Scientists have long sought easier ways to make the costly material known as enriched uranium — the fuel of nuclear reactors and bombs, now produced only in giant industrial plants.
One idea, a half-century old, has been to do it with nothing more substantial than lasers and their rays of concentrated light. This futuristic approach has always proved too expensive and difficult for anything but laboratory experimentation.
Until now.
In a little-known effort, General Electric has successfully tested laser enrichment for two years and is seeking federal permission to build a $1 billion plant that would make reactor fuel by the ton.
That might be good news for the nuclear industry. But critics fear that if the work succeeds and the secret gets out, rogue states and terrorists could make bomb fuel in much smaller plants that are difficult to detect.
Iran has already succeeded with laser enrichment in the lab, and nuclear experts worry that G.E.’s accomplishment might inspire Tehran to build a plant easily hidden from the world’s eyes.
Backers of the laser plan call those fears unwarranted and praise the technology as a windfall for a world increasingly leery of fossil fuels that produce greenhouse gases.
But critics want a detailed risk assessment. Recently, they petitioned Washington for a formal evaluation of whether the laser initiative could backfire and speed the global spread of nuclear arms.
“We’re on the verge of a new route to the bomb,” said Frank N. von Hippel, a nuclear physicist who advised President Bill Clinton and now teaches at Princeton. “We should have learned enough by now to do an assessment before we let this kind of thing out.”
New varieties of enrichment are considered potentially dangerous because they can simplify the hardest part of building a bomb — obtaining the fuel.
General Electric, an atomic pioneer and one of the world’s largest companies, says its initial success began in July 2009 at a facility just north of Wilmington, N.C., that is jointly owned with Hitachi. It is impossible to independently verify that claim because the federal government has classified the laser technology as top secret. But G.E. officials say that the achievement is genuine and that they are accelerating plans for a larger complex at the Wilmington site.
“We are currently optimizing the design,” Christopher J. Monetta, president of Global Laser Enrichment, a subsidiary of G.E. and Hitachi, said in an interview.
The company foresees “substantial demand for nuclear fuel,” he added, while conceding that global jitters from the crisis at the Fukushima Daiichi plant in Japan “do create some uncertainty.” G.E. made those reactors.
Donald M. Kerr, a former director of the Los Alamos weapons lab who was recently briefed on G.E.’s advance, said in an interview that it looked like a breakthrough after decades of exaggerated claims.
Laser enrichment, he said, has gone from “an oversold, overpromised set of technologies” to what “appears to be close to a real industrial process.”
For now, the big uncertainty centers on whether federal regulators will grant the planned complex a commercial license. The Nuclear Regulatory Commission is weighing that issue and has promised G.E. to make a decision by next year.
The Obama administration has taken no public stance on plans for the Wilmington plant. But President Obama has a record of supporting nuclear power as well as aggressive efforts to curtail the bomb’s spread. The question is whether those goals now conflict.
The aim of enrichment is to extract the rare form of uranium from the ore that miners routinely dig out of the ground. The process is a little like picking through multicolored candies to find the blue ones.
The scarce isotope, known as uranium 235, amounts to just 0.7 percent of mined uranium. Yet it is treasured because it splits easily in two in bursts of atomic energy. If concentrations are raised (or enriched) to about 4 percent, the material can fuel nuclear reactors; to 90 percent, atom bombs.
Enrichment is so difficult that successful production is quite valuable. A pound of reactor fuel costs more than $1,000 — less expensive than gold but more than silver.
The Laser Race
The first laser flashed to life in 1960. Soon after, scientists talked excitedly about using the innovation to shrink the size of enrichment plants, making them far cheaper to build and run.
“It was in the air,” recalled Leonard R. Solon, a physicist who worked for a New York company that in early 1963 suggested the idea to the federal government.
The plan was to exploit the extraordinary purity of laser light to selectively excite uranium’s rare form. In theory, the resulting agitation would ease identification of the precious isotope and aid its extraction.
At least 20 countries and many companies raced to investigate the idea. Scientists built hundreds of lasers.
Ray E. Kidder, a laser pioneer at the Livermore nuclear arms lab, estimated that the overall number of scientists involved globally ran to several thousand.
“It was a big deal,” he said in an interview. “If you could enrich with lasers, you could cut the cost by a factor of 10.”
The fervor cooled by the 1990s as laser separation turned out to be extremely hard to make economically feasible.
Not everyone gave up. Twenty miles southwest of Sydney, in a wooded region, Horst Struve and Michael Goldsworthy kept tinkering with the idea at a government institute. Finally, around 1994, the two men judged that they had a major advance.
The inventors called their idea Silex, for separation of isotopes by laser excitation. “Our approach is completely different,” Dr. Goldsworthy, a physicist, told a Parliamentary hearing.
An old black-and-white photograph of the sensitive technology — perhaps the only image of its kind in existence publicly — shows an array of pipes and low cabinets about the size of a small truck.
‘Game Changing’ Technique
In May 2006, G.E. bought the rights to Silex. Andrew C. White, the president of the company’s nuclear business, hailed the technology as “game-changing.”
Mr. Monetta of Global Laser Enrichment, the G.E.-Hitachi subsidiary, said the envisioned plant would enrich enough uranium annually to fuel up to 60 large reactors. In theory, that could power more than 42 million homes — about a third of all housing units in the United States.
The laser advance, he added, will promote energy security “since it is a domestic source.”
In late 2009, as G.E. experimented with its trial laser, supporters of arms control wrote Congress and the regulatory commission. The technology, they warned, posed a danger of quickening the spread of nuclear weapons because of the likely difficulty of detecting clandestine plants.
Experts called for a federal review of the risks. In early 2010, the commission resisted.
Late last year, the American Physical Society — the nation’s largest group of physicists, with headquarters in Washington — submitted a formal petition to the commission for a rule change that would compel such risk assessments as a condition of licensing.
“The issue is too big” to leave to the federal status quo, Francis Slakey, a physicist at Georgetown University and the society official who drafted the petition, said in an interview. He added that Mr. Obama or Congress might eventually have to get involved.
This year, thousands of citizens, supporters of arms control, nuclear experts and members of Congress wrote the commission to back the society’s effort. Many of them cited well-known failures in safeguarding secrets and detecting atomic plants.
But the Nuclear Energy Institute, an industry group in Washington, objected. It said new precautions were unnecessary because of voluntary plans for “additional measures” to safeguard secrets.
A commission spokesman said the petition would be considered next year. In theory, the risk-assessment plan, if adopted, could slow or stop the granting of a commercial license for the proposed laser plant or could result in design improvements.
A POSITIVE ASSESSMENT
G.E., seizing the initiative, did an assessment of its own. It hired Dr. Kerr, the former director of Los Alamos and a former senior federal intelligence official, to lead the evaluation. He and two other former government officials concluded that the laser secrets had a low chance of leaking and that a clandestine laser plant stood a high chance of being detected.
“It’s a major industrial facility,” Dr. Kerr said of the planned Wilmington complex in an interview. “Our observation was this was not something that would sit in a garage or be easily hidden.”
Global Laser Enrichment declined a request by The New York Times for a copy of the Kerr report. It said the document ran to seven pages.
In the interview, Mr. Monetta, the company’s president, said the Kerr review had confirmed that the laser complex would “not result in the proliferation of enrichment technology.” His position seemed to go beyond Dr. Kerr’s citing of likelihoods.
Mr. Monetta added that the technical complexity and “significant size” of the laser plant were major barriers to its covert adoption abroad.
Global Laser Enrichment plans to build its complex on more than 100 acres at the Wilmington industrial park, with the main building covering nearly 14 acres. That, like Iran’s main enrichment plant, is roughly half the size of the Pentagon.
But critics say a clandestine bomb maker would need only a tiny fraction of that vast industrial ability — and thus could build a much smaller laser, perhaps like the modest apparatus in the old photograph. Each year, they note, the enrichment powers of the Wilmington plant would be great enough to produce fuel for more than 1,000 nuclear weapons.
Iran began its laser program in the 1970s during the global rush. But it kept the results secret. The silence violated Iran’s agreement with the International Atomic Energy Agency, an arm of the United Nations that is based in Vienna and acts as the world’s nuclear police.
The cover-up ended in early 2003. Soon, the I.A.E.A. learned of contracts, enrichment runs and even a prototype plant. Iran insisted that it dismantled the facility in May 2003 and dropped laser enrichment.
But then, out of the blue, President Mahmoud Ahmadinejad in February 2010 praised Iranian scientists for their “relentless efforts” to build lasers for uranium enrichment. Ever since, the I.A.E.A. has sought unsuccessfully to learn more.
When experts cite possible harm from the commercialization of laser enrichment, they often point to Iran. The danger, they say, lies not only in pilfered secrets, but also in the public revelation that a half-century of laser failure seems to be ending.
Their concern goes to the nature of invention. The demonstration of a new technology often begets a burst of emulation because the advance opens a new window on what is possible.
Arms controllers fear that laser enrichment is now poised for that kind of activity. News of its feasibility could spur wide reinvestigation.
Dr. Slakey of the American Physical Society noted that the State Department a dozen years ago warned that the success of Silex could “renew interest” in laser enrichment for good or ill — to light cities or destroy them.
That moment, he said, now seems close at hand.
[ nytimes ]
Nessun commento:
Posta un commento