Comparison of the nuclear code systems LINEAR-RECENT-NJOY and NJOY

The reconstructed cross sections of the code systems LINEAR-RECENT-GROUPIE (Version 1982) and NJOY (Version 1982) have been compared for several materials. Some fuel cycle isotopes and structural materials of the ENDF/B-4 general purpose and ENDF/B-5 dosimetry files have been choosen. The reconstructed total, capture and fission cross sections calculated by LINEAR-RECENT and NJOY have been analized. The two sets of pointwise cross sections differ significantly. Another disagreement was found in the transformation of ENDF/B-4 and 5 files into data with a linear interpolation scheme. Unshielded multigroup constants at O0K (620 groups, SANDII) have been calculated by the three code systems LINEAR-RECENT-GROUPIE, NJOY and RESEND5-INTEND. The code system RESEND5-INTEND calculates wrong group constants and should not be used any more. The two sets of group constants obtained from ENDF/B-4 data using GROUPIE and NJOY differ for some group constants by more than 2%. Some disagreements at low energies (10-3-eV) of the total cross section of Na-23 and Al-27 are difficult to understand. For ENDF/B-5 dosimetry data the capture group constants differ significantly. (Author)