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Weapons of Mass Destruction (WMD)

U.S. Nuclear Security Agency Converts Czech Reactor

04 November 2005

Russian-supplied research reactor no longer uses weapons-grade fuel

Washington -- For the first time, a Russian-supplied research reactor has been  converted successfully from weapons-grade fuel to a fuel not of weapons grade, after a secret mission that removed its weapons-usable fuel and returned it to Russia, the National Nuclear Security Administration (NNSA) says.

The reactor belongs to the Czech Technical University, NNSA said in a November 4 statement.  Its original fuel, highly enriched uranium (HEU), is one of two principal substances from which nuclear weapons are made (the other is plutonium).  The Czech reactor has now been converted to use low enriched uranium (LEU), which is not suitable for use in nuclear weapons.

The reactor was converted as part of NNSA's Global Threat Reduction Initiative program, in which research reactors are converted from using HEU to LEU fuel.  This is done by developing high-density LEU fuels, and by assisting with the reactor conversion process.  The assistance can include feasibility studies, conversion analysis and licensing support, according to NNSA.

So far, 42 research reactors have been either fully or partially converted from HEU to LEU fuel, but this is the first conversion of a Russian-made reactor to be finished.

"The Czech government is the first country to convert a Soviet-supplied reactor and should be commended for showing leadership that benefits international security," said NNSA Administrator Linton Brooks.

This specific research reactor is a low-power, university training reactor, NNSA said.  It had been operating with an HEU fuel core.  The HEU (14 kilograms, or 31 pounds) was removed in secret on September 27, and sent to Russia as part of the GTRI's Russian Research Reactor Fuel Return program. 

The HEU was airlifted under guard from an airport near Prague, Czech Republic, to a secure facility in Dimitrovgrad, Russia.  There the material will be down-blended to LEU.  This was the eighth shipment of HEU from various countries (a total of 122 kilograms), according to the NNSA.

After removal of the HEU fuel, the reactor was then converted to use LEU.  In October, replacement LEU fuel was delivered to the Czech Technical University, and the research reactor was restarted with it.

"We are proud to lead the way in nonproliferation efforts, and in particular we are pleased to be the first Russian-supplied reactor to convert to LEU," said Professor Karel Matejka, head of the Department of Nuclear Reactors at Czech Technical University.  "We look forward to working with NNSA and other U.S. programs to further cooperation on nonproliferation efforts worldwide."

The complete announcement is available on the NNSA Web site. 

(Distributed by the Bureau of International Information Programs, U.S. Department of State. Web site:

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