Document: NRC Regulatory Guide
Document ID: cf1737d6-2a8a-4765-aaf5-f5f2a617ef91
Document Type: regulatory_guide
Title: Design of Main Steam Isolation Valve Leakage Control Systems for Boiling Water Reactor Nuclear Power Plants
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740263.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.96
CFR Part: 
CFR Title: 

Content:
d in accordance with Seismic Category I and Quality Group A requirements supplemented by Appen dix A of this guide. 2. The LCS (and any necessary subsystems) should be capable of performing its safety function, when 1.96-2 necessary, considering effects resulting from a LOC• including (a) missiles that may result from equipme failures, (b) dynamic effects associated with pipe wh and jet forces, and (c) normal operating and accider caused local environmental conditions consistent wi the design-basis event. Further, any portion of the L( that is Quality Group A and is located outside tC primary containment structure should be protected fro missiles, pipe whip, and jet force effects originati outside containment so that containment integrity maintained. 3. The LCS should be capable of performing i safety function following a LOCA and assumed sing active failure (including failure of any one of the ma stearn isolation valves to close). 4. The LCS should be designed so that effec resulting from failure of a single active component of ti leakage control system will not affect the integrity operability of the main steam lines or main stea isolation valves. 5. The LCS should be capable of performing i safety function following a loss of all offsite pow coincident with a postulated design-basis LOCA. 6. The LCS should be designed with sufflcie: capacity and capability to control leakage from the ma steam lines for as long as postulated accident conditic. require containment integrity to be maintained. 7. The LCS may be manually or automatical actuated and should be designed to permit actuati( within about 20 minutes after a postulated design-ba! LOCA. This time period is considered to be consiste. with loading requirements of the emergency electric buses and with reasonable times for operator action. 8. Instrumentation and circuits necessary for ti functioning of the LCS should be designed in accordan with standards applicable to an engineered safe feature. 9. The LCS