Bent tube gauge design for ACR-1000 fuel bundles

The Bent Tube Gauge (BTG) is used in fuel bundle manufacturing to ensure that the bundles will pass through the fuel channel. Since the fuel bundle and the fuel channel dimensions, and in particular pressure tube dimensions change with time because of thermal, irradiation and gravity effects, the design of the BTG must account for irradiated bundle dimensions and the end-of-life pressure tube conditions. The BTG was first designed for the 28-element bundle in the Pickering A Nuclear Generating Station. All subsequent fuel bundle designs for CANDU reactors have used this BTG design. The methodology used for designing the Picketing BTG is examined and modifications to this methodology for application to the ACR-1000 are identified. Differences in CANFLEX-ACR fuel bundle and ACR-1000 fuel channel dimensions indicate the necessity for establishing a new BTG applicable to the ACR-1000. The assessment of the Pickering BTG design methodology and the changes to this approach that were used to design the ACR-1000 BTG are presented in this paper, as is the final configuration of the BTG selected for ACR-1000. (author)