Tesoro: Hydrogen Attack Caused Anacortes Blast
August 30, 2010

Tesoro Anacortes Refinery announced Friday what investigators determined was the likely cause of an April 2 blast that killed seven workers.

The refinery has been shut down since April but plans to restart operations in early October, with the affected units being replaced by next week.

Testing of the damaged heat exchanger at an Ohio lab revealed that a chain of events called a high temperature hydrogen attack caused the fire, Tesoro investigators found.

They believe hydrogen molecules worked their way over time into small imperfections in the steel casing of the heat exchanger. The hydrogen then reacted with carbon in the steel, forming bubbles of methane. Those bubbles led to cracks in the steel, causing it eventually to give way.

Tesoro investigators believe such a reaction caused the heat exchanger's casing to rip apart, releasing hydrocarbons and hydrogen that mixed into a deadly fireball, company spokesman Lynn Westfall said.

Source: Skagit Valley Herald

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