Defective Fuel Detection in CANDU-600's

Abstract

Fuel failures in CANDU 600s are detected and located by two independent on-power systems: the Gaseous Fission Product monitoring and Delayed Neutron Systems. The data generated by these systems can also be analyzed to: estimate the number of defective elements from Xe-133 activity concentrations, assess the defect condition from Xe-133/Kr-88 activity ratios, determine when fuel defects deteriorate and release uranium from delayed neutron signals, and evaluate in-core uranium levels from average delayed neutron signals. Criteria presented in this paper, for deciding when to remove fuel failure, have been substantiated with operational data from Point Lepreau NGS.