CSB recommends facility siting evaluation to U.S. Steel

The CSB recently issued two interim safety recommendations in connection with its ongoing investigation into the fatal August 11 explosion at U.S. Steel’s Clairton Coke Works facility in Clairton, Pennsylvania.

Although the CSB’s investigation is in its early stages, the agency already has identified potentially unmitigated hazards for workers at Clairton Coke Works that warrant immediate attention. The CSB’s interim recommendations are intended to address those potential hazards.

“Even though our investigation into this terrible tragedy is ongoing, the CSB is issuing these initial recommendations to ensure that workers at the Clairton Coke Works facility are not put in harm’s way hereafter,” said Steve Owens, CSB chairperson.

Explosion killed two, injured 10

The explosion occurred during the flushing of a 70-year-old cast-iron valve. Coke oven gas was released from process piping in the Battery 13/14 transfer area at the facility and ignited.

Two U.S. Steel employees were killed in the explosion, four additional employees and a contractor were seriously injured, and six other workers suffered non-hospitalization injuries. The explosion also severely damaged nearby structures.

Gas supply piping rebuilt in almost the same layout

The CSB’s first recommendation calls on U.S. Steel to perform a thorough evaluation of all buildings at the Clairton Coke Works facility that are currently occupied or could be occupied to identify and assess any potential hazards to workers based on where the buildings are located.

The CSB’s investigation has determined that both of the fatally injured workers and two of the five seriously injured workers were inside or near buildings in the area where the explosion occurred.

The CSB also found that the occupied buildings in the Battery 13/14 transfer area were not capable of protecting occupants from explosion hazards. U.S. Steel already rebuilt the damaged Battery 13/14 coke oven gas supply piping in almost the same location and layout as it was prior to the explosion.

The explosion occured in the basement of the Battery 13/14 reversing rooms. Source: CSB

Although the company is relocating the control rooms for Battery 13/14 to a building approximately 100 feet away from the area, the CSB has concluded that without a facility siting evaluation, it is not clear that U.S. Steel has chosen a safe location to relocate its workers.

Additional coke batteries occupied near hazardous processes

The CSB also has found that the Clairton Coke Works facility operates four other coke batteries with personnel-occupied buildings located near potentially hazardous processes. The facility siting evaluation recommended by the CSB also would identify and assess hazards that may exist in these other buildings as well.

The CSB’s second recommendation calls on U.S. Steel to address and reduce any safety risks identified in the facility siting evaluation, following accepted industry safety principles.

“Without a comprehensive facility siting evaluation, it is not clear that workers are being relocated to buildings that are safe from future fires, explosions, or toxic releases,” said Drew Sahli, investigator in charge.

Additional findings and analyses from the CSB’s ongoing investigation, as well additional recommendations, if any, will be included in the agency’s final investigation report when it is issued.