Idaho Falls, ID. – U.S. Department of Energy officials say a fire alarm was triggered at the Radioactive Waste Management Complex, on the grounds of the Idaho National Laboratory on Wednesday night.

The alarm was triggered as a result of the rupture of a 55 gallon radioactive sludge barrel. The barrel was said to have contained a mixture of fluids and solvents left over from nuclear weapon production. INL firefighters were able to extinguish the barrel, then move it away from other nearby barrels.

For decades, the Radioactive Waste Management Complex, served as a burial location for radioactive waste from all around the nation. Workers have been digging-up and prepping the waste at the site for transport to another storage facility in New Mexico.

According to a fire department spokesperson, the responding firefighters were not injured, but had small amounts of radioactive material washed from their skin. They were sent to a medical facility as a precaution, but showed no signs of inhaling radioactive material.

Early assessments suggest the cause of the rupture could have been due to radioactive decay, causing the barrel heat up.

Federal officials say that this is the first rupture of a radioactive barrel on-site, that they are aware of, but cautioned that more ruptures could be possible. An INL spokesman says that Cold War tensions kept record keeping secretive, so the exact content of barrels is difficult to determine.

An investigation will be opened to see if other barrels are at risk of rupturing.

According to officials, there is no threat to the public, and no radiation has been detected outside of the facility.

Officials did say that the incident could slow the process of shipping waste out of state.