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:
age 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 based on the specifications. 6. Containment Building Leakage Rate - 240 lb/day hot primary coolant with a partition factor of 0.1 for radioiodine. 7. Auxiliary Building Leakage Rate - 160 lb/day primary coolant with a partition factor (PF) of 0.005 for radioiodine. If the letdown heat exchangers are located within the containment building, assume that all of the leakage is cold and use a PF of 0.001. 1. 42-•A4 * 0 8. Turbine Building Steam Leakage Rate (gaseous source term only) a. If no special design features are provided to reduce the leakage from steam line valves, use a leakage rate of 1700 lb/hr and a PF of 1 for radioiodine. b. If special design features are provided to reduce the leakage from "Stop, Control, and Bypass" valves 24 inches and larger, use a leakage rate of 1350 lb/hr and a PF of 1 for radioiodine. c. If special design features are provided to reduce the leakage rate from all steam line valves 2-1/2 inches and larger, use a leakage rate of 340 lb/hr and a PF of 1 for radioiodine. 9. Frequency of Containment Building Purge - 4 purges/yr 10. Primary System Volumes Degassed Per Year - Sum of a and b below. a. The number of coolant volumes consistent with two cold shut- downs per year, plus b. Total number of volumes degassed per year due to continuous stripping based on information in the Safety Analysis Report. 11. Waste Gas Storage Tanks - Holdup Time Calculate the holdup time by the following equations: Tf - VP/140 T = VP(n-2)/140 h where Tf is the time required to fill one tank, days 0. fo 1. 42-A2 Th - holdup time, days V = volume of each tank, ft 3 P = storage pressure, atmospheres (absolute) n total number of storage tanks (n-2) = correction to subtract the tank being filled and the tank held in reserve 140 = average waste gas flow rate per