US-based Westinghouse on 28 February announced the launch of a new generation fuel assemblies designed for boiling water reactors (BWRs) with the commercial name Triton11, of technical name 11×11 BWR.

Westinghouse said the new fuel is designed to significantly reduce the cost of the fuel cycle and to increase the reliability and safety of operation. The fuel assembly is a square shaped and includes 91 full-sized fuel rods, ten rods one-third the maximum length, and eight rods two thirds long. It also has three central water channels – known as water rods – and is optimised for efficiency in 12- and 24-month cycles, as well as for uprated cores and higher burnups. The water rods are connected to the bottom tie plate and top handle, which altogether constitute the load bearing structure of the fuel bundle. This ensures a robust load chain, and allows fuel rods to be freed from external forces during handling and operation.

The first NPP to test the new fuel will units 1 and 2 at Teollisuuden Voima Oy's Olkiluoto NPP in Finland, which have 900MWe ABB-III BWRs. Westinghouse said eight new fuel assemblies have been delivered to Olkiluoto 2, and will be loaded into the reactor during the scheduled repair outage that is currently underway. Triton11 fuel is produced at the Västerås plant in Sweden, owned by Westinghouse.

Assuming successful results of testing Triton11 fuel at Olkiluoto, industrial use of the new fuel will also begin at the Swedish Oskarshamn NPP, which operates the world's most powerful boiling reactor with a capacity of 1400 MWe. A delivery of ten Triton11 fuel assemblies is scheduled for delivery to OKG's Oskarshamn NPP in the middle of this year.

Photo: Teollisuuden Voima (TVO) recently received the first eight TRITON11™ fuel assemblies at the Olkiluoto nuclear power plant (Credit: Westinghouse)