- 48 - be considered as acceptable limits, or whether design basis accidents that are currently evaluated under these criteria are “of exceedingly low probability of occurrence," we recommend that 10 CFR 100.1ll(a) (1) be modified as follows in order to establish a hot particle standard that is equivalent to the risk associated with 25 (1) rem whole body irradiation: An exclusion area of such size that an individual located at any point on its boundary for two hours immediately following onset of the postulated fission product or other radionuclide release would not receive a total radiation dose to the whole body in excess of 25 rem2 or a total radiation dose in excess of 300 rem¢ to the thyroid from iodine exposure, or receive a lung particle burden in excess of 10 hot particles.3 a 2 (unchanged from original text) 3~4 hot particle is a particle that contains sufficient activity to deliver at least 1000 rem/yr to the surrounding lung tissue. For isotopes having half-lives greater than one year, this would correspond to particles containing at least 0.07 s pCi of alpha activity. r We also recommend that similar criteria be established limiting hot particle releases for nuclear facilities not now covered under 10 CFR 100. D, , Surface Contamination Hot particles deposited on land surfaces can be resuspended into the air by any number of means, including wind, automobile traffic, human or animal movements, ge rye oo RT ws we . Comoe I eg AR Fee RB hee Pe ete ‘ afoy ,eae ave uy . Following