Document: NUREG-0800
Document ID: 02fef38f-79ed-4d55-825f-81551bcfdcdc
Document Type: srp
Title: LOSS-OF-COOLANT ACCIDENTS RESULTING FROM SPECTRUM OF
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550016.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.6.5
CFR Part: 
CFR Title: 

Content:
requirements specified in 10 CFR 50.46 provide an acceptable and conservative means of calculation of the consequences of LOCAs from a spectrum of pipe break sizes and locations that have been subject to careful review and experimental verification. If the calculations of the performance of the emergency core cooling system are conducted in accordance with these methods, there is a high level of probability that the acceptance criteria on core performance will not be exceeded and damage to the core and offsite consequences will be minimized. Regulatory Guide 1.157, "Best Estimate Calculations of Emergency Core Cooling System Performance," and Appendix K to 10 CFR Part 50, provide guidance and requirements on evaluation models needed to demonstrate compliance with the acceptance criteria. Appendix K also specifies documentation required for evaluation models. Meeting the requirements outlined in the references provides assurance that following a LOCA the reactor core will remain in a coolable geometry and offsite consequences will be within the guidelines specified in 10 CFR 100 or 10 CFR 50.67. 2. GDC 13 requires the provision of instrumentation that is capable of monitoring variables and systems over their anticipated ranges to assure adequate safety, and of controls that can maintain these variables and systems within prescribed operating ranges. GDC 13 applies to this section because the reviewer evaluates the sequence of events, including automatic actuations of protection systems, and manual actions, and determines whether the sequence of events is justified, based upon the expected values fo the relevant monitored parameters and instrument indications. 3. Compliance with GDC 35 requires that a means of providing abundant emergency core cooling be provided that will transfer heat from the reactor core in the event of a LOCA, and that suitable redundancy of components and features is provided so that the safety function can be accomplished assuming a single