The material reached criticality, and a self-sustaining nuclear reaction continued for more than 18 hours. Twelve hours after the accident began, radiation levels at one mile away from the plant measured 15,000 times greater than normal. Certainly, these facilities need to be carefully reviewed to ensure that a similar problem isn't lurking. Nearly all U.S. criticality accidents took place at federal facilities. DOE is responsible for one of the world's largest inventories of concentrated fissile materials.
Nuclear criticalities are among the most serious accidents in the nuclear industry.
Controls to avoid a nuclear criticality accident in storage and processing facilities are of paramount importance. Unfortunately, these essential safety controls are diminishing at DOE sites, as tens of tons of fissile materials remain in unsafe or questionable storage modes. Dozens of problems were identified at sites such as the Hanford nuclear reservation in Washington, the Rocky Flats facility in Colorado, the Oak Ridge nuclear complex in Tennessee, the Los Alamos National Laboratory in New Mexico, the Idaho National Environmental and Engineering Laboratory, the Pantex weapons facility in Texas, the Savannah River Site in South Carolina, and Lawrence Livermore National Laboratory in California. The Y-12 nuclear weapons plant at the DOE's Oak Ridge, Tennessee site is a case in point. Sixty percent of the drums containing HEU at the Y-12 plant have never been opened.