Pipe fragments may contain clues to refinery explosion

Investigators have recovered fragments of pipes that could reveal where and how an explosion at the Irving Oil refinery started.

The refinery explosion shook east Saint John on Thanksgiving weekend last year. Almost 3,000  people were working on site as a massive maintenance project was underway.

Eric Brideau, assistant director of investigations for WorkSafeNB, said inspectors are studying pipes inside the refinery - specifically inside a diesel-treating unit where the explosion started.

"It's certainly one of those pipes that failed," he told Information Morning Saint John. "So the theory, or what we're trying to get at is, which one of those [caused the explosion]?

"And from there, what's in those vessels that could contribute to the failure?"

Brideau said investigators still need months to find out what happened, partly because after the blast, the site was too dangerous to reach.

"There was overhead hazards, there was a lot of hazards because of the explosion," he said. "It created a lot of damage that need to be fixed before we could get closer."

He said they couldn't get to the site to investigate until the end of November.

Brideau said more than five employees and contractors filed claims for worker compensation benefits. In October, Horizon Health said five people were treated in hospital, and a Saint John family doctor has said they treated several other workers in the following days.

"This was a very serious explosion," he said. "We will get to the cause of this."

Chemicals, or something else?

The unit where the explosion happened uses chemicals to remove sulphur from diesel. Brideau said it's still unclear whether the explosion was caused by a chemical reaction, or "wear and tear."

"Or it could be a bunch of different things," he said. "But we need to know which one failed first, and then that's what we're pretty much close, I guess, to know."

Hands on deck

Brideau said WorskSafeNB is not the only organization investigating the explosion. Irving hired experts of its own, and the Saint John Fire Department, the Fire Marshal's Office, boiler and pressure vessel inspectors and environmental inspectors are also involved.

"There's a lot of people involved in this investigations," he said. "What we found, we can share, so we can all at the end of the day understand what happened and make sure it doesn't happen again."

Brideau said Irving Oil has been co-operating with investigators.

"The company let us on their site and we've worked towards the same goal: What happened? [How] can we prevent a future explosion?" he said.

There are no stop-work orders in effect, but Brideau said depending on what investigators find, they may ask for a stop-work order — to fix faulty pipes, for example.