Canflex-An Advanced Bundle Deisgn for Introducing Slightly-Enriched Uranium into CANDU

Abstract

The CANDU reactor is performing well with the current once-through, natural uranium (NU) fuelling; more than 600 000 bundles have been irradiated commercially with a low defect rate. One component of the Atomic Energy of Canada Limited (AECL) strategy to maintain and improve the competitive position of CANDU is the introduction of slightly-enriched uranium (SEU), less than 1.5 wt% U-235 in U. The CANFLEX (CANDU FLEXible) advanced bundle-design is a superior format for introducing SEU and other advanced fuel cycles into CANDU. The advanced bundle is a logical extension of existing technology, and contains 43 elements with two element sizes. The CANFLEX development and demonstration program comprises performance testing, design and specification, thermal hydraulic confirmation, safety analysis, reactor physics, and handling/endurance tests. An important component of the CANFLEX product is the data base and modelling capability generated during development, to support licensing. The goal is a bundle design available for a large-scale commercial demonstration by 1992/93.