A U.S. Department of Energy (DOE) investigation of a December 1999 explosion at the Y-12 plant in Oak Ridge, Tenn., concluded that the accident could have been prevented if managers and workers had done their jobs more efficiently.
Specifically, if managers and workers followed the guidelines for planning work and analyzing potential hazards consistent with DOE's Integrated Safety Management (IMS) program, the accident may have been avoided.
"This investigation shows that there were failures in DOE's Oak Ridge Operations Office and at every level of the Lockheed Martin Energy Systems management chain," said Dr. David Michaels, DOE assistant secretary for environment, safety and health. "I am especially concerned that managers and workers failed to understand the nature of the chemical hazard involved, and failed to obtain the information or expertise needed to handle the unusual or unexpected conditions they faced.
The accident took place on Dec. 8, 1999, after Y-12 workers used a new procedure to change out the crucible in the caster furnace, an operation that last occurred in 1993.
When workers removed a hose from the crucible, several gallons of chemical coolant -- a sodium-potassium liquid metal alloy -- sprayed into the furnace.
Several days later, workers noticed unusual conditions in the furnace and sprayed mineral oil on the deposits to minimize oxidation.
The chemical explosion occurred with workers then used metal probes to break up and remove the coolant spill.
The explosion's damage was exacerbated by a lack of appropriate protective equipment for personnel and resulted in 11 worker injuries, three of who required hospitalization.
According to DOE, the investigation concluded that the direct cause of the explosion was the impact of a metal tool on the shock-sensitive mixture of liquids.
Warnings against such an action are contained in safety sheets and numerous publications and lessons learned documents, all available on site, said DOE.
The report concluded that the primary cause of the accident was the site's multiple failures to effectively implement ISM practices.
"Implementation of ISM was significantly deficient, indicating a lack of understanding of the policy, a failure to adhere to established procedures, and a continuing reliance on informal, expert-based approaches to work and hazard control," the DOE report concluded.
In order to prevent similar accidents in the future, the department has come up with a series of corrective actions.
These actions include the following:
- Improving communications and safety training for supervisors and workers;
- Increasing workers involvement in safety planning and their involvement in the ISM program itself;
- Revising procedures to specifically address operations such as the one that led to the explosion;
- Clarifying start-up and shut down procedures in an emergency;
- Conducting frequent, no-notice inspections by the Y-12 independent assessment team;
- Increasing management presence on the work floor to obtain first-hand feedback from workers; and
- Training managers and supervisors in decision making.
The investigation showed that for the most part, the Y-12 site's emergency medical responses were effective.
Workers promptly assisted the most severely injured workers.
The Y-12 fire department and radiation control personnel responded promptly and effectively to transport injured workers and prevent the spread of contamination.
Nevertheless, DOE's overall findings of the accident point toward a need for change in the execution of Y-12's ISM programs.
Deputy Secretary of Energy T.J. Glauthier issued a directive to all DOE and contractor personnel, instructing them to carefully examine their ISM programs.
"Care must be taken to ensure that the pressure of schedules, over-reliance on skill-of-the-craft, or the designation of work as 'routine' do not contribute to circumventing this structured approach to controlling work," said Glauthier.