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| | | published Sunday, November 13, 2011 | 781 Views :: 0 Comments | |  |
| Nov 13, 2011 From the Albuquerque Journal
LOS ALAMOS – From the fourth floor of the newest building on Los Alamos National Laboratory’s plutonium row, geophysicist Terry Wallace can see the Pajarito Fault three miles away.
The fault’s forested stair step, created in a series of earthquakes over the past million years, defines the base of the mountains rising to the west. It has also come to play a defining role in discussions of the major buildings along Pajarito Road, home to the lab’s main nuclear facilities. To the north, the lab’s Plutonium Facility is in the midst of a major retrofit because of concerns about earthquake safety. The work will not be done until 2020.
Up the road, lab officials are struggling to move out as quickly as they can from the Chemistry and Metallurgy Research Building, an old nuclear lab not designed to modern earthquake standards. Below Wallace’s vantage point is the site of what lab officials hope will become, in the next decade, a major new plutonium lab.
Questions about earthquake safety surround all of the projects.
Driven by a desire to harden the new plutonium building against a worst-case future quake, federal and lab officials have been pouring money during the past decade into a design they hope will ensure against such a quake, the type they believe could occur every few thousand years in northern New Mexico. “We have a responsibility on this site to make sure we don’t increase the risk to the public in any way as a result of the failure of a nuclear facility,” Wallace said.
The result in the case of the new building is a massive steel-and-concrete design with internal fixtures, such as fire-control systems, designed to withstand a magnitude-7.3 earthquake on the nearby Pajarito Fault and keep working. The building standards are based on the Department of Energy facility codes that require the building to contain all the nuclear material inside it during the worst-case earthquake, preventing a leak that might threaten the public.
The resulting design could leave the new plutonium building intact in a worst-case earthquake while many of the rest of the buildings on the plateau – office buildings, stores and homes – are not, said University of New Mexico geologist John Geissman. “Everything else could be crumbled to smithereens,” Geissman said.
In the process, the design for the new plutonium lab has driven the cost of the project so high – as much as $5.7 billion – that there are now questions about whether the government can afford to build it. Meanwhile, project officials are under attack from critics who say they are not making it safe enough.
Questions about all those earthquake safety efforts will get a public airing Thursday in Santa Fe before the Defense Nuclear Facilities Safety Board, created by Congress to provide independent oversight of the safety of U.S. nuclear weapons operations. “Our No. 1 goal is to ensure these (lab buildings) are adequately protective of the public and workers,” board chairman Peter Winokur said in an interview.
Los Alamos, the nation’s primary center for working with dangerously radioactive plutonium used in nuclear weapons, is spread across a series of finger mesas west of Santa Fe, jutting out of the Jemez Mountains toward the Rio Grande.
Like much of New Mexico, it is a landscape shaped by earthquakes as Earth’s crust pulls apart. The Rio Grande flows down the valley that results, and the mountains that flank the valley east and west are a product of the geologic forces involved.
On the plateau that houses Los Alamos, great slabs of rock slip slowly downward as the rift pulls away. Geologists have measured several hundred feet of movement on the Pajarito Fault in the past million years, said Wallace, the lab’s associate director for science.
A decade ago, earthquake risk at Los Alamos seemed like less of a problem. A 1999 lab report estimated the last major quake on the Pajarito Fault happened 45,000 years ago. But in the years since, new data collected by lab researchers shows that was wrong. Between 1,400 and 2,000 years ago, the Pajarito saw a quake that could have been as large as magnitude 7 – the strength of the 2010 earthquake in Haiti. The nearby Rendija Canyon and Guaje Mountain faults saw quakes that could have been as large as magnitude 6.5 in the last 10,000 years.
In response to those discoveries, the lab has undergone a major shift in how it thinks about earthquake safety. Current designs for the new plutonium laboratory, known as the Chemistry and Metallurgy Research Replacement-Nuclear Facility, assume a “maximum credible earthquake” of magnitude 7.3. Building a plutonium laboratory capable of withstanding that earthquake not only standing, but with fire protection and other safety systems intact, is now estimated to cost $3.7 billion to $5.7 billion.
Retrofitting the 1970s-era Plutonium Facility to handle stronger earthquakes could cost tens of millions of dollars, and federal officials have decided that retrofitting the even older Chemistry and Metallurgy Research Building to meet earthquake standards simply can’t be done.
But even as that additional spending has drawn questions from Congress about cost, lab critics question whether magnitude 7.3 is enough. Independent geologist Robert Gilkeson, working with the Santa Fe group Concerned Citizens for Nuclear Safety, argues that quakes rupturing multiple faults in the area at roughly the same time could unleash a magnitude-8.0 earthquake, and the design needs to take that risk into account. Gilkeson also argues there is substantial uncertainty in the lab’s knowledge of area earthquake history, which urges caution.
Gilkeson’s group believes a worse-case scenario could result in a major plutonium release.
Gilkeson’s argument played a significant role in environmental hearings on the new plutonium lab this summer, with citizens opposed to the project citing it repeatedly.
Other independent analysts side with the lab’s lower number for the maximum credible earthquake. The U.S. Geological Survey’s earthquake risk mapping program concluded that earthquakes of magnitude 7.0 are possible but extremely rare in this region of northern New Mexico, while the risk of an 8.0 is essentially zero.
Geissman said an 8.0 earthquake would be inconsistent with everything geologists know about earthquakes on fault systems in New Mexico.
The Safety Board – which has a reputation of being a frequent thorn in the lab’s side on nuclear safety issues – in a report to Congress said it agreed with the lab’s earthquake risk analysis. |
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