The RIAR JSC, ROSATOM, JSC Science and Innovations, successfully refurbished the VK-50 reactor. For the first time in the last 20 years it delivered 50 MW of high power.

VK-50 supplies energy and heat to the Ulyanovsk region utilities as well as to the RIAR’s site. Besides, it is used for a wide range of experimental work. This is the first and the only one operating Boiling Water Reactor with natural coolant circulation.

Over eight months, the steam turbine and cooling tower were overhauled, the power equipment was partially refurbished, and the reactor buildings were reconstructed. Andrey Vorobey, Chief Engineer of RIAR JSC commented: “The repairs improved the reliability of the VK-50 equipment and, as a result, RIAR’s energy security is ensured until the turbine generator of the under-construction MBIR facility is commissioned. I believe that the VK-50 team, with an active support of the repair service, did an excellent job and demonstrated high competence, goal orientation, and real devotion to their “cherished machine”. I am sincerely grateful to all the participants”.

During the refurbishment, the reactor personnel together with their colleagues from other RIAR’s Departments upgraded the reactor safety-critical equipment. The upgrades included: repairs of the control and protection system and heat exchangers, total repair of water pumps, reactor core refueling, pressure leak test of the fuel assembly ducts, etc.

Third-party organizations, including the Kaluga Power Engineering Plant, building and engineering companies were involved. The sub-contractors performed a major overhaul of the steam turbine unit, restored the performance of the cooling tower, completely replaced the irrigation system and water distribution devices. They also reinforced two buildings and renovated the central and turbine rooms.

When finishing the repair work, expert organizations examined the reactor buildings and reviewed the documents substantiating their residual life-time and confirmed the operator’s decision to extend it till 2041,” said Yaroslav Rogovoy, Head of the VK-50 reactor.

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The VK-50 reactor was designed under the initiative of Academician Igor Kurchatov to study in the reactor building area. Since 1965, a large scope of experimental and R&D work has been performed to justify safety of operating and in-design NPPs in Russia and abroad. These outcomes were used for a number of PhD papers. In addition to a wide range of R&D activities to study the operation of a Boiling Water Reactor with natural coolant circulation, the VK-50 reactor also generates and delivers electricity and heat to RIAR site and Ulyanovsk region utilities.


RIAR JSC (Research Institute of Nuclear Reactors, State Scientific Centre, ROSATOM scientific division) is the largest research center in Russia and in the world. RIAR provides R&D-intensive hi-tech services for a wide range of reactor and post-irradiation experiments. RIAR has the unique experimental base to face the challenges of reactor materials science and closed nuclear fuel cycle. RIAR is a leading producer and supplier of a wide range of radioisotopes for medical, industrial and other purposes.