Dry storage instrumented bundle experiments

Analysis of the potential degradation mechanisms for spent LWR fuel under dry storage indicates that hoop strain would appear to limit the insertion temperature to 4000C. To demonstrate the storage performance, two tests are conducted at t(max) = 3000C (2 kW decay heat) and t(max) = 4000C (3 kW decay heat). The fuel elements are composed of different design and burnup up to an average rod burnup of more than 40 GWd/tU accumulated in 4 reactor cycles. The experiments are instrumented with thermocouples and equipped with a gas monitoring line. Experiment no. 1 (t(max) = 3000C) was terminated after 60 days. Experiment no. 2 (t(max) = 4000C) is still in operation. There is no indication of any defect