New evidence of the location of the Bow Ridge earthquake fault line prompted designers of the Yucca Mountain nuclear waste project to change where they had planned to build concrete pads for cooling thousands of tons of highly radioactive spent fuel.
But the design change made in June as project officials rushed to complete bore hole drilling operations wasn’t discussed with a presidential board overseeing the scientific work until last week, the board’s chairman said Tuesday.
“It was not discussed in our meetings,” said B. John Garrick, chairman of the Nuclear Waste Technical Review Board.
He said the first he heard about the realignment of the Bow Ridge fault line was last week during a private “fact-finding” session with project scientists between public sessions of the board’s meeting in Las Vegas.
“This is a work-in-progress issue,” Garrick said. “It isn’t just a matter of the aging pad. It has to be addressed in the context of all the facilities.”
Garrick said government scientists are still trying to calibrate how active the Bow Ridge fault is and the potential force it could unleash.
Garrick said the Department of Energy has provided few details about the aging pads or other surface facilities where spent nuclear fuel canisters from the nation’s commercial power reactors will be handled and stored for decades before they are entombed in the mountain, 100 miles northwest of Las Vegas.
Garrrick said it’s unclear if the pads will be covered or not.
“I have not seen any drawings that the pads will be sheltered, but they may be,” he said. “One thing for sure; the canisters will be warm.”
Project spokesman Allen Benson said scientists found out several months ago after analyzing rock core samples that the Bow Ridge fault line runs hundreds of feet east of where they thought it was located.
As a result, the surface facilities design was changed June 18 so that the pads wouldn’t be built directly over the fault line. Instead, they were moved about 100 feet east of where designers had planned them on March 29.
Last week the Review-Journal obtained a May 21 letter to project officials from the U.S. Geological Survey describing “preliminary drilling results” that indicated the Bow Ridge fault was farther east than originally mapped.
A story about the letter Monday quoting Nevada Nuclear Agency Projects chief Bob Loux revealed that the Energy Department would either have to change the design or show regulators in a license application that the pads could be fortified to withstand a surface offset of the Bow Ridge fault.
In an e-mail Monday, Benson said, “Changing the design and location of facilities to enhance safety is the right thing to do. “The information presented here is not new. It has been discussed at Nuclear Waste Technical Review Board meetings.”
But Tuesday, Benson said he misspoke before learning that Garrick confirmed that board members had only heard about Bow Ridge fault line’s realignment for the first time in last week’s private session.
Loux, a longtime critic of the project, reacted, saying, “DOE only tells information that they think helps them out. This is certainly not going to be the only 11th hour surprise they find as they move toward a license application.
“They have a fundamental lack of knowledge about the geology of the site, otherwise they would have known where these things are,” Loux said.
The Department of Energy couldn’t provide the Review-Journal with a map that shows the location of faults in reference to the planned location of surface facilities and the proposed repository site.
“All of that will be in the license application,” Benson said. “We are not going to piecemeal discuss our license application in the media.”
DOE officials have repeatedly said they will meet a self-imposed deadline of submitting a license application for the Nuclear Regulatory Commission to review by June 2008.
Garrick said he expects the detailed design at that time will only be 35 percent complete based on Energy Department estimates.
Geologist Steve Frishman, a full-time consultant to Nevada Agency for Nuclear Projects, said the danger posed by earthquake faults in the area of surface facilities is not just limited to displacement of the surface but ground shaking as well.
“If you have strong ground motion, things can tip over and bounce,” he said about the waste canisters. “The danger is they’ll fall over and rupture.”
If that happens, the highly radioactive materials could contaminate the surface and spread potentially deadly particles into the environment.
He said by moving the planned location of one of the aging pads 100 feet away from the Bow Ridge fault line “doesn’t mean it’s still not sitting on top of it.”
Frishman said Energy Department is designing the aging pads to hold up to 23,000 tons of spent fuel, or roughly one-third of the repository’s capacity, which is 77,000 tons. Officials expect it will take 24 years to fill the repository.
Frishman said the transport, aging and disposal canisters are being designed for a 100-year life span because the canisters could sit outside the repository site without any maintenance for as long as 60 years after having sat at reactor sites for 40 years.
“One of the issues we’ve had with the NRC (Nuclear Regulatory Commission) all along since they (DOE) came up with aging pads is they shouldn’t be regulated under the repository license,” he said.
“Instead, if it’s a big storage facility, it should be regulated the same way as private fuel storage, the same as for a nuclear power plant,” Frishman said.
“If you look at the faults at Yucca Mountain, it is highly unlikely you could license a nuclear power plant there.”More about Yucca Mountain