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:
eers, New York, N.Y. 2. Slade, D. H. (ed.), Meteorology and Atomic Energy-1968, TID-24190, USe^=C Division of Technical Information Extension, Oak Ridge, Tennessee. 3. Briggs, G. A., 1969, Plume Rise, TID-25075, USAEC Critical Review Series, USAEC Division of Technical Information Extension, Oak Ridge, Tennessee. a 1. 42-B2 APPENDIX C CALCULATIONAL MODELS FOR OFFSITE THYROID DOSES TO MAN VIA MILK AND LEAFY VEGETATION PATHWAYS Annual average values of the relative concentration* (x/Q) should be calculated as a function of distance from plant release points in 16 equiangular directions from potential sources. The estimates of x/Q and the quantities of radioiodines released from the plant sources allow cal- culation of annual average air concentrations of radioiodine effluent in each of the 16 directions examined. The annual average concentration of gaseous radioiodine effluent species i at the location (r, 0) from the (0,0) release point may be determined from Qi R(r,h) exp [-X i(r/v.)] ijj 3.15 x 107 (1 In Equation 1: Cij(r, 0) is the annual average air concentration of radioiodine i as 12 at the distance r and in the jth sector from the source (curies per cubic meter), Qi is the quantity of radioiodine i annually released from the source as 12 (curies per year), r is the distance from the source to the location where x/Q is determined (meters), is the wind direction angle from the source to the location of interest in the jth sector, * Concentration normalized to a unit release rate. 1. 42-Cl is the annual average wind speed for winds directed into the jth sector (meters per second), is the radiological decay constant of the radiolodine species i (inverse seconds), (x/Q)j is the annual average relative concentration at the distance r meters from the source in the j sector (seconds per cubic meter), and R(r, h) is a dimensionless iodine cloud depletion factor which is dependent upon distance from the source, r, and the height of release at the source, h. The value of