Environmental radioactivity at the TMI (Three Mile Island), venting phase

From June 28 through July 12, 1980, approximately 44,000 curies of krypton-85 were discharged into the environment from the reactor building housing the crippled nuclear reactor at Three Mile Island (TMI). The U.S. Environmental Protection Agency (EPA) operated monitoring networks for krypton 85 (5 stations) and airborne particulates (19 stations). These fixed station networks were supplemented, for the duration of the venting, by two mobile units which sampled within the discharge plume. Calculations of the maximum exposure, based upon measured concentrations of krypton-85, indicated the maximum dose equivalent to the skin to be 0.86 mrem and to the whole body to be 0.0071 mrem. Because the calculated doses derived largely from a few relatively high concentrations of krypton 85, the reported values are well within + or - 10 percent at the 95 percent confidence level