1990 年 32 巻 10 号 p. 1023-1031
This paper describes the result of reactivity initiated accident (RIA) experiments using prepressurized (1.3 and 2.9-3.6MPa) hollow UO2 pellets recognized to conventional PWR remedy fuel. Major results obtained are:
(1) The failure thresholds of the tested hollow fuels were not less than 120cal/g fuel (0.50kJ/g fuel) in enthalpy. This showed the safety margins against past NSRR prepressurized fuel experimental data for fuel failure in RIA standard. No measurable differences in failure thresholds were observed between hollow fuels and solid fuels.
(2) The failure mechanisms of the hollow fuels were cladding rupture induced by ballooning. No significant differences were existed between the hollow fuels and the solid fuels or between the hollow fuels and past NSRR prepressurized standard fuels.
(3) The magnitude of pressure increase in the hollow fuels was approximately twice larger than that of the solid fuels.