A STUDY ON THE CRITICALITY SEARCH OF TRANSURANIUM RECYCLING BWR CORE BY ADJUSTING SUPPLIED FUEL COMPOSITION IN EQUILIBRIUM STATE

There have been some difficulties in carrying out an extensive evaluat ion of the equilibrium state of Light Water Reactor (LWR) recycling op erations keeping their fixed criticality condition using conventional design codes because of the complexity of their calculation model for practical fuel and core design and because of a large amount of calcul ation time. This study presents an efficient approach to secure the cr iticality in an equilibrium cycle by adjusting a supplied fuel composi tion. The criticality search is performed by the use of fuel importanc e obtained from the equation adjoint to a continuously fuel supplied c ore burnup equation. Using this method, some numerical analyses were c arried out in order to evaluate the mixed oxide (MOX) fuel composition of equilibrium Boiling Water Reactor (BWR) cores satisfying the criti cality requirement. The results showed the comprehensive and quantitat ive characteristics on the equilibrium cores confining transuraniums f or different MOX fuel loading fractions and irradiating conditions. (C ) 1998 Elsevier Science Ltd.