Closed nuclear fuel cycle will allow recycling of spent fuel for an infinite resource base 

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The success of the ongoing experiments on closing the nuclear fuel cycle is of utmost importance to the nuclear industry that is faced with the serious challenge of stopping the accumulation of spent fuel and ensuring the recycling of fissionable materials. 

The second day of Atomexpo 2022 at Sochi, Russia, on November 22 featured a roundtable discussion on “Closed Nuclear Fuel Cycle – New Opportunities and Products”. Officials from leading global power generators, industrial companies and scientific organisations participated in the roundtable which discussed developments in closing the nuclear fuel cycle (NFC) from the perspective of nuclear reprocessing and treatment of radioactive waste.

In his welcome address, Rosatom’s Director (Lifecycle Management of NFC) Vladislav Korogodin said that closing the NFC offers a solution to the problems of accumulation of spent fuel and the recycling of fissionable materials. 

Nobuo Tanaka, Chair of the Steering Committee, Innovation for Cool Earth Forum (ICEF), noted in his speech that developing a sustainable model for closing the NFC has important sociopolitical implications in addition to technological significance. According to Tanaka, a key role in developing such a model lies with political leaders as exemplified by the former Japanese Prime Minister Shinzo Abe. 

Igor Gusakov-Stanyukovich, who is Director for Spent Nuclear Fuel (SNF) and Sustainable Nuclear Fuel Cycle (NFC), at Rosatom subsidiary Tenex said a sustainable NFC builds upon existing Russian infrastructure of SNF and radioactive waste (RW) handling by enhancing it with a number of innovative solutions, including high level waste fractionation, minor actinide transmutation, efficient systems for SNF and RW transport, among others.  

“In combination, these solutions help reduce the amount of waste that is sent for disposal”, Gusakov-Stanyukovich said.  

Rosatom fuel arm TVEL’s Senior Vice-President (R&D), Alexander Ugryumov, touched on the major developments in Russia, including the ongoing work on fast neutron reactors, and on closed nuclear fuel cycle technologies, which are based on fabrication of fresh uranium-plutonium fuel from reprocessed irradiated fuel.    

Ugryumov noted that Rosatom has extensive experience in operating experimental and commercial fast-neutron reactors, while existing plans call for developing a dual-component nuclear power industry, which operates both thermal and fast-neutron reactors in parallel, and creates conditions for using byproducts, such as depleted uranium and materials generated during irradiated fuel reprocessing, in the nuclear fuel cycle. 

This Rosatom strategy would help accomplish several highly important tasks. First, it would exponentially boost the feedstock for nuclear power plants. Second, it would enable recycling of spent nuclear fuel instead of storage. Moreover, as part of the nuclear fuel cycle this would allow utilising the accumulated ground stocks of depleted uranium hexafluoride and plutonium for production of fresh fuel.    

TVEL has already started construction of a 300 MW nuclear power unit equipped with the BREST-OD-300 fast neutron reactor at the Siberian Chemical Combine in Seversk.    

Both the fuel fabrication and the reactor units form part of the Pilot Demonstration Energy Complex (PDEC) being built at the Siberian Chemical Plant by TVEL. The PDEC is underway as part of the strategic “Proryv” (‘Breakthrough’ in Russian) project. It will include three linked facilities, making up a closed nuclear fuel cycle at one site — the fuel fabrication/re-fabrication unit, the 300 MW nuclear power plant with the fast neutron BREST-OD-300 reactor, and the unit for spent fuel reprocessing.   

According to TVEL, “after reprocessing, the irradiated fuel from the reactor will be sent for refabrication (that is, reproduction into fresh fuel), thereby giving this system the means to gradually become practically autonomous and independent of external resources supplies”.    

TVEL announced last year it has developed a fuel rod design based on nitride uranium-plutonium (MNUP) fuel for the BREST-OD-300 fast neutron reactor,     

The world’s most powerful fast neutron reactor called the BN-800, currently operating at unit 4 of the Beloyarsk NPP in Russia, was loaded last year with the first serial batch of MOX fuel made of depleted uranium and plutonium oxides. The BN-800 fast neutron reactor is designed to use MOX fuel as one of the stages in the development of a closed nuclear fuel cycle.   

According to TVEL “distinct from traditional nuclear fuel with enriched uranium, MOX fuel pellets are based on the mix of nuclear fuel cycle derivatives, such as oxide of plutonium bred in commercial reactors, and oxide of depleted uranium which is derived by defluorination of depleted uranium hexafluoride (UF6)”.   

Experts at the roundtable opined that technologies to close the NFC will expand the resource pool of nuclear energy almost indefinitely and will help substantially reduce volumes of spent nuclear fuel and nuclear waste in line with Sustainable Development Goals. Moreover, the Russian experience can lay the foundations for wide-ranging international cooperation and transformation of the global nuclear industry. 

The roundtable highlighted that development of a global dual-component nuclear power industry is a potential environmentally optimal solution for countries developing nuclear power generation. With a sustainable NFC, the nuclear power industry’s resource base will practically become inexhaustible thanks to the infinite reprocessing of nuclear fuel. At the same time, future generations will be spared the problem of accumulating spent nuclear fuel.