The decay data in ENDF/B: History and current status

In recognition of the importance of radioactive-nuclide decay data for a variety of reactor-related applications, the scope of the Evaluated Nuclear Data File/B (ENDF/B) was expanded in 1973 to include such information. The impetus for this expansion was provided by the need for a common base of evaluated decay data for input to the computer codes developed to carry out summation-type' calculations of the fission product decay-heat source term in nuclear reactors. In its original formulation, this data base was called the Fission Product File, and an ad hoc group, the Decay Heat Task Force, was set up under the Fission Product Subcommittee of the Cross Sections Evaluation Working Group to prepare it. This group began work on the project early in 1973. The ENDF/B data file is profiled from its formation through various evaluation, developments, and changes to the present Version VI.