ATRIUMTM Fuel – Continuous Upgrading for High Duty BWR Plants

The evolution of BWR fuel assemblies over the last forty years was driven by improvement of plant economics in combination with a substantial increase of fuel assembly burnup from 30 MWd/kgU up to 70 MWd/kgU. Additional thermal margins obtained by transition from 7x7 to 10x10 lattices were consumed in more efficient core loadings. Despite increasingly demanding operating conditions, the failure rate for BWR fuel could be significantly reduced and has reached a low level. Debris fretting and pellet cladding interaction (PCI) are the main causes for fuel failures and require further design improvement efforts. AREVA developed in the frame of the DELTA project the next generation BWR fuel assembly with the clear goal to realize a problem- and failure-free product. Furthermore, the new fuel must be suited to reactor power uprates from 10% up to 30%, which the majority of BWRs worldwide will have completed by the year 2015 and which will limit flexibility of operation of today’s fuel assemblies. The combination of these requirements resulted in the development of the ATRIUMTM 11 which will be available to the market by the year 2012.