The world’s first fuel assemblies containing uranium-plutonium mixed oxide (MOX) fuel along with minor actinides have been loaded into Russia’s BN-800 fast reactor. Minor actinides are the most radiotoxic and long-lived components contained in used fuel. Three experimental MOX assemblies containing americium-241 and neptunium-237 manufactured at Rosatom’s Mining & Chemical Combine (MCC) was loaded into the reactor core after coordination with the regulator. The Federal Service for Ecological, Technological and Nuclear Supervision (Rostekhnadzor) confirmed the safety of the operation of innovative assemblies.
In the BN-800 reactor at unit 4 of the Beloyarsk NPP, the assemblies will undergo experimental industrial operation during three micro-campaigns (tentatively – one and a half years).
“The micro-campaign in the BN-800 reactor should experimentally confirm the possibility of industrial disposal of minor actinides. The possibility of eliminating minor actinides using fast neutron reactors will reduce the volume of radioactive waste from the entire infrastructure of the nuclear fuel cycle resulting from the operation of nuclear power plants,” said the Beloyarsk Director NPP Ivan Sidorov.
According to scientists, burning minor actinides will make it possible to achieve radiation equivalence between the source uranium and stored nuclear waste in just 300 years – 2,300 times faster compared with the 700,000 years required using an open nuclear fuel cycle.
The technology of combining MOX fuel with minor actinides was developed by scientists from Rosatom Fuel Division TVEL. To produce MOX fuel assemblies with minor actinides using standard technology using the industrial equipment MCC, 38 methods for the analytical control of the MOX fuel were verified and validated.
“MOX fuel with minor actinides produced by Rosatom for an industrial fast neutron reactor has no analogues in the world and demonstrates a fundamental technological ability to implement the most important component of generation IV nuclear energy systems. The service for afterburning minor actinides in nuclear fuel from fast reactors is a completely new product for the global nuclear industry,” said Alexander Ugryumov, Senior Vice President for Scientific & Technical Activities at TVEL.
“Uranium-plutonium fuel itself makes it possible to expand the raw material base of nuclear energy, reprocessing used fuel instead of storing it, and reducing the volume of nuclear waste generation. And the utilisation of minor actinides provides an opportunity to also significantly reduce the level of radioactivity of the waste, which will make it possible in the future to abandon complex and expensive deep burial.”
Fast neutron reactors can use not only enriched uranium as fuel, but also secondary products of the nuclear fuel cycle – depleted uranium and plutonium extracted from used nuclear fuel. Afterburning of minor actinides in a fast reactor is the next step in closing the nuclear fuel cycle. At the Beloyarsk NPP, elements of the technology of the future are now being tested and a larger fast reactor is being designed.
“Based on the operating experience of the unique power units of the Beloyarsk NPP – the BN-600 (unit 3) and BN-800 (unit 4) a generation 4 fast reactor for serial production is being developed,” noted Alexander Shutikov, General Director of nuclear utility Rosenergoatom. “The main power unit from this series – the BN-1200M reactor – will be built at the Beloyarsk NPP (unit 5). New technological solutions will make it possible to fully utilise the energy potential of uranium raw materials, and also ensure a new level of safety.”
