KUCA critical experiments using medium enriched uranium fuel

In accordance with the joint ANL-KURRI program, the critical experiments using MEU fuel in the KUCA, a light-water-moderated and heavy-water-reflected single-core, were started in May, 1981. In advance of the critical experiments, the MEU fuel elements and the boron loaded side-plates were fabricated by CERCA in France. The first critical state of the core using MEU fuel was achieved at 3 : 12 p.m., May 12, 1981. After that, several experiments were performed. The paper provides the results of measurements concerning the critical approach, the reactivity effects of side-plates containing boron burnablepoison, the space dependent effects of void reactivities and the temperature reactivity coefficients. These data will be used to examine the computer code systems in various countries and also used for core conversion of the KUHFR from HEU to MEU. (author)