ) (A/ K) for Mark II plants and 929 cm (1 ft ) (A/ K) for Mark III 2 2 2 2 111 plants. 6.2.1.1.C-15 DRAFT Rev. 7 - April 1996 a. Containment Wetwell Sprays The wetwell spray system, including the electrical instrumentation and controls, should meet the standards appropriate to engineered safety features; i.e., quality, redundancy, testability, and other appropriate criteria. The wetwell spray should be automatically actuated 10 minutes following a LOCA signal and an indication of pressurization of the wetwell. In addition, the instrumentation and control systems provided to actuate the wetwell spray should be actuated by diverse parameters. If the existing wetwell spray system is to be used to improve the bypass capability, the consequences of actuation of the wetwell spray system on ECCS function and long-term pool cooling considerations should be evaluated to show that minimum ECCS and pool cooling requirements are met. b. Transient Bypass Capability Analyses Transient analyses should be provided to establish the capability for a small break. A normal plant shutdown time of 6 hours should