Document: NRC Regulatory Guide
Document ID: 4d46a966-d280-43da-9b03-8b0abe7b29ce
Document Type: regulatory_guide
Title: Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2120/ML21204A065.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.183
CFR Part: 
CFR Title: 

Content:
vior in a PWR Cooling System Following a Postulated Steam Generator Tube Rupture Accident,” NUREG-0409, January 1978 (ADAMS Accession No. ML19269F014). E-3. U.S. NRC, “Steam Generator Tube Rupture Analysis Deficiency,” Information Notice 88-31, May 25, 1988 (ADAMS Accession No. ML031150151). 1 Publicly available NRC published documents are available electronically through the NRC Library on the NRC’s public Web site at http://www.nrc.gov/reading-rm/doc-collections/ and through the NRC’s Agencywide Documents Access and Management System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html The documents can also be viewed online or printed for a fee in the NRC’s Public Document Room (PDR) at 11555 Rockville Pike, Rockville, MD. For problems with ADAMS, contact the PDR staff at 301-415-4737 or (800) 397-4209; fax (301) 415-3548; or e-mail pdr.resource@nrc.gov. DG-1389, Appendix F, Page F-1 APPENDIX F ASSUMPTIONS FOR EVALUATING THE RADIOLOGICAL CONSEQUENCES OF A PRESSURIZED-WATER REACTOR MAIN STEAMLINE BREAK ACCIDENT This appendix provides assumptions acceptable to the staff of the U.S. Nuclear Regulatory Commission (NRC) for evaluating the radiological consequences of a main steamline break accident at pressurized-water reactors. These assumptions supplement the guidance provided in the main body of this guide.1 Source Term F-1. Regulatory Position 3 of this regulatory guide provides assumptions acceptable to the NRC staff regarding core inventory and the release of radionuclides from the fuel. F-2. If no or minimal2 fuel damage is postulated for the limiting event, the activity released should be the maximum coolant activity allowed by the technical specifications. Two cases of iodine spiking should be assumed: F-2.1 A reactor transient has occurred before the postulated main steamline break (MSLB) and has raised the primary coolant iodine concentration to the maximum value (typically 60 microcuries per gram (μCi/g) dose equivalent (DE) iodine (I)-131 (DE