According to the information released by CORE (Cumbrians Opposed to a Radioactive Environment), U.K. Nuclear Decommissioning Authority (NDA) and U.S. Department of Energy are planning to transfer spent HEU fuel assemblies that are currently stored at Dounreay, Scotland to the Savannah River Site in Aiken, South Carolina. According to CORE, these plans contradict the previously stated intent to transfer all "exotic fuels" from Dounreay to Sellafield for long term management.
The shipment is handled by a U.S. company, NAC International, which requested the authorization from the U.S. Nuclear Regulatory Commission in November 2011. The authorization was granted by NRC in January 2012. The shipment was scheduled to take place before the end of 2013, but in June 2013 NAC International requested an extension until the end of 2014.
According to NRC documents, the shipment will include five spent fuel assemblies described as three EK-10 type assemblies with nominal uranium enrichment of 10% U-235 (1400g of uranium per assembly), one ITR [should be IRT-2M] assembly (90% U-235, <170g of U-235, 220g of uranium), and one TTR assembly (90% U-235, <400g of U-235, 500g of uranium).
The fuel assemblies are apparently the spent fuel of the IRT-M reactor that operated in the Institute of Physics in Tbilisi, Georgia. All fresh and spent nuclear fuel from that reactor was removed on 24 April 1998 during the operation Auburn Endeavor, a cooperative effort involving the United States, the United Kingdom, and Georgia. During the operation 4.3 kg of fresh HEU and 0.8 kg of spent fuel were transferred to Dounreay.
The April 1998 shipment from Georgia included the following materials:
- 83 IVV-2 fuel pins in the form of U-Al alloy with Al cladding 4.5 mm diameter x 550 mm, active length is 500 mm.
- 594 TTR fuel rods in the form of U-Al alloy with Al cladding 5.5 mm diameter x 550-560 mm, active length is 500 mm.
- 29 (central core) IRT-2M fuel elements in the form of U-Al alloy with Al cladding 28 mm x 28 mm x 700 mm, active length is 580-600 mm.
- 72 EK-10 fuel rods in the form of UO2 dispersed in magnesium or magnesium oxide with 1 mm thick aluminium cladding 10 mm x 550-555 mm, active length is 500 mm.
- 1 bottle of powdered fuel pellets from one EK-10 rod in the form of UO2 dispersed in magnesium or magnesium oxide with Al cladding (if present).
- 1 TTR fuel assembly after 1.5 per cent burn-up in the form of U-Al alloy 81.7 mm diameter x 800 mm.
- 3 IRT-1000 fuel assemblies, each having 16 EK-10 rods after 10 per cent burn-up in the form of UO2 dispersed in magnesium or magnesium oxide 68 mm x 76.5 mm x 765 mm.
- 1 IRT-2M spent fuel assembly after 3 per cent burn-up in the form of U-Al alloy 67 mm x 67 mm x 880 mm.
The United Kingdom initially planned to use fresh HEU for medical isotope production and to reprocess the spent fuel. However, the unirradiated material had been transported to the United States. Apparently, the spent fuel will be transferred to the United States as well.