America is reconsidering how it will dispose of 34 tonnes of plutonium as the previous plan involving a MOX plant has been said to be twice as costly as a dilution and disposal option in a leaked Department of Energy (DOE) report.
The plutonium arises from a June 2000 nuclear weapons reduction agreement with Russia under which both countries would put 34 tonnes of plutonium beyond military use. Russia opted to use its plutonium as fuel for fast reactors generating power at Beloyarsk.
The USA, meanwhile, decided to build a mixed-oxide (MOX) nuclear fuel plant at Savannah River, where the plutonium would be mixed with uranium and made into fuel for light-water reactors. The design is similar to Areva’s Melox facility at Marcoule, but modified to handle metal plutonium ‘pits’ from US weapons and their conversion from metal to plutonium oxide. It is this part of the process that has been problematic. Construction started in 2007 with an estimated cost of $4.9 billion but work ran into serious trouble before being ‘zeroed’ in the DOE’s 2014 budget, putting development on ice.
The Union of Concerned Scientists yesterday published what it said was an unreleased DOE report that compared the cost of completing the MOX plant to other options. Use in fast reactors was considered briefly, but with this technology not readily available in the near term, the prime comparison was against a ‘dilution and disposal’ option which would see the plutonium mixed with inert materials and disposed of in the Waste Isolation Pilot Plant, or WIPP, in New Mexico.
Despite being 60% built, the MOX plant still needs some 15 years of construction work, said the leaked report, and then about three years of commissioning. Once in operation the plant would work through the plutonium over about 10 years with this 28-year program to cost $700-800 million per year – a total of $19.6-22.4 billion on top of what has already been spent. Not only is the price tag very high, but the timescale is too long: the report said this would not meet the disposal timeframe agreed with Russia.