Test assembly of elements of MBIR fast neutron research reactor performed in Russia 


Russian state atomic energy corporation Rosatom has performed a test assembly of elements of a multi-purpose fast neutron research reactor (MBIR) being constructed in Russia, Rosatom announced earlier this week.   

An official statement said the test assembly of the MBIR reactor with a thermal capacity of 150 MW, which is scheduled for commissioning during the second half of this decade, was undertaken by Rosatom subsidiary Atommash at Rosatom’s Research Institute of Atomic Reactors (RIAR) in Dimitrovgrad located in the Ulyanovsk region of Russia. 

“The scope of the test assembly includes 6 items of equipment with a total weight of 164 tons. The vessel with the support ring was installed using a crane into a 20 meters deep caisson on a specially designed support with a deviation of no more than 0.1 mm from the horizontal position of the main connector”, it said. 

“A basket was installed inside the vessel to separate the coolant flows (liquid sodium) entering and leaving the MBIR and to organize the cooling of the reactor vessel and in-vessel internals”, the statement added.   

Regarding the specifications, Rosatom said the assembly is 12 meters high, 4.1 meters in diameter, and the vessel’s weight is 83 tons. On completion of its construction, the MBIR will be the most powerful research reactor in operation in the world.  

The MBIR’s main purpose is to conduct mass reactor tests of innovative materials and prototypes of core elements for nuclear power systems of the fourth generation, including fast neutron reactors with fuel cycle closure, as well as thermal reactors of small and medium power. 

According to Rosatom, the MBIR’s unique technical characteristics will provide the nuclear industry with a technologically advanced research infrastructure for the next 50 years and will allow solving a wide range of research problems, paving the way for the creation of new competitive and safe nuclear power plants, including fast neutron reactors and the nuclear fuel cycle closure, “while ensuring an enormous enhancement of the opportunities for experimental research.” 

In December 2021, Rosatom announced that the International Advisory Board to determine the research program for the world’s most powerful multi-purpose fast neutron research reactor is planned to be established this year. The Board, which will include leading Russian and international experts, and its technical committees drawn from various fields would be vested with all the powers required to manage the research side of the MBIR project. 

Meanwhile, Rosatom’s fuel arm, TVEL, has 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 (i.e., reproduction into fresh fuel), thereby giving this system the means to gradually become practically autonomous and independent of external resources supplies”. 

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, Rosatom Director General Alexey Likhachev said in a statement.