The effect of Am241 on UK plutonium recycle options in thorium-plutonium fuelled LWRs - Part Ⅱ: BWRs

摘要

UK plutonium is expected to be managed using uranium-plutonium (U-Pu) mixed oxide (MOX) fuels in Light Water Reactors (LWRs). However, studies have shown that thorium-plutonium (Th-Pu) may be preferential. Part 1 of this study considered the effect of americium (Am) in UK Pu in Pressurized Water Reactors (PWRs) and found that, while the reactivity response was sensitive to isotopic and spectral variations, trends were predictable. Part 11 focusses on separation of Am in Boiling Water Reactors (BWRs) and compares fuel performance to the uniformly distributed and spatially separated cases outlined in Part I. Comparable incineration rates are achievable but, while a single PWR assembly bears a greater mass of Am/Pu than a single BWR assembly, the full BWR core may be capable of operating with significantly greater fissile masses. Transmutation of Am241 to Am242 appears preferable to fast fission of Am241 as increased incineration rates occur in lower void, bottom-of-assembly locations. (C) 2019 Elsevier Ltd. All rights reserved.