Radioactive waste was found in scrap metal sent for recycling at Sheffield Forgemasters in one of 30 cases where nuclear material went missing around the country over the last decade.
According to information released by the Health and Safety Executive, a 13kg ball of depleted uranium was discovered and had to be disposed of by a specialist contractor.
Concern has been raised by Sheffield South East MP Clive Betts that details of the incident, which happened in June 2008, were not made public until now.
But the Health and Safety Executive said the level of risk to the public was ‘very low’.
The agency ‘offered written advice’ to Forgemasters and the material was disposed of by a specialist contractor.
Labour MP Clive Betts, whose constituency includes Forgemasters, said: “I certainly want to ask some questions about what happened. I would like to know what happened and why the decision was taken not to make this incident public.”
In its report about the Forgemasters incident, the HSE said: “Different radioactive sources present different levels of risk from exposure, depending upon their physical and or chemical form.
“The large ball of uranium found in Sheffield was determined to be depleted uranium, a form of uranium from which most of the highly radioactive radionuclides have been removed, resulting in a material which is much less radioactive than ‘ordinary’ uranium metal.”
The HSE added it was ‘highly likely the ball was an old industrial radiography source container’.
“The main radiation emission from depleted uranium is such that it can be handled with minimal precautions and it does not normally present a significant risk of exposure,” the report said.
There was no need for enforcement action in the case, the HSE added.
Graham Honeyman, chief executive of Sheffield Forgemasters, said: “We do not have, or allow, any radioactive substances onto our site.
“The inadvertent inclusion of radioactive sources in scrap metal is a recognised hazard in the steel industry. Several plants globally have been affected.
“Our raw material is scrap metal brought in from the external scrap metal processing industry.”
Any radioactive material found would be held in a secure, isolated area while the HSE and Environment Agency are notified.
“The material would then be removed under official supervision using specialist contractors who are equipped, experienced and licensed to do so,” he said.
“Our procedures at Forgemasters are consistent with those employed at all major steelworks and comply with the Environment Agency and UK Steel’s code of conduct.”
Peter Birtles, group non-executive director for Forgemasters, said: “Every piece of material we receive goes through a Geiger counter check. It is not inconceivable that nuclear waste could be included.
“But we do not use nuclear material and don’t manufacture it.”