The effects of minor actinide transmutation on PWR temperature coefficients

Abstract

We study effects on temperature coefficient with three different minor actinide (MA) loading patterns on PWR burnable poison rods. MA transmutation on PWR burnable poison rods ameliorates FTC and MTC. Three different MA loading patterns on PWR burnable poison rods cause no distinct difference to FTC and MTC in normal operation temperature range. This indicates that mixing MA with burnable poison homogeneously may be an ideal MA loading pattern, because it is technical easy to implement.The more MA added to PWR the more keff drops at high temperature. Comprehensive consideration of all the effects on keff variations with fuel and moderator temperature, loading total 256 kg MA in MA mixing with burnable poison is the optimal MA loading amount, which is equivalent to 0.03 cm MA coating thickness in other two loading patterns. With 256 kg MA loading amount, reactor can operate well above criticality at high operation temperature.