A Method to Estimate the Channel Power Peaking Factors in Low-Enriched Uranium CANDU Reactors

Abstract

The use of low-enriched (rather than natural) uranium fuels in CANDU type reactors can effect economic and uranium resource savings. However, the channel power peaking problem, generic to on-power refuelling, is more severe with enriched fuels. Two situations can arise:

• (a) Natural core refuelled with enriched fuel (natural-to-enriched reactor conversion).
• (b) Enriched core refuelled with enriched fuel (equilibrium operation).

This paper illustrates an effort to provide approximate quantitative relationships between channel power peaking and other core parameters (eg, enrichment, discharge burnup). It includes:

• (a) A simple method to generate refuelling peaking factors,using the core design code CHEBY.
• (b) Correlations of the results and the comparison with SORO (Simulation Of Reactor Operation Program) and FMDP (Fuel Management Design Program) data.