Very high burn-ups in light water reactors

Average fuel burn-up in light water reactors (LWRs) has steadily increased with time as technological advances have been made. The practical limit is currently in the region of 50 GWd/t. The main driving forces behind this increase have been to reduce the cost of the nuclear fuel cycle and to benefit from the increased operational flexibility that high burn-ups allow. One of the main questions at this stage is whether this historic trend will continue, or whether there are scientific and technological limits to current LWR fuel burn-ups. This publication investigates the limitations and potential benefits of very high fuel burn-up (60-100 GWd/t) in light water reactors. It covers technical aspects, such as fuel fabrication, thermal-hydraulic design limits and fuel performance, as well as economic aspects. The report provides several recommendations regarding scientific and technological areas in which further development is required to achieve these very high burn-ups. (author)