Tesoro restarts Anacortes refinery, appeals citations

By OGJ editors
HOUSTON, Nov. 5 -- Tesoro Corp. is restarting its 120,000-b/d refinery at Anacortes, Wash., which it shut down in April after an explosion that killed seven workers, and appealing state citations of safety violations (OGJ, Apr. 19, 2010, Newsletter).

The explosion occurred in a naphtha hydrotreater undergoing maintenance.

“Most of the refinery is operating, and we expect to be back to normal operations soon,” said Greg Goff, president and chief executive officer. “In addition to completing repairs to the damaged units, extensive future inspections and maintenance work was accelerated to take advantage of the down time."

Tesoro has filed a notice of appeal against citations and penalties imposed last month by the state Department of Labor of Industries, which cited the company for 39 “willful violations” and five “serious violations” of workplace safety and health rules.”

The department fined Tesoro $2.39 million, which Michael Silverstein, assistant director of the Division of Occupational Safety and Health, said in a news conference was the highest penalty the agency ever had issued for workplace safety and health violations.

He said a department investigation determined that a nearly 40-year-old heat exchanger in the hydrotreater burst after temperature and pressure surged while a nearby bank of heat exchangers was being restarted.

Silverstein said laboratory tests conducted after the explosion showed cracks along several welds in the heat exchanger. He said tests that would have revealed the cracks hadn’t been conducted since 1998. And tests conducted then didn’t examine the most vulnerable part of the unit, he said.

Silverstein also said investigators determined that the six heat exchangers in the hydrotreater had a history of leaking flammable fluids during start-up and that, because Tesoro’s efforts to stop the leaks had failed, workers routinely dispersed leaks with steam lances.

The investigation found that workers had been accelerating increases in temperature and pressure during start-up of the unit, in violation of Tesoro policy, in an effort to reduce leaks, Silverstein said. The practice increased stress on the heat exchangers and forced some workers to enter the danger zone to turn valves, he said.