Document: NRC Regulatory Guide
Document ID: c0dbb594-6262-4b83-96b1-366758ad9676
Document Type: regulatory_guide
Title: Interim Licensing policy on as low as Practicable for Gaseous Radiodine Releases from Light-Water-Cooled Nuclear Power Reactors (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1229/ML12298A137.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.42
CFR Part: 
CFR Title: 

Content:
see should establish an appropriate surveillance and monitoring program to.: (1) Provide data on quantities of radioactive iodine released in gaseous effluents to assure that the guidance of C.l.a and C.1.b is met; (2) Provide data on measurable levels of radioactive iodine in the environment to evaluate the relationship between quantities of radioactive iodine released in gaseous effluents and resultant radiation doses to individuals from principal pathways of exposure; and (3) Identify changes in the use of unrestricted areas (e.g., for agricultural purposes) to permit modifications in monitoring programs for evaluating doses to individuals from principal pathways of exposure. d. If the data developed in the surveillance and monitoring program described in C.2.c or from other monitoring programs show that the relationship between the quantities of radio- active iodine released in gaseous effluents and the dose to 1.42-6 individuals in unrestricted areas is significantly different from that assumed in the calculations used to determine design objectives pursuant to C.l, the Commission may modify the quantities in the technical specifications defining the limiting conditions for operation in a license authorizing operation of an LWR. 1.42-7 APPENDIX A PRINCIPAL PARAMETERS USED IN SOURCE TERM CALCULATIONS A. Principal Parameters Used in PWR Source Term Calculations 1. Thermal Power Level - The maximum thermal power level (MWt) evaluated for safety considerations in the Safety Analysis Report. 2. Plant Capacity Factor - 80% 3. Fraction of Fuel Releasing Fission Products to the Primary Coolant Zircaloy-clad fuel 0.25% Stainless-steel-clad fuel 0.10% 4. Equilibrium Primary Coolant Radioiodine Concentration Escape Rate Coefficient - 1.3 x 10 sec 5. Primary to Secondary Leakage Rate - 110 lb/day If the technical specifications limit the leakage rate to less than 110 lb/day (i.e., limitation on tritium activity in steam generator blowdown stream), calculate a leakage rate