Can radioactive waste at Trojan withstand a major quake?


PORTLAND, Ore. (KOIN) — Along the Columbia River, just an hour north of Portland, is the former Trojan Nuclear Power Plant. It went online in 1976 and went offline in 1992.

The reactor, control room and cooling tower were demolished in 2006, but something dangerous, and possibly lethal, remain.

A total of 34 concrete cylinders, or casks, which hold more than 379 tons of highly radioactive nuclear waste, remain at the site, guarded 24 hours a day, 7 days a week.

The Trojan Nuclear Power Plant in 1978 (Oregon Encyclopedia/Oregon Historial Society)

Inside the cement silos are stainless steel containers which hold 790 spent uranium fuel rods that once powered Oregon’s only nuclear plant.

“When you get right down to it, a facility like this is designed to be boring,” says Steve Corson with Portland General Electric. “The goal is to make sure that nothing happens here.”

But what the security guards can’t prevent, an earthquake, is the biggest threat to Trojan. The silos sit on an earthquake fault, and scientists have been warning the public about a large Cascadia subduction zone quake for years.

A diagram of the Cascadia Subduction Zone provided by the Oregon Historical Society.

The big question is, will the casks survive a major quake intact?

“We would not expect to see any damage to these storage containers as a result of something like that,” says Corson.

But, officials weren’t expecting that to happen in Virginia in 2011 either.

On August 23, 2011, a 5.8 magnitude earthquake rattled Virginia’s North Anna Nuclear Reactor, causing an emergency shutdown. That was expected. What wasn’t expected was the giant casks holding spent nuclear fuel shifting several inches. Concrete even flaked off some of the cylinders.

“I said, ‘I can’t believe that’ because that…magnitude was not really super significant compared to the big earthquakes that affect us out here and do major amounts of damage,” says Scott Burns, a professor of geology at Portland State University.

Fuel rods stored outside the now-demolished Trojan Nuclear Plant in Oregon, April 2016 (KOIN)

He says a major Cascadia subduction zone quake would be 27,000 times more powerful than that Virginia quake.

Burns is concerned about the shaking, but PGE isn’t because the Trojan casks are 30 tons heavier than the casks in Virginia.

“Just moving an inch or two, although that’s pretty unlikely, these are very heavy containers,” says Corson. “Even movement shouldn’t be a problem, even if you knocked one over, that should not be a problem.”

Following the Virginia quake, some nuclear experts suggested casks holding spent fuel rods in earthquake prone areas should be bolted down to prevent movement. The casks at Trojan simply rest on a concrete pad. Corson says a cask would have to move more than 7 feet before it would be in danger of falling off the pad.

Corson also says the casks themselves are designed to withstand a major quake. But, if something did happen and the spent rods became exposed, Corson says it would be a localized problem.

Watch KOIN video archives: Trojan Nuclear Facility

“Standing right here [at Trojan] we would have a problem…so if you were down in Rainier, for instance, you wouldn’t have a problem there.”

While they can only speculate about earthquake damage, PGE is confident the radioactive waste stored at Trojan will survive a natural disaster.

Trojan was never supposed to be the permanent home for its own nuclear waste. It was only designed to be a temporary holding site, until a national Nuclear Repository Site is established. Nevada’s Yucca Mountain Site is set up to receive the waste, but concerns over the danger has kept it from opening. For now, the spent radioactive rods will remain at Trojan, until a permanent site is chosen.

Fuel rods stored outside the now-demolished Trojan Nuclear Plant in Oregon, April 2016 (KOIN)

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