title: Accuracy of Cloudshine Gamma Dose Calculations in the CAP-88 Dispersion Model.
abstract: The U.S. Environmental Protection Agency dispersion model, CAP-88, calculates ground-level dose using the ground-level concentration and the semi-infinite cloud approximation. Doses can be underestimated for elevated plumes during stable atmospheric conditions at receptor locations within a kilometer downwind of a stack. The purpose of this paper is to identify when CAP-88 calculations of gamma dose from cloudshine are inaccurate and provide estimates of the inaccuracy. The method used compares CAP-88 estimates with Monte Carlo N-Particle (MCNP) estimates. Comparisons were made at distances of 800 m and 3,000 m downwind of the stack and for plume heights from 0 to 50 m. For these conditions, the annual dose calculated by CAP-88 is greater than or equal to that calculated by MCNP.
authors.affiliation: *MS J978, Los Alamos National Laboratory, Los Alamos, NM 87545.
authors.forename: Michael W
authors.initials: MW
authors.lastname: McNaughton
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Gillis
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Ruedig
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Whicker
authors.forename: David P
authors.initials: DP
authors.lastname: Fuehne
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D003198:Computer Simulation; D015233:Models, Statistical; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis*; D011834:Radiation Monitoring / Q000379:methods*; D011868:Radioisotopes / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D013051:Spectrometry, Gamma / Q000379:methods*; D014481:United States; D014887:Weather
chemical_list: D000396:Air Pollutants, Radioactive; D011868:Radioisotopes