The Advanced CANFLEX Fuel Bundle - Development Status

Abstract

The performance of CANDU pressurized heavy-water reactors, in terms of lifetime load factors, is excellent. More than 700 000 bundles containing natural-uranium fuel have been irradiated, with a low defect rate; reactor unavailability due to fuel incidents is typically zero. To maintain and improve CANDU's competitive position, Atomic Energy of Canada Limited (AECL) has an ongoing program comprising design, safety and availability improvements, advanced fuel concepts and schemes to reduce construction time. To ensure that the duty- cycle targets for advanced fuel cycles and load-following are achieved, AECL is developing a new fuel bundle, termed CANFLEX (MDU FLEXible), where "flexible" refers to the versatility of the bundle with respect to operational and fuel- cycle options. Though the initial purpose of the new 43-element bundle is to introduce SEU into CANDU, CANFLEX is extremely versatile in its application, and is compatible with other fuel cycles of interest: natural uranium in existing CANDU reactors, recycled uranium and mixed-oxides from light-water reactors, and thoria-based fuels. Capability with a variety of fuel cycles is the key to future CANDU success in the international market. The improved performance of CANFLEX, particularly at high burnups, will ensure that the full economic benefits of advanced fuel cycles are achieved. A proof-tested CANFLEX bundle design will be available in 1993 for large-scale commercial-reactor demonstration.