Document: NUREG-0800
Document ID: 74415b71-98a0-4109-9ba7-8a72a89a3d18
Document Type: srp
Title: ULTIMATE HEAT SINK
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070520.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.2.5
CFR Part: 
CFR Title: 

Content:
imate Heat Sink for Nuclear Power Plants." 7. Regulatory Guide 1.29, "Seismic Design Classification." 8. Regulatory Guide 1.72, "Spray Pond Plastic Piping made from Fiberglass-Reinforced Thermosetting Resin."56 DRAFT Rev. 3 - April 1996 9.2.5-12 9. Branch Technical Position ASB 9-2, "Residual Decay Energy for Light Water Reactors for Long-Term Cooling." 10. Regulatory Guide 1.127, "Inspection of Water-Control Structures Associated with Nuclear Power Plants."57 11. Federal Coordinating Council for Science, Engineering, and Technology, "Federal Guidelines for Dam Safety," June 25, 1979.58 12. NRC Letter to All Holders of Operating Licenses or Construction Permits for Nuclear Power Plants, "Service Water System Problems Affecting Safety-Related Equipment, (Generic Letter 89-13)" July 18, 1989.59 13. ANS 5.1, "Decay Heat Power for Light Water Reactors," October 1979.60 P Po ( ,ts) 1 200 n 11 n 1 Ane an ts ANS 5.1, "Decay Heat Power for Light Water Reactors" (October 1979), can also be used 1 to establish decay heat generation rates in lieu of the methods described below. 9.2.5-13 DRAFT Rev. 3 - April 1996 (1) BRANCH TECHNICAL POSITION ASB 9-2 RESIDUAL DECAY ENERGY FOR LIGHT-WATER REACTORS FOR LONG-TERM COOLING A. BACKGROUND The Auxiliary Systems Branch has developed acceptable assumptions and formulations that may be used to calculate the residual decay energy release rate for light-water-cooled reactors for long-term cooling of the reactor facility. Experimental data (Refs. 1 and 2) on total beta and gamma energy releases for long half-life (> 60 seconds) fission products from thermal neutron fission of U-235 have been considered reliable for decay times of 10 to 10 seconds. Over this decay time, even with the exclusion of 3 7 short-lived fission products, the decay heat rate can be predicted to within 10% of experimental data (Refs. 3, 7, and 8). The short-lived fission products contribute appreciably to the decay energy for decay times less than 10 seconds. Although