Rez research reactor fuel returned to Russia

10 December 2007

Used fuel assemblies from the research reactor at Rez, near Prague, Czech Republic, have been transferred by rail to Russia for reprocessing.


The 549 irradiated fuel assemblies left Rez on 1 December and reached Russia on 8 December. The Russian-produced fuel, which was shipped in transportation packages specially made by Czech engineering company Skoda, will be sent to the Mayak reprocessing complex near Chelyabinsk. The radioactive waste produced as a result of reprocessing the used fuel will be returned to the Czech Republic for disposal.


The project was carried out under the 2004 Russian-US government agreement on cooperation in removing Russian-made nuclear fuel from research reactors to Russia. The primary goal of the Russian Research Reactor Fuel Return (RRRFR) program is to eliminate high-enriched uranium (HEU) stockpiles and persuade eligible countries to convert their research reactors from HEU to low-enriched uranium (LEU) fuel upon availability, qualification, and licensing of suitable LEU fuel. Under the RRRFR program, Russia has agreed to take back used and fresh nuclear fuel from research reactors so long as the reactor operators agree to convert the reactors to operate on LEU or shut down.


The RRRFR program intends to move 2 tonnes of HEU and 2.5 tonnes of LEU spent fuel to the Mayak plant over the ten years to 2012. The program envisages 38 shipments (of both fresh and spent fuel) from ten countries over 2005-08, then 8 or more shipments from six countries to remove all HEU fuel discharged before reactors are converted to LEU or shut down. Seventeen countries have Soviet-supplied research reactors, and there are 25 such reactors outside Russia, 15 of them still operational.

S even previous shipments have repatriated over 108 kg of Russian-origin fresh HEU fuel under the RRRFR program:

  • August 2002, 48 kg from Serbia;
  • September 2003, 14 kg from Romania;
  • December 2003, 17 kg from Bulgaria;
  • March 2004, 17 kg from Libya;
  • September 2004, 3 kg from Uzbekistan;
  • December 2004, 6 kg from the Czech Republic
  • May 2005, 3 kg from Latvia.

In September, officials from the Czech Republic and the USA signed an agreement under which the US National Nuclear Security Administration (NNSA) would provide $35 million for the Czech government to transfer the used HEU fuel from Rez to Russia for reprocessing. The NNSA is currently helping to convert the Rez reactor to LEU fuel.


The research reactor at Rez is an LVR-15 light-water moderated and cooled tank nuclear reactor with forced cooling. The fuel type IRT-2M, enriched to 36% U-235. There is an interim storage facility for used reactor fuel at Rez.


Further information

Nuclear Research Institute Rez

National Nuclear Security Administration

WNA's Research Reactors information paper

 Vietnam returns HEU fuel, Czech Republic to follow suit