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:
e per year (3 months) has been taken into account. In those areas where a 1. 42-C12 greater or lesser time duration of consumption of leafy green vegetables normally occurs, the calculated dose values may be revised proportionately. Infant and Adult Thyroid Dose Via Inhalation The average annual concentration, C (r, 0), of a gaseous radioiodine effluent species i at a location (r, 0 ) from the (0,0) release point is given in Equation 1 in curies per cubic meter. The thyroid dose via in- halation delivered to an infant present in this concentration environment during a year may be readily calculated by the use of the appropriate iodine air concentration values in column 1 of Table II in Appendix B of 10 CFR Part 20. The concentration values provided there are those that would provide a resident infant with a 2-gram thyroid and a 3 cubic meter per day breathing rate, a thyroid dose of 1500 millirem per year. The annual dose that would be delivered to an infant residing in a radioiodine concentration of Cij (r,ej) curies per cubic meter is then as given below: Nuclide Infant Annual Inhalation Thyroid Dose (mrem/yr) 1-131C 3C131 (1500) HPC a 1-133C 3C133 (1500) MPC a The above alternative representations of infant dose relations are: D 31(mrem/yr) = 4.8 x 105 (x/Q) Q 31R (24) Saand 1.42-C13 S-.-~~. ~~ k A .- ~- 0 D1 3 3 (mrem/yr) = 1.2 x 105 (x/Q)j Q1 3 3 R (25) In Equations 24 and 25, (x/Q) 1 is given in seconds per cubic meter, Qi is given in curies per year, and R, from Equation 2, is dimensionless. In the calculation of inhalation thyroid dose to an adult residing in an environment containing the same radioiodine concentration, Cij (r,e ), as the infant, the identical corrections are made for thyroid masses, inhalation rates, and energy depositions as in the treatment provided in the calculation of adult vegetation pathway thyroid dose. Consequently, the annual dose that would be delivered to an adult re- siding in a radioiodine concentration of Cij (r,e O) curies