Russia charts progress with new MOX fuel development

The director general of Russia's Mining and Chemical Combine (MCC) said yesterday that the enterprise's mixed-oxide (MOX) fuel fabrication facility will increase its annual production of fuel assemblies from 20 this year to 400 in 2017.

These will be the first nuclear fuel assemblies for the BN-800 fast neutron reactor - unit 4 at the Beloyarsk nuclear power plant in the Sverdlovsk district. MCC is a subsidiary of Russian state nuclear corporation Rosatom.

Speaking at the side of the World Nuclear Association's annual Symposium being held in London this week, Pyotr Gavrilov said MCC is licensed to produce 20 fuel assemblies, but expects to receive regulatory approval to produce 200 fuel assemblies next year.

MCC said in August that it had completed tests on putting together the first fuel assemblies for the BN-800 unit. Earlier the same month, the reactor had been for the second time brought to the minimum controlled power level, moving it a step closer to starting commercial operation. It was first brought to minimum controlled power on 27 June 2014, with the start of operation planned for the end of that year. But in December, Russian nuclear power plant operator Rosenergoatom, another Rosatom subsidiary, announced that nuclear fuel for the unit would first be developed further. The unit is now expected to start operations before the end of this year.

Gavrilov said Rosenergoatom's decision to delay the project was not related to the MOX fuel that MCC is producing.

"There has been no pause in the process of producing MOX fuel and the first fuel assemblies are already being produced," Gavroliv told World Nuclear News. "We are working on developing the technical process to improve the production level, to reach the point of 400 fuel assemblies per year within three years."

The MOX production line - located in a mine 200 meters underground at MCC's Zheleznogorsk site - became fully operational at the end of last year. The facility was built as part of Russia's 'Proryv', or Breakthrough, project to enable a closed nuclear fuel cycle. The ultimate aim is to eliminate production of radioactive waste from nuclear power generation. Russia has no commercial reactors using MOX fuel, but pellets of the fuel will enter serial production for use at the BN-800 reactor. MOX is a mixture of plutonium and uranium dioxides.

Gavrilov highlighted the fact that this is the first industrial-scale development of the potential of plutonium in Russia's nuclear fuel cycle.

A centralized 'dry' interim storage facility for used nuclear fuel from Russia's RBMK-1000 reactors has been in operation at the MCC site since February 2012.

This initial stage of the facility will be used for storing 8129 tonnes of RBMK fuel from the three power plants in the country using that kind of reactor: Leningrad, Kursk and Smolensk. The used fuel from these plants is currently stored in on-site water-filled pools, but these are reaching full-capacity.

Later, used VVER-1000 fuel from reactors at the Balakovo, Kalinin, Novovoronezh and Rostov plants will also be stored at the facility. Such fuel has already been sent to Zheleznogorsk for storage in water pools. The facility - measuring some 270 metres in length, 35 metres wide and 40 metres high - will ultimately hold 38,000 tonnes of used RBMK and VVER fuel.

Full-scale commissioning of the storage complex is scheduled for this year, leading to the storage of VVER-1000 used fuel, Gavrilov said. In future, the complex could welcome foreign customers, he said.

"There was no thought given in 2012 to using the dry storage facility for anything other than Russian fuel," he said. "But there is the possibility to discuss international cooperation with the storage of VVER-1000 fuel."

Fuel will be stored in the facility for up to 50 years, during which time substantial reprocessing capacity should be brought online. In the long-term, a geological repository for high-level radioactive waste is planned. Dry nuclear fuel storage technology is said to have a number of advantages over 'wet' storage technology. Dry storage, for example, does not require storage pools and the casks in which the fuel is stored can withstand large impacts and temperature changes.

Researched and written
by World Nuclear News