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:
REVIEW RESPONSIBILITIES Primary - Auxiliary Systems Branch (ASB) Secondary - None 1. AREAS OF REVIEW Direct cycle boiling water reactor (BWR) plants have redundant quick-acting isola- tion valves on each main steam line from the reactor to the turbine. In the event of a loss-of-coolant accident (LOCA), any leakage of contaminated steam through these valves is controlled by a leakage control system. The leakage control system must satisfy the requirements of General Design Criteria 2, 4, and 54. The review of the main steam isolation valve leakage control system (MSIVLCS) covers the entire leakage control system including the source of the sealing medium, if any, and pumps, valves, and piping to the points of connection or interface with the main steam supply system. Emphasis is placed on the components of the leakage control system that are required to remain functional following a design basis LOCA. 1. ASB reviews the design of the MSIVLCS and essential subsystems to assure their ability to function following a postulated LOCA including the loss-.of offsite power. The system is reviewed to determine that: a. A malfunction or failure of an active component of the system, or loss of the source of sealing fluid, if any, will not impair the functional j performance of the system. b. The failure of nonseismic Category I equipment or components will not have an adverse effect on the ability of the system or components to function. c. The capability of the system to perform its intended safety function is maintained assuming a single active failure of a main steam line isola- tion valve. Rev. 2 - July 1981 USNRC STANDARD REVIEW PLAN Standard review plans are prepared for the guidance of the Office of Nuclear Reactor Regulation staff responsible for the review of applications to construct and operate nuclear power plants. These documents are made available to the public as part of the Commission's policy to inform the nuclear Industry and the general public of regulatory