Definition and Analysis of Heavy Water Reactor Benchmarks for Testing New Multigroup Libraries

Abstract

A set of heavy water reactor benchmarks has been selected for testing new WIMS-D libraries. The libraries were constructed using data from ENDF/B–VI, Release 7, JENDL-3.2 and JEF–2.2 evaluated nuclear data files. The benchmarks cover a wide variety of reactor types and conditions, from fresh fuel to high burnup, and for natural and enriched uranium and Th-U fuels. The main parameters compared are the effective multiplication factor and other integral parameters, and isotopic composition of actinides on burnup cases. Besides, further investigations related with energy spectra used for preparation of WIMS-D libraries when applied on HWTR reactor calculations are included. Mostly of the benchmarks show a good agreement between experimental measurements and calculated values for all libraries. One exception is Th232 benchmark, were it is found that a library with JEND-3.2 Th232 data produces better results than ENDF/B-Vl, R.7 and JEF-2.2 Th232 data. Results are slightly improved when HWTR spectra are used for weighting function to prepare the multi-group cross sections. This work is part of the International Atomic Energy Agency’s Coordinated Research Project on “Final Stage of WIMS-D Library Update Project”.

Keywords:

• heavy water reactors
• criticality benchmarks
• evaluated nuclear data
• thorium 232
• multigroup lattice codes