Reactor Cores and Fuel Print

Development and comprehensive scientific and technical justification of nuclear reactor cores is one of the major independent areas of OKBM activities in the design and development of power plants for nuclear-powered icebreakers, warships and submarines, as well as small nuclear plants. This activity includes fuel and core design development; validation of mechanical strength, physical and thermotechnical characteristics of reactor cores, nuclear safety and long-term reliability; performance of required analyses and experiments on test facilities.

The aforementioned activities are performed in cooperation with the leading scientific institutes of the nuclear industry, and in the first place with JSC “VNIINM”, RRC "Kurchatov Institute", SSC RF “NIIAR” and industrial enterprises such as JSC “MSZ” and JSC “MZP”.

More than twenty reactor core designs have been developed by OKBM since the day when the first KLT-40 type reactor for the civil nuclear-powered vessels was put into operation in 1970. The designs were brought to the fabrication and operation stages, which provided continuous improvement of their lifetime, technical and economic characteristics.

Nowadays, the commercial reactor cores for nuclear-powered icebreakers provide their intensive operation for 5 to 7 years without fission product release to the coolant. It ensures the high radiation-protection and environmental characteristics of reactor plants.

The reactor cores developed for submarines under construction and in operation meet the current and advanced Navy requirements for reliability, safety, efficiency, fuel cycle duration and service life, as well as stability under conditions of extreme external impacts.

Based on the scientific and technical potential gained by the OKBM reactor core design team, in cooperation with JSC MSZ, JSC “VNIINM” and RRC "Kurchatov Institute", and under the leadership of JSC “TVEL”, an advanced TVSA fuel assembly for VVER-1000 reactors was developed. It provides better geometrical stability of reactor cores with high fuel burnup and meets the requirements for advanced fuel cycles. All TVSA design characteristics were confirmed by pre-reactor and reactor tests, which makes it possible to implement the economically efficient fuel cycles of as much as 6-year duration, with the capacity factor of 0.85 to 0.92 and average burnup not less than 60 MW∙day/kg U.

The positive results of operation and the potential of further upgrading make the TVSA a preferable and competitive type of nuclear fuel both on the domestic market and on traditional foreign markets. It has been supported by the fact that TVSA won the international tender for nuclear fuel delivery to the Temelin NPP in Czech Republic, and by large-scale introduction of the TVSA into VVER-1000 power units in the Ukraine and Bulgaria.

For the first time in Russia JSC “Afrikantov OKBM” has designed and fabricated an inspection bench for fuel assemblies (FA) repair based on modular approach that allows to perform repairing and non-destructive investigation of irradiated FA directly in the cooling pond.

The inspection bench for FA repair provides:

  • Visual inspection and fuel assemblies and FA structural elements control through the television system;
  • Dismantling (assembling) of FA heads;
  • Leaky FAs detection;
  • Dismantling of a FA from the cluster;
  • Installation of a FA displacer;
  • Eddy current testing of a derived FA cladding;
  • Installation of a derived FA into the hold cover;
  • Installation of a dummy element in the cluster.

 Testing of the inspection bench for fuel assemblies repair has been successfully carried out at the Kalinin NPP and NPP “Temelin”.

The reactor core design team of OKBM is now working on another important task – development of a cassette-type reactor core meeting modern non-proliferation requirements for the first in the world floating NPP under construction in Severodvinsk.

Solution of this task will allow improvement of the technical and economic characteristics, investment attractiveness and export potential of Russian floating NPPs.