US duo teams up for metal fuel development
Babcock & Wilcox Nuclear Energy (B&W NE) is to work with nuclear technology company Lightbridge in developing a pilot plant for manufacturing metal fuel for light water reactors.
Lightbridge has developed an advanced metallic fuel, made from a zirconium-uranium (Zr-U) alloy, which uses a unique composition and fuel rod geometry enabling it to operate at a higher power density than uranium oxide fuels in use today. Current fuel comprises of uranium oxide pellets encased in zirconium alloy cladding which are bundled into fuel assemblies. The new fuel, the company says, can enable pressurised water reactors (PWRs) to operate at higher power outputs while also extending operating cycles, improving economics as well asproviding safety and fuel performance benefits.
In a joint press release, the two US companies said that they have signed a memorandum of understanding under which they will "jointly identify" a pilot fabrication facility to demonstrate the feasibility of manufacturing the fuel rods, and will perform scoping studies and explore potential teaming arrangements. If the arrangement proves feasible, the two companies could enter into a definitive agreement early in 2014.
B&W NE president Joe Zwetolitz praised the fuel. "The nuclear fuel design concept that Lightbridge is developing has the potential to provide utilities with improved safety and performance," he said.
Lightbridge president and CEO Seth Grae described the collaboration as an "important milestone" for the commercial advancement of the fuel.
According to a 2012 paper published in the American Nuclear Society's peer-reviewed journal Nuclear Technology and reproduced on Lightbridge's website, the alloy used in the fuel contains a zirconium content of nearly 50% by weight, but requires uranium enrichment levels of up to 20% - far in excess of typical uranium oxide fuels for PWRs, which are typically enriched up to 4.8% uranium-235. Reactor safety is enhanced thanks to the lower fuel temperature, increased heat transfer characteristics and improved cladding integrity offered by the fuel.
The elevated enrichment levels, while within accepted bounds from a non-proliferation point of view, would necessitate infrastructure changes to existing enrichment and fabrication plants as well as amendments to plant licensing, fuel transport and storage.
Researched and written
by World Nuclear News
