Document: NUREG-0800
Document ID: eb937958-fe7c-410a-91e3-63f04734878a
Document Type: srp
Title: MAIN STEAM ISOLATION VALVE LEAKAGE CONTROL SYSTEM (BMR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350465.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.7
CFR Part: 
CFR Title: 

Content:
prevented or controlled. Such leakage could bypass the leakage control. system and result in untreated releases to the environment. The means for prevention or control need not be part of the leakage control system itself, but should meet the same design criteria. 7. The leakage control system design is reviewed to determine if a third main steam line valve, located between the main steam isolation valve and the turbine stop valve, is required to assure that the MSIVLCS can perform its safety function following a design basis LOCA. IV. EVALUATION FINDINGS The reviewer verifies that sufficient information has been provided and his review supports conclusions of the following type, to be included in the staff's safety evaluation report: The main steam isolation valve leakage control system (MSIVLCS) includes [the source of the sealing medium, (if used)] pumps, valves, and piping to the points of connection or interface with the main steam lines. The system is designed to seismic Category I, Quality Group B requirements since it is necessary for postaccident fission product removal. That portion of the system connected tp the piping between the MSIVs is designed to seismic Category I, Quality Group A requirements since it is part of the primary coolant system pressure boundary. Based on the review of the applicant's proposed design criteria, design bases, safety classification of system and components, and the requirements for operation of the system during loss-of-coolant accident conditions, the staff concludes that the design of the main steam isolation valve leakage control system is in conformance with the Commission's regulations as set forth in General Design Criteria 2, 4, and 54. This conclusion is based on the following: 1. The applicant's design meets the requirements of General Design Criterion 2 since the design is in accordance with position C.1 of Regulatory Guide 1.29 and position C.1 of Regulatory Guide 1.96. 2. The applicant's design meets General