Thorium return to Dounreay

Friday, 10 August 2007 A quantity of thorium, bought in error by a Peruvian company, has been returned to Scotland's Dounreay site where it will be conditioned for long-term storage.

The material originated from unused stocks at Germany's Thorium High Temperature Reactor facility, which was permanently shut down in 1988. The unused nuclear fuel, consisting of 360,000 spheres of thorium and uranium clad in graphite, was transferred to Dounreay to be processed as part of UKAEA's commercial nuclear materials business.

Chemical separation produced uranium, which was traded on the European market by Nukem Inc, and thorium, containing certain known aluminium, copper and uranium impurities.

Nukem Inc found a buyer in Peru for some of the thorium, which could be  used in the manufacture of gas mantles. In 1998, 2.8 tonnes of thorium nitrate was shipped in drums to the Peruvian company under an export licence granted by the UK government.

However, the company subsequently found the presence of the aluminium, copper and uranium made the material unsuitable and, after discussions, it was decided to return the material to Dounreay. According to the UKAEA, neither the gas mantle company nor Peru itself had facilities suitable to dispose of or recondition the thorium.

The  return was managed by the UKAEA, while the Nuclear Decommissioning Authority funded the operation at an estimated cost of GBP1.7 million ($3.4 million).

UKAEA also still holds 900 kg of thorium from the processing operation which is set to be mixed with cement and stored as intermediate-level radioactive waste. The returned thorium will be treated in the same way, the UKAEA said, because there is no market demand for the substance.

Further information

Nukem Inc
UKAEA

Nuclear Decommissioning Authority