KRITZ-2 benchmark calculations using different nuclear data libraries

A set of KRITZ-2 experiments with light water moderated lattices with uranium rods and mixed-oxide rods, at room and elevated temperatures, were performed in the early 1970's. Using the results of these experiments, an international benchmark was developed and launched by the OECD/NEA in co-operation with ORNL. This paper presents the results obtained from two versions of MCNP calculations (4C and 4B) for the KRITZ-2 experiments, using three different nuclear data libraries (JEF-2.2, ENDF/B-VI.5 and JENDL-3.2). For the MCNP library generation, the nuclear data processing system NJOY (version 97.114) is used. For both sets of calculations, the three KRITZ-2 cores are explicitly modelled in 3-D geometry. The linear thermal expansion coefficients given in the specification are used to determine the dimensions of the core geometry, the material densities, and the atomic number densities of the materials at high temperatures. The calculated results are compared with experimental results for both k_eff and pin powers in different cores (two UO₂- and one MOX-fuelled cores). The influence of the nuclear data libraries on calculated results are examined. The calculated k_eff results show a strong dependence on the basic data libraries used. The calculated pin powers are in general in good agreement with the experimental values within ±2% of discrepancy for most of the fuel pin positions. (author)