Document: NUREG-0800
Document ID: 0b93bfa1-19be-488b-8c78-a6c71cf3b42e
Document Type: srp
Title: MASS AND ENERGY RELEASE ANALYSIS FOR POSTULATED
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0535/ML053560191.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.1.3
CFR Part: 
CFR Title: 

Content:
ng and secondary water. Calculations of the energy available for release from the above sources should be done in general accordance with the requirements of 10 CFR Part 50, Appendix K, paragraph I.A. However, additional conservatism should be included to maximize the energy release to the containment during the blowdown and reflood phases of a LOCA. An example of this would be accomplished by maximizing the sensible heat stored in the reactor coolant system (RCS) and steam generator metal and increasing the RCS and steam generator secondary mass to account for uncertainties and thermal expansion. The requirements of paragraph I.B in Appendix K to 10 CFR Part 50, concerning the prediction of fuel clad swelling and rupture should not be considered. This will maximize the energy available for release from the core. B. Break Size and Location i. The staff’s review of the applicant's choice of break locations and types is discussed in SRP Section 3.6.2. 6.2.1.3-4 Revision 3 - March 2007 ii. Of several breaks postulated on the basis of a., above, the break selected as the reference case for subcompartment analysis should yield the highest mass and energy release rates, consistent with the criteria for establishing the break location and area. iii. Containment design basis calculations should be performed for a spectrum of possible pipe break sizes and locations to assure that the worst case has been identified. C. Calculations. In general, calculations of the mass and energy release rates for a LOCA should be performed in a manner that conservatively establishes the containment internal design pressure (i.e., maximizes the post-accident containment pressure and the containment subcompartment response). The criteria given below for each phase of the accident indicate the conservatism that should exist. i. Subcompartment Analysis The analytical approach used to compute the mass and energy release profile will be accepted if both the computer program and volume noding of