The status of nuclear data for transmutation calculations

At this point, the accurate description of transmutation products in a radiation environment is more a nuclear data problem than a code development effort. We have used versions of the CINDER code for over three decades to describe the transmutation of nuclear reactor fuels in radiation environments. The need for the accurate description of reactor neutron-absorption, decay-power, and decay-spectra properties have driven many AEC, ERDA, and DOE supported nuclear data development efforts in this period. The level of cross-section, decay, and fission-yield data has evolved from rudimentary to a comprehensive ENDF/B-VI library permitting great precision in reactor calculations. The precision of the data supporting reactor simulations provides a sturdy foundation for the data base required for the wide range of transmutation problems currently studied. However, such reactor problems are typically limited to neutron energies below 10 MeV or so; reaction and decay data are required for actinides of, say, 90 {le} Z {le} 96 neutron-rich fission products of 22 {le} Z {le} 72. The expansion into reactor structural materials and fusion systems extends these ranges in energy and Z somewhat. The library of nuclear data, constantly growing in breadth and quality with international cooperation, is now described in the following table.