Workers at Idaho National Laboratory (INL) have completed the transfer of all the used fuel from the Experimental Breeder Reactor-II (EBR-II) from wet to dry storage, a major milestone under a 1995 agreement with the state of Idaho. The fuel was the last to be retrieved from the water-filled storage basin at the Idaho Nuclear Technology and Engineering Center (INTEC).

INL workers mark the removal of the final fuel from the wet storage facility (Image: DOE EM)

EBR-II operated from 1964 to 1994 at Argonne National Laboratory-West (later incorporated into the INL site). Originally built to demonstrate a complete sodium-cooled breeder reactor power plant with onsite reprocessing of metallic fuel, the reactor was later modified to test other reactor designs and to test materials and fuels for fast reactors, as well as generating power and heat for the site. Several of today's designs for small modular reactors leverage the EBR-II, including GE-Hitachi's PRISM and ARC's ARC-100.

In 1995, the US Department of Energy (DOE), the state of Idaho and the US Navy signed the Idaho Settlement Agreement to support the cleanup and disposition of used nuclear fuel and high-level and transuranic radioactive legacy waste at INL and prevent shipments of spent nuclear fuel to Idaho for permanent storage. Transferring the fuel from wet to dry storage is part of that agreement.

A dry storage cask containing EBR-II sodium-bonded driver fuel (Image: INL)

By the end of 1996, the used fuel from EBR-II had been transferred to wet storage. Work to transfer the used fuel to dry storage began in 2011. DOE said it has now successfully transferred more than 100 shipments of EBR-II sodium-bonded driver fuel from wet to dry storage as part of the agreement, reaching this milestone nearly nine months ahead of schedule.

Some of the EBR-II fuel is being treated to recover uranium products which could potentially be used as a source for high-assay low-enriched uranium - HALEU - to support fuel qualification testing and DOE-supported advanced reactor demonstration projects.

Connie Flohr, manager of the DOE Office of Environmental Management (EM) Idaho Cleanup Project, said the wet- to dry-storage transfer is one of the most meaningful cleanup accomplishments to date at the INL site. "The removal of the last elements in underwater storage was a well-coordinated effort by our high-performing workforce and brings an end to a massive effort to safely transfer thousands of spent nuclear fuel elements from wet to dry storage over the past decade," she said.

The wet storage basin at INTEC is described by the EM as the largest used nuclear fuel storage basin in the world.  Emptying the basin is an effort that that has taken more than two decades to achieve, EM said, and has  seen it work with DOE's Office of Nuclear Energy and the Office of Naval Reactors Idaho Branch Office, with the support of five contracting companies over that time.

Researched and written by World Nuclear News