Oak Ridge prepares for legacy waste processing

23 January 2020

A facility at the US Department of Energy's (DOE) Oak Ridge National Laboratory site in Tennessee is being prepared to process an inventory of legacy high-dose uranium-233 from which materials will be extracted for medical research.

Old equipment inside hot cells must be removed (Image: EM)

Protective shielding and remote mechanical arms are needed to handle the uranium-233 canisters. DOE Office of Environmental Management (EM) contractor Isotek Systems - a subsidiary of Atkins - is carrying out upgrades to existing hot cells at Oak Ridge Building 2026, where the canisters will be processed. The hot cells have radiological contamination from previous DOE research missions, and crews wear protective suits and construct containment tents to prevent the spread of radiological contamination once a hot cell is opened.

Old equipment is being removed to make way for new installations, including a cell portal to make material entry easier, cutting tools to open the uranium-233 storage canisters, pumping systems for chemicals, filtration systems to extract the thorium, and remote manipulators. Rooms will be remodelled to store large tanks of downblended material, and a two-story mixing silo will be constructed outside the facility to provide cement to mix with the downblended material, EM said.

Workers enter a Building 2026 hot cell through a 36,000-pound (16 tonne) concrete door (Image: EM)

According to EM, the uranium-233 was created as an alternative fuel source for nuclear reactors but was found not to be viable. The Cold War-era material is stored in Oak Ridge's Building 3019, which EM describes as the world's oldest operating nuclear facility. Isotek Systems, TerraPower and DOE in November signed a public-private partnership agreement to use thorium material recovered from the uranium-233 inventory to increase the supply of the medical radioisotope actinium-225. Such processing will also convert the remaining material into a disposal-ready form. EM has previously described disposition of the inventory as its highest priority project at the Oak Ridge site.

Isotek is currently processing low-dose uranium-233 in gloveboxes, and expects to begin hot cell processing later this year.  

Researched and written by World Nuclear News