Document: NUREG-0800
Document ID: bb823f40-ee8a-48c3-b347-aa5265dc04e4
Document Type: srp
Title: Revision 5 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0704/ML070460345.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
m a systems analysis to avoid these problems. There have been a number of recommendations for accomplishing this aim. Until a more definitive guide is published, the criteria in Part B, below, provide an adequate and acceptable design solution for this concern. BTP 7-1-2 Revision 5 - March 2007 B. Branch Technical Position The following measures should be incorporated in designs of the interfaces between low-pressure systems and the high-pressure reactor coolant system: 1. At least two valves in series should be provided to isolate any subsystem whenever the primary system pressure is above the pressure rating of the subsystem. 2. For system interfaces where both valves are motor-operated, the valves should have independent and diverse interlocks to prevent both from opening unless the primary system pressure is below the subsystem design pressure. Also, the valve operators should receive a signal to close automatically whenever the primary system pressure exceeds the subsystem design pressure. 3. For those system interfaces where one check valve and one motor-operated valve are provided, the motor-operated valve should be interlocked to prevent the valve from opening whenever the primary pressure is above the subsystem design pressure, and to close automatically whenever the primary system pressure exceeds the subsystem design pressure. 4. Suitable valve position indication should be provided in the control room for the interface valves. 5. For those interfaces where the subsystem is required for emergency core cooling system operation, the above recommendations need not be implemented. System interfaces of this type should be evaluated on an individual basis, as discussed in GL 87-12 and GL 88-17. 6. The system should satisfy the requirements of the General Design Criteria and Section 50.55a(h) of 10 CFR Part 50. 10 CFR 50.55a(h), “Protection and Safety Systems,” requires compliance with IEEE Std 603-1991, “IEEE Standard Criteria for Safety Systems for