Excessive pressure in several large area tanks caused the July 5, 1999, explosion at the Kaiser Aluminum and Chemical Corp. plant in Gramercy, La., that injured 29 people, investigators from the Mine Safety and Health Administration (MSHA) concluded in a report issued Monday.
According to investigators, Kaiser's failure to identify and correct hazardous conditions and unsafe practices contributed to the early morning explosion.
"Kaiser's apparent failure to follow well-known safety rules and practices resulted in serious injury to workers at the Gramercy Plant," said Assistant Secretary of Labor for MSHA Davitt McAteer. "We are hopeful that these actions will be immediately addressed by Kaiser management so that we may avoid such tragic accidents in the future. And, most importantly, we hope others in the mining community will take not of the lessons learned here."
Mine safety investigators found that an electrical power failure that occurred about 30 minutes prior to the explosion caused the Kaiser plant's electrically-powered process machinery to stop.
Electrically powered pumps, therefore, could no longer move the extremely hot liquid called "slurry" through the tanks in the process.
The flow stopped and pressure built up in the tanks. Investigators also found that the plant's gas-fired boilers continued to deliver high pressure steam to vessels in the digestion area, increasing pressure.
The tanks then exploded with great force, resulting in the near total destruction of four tanks and the release of hot caustic material across the plant and into the surrounding community.
Investigators found that the plant's system of relieving pressure in the tanks failed to prevent the build-up of pressure because relief valves had been impermissibly blocked.
Among the many findings MSHA concluded that:
- Kaiser failed to follow the industry standard requiring functional pressure relief safety systems to be maintained for the digestion area pressure valve.
- Kaiser management failed to conduct required workplace examinations to identify conditions and practices that posed hazards to employees, and did not promptly correct the hazardous conditions and unsafe practices that were evident.
- Kaiser did not provide adequate safety and health training for employees nor did it provide proper training on safe operating procedures of their assigned tasks.
- Kaiser failed to provide adequate protective clothing for employees who were exposed to hazardous chemicals.
In early January, MSHA issued Kaiser 21 citations for violation of federal mine safety regulations as a result of the accident investigation.
The citations, which entail civil penalties that can range as high as $55,000 per violation, will be assessed for penalties at a later date.
The United Steelworkers of America (USWA) were supportive of the citations issued against Kaiser Aluminum and MSHA's report.
"MSHA's final report only confirms what we've been saying for more than a year -- that there is no substitute for a skilled and experienced workforce if you want to run an operation both safely and productively," said David Foster, director of USWA district 11 and chair of the union's Kaiser negotiating committee.
USWA members at Kaiser went on strike Sept. 30, 1998. Workers offered to return to work while continuing to negotiate, but the company refused. The workers have been locked out since Jan. 14, 1999.
"We hope that Kaiser will take this finding as a wakeup call to end its lockout of our members, bargain with us for a fair agreement, and work with us to reopen Gramercy and make it once again a safe and productive place to work," said Foster.