U.S. Steel strengthening safety protocols following deadly explosion at Clairton coke plant
U.S. Steel says they are strengthening several safety protocols following August's deadly explosion at the Clairton coke plant.
The changes include prohibiting the use of high-pressure water for cleaning valves as they review best practices.
The explosion took place after high-pressure water was used to clean a cast-iron valve, with the water exceeding the pressure rating of the valve, according to initial findings released in a report U.S. Steel shared last week from EDT, which is conducting an ongoing independent investigation into the cause of the explosion.
Previously, low-pressure steam had been used to clean the valves, the report said.
KDKA-TV was the first to report in August that contactors had "significantly overpressurized" the valve with water, according to a union vice president.
EDT's public report revealed U.S. Steel did not have a "specific procedure addressing the use of high-pressure water to flush valves."
According to the report, U.S. Steel does have an established management of change procedure, the EDT report says that should have been used to evaluate the change from low-pressure steam to high-pressure water.
In U.S. Steel's recent statement, they said they are conducting a "thorough review and restructuring of our Management of Change program, which assesses proposed changes in procedures and evaluates risk."
U.S Steel says they are reviewing corporate guidance documents following the explosion, adjusting language to provide more detailed guidelines when needed. They also said they will train employees on any program or procedure changes that are implemented.
EDT is a forensic engineering and safety firm, per U.S. Steel. Their initial findings are consistent with those made by U.S. Steel, they said.
Separate investigations from the U.S. Chemical Safety Board, as well as the Occupational Safety and Health Administration, are also ongoing.
Preliminary findings released by the U.S. Chemical Safety Board found in September that a gas isolation cast-iron valve was the source of the tragedy, which killed two.
"Throughout this process, our top priority continues to be the safety and well-being of our employees, their families, and our communities," U.S Steel's statement said. "Safety first will always be our core value."
The valve that ruptured was manufactured in 1953 and was refurbished about 10 years ago, EDT's initial public findings found.
"At the time that the valve ruptured, U. S. Steel employees and employees of MPW Industrial Services were opening and closing the valve to ensure proper operation in advance of planned maintenance activities," EDT's findings said.
The high-pressure water was used to flush "accumulated deposits" in the valve as part of the opening and closing work, the findings said.
When the valve ruptured, it released flammable coke oven gas, which then exploded when it reached an ignition source at battery 13. The gas had been accumulating in the transfer area's basement.