The all-uranium seed-blanket fuel assembly (U-SBU) is designed to provide up to a 17% power increase in existing PWRs operating on 18 month fuel cycles, including Westinghouse-type 4-Loop plants. A smaller power uprate can accommodate longer fuel cycle lengths, for example the U-SBU is capable of increasing power output by 10% and operating on 24 month cycles, saving one fuel outage every six years.
The design of the U-SBU allows drop-in replacement of the fuel assembly with conventional UO2 assemblies. No changes to reactor internals are required to use Lightbridge’s U-SBU (some changes to plant systems may be required depending on the desired level of uprate). The U-SBU design utilizes Lightbridge’s metallic fuel in the central region of the assembly and a peripheral row of standard, pelletized UO2 fuel rods. The design is fully compatible with existing UO2 assemblies to facilitate insertion of lead test assemblies and batch reloads.