906. 反応度事故時のPWR型燃料棒の挙動,(I)

A behavior of waterside corroded PWR fuels under RIA conditions was studied. In order to simulate the corroded condition, the test fuel rods were fabricated with cladding oxidized to 40μm and hydrided to the hydrogen contents of 110ppm at maximum and prepressurized to a range of 3.06-3.58MPa. Major results obtained are:(1) The failure thresholds of the tested fuels were 120cal/g fuel (0.50kJ/g fuel) in enthalpy.This showed that the oxidized fuel rods had enough safety margins against the acceptable fuel design limit in the Licensing Guide for RIA.(2) The failure mechanisms of the tested rods were cladding rupture. No significant differences in failure mechanisms were existed between the oxidized fuels and the prepressurized fresh fuels of past NSRR experiments.