The first batch of 56 mixed uranium-plutonium oxide (MOX) fuel assemblies has been shipped to Beloyarsk 4 as Russia's first-of-a-kind BN-800 fast reactor prepares to start up.
|MOX fuel assemblies for the Beloyarsk 4 BN-800 fast reactor (Image: NIIAR)
The assemblies have been produced at the Research Institute of Atomic Reactors (NIIAR) in Dmitrovgrad. In total the NIIAR has made 106 MOX assemblies for the plant, and expects to ship a second batch to Beloyarsk by the end of March.
The NIIAR's MOX fuel fabrication plant, which has recently undergone modernisation, produces vibropacked MOX fuel made by agitating a mixture of granulated uranium and plutonium oxides with uranium powder, binding oxygen and other gases added during the agitation process. Compared with pelletised MOX fuel, the vibropacked version is more easily recycled and also has less problems with chemical interactions between the fuel and cladding.
Forty of the 106 assemblies that NIIAR has produced for the reactor have been manufactured using the institute's technology, with the remainder using MOX fuel pellets from the Mayak MOX plant.
Fast reactors, fuelled by MOX, vastly increase the efficiency of the nuclear fuel cycle and feature heavily in Russia's long-term nuclear energy plans. Beloyarsk 4, expected to start up later this year, will become the most powerful fast reactor in operation.
Fast reactors can also be used to dispose of ex-military plutonium, and Beloyarsk 4 is a key part of Russia's commitment to dispose of 34 tonnes of such plutonium under a 2000 bilateral agreement with the USA. The USA had likewise planned to dispose of an equivalent amount of plutonium by converting it into MOX for use in existing nuclear power plants, but the US National Nuclear Security Administration has now decided to place its own partially built MOX fuel fabrication facility on cold standby and to reconsider its plutonium disposition pathway.
Researched and written
by World Nuclear News