The Mass2Rad Excel Workbook for Converting Radionuclide Inventories Between Mass and Radiation Units, plus Inventory-Dependent Radionuclide Energy Release Rates

ABSTRACT The radionuclide source inventory provided as input to post-irradiation radiological analyses is typically in curies, grams, gram-atoms, or becquerels, with the radionuclide name itself being identified by either alphanumeric characters or by a numeric ID. The preferred inventory unit in the USA is curies, and the radionuclide name format is alphanumeric, though some software can accept other options. Clearly, there is a need for a validated, simple-to-use tool that can provide the conversion of radionuclide names and inventories between any combination of the listed options and thus facilitate the transfer of radionuclide data between various software. This, indeed, is the primary design objective of the Excel workbook (Mass2Rad.xlsx) described in the present paper. Additionally, the workbook was programmed to provide the energy release (or decay heat) separately for each user-specified radionuclide inventory, and the totals. In addition to facilitating the transfer of data between various software, the workbook may also be of interest for other applications, such as (a) the quantification of post-accident natural deposition/depletion of airborne aerosols in nuclear-power-plant containments, (b) assessment of the radiolysis of organic materials in contaminated fluids, and (c) the heat up of emergency filtration systems by decay heat. It is noted, however, that the workbook was not designed to account for source depletion by any removal mechanism, such as radioactive decay, transport or filtration. The Mass2Rad.xlsx workbook includes all 1252 radionuclides in ICRP-107, along with their nuclear properties of interest, and forms an integral part of the software package.