PCI-OGRAMS: Application of CANDU FUELOGRAM methodology to PCI data from light-water reactors

The FUELOGRAM model was derived to predict PCI defect probabilities for CANDU fuel bundles that had experienced power increases after being irradiated to burnups mostly in the range 100+-60 MW.h/kg U. It is inappropriate to extrapolate the FUELOGRAM model to predict the performance of differently designed fuels at burnups up to 600 MW.h/kg U. Therefore data obtained from the operation of a Boiling Water Reactor were analyzed using the FUELOGRAM methodology to assess fuel performance criteria at high burnups. The resultant PCI-OGRAMS evaluate defect probabilities in terms of power increase (ΔP), ramped power (P), and the burnup (ω) of the most highly rated rod in a fuel assembly. Defect probability also depends on the dwell time (t) of fuel at the ramped power. The predictions of the PCI-OGRAM, FUELOGRAM and other models are compared in three dimensional sketches of P, ΔP and ω with the dwell time t held constant. (author)