ICONE23-1340 DIFFERENCE OF GRAPHITE CAPTURE CROSS SECTIONS IN ENDF/B LIBRARIES

Abstract

Graphite cross section differs among various evaluated nuclear data libraries as a result of distinct theoretical models and experimental technologies which are utilized by different nuclear data organizations all over the world. It has been revealed that graphite cross section plays a significant role in criticality calculation of graphite-moderated reactors in which graphite is one of the most important composing components; therefore, researches on the difference of graphite cross sections and the resulting effect on core parameters are highly recommended to be carried out. In the present paper, the differences of graphite capture cross sections in ENDF/B V, ENDF/B VII and ENDF/B VII.1 libraries were investigated in a unique group structure which is employed by the VSOP code. The resulting deviation of k_<eff> has also been investigated by running exactly the same VSOP calculation routine with each considered nuclear data library for HTR-PM model. The results show that there is obvious difference among these three ENDF/B library versions. The significances of graphite capture cross section vary with energy region, which have distinguishing influence on the reactor core parameters, including k_<eff>. The calculated k_<eff> are more sensitive to graphite capture cross sections in thermal energy region than that in epithermal energy region.