A Probabilistic Approach to Channel-Power-Limit and Bundle-Power-Limit Compliance Analysis

Abstract

The formulation of a probabilistic approach to channel-power-limit and bundle-power limit compliance analysis is described. The performance indicator is the probability that no channel (bundle) exceeds its limit. In contrast to monitoring only the maximum power channel and the probability that the maximum channel power does not exceed the limit, the proposed approach accounts simultaneously for all channels. Xenon transients in the fresh bundles in the refuelled channels are treated rigorously. The time variation of xenon build-up is accounted for according to the elapsed time since refuelling for each of the refuelled channels. Instantaneous probability is then computed. Average probabilities over the time interval between surveillance calculations can also be computed, as well as time-integrated probability below certain targets. The proposed method has been demonstrated in sample applications using Point Lepreau Generating Station operation data. Sensitivity to key input uncertainty is also illustrated.