Irradiation risk
aren't required to undergo background checks, increasing the
potential for theft or sabotage, a US lawmaker has said.
Workers in the food industry with access to irradiation equipment aren't required to undergo background checks, increasing the potential for theft or sabotage, a US lawmaker has said.
Workers who transport materials for irradiation aren't checked either, and shipments aren't required to be screened for hidden explosives, said Representative Edward Markey, the co-chairman of a bipartisan congressional task force on nuclear nonproliferation.
"Such a detonation could blow a hole in the walls (or) roof of the facility and disperse radioactive materials over a large area," said Markey, who released a Nuclear Regulatory Commission response to questions he raised last month about the security of irradiators used by food plants and other facilities.
A dirty bomb uses conventional explosives to disperse radioactive materials. Most nuclear experts say such an attack would cause radiation contamination over several city blocks, but probably no deaths from radiation because of the low doses as the material is dispersed.
Concern about the security of radioactive materials used in medicine and industry increased, particularly in the US, following the attacks of September 11.
Markey asked the NRC for detailed information on the tracking and security of cobalt 60, used to irradiate food, and cesium 137, used to sterilise medical equipment.
Currently the equipment is used in forty-eight US states.
In a four-page response, dated July 24, the NRC said that no background checks were required because, "Prior to the September 11 terrorist attacks, the risk of intentional misuse of the radioactive material was considered to be very low." Since the attacks, the NRC has advised irradiator operators to increase security measures, including additional controls on persons and materials entering the irradiator facilities. It is evaluating further measures.
Under current US regulations Irradiators - both cabinet-sized units and larger ones - are to be kept locked or under constant surveillance, according to NRC rules. Smaller irradiators are usually inspected every 3-5 years, larger ones every 1-2 years.
The NRC said that removing a radioactive source with its heavy shielding from a larger unit would require equipment. Anyone who tried to remove a source without shielding would be quickly killed by radiation, it said.
