A comparison of dose results from the Clean Air Act Assessment Package-1988, personal computer (CAP88-PC), version 3...

Computer software packages approved by the U.S. Environmental Protection Agency (U.S. EPA), including CAP88-PC, are used by U.S. Department of Energy (U.S. DOE) sites to demonstrate compliance with the radionuclide air emission standard under the Clean Air Act. CAP88-PC version 3, was approved by the U.S. EPA in February 2006 for use by U.S. DOE facilities. Version 3 incorporates several major changes that have the potential to affect calculated doses relative to calculations using earlier versions. This analysis examined the types and magnitudes of changes to dose estimates for specific radionuclides calculated using the version 3 software compared with the previous versions. For parent radionuclides and for the total dose from radionuclide chains, total effective dose calculated with version 3 was compared to effective dose equivalent calculated with previous versions. Various comparisons were also performed to determine which of the updates in version 3 accounted for changes in overall dose estimates. CAP88-PC version 3 would produce substantially different results relative to previous versions of the code for a number of radionuclides, including some isotopes that may be present at U.S. DOE facilities, as well as those used for industrial and medical applications. In general, doses for many radionuclides were lower using version 3 but doses for a few key radionuclides increased relative to the previous versions.