Wash. refinery, site of blast, fire that killed 7, will stay closed at least through September

SEATTLE (AP) — Tesoro Corp.'s Anacortes refinery, where an April explosion and fire killed seven people, will remain closed at least through September — three months longer than once expected — a company spokesman said Thursday.

Meanwhile, Robert Hall, who is leading the accident investigation for the U.S. Chemical Safety and Hazard Investigation Board, confirmed that the blast occurred when a heat exchanger ruptured on the unit that processes naphtha, a highly flammable chemical used to make finished petroleum products. Hydrocarbons released by the rupture then found an ignition source, he said.

Tesoro has said the April 2 explosion and fireball at the refinery about 70 miles north of Seattle happened when the unit, called a hydrotreater, was being returned to service after routine maintenance. Experts say the startup process is especially dangerous because the liquid is being heated to high temperatures at great pressure.

Federal investigators say all seven victims were within 50 feet of the unit and had no chance of escaping.

A heat exchanger raises the temperature of material coming into a processing unit while cooling the product going out. Hall said it's not yet known why the device ruptured, and metallurgical tests will begin Friday at a laboratory in Cleveland.

Sandy Gilmour, a spokesman for the investigative board, said it hopes to have preliminary findings on why the exchanger failed before October. Hector Castro, spokesman for Washington's Department of Labor & Industries, said the state's investigation into the cause and possible safety violations also should be completed by then.

Investigators had to wait until mid-May to begin examining and removing the exchanger because asbestos that had been scattered by the blast had to be cleaned up.

Tesoro had earlier said the refinery would be closed through June, and that employees would keep their jobs and benefits during the shutdown. But Lynn Westfall, a senior vice president with the San Antonio-based petroleum company, said it still has to finish cleaning the burned area, make repairs and install new equipment, which will take months.

Other parts of the refinery can still function, he said, but the plant can't make finished and marketable products without the naphtha unit.

Kim Nibarger, a health and safety specialist with the United Steelworkers union, told a Senate hearing in Washington, D.C., on Thursday that "the high number of fatalities at Tesoro was the result of too many people being where they didn't need to be."

Nibarger, a former worker at what is now a Shell Oil Co. refinery at Anacortes, said he was visiting his parents at the time and felt the Tesoro explosion.

Westfall said Tesoro would not speculate on a cause of the accident until a full investigation has been completed.

"We know there were a lot of people there, but can't speculate on why they were there and whether it was justified," he said.

The Senate hearing was called by Sen. Patty Murray, D-Wash., to look into petroleum industry accidents, including the Gulf of Mexico oil spill. She said she found it "outrageous" that representatives of BP PLC were invited to testify but declined.

Jordan Barab, deputy assistant secretary of labor for Occupational Safety and Health, told the panel that OSHA stepped up its inspections of refineries and petrochemical plants in 2007 following the explosion two years earlier that killed 15 and injured more than 170 at BP's Texas City, Texas, refinery. The agency had found BP committed more than 300 willful violations at the Texas plant.

OSHA inspectors are frustrated with the industry, because there's "a clear indication that essential safety lessons are not being learned," Barab said.

"Not only are we finding a significant lack of compliance during our inspections, but time and again our inspectors are finding the same violations," he said.

Charles Drevna, president of the National Petrochemical & Refiners Association said, "Absolutely nothing is more important to us than workplace safety," but added, "If there is a bad actor out there, the government should act against them."