Systematic approach to nuclear data modeling, evaluation, processing and integral testing
Arjan Koning
NRG Petten
A nuclear data system is presented which connects basic experimental and theoretical nuclear data to a large variety of nuclear applications. This software system, built around the TALYS nuclear model code, has several important outlets: (a) The TENDL nuclear data library: complete isotopic data files for 2430 nuclides for incident gamma’s, neutrons and charged particles up to 200 MeV, including covariance data, in ENDF and various processed data formats. In 2014, TENDL has reached a quality nearing, equalling and even passing that of the major data libraries in the world. It is based on reproducibility and is built from the best possible data from any source. (b) Total Monte Carlo: an exact way to propagate uncertainties from nuclear data to integral systems, by employing random nuclear data libraries and transport, reactor and other integral calculations in one large loop. For example, the entire ICSBEP database can now be predicted including uncertainty estimates. (c) Automatic optimization of nuclear data to differential and integral data simultaneously by combining the two features mentioned above. Both the differential quality, through theoretical-experimental comparison of cross sections, and the integral performance of the entire system will be demonstrated. The impact of the latest theoretical modeling additions to TALYS on differential nuclear data prediction will be outlined, while integral validation will be presented for a selection of cases from criticality benchmarks, safety-related (Doppler and void) coefficients, burnup, radiotoxicity, 14 MeV structural material shielding for fusion, and proton-induced medical isotope production. Comparisons with the major world libraries will be shown. Since the system is designed with a high level of QA and reproducibility and at the same time is based on high quality experimental and theoretical nuclear physics, we expect that the features mentioned above will soon play an important role in the analysis of any nuclear application.