Munich

A nuclear watchdog is warning that a German research reactor will continue to pose a security risk, despite a last-minute plan to cut the amount of weapons-grade uranium to be used at the site.

Under attack: the FRM-II research reactor is designed to run on weapons-grade uranium. Credit: FRM-II

The FRM-II reactor, housed at the Technical University of Munich in Bavaria, is designed to run on highly enriched uranium (HEU), weapons-grade material that contains a high percentage of the uranium-235 isotope.

Under the compromise, the reactor would be converted to run on medium-enriched uranium (MEU) by 2010. The Bavarian government, which is responsible for running the reactor, defines MEU as containing less than 50% uranium-235.

But the Washington-based Nuclear Control Institute, a non-profit body that monitors worldwide nuclear activity, says that the compromise will do little to reduce the proliferation risk from the reactor.

“MEU is an artificial term,” says Paul Leventhal, director of the NCI. “Uranium containing more than 20% of uranium-235 is weapons-grade, and therefore classified as HEU. This agreement means that weapons-grade material will have to be stored at a place without military protection against terrorist attacks.”

The NCI says that low-enriched uranium (LEU), which contains less that 20% uranium-235, is the only safe option. But the Bavarian authorities have previously rejected this idea because costly structural changes would be needed for the reactor to use LEU.

Construction of FRM-II was finished in July, but the federal government refused to let it go into operation until the plan to phase out HEU was agreed.

The reactor could enter its eight-month test phase this coming January if, as expected, the government grants the reactor an operating licence next month. The compromise has the backing of the German cabinet, as well as scientists who have booked research time at the facility.

→ http://www.nci.org