37-Element CANDU Fuel Reliability

Abstract

Fuel performance was predicted using the Canadian industry standard codes, ELESTRES and ELOCA, which respectively model fuel behaviour during normal operation and transient conditions. Probability distributions of fuel element related input variables were adapted from real manufacturing data. The inputs for fuel element operating data were simulated from a pool of core- following data generated using a 3D diffusion code, the Reactor Fuelling Simulation Program. Random sampling was used to obtain input parameter values for the codes, and the outputs were compared against failure criteria derived from industry norms to determine the probability of failure. The probability distributions of variations in fuel performance outputs were obtained via the method, which predicts zero probability of failure during normal operation of the fuel. Results suggest that there is greater safety margin available than predicted by current safety benchmarks.