Thorium: REAL Alternative Energy

[dharma]

Ethanol and other biofuels, hydrogen, fuel cells, solar generators, wind power, wave power: bah. Humbug. Silly money-eating boondoggles whose chief proponents are apparently incapable of operating a calculator. We have natural gas (a lot), we have coal (a lot); let's figure out how to use them.

And: we have thorium (a lot). - d

IS THIS THE DAWNING OF THE AGE OF THORIUM?

By Jack Lifton

4 Feb 2009 at 10:17 AM

There's great rejoicing tonight in Salmon, Idaho, because Salmon is the closest town to the Lemhi Pass, and the Lemhi Pass is the location of America's largest and possibly the world's richest high grade thorium oxide deposits.

"So what?" Well, here's what's what.

On Oct. 2, 2008 Senator Hatch (R-UTt) and Senator Reid (D-NV), then as now the Senate Majority Leader, introduced into the agenda for consideration by the United States Senate a bi-partisan bill, S-3680, entitled Thorium Energy Independence and Security Act of 2008, http://thomas.loc.gov/cgi-bin/query/z?c110:S.3680 .

The press release put out by Senator Hatch's office that same day, http://hatch.senate.gov/p...78-be3e-e031-1635aee6efa9 contained the following paragraph:

"Using thorium for nuclear power has a number of potential benefits over conventional uranium. As a resource, thorium is abundant in the U.S. and throughout the world. A thorium fuel rod would remain in the reactor about three times as long as conventional nuclear fuel, cutting the volume of spent nuclear fuel by as much as two-thirds. Also, thorium nuclear fuel would significantly reduce the possibility that weapons-grade material would result from the process. Finally, a thorium fuel cycle could be used to dispose of existing plutonium stockpiles, which is the national security goal."

The above paragraph sums up the arguments for using thorium based fuel as an alternative to uranium based fuel for nuclear reactors that I myself first wrote about on ResourceInvestor.com in 2006 in an article I called "Thorium: An Alternative to Uranium," http://www.resourceinvest...om/pebble.asp?relid=16813.

I updated that article in early 2007 in my next thorium themed article," Thorium, An Alternative to Uranium, 2007 Update, " http://www.resourceinvest...=29249&phrase=thorium .Later that year I wrote "Thorium, the Answer to the Question 'How Do You Hedge Uranium?" http://www.resourceinvest...=37707&phrase=thorium . In February of 2008 I wrote "How to Invest in Rare Earths and Thorium ," http://www.resourceinvest...=40858&phrase=thorium, and now one year later I think that my timing has been right on the mark, and I want to tell you what has happened and what the natural resource investment opportunities for thorium are and are going to be.

I want to direct your attention to news releases that have been published since the beginning of 2009. If they don't quicken your interest in the potential of thorium, especially when combined with the Hatch-Reid Bill, then you are simply uninterested in the future direction of non-proliferative low-waste nuclear power. This technology uses a natural resource the United States now possesses in such abundance that, since American mining and refining technology for minor metals, and radioactive metals in particular, is the most advanced and safest in the world. It could make America the principal producer, refiner and exporter of the thorium fuels that are being developed around the world, because, my dear investing public, America probably has more accessible high-grade deposits of thorium than anyone else.

Back to the 2009 news: Check out the International Herald Tribune for February 3, 2009, and you will see the analytical news piece called "A model nuclear-power deal? http://www.iht.com/articl...deast/letter.1-421715.php. This details the negotiations and agreement between the USA and the Arab states of the Persian Gulf, such as Dubai and Kuwait, that was done in Condoleezza Rice's last days as Secretary of State. It would give the Emirates the right to buy nuclear power reactor technology from American companies in return for the agreements of the Gulf governments not to ask for or obtain any technology that can be used to make nuclear weapons. As the article points out, a good way to achieve this goal, with no possibility of cheating by either side, is to utilize thorium-based fuel for the reactors. This deal has been announced since the Obama administration took office and therefore we must assume that it is in line with the new President's policies for reducing greenhouse gas emitting power plant construction and reducing and stopping the proliferation of nuclear weapons. It can be no coincidence that the Hatch-Reid Bill is about to be re-introduced into the new Congress. Clearly, the administration has signaled its support for amending the Atomic Energy Act of 1954 to include funding for research and development of thorium based fuels, thorium reactors, and thorium reactor waste disposal techniques.

I am personally aware of the fact that, even as I write, major American, Canadian, French and British nuclear engineering companies are forming strategic alliances to seek funding under Hatch-Reid to go forward with the development of thorium based nuclear power reactors for the production of electricity for civilian use.

One year ago at the SME, the USGS sponsored the first annual rare earth's seminar. The second annual one will be held at the SME annual meeting this year in Denver on Feb. 26. I attended last year's conference in Salt Lake City, and I asked, as did others, what about the thorium normally found in rare earth ore bodies in North America. The uniform answer from almost all of the miners attending was that "we contain it." It is removed early on in the separation of the light rare earths, lanthanum to neodymium, and is then contained by being put aside and immobilized. There is often uranium as well as thorium associated with rare earth ore bodies, so I was told that thorium containment is "no problemo" as some miners put it at the conference.

I noted that although everyone at the conference had knowledge of the possible use of thorium in non-proliferative low waste reactors they viewed that as a rather distant possibility and clearly then, in February 2008, classed thorium as a liability and as a cost to be contained.

As the song says, "What a difference a year makes." The Indian Atomic Energy Authority announced at the beginning of 2009 that it would convert an existing reactor to use thorium-based fuel, with the thorium coming from India's own monazite sands.

Even earlier than that in Hong Kong in September, I was told that the Chinese government had asked an American manager of a Bayanobo mining operation to tell them just what happened to the thorium separated there from the rare earths. He told me that he was instructed to gather and hold thorium concentrates from now on, and that they would be picked up by the Chinese nuclear power authority, because China was going ahead with the design and building of thorium based fuel for "thorium" reactors, since China has so much thorium as a byproduct of its world's largest rare earth mining operations.

Last week, Canada's Great Western Minerals Group, which told the SME conference in 2007 that its Hoidas Lake, Saskatchewan rare earth deposit was particularly low in thorium, and saw that as a positive, announced that it had bought a concession in the Republic of South Africa to reopen a mine for rare earths that was developed in the 1950s by AngloAmerican originally to produce thorium. Great Western further disclosed that a South African utility had made a deal with GW to have it "contain" the thorium produced in the rare earth mining operation in concrete, so that the utility could take it to their own site when they have prepared it. The utility told them that the South African government has evinced a strong interest in building thorium-based nuclear reactors and that the utility wants to have a domestic fuel source.

So now, what does this have to do with Salmon, Idaho? The answer is that it is the closest town to the claims of the private junior mining company, Thorium Energy Inc., which announced last year at the SME that its Lemhi Pass, Idaho and other nearby properties were being validated with regard to reserves and resources of thorium, which the company said looked like they might be the richest and most extensive in North America. The USGS has now recognized that the company's thorium reserves and resources are among the largest in the world and recently amended its Commodity Survey of Thorium to reflect that. Thorium Energy's claims also contain substantial quantities of the rare earths, particularly of the light rare earths. An engineering manager at an American nuclear engineering company moving forward on the development of thorium reactors pointed out to me last week that TEI could produce thorium as a product along with rare earth elements as a secondary product or the other way around. In the one case, he noted that TEI would become and could well become the world's first primary thorium miner in half a century, and perhaps the largest one ever if the validation is accurate.

The engineer thought that as a step towards American energy self sufficiency and independence, it was potentially a giant step. Perhaps we are about to step into the age of the last of the power metals to be developed for mankind's use, thorium.

Jack Lifton is a featured contributor to the new Resource Investor. With 35 years experience in the OEM electronics and automotive supply industries, he is today a metals sourcing consultant for OEM heavy industry and offers due diligence analysis for institutional investors. Lifton is a prominent speaker on the market fundamentals of minor metals and their end-uses and travels the world on behalf of Fortune 500 and Global 1000 corporations. Reach him directly at JackLifton@aol.com.

http://www.resourceinvestor.com/pebble.asp?relid=49032

[frodo]

Just be aware that Thorium was used to make lamp mantles for years because it glows very brightly. Two kids made a nuclear reactor for a bet out of lamp mantles and it worked.

But be aware that there was a company in this city that made and sold Thorium lamp mantles and the majority of it's staff died of stomach cancer.

You have been warned.

[Ought Six]

Wow! Radioactive substances can cause cancer? Who knew!

[Mousehound]

So thorium sounds interesting and abundant, so why haven't they used it sooner? Is there some catch?

[shalym]

From wikipedia:
http://en.wikipedia.org/wiki/Thorium

Thorium as a nuclear fuel

Main article: Thorium fuel cycle

Thorium, as well as uranium and plutonium, can be used as fuel in a nuclear reactor. Although not fissile itself, 232Th will absorb slow neutrons to produce 233U, which is fissile. Hence, like 238U, it is fertile. Theoretically thorium is more suitable fuel source than uranium: thorium is about 550 times more abundant in nature than uranium-235, potentially all of thorium fuel can be usefully burned in nuclear fission (current state of the art uranium based reactors burn only about 1-2% of fuel), thorium is fairly evenly spread around Earth with a lot of countries having huge supplies of it, thorium fuel cycle creates mainly Uranium-233 contaminated with Uranium-232 which makes it ill suited to weapons proliferation.

Problems include the high cost of fuel fabrication due partly to the high radioactivity of 233U which is a result of its contamination with traces of the short-lived 232U; the similar problems in recycling thorium due to highly radioactive 228Th; some weapons proliferation risk of 233U; and the technical problems (not yet satisfactorily solved) in reprocessing. Much development work is still required before the thorium fuel cycle can be commercialized, and the effort required seems unlikely while (or where) abundant uranium is available.

Nevertheless, the thorium fuel cycle, with its potential for breeding fuel without fast neutron reactors, holds considerable potential long-term benefits. Thorium is significantly more abundant than uranium, and is a key factor in sustainable nuclear energy. Perhaps more importantly, thorium produces several orders of magnitude less long-lived radioactive waste.

One of the earliest efforts to use a thorium fuel cycle took place at Oak Ridge National Laboratory in the 1960s. An experimental reactor was built based on molten salt reactor technology to study the feasibility of such an approach, using thorium-fluoride salt kept hot enough to be liquid, thus eliminating the need for fabricating fuel elements. This effort culminated in the Molten-Salt Reactor Experiment that used 232Th as the fertile material and 233U as the fissile fuel. Due to a lack of funding, the MSR program was discontinued in 1976.

I wish I understood more about this...Why was there no funding in 1976? Was it because of the "abundant uranium...available"? Is it STILL all about special interests? (the uranium industry--does this really exist? IS there a uranium "industry"?)

Shari--off to do more research before I get sidetracked...

[shalym]

Here's some more information about it:

Safety a possible disadvantage

Breeder Reactors (Fast Neutron Reactors)

"Of the fissile materials usable for practical nuclear energy production, only uranium-235 occurs in any substantial quantities in nature. The other two, plutonium-239 and uranium-233, must be made from uranium-238 and thorium-232 respectively, which are far more abundant than naturally-occurring fissile uranium-235. The process of converting "fertile" uranium-238 and thorium-232 into fissile materials is called "breeding," evidently by analogy with biological reproduction.

Since doubling times for breeding U-233 are far longer than for breeding Pu-239, almost all breeder reactors so far have been built to breed Pu-239. A further disadvantage of thorium-232-based breeder reactors cycle is the high gamma radioactivity due to contaminants in recovered uranium-233. This radioactivity arises mainly from the decay products of uranium-232, which is created in thorium-uranium fueled breeders by various nuclear reactions.

India seems to be the only country with a substantial active program to pursue U-233 breeding, since it has very large thorium-232 reserves, which are far greater than its domestic uranium-238 resources.

Fast breeders, by definition, need no moderators, which slow down neutrons, since they use fast neutrons for fission and breeding. They cannot use ordinary water or heavy water as a coolant because these materials also act as moderators. Liquid sodium, which has a mass number of 23, compared to 1 for ordinary hydrogen and 2 for deuterium, is the most common breeder reactor coolant. Since a coolant must continually flow across fuel elements, it must be a gas or liquid. Since sodium is a solid at room temperature, it must be maintained in liquid form in a breeder reactor by heating it continually, even when the reactor is shut down.

Sodium catches fire on contact with air and explodes on contact with water. Further, the nucleus of ordinary sodium absorbs a neutron and turns into a highly radioactive isotope sodium-24. This is a major threat in case of a breeder reactor accident. To prevent leakage of sodium-24 into the environment, sodium-cooled reactors are designed with two liquid sodium loops. The secondary, non-radioactive sodium loop draws heat from the primary loop and, in turn, is used to boil water in a steam generator. The December 1995 accident at the Japanese breeder reactor at Monju involved a large leak of sodium from the secondary loop.

Despite its theoretical attractiveness in converting non-fissile into fissile material, the breeder reactor has turned out to be a far tougher technology than thermal reactors. Despite five decades of effort during which many pilot and "demonstration" plants have been built, the sodium-cooled breeder reactor design remains on the margin of commercial nuclear technology."

Source IEER.ORG

Interesting discussion about it here

Shari

[Darkimbolc]

The real questions are:
1) Even though 2/3 is a lot less waste than conventional reactors, how much waste would we be talking if we moved over to it?

2) Uranium and its reactive byproducts have a half-life measured in millions of years. How would thorium compare?

3) How does it compare to uranium safety-wise? Is it more likely, less likely, or just as much a risk as conventional uranium reactors?

[dharma]

Originally Posted by Darkimbolc

The real questions are:
1) Even though 2/3 is a lot less waste than conventional reactors, how much waste would we be talking if we moved over to it?

Excellent question. The first thing we must know is, well, how much nuclear waster does a regular plant produce?

I went looking for the answer once. It's tough to find, because the anti-nuke folks inflate the number by including very low level nuclear waste, like the paper suits and booties worn by technicians that are essentially harmless, while the nuke proponents try to cut the answer down to the waste that is actually output from the plant but don't recognize the need for decommissioning down the line; those steel containment vessels are going to be hot, though not markedly so, and not forever.

If you count what would be left if we reprocessed our fuel like the French (currently illegal courtesy of Jimmy Carter), truly high level waste would amount to about a cupful for a family of four for their lifetimes. Without reprocessing, more like a cigar box. This is nasty, deadly, long-life stuff, that needs to be vitrified and buried in Yucca Mountain with a lame Crosby/Nash song playing over it to drive people away. Compare that with the amount of gasified mercury, cadmium, lead, sulfur, and yes, uranium and thorium put directly into the atmosphere by a coal plant, it looks like a HUGE bargain. Especially when you cut it by two-thirds for thorium reactors.

Sorry, no link—this is off the top of my head. YMMV.

Originally Posted by Darkimbolc

2) Uranium and its reactive byproducts have a half-life measured in millions of years. How would thorium compare?

Shalym answered this question.

Originally Posted by Darkimbolc

3) How does it compare to uranium safety-wise? Is it more likely, less likely, or just as much a risk as conventional uranium reactors?

Less. As noted.

[Samen]

http://www.dangerouslaboratories.org/radscout.html

Note: This article is being reprinted here as an example of what NOT to do with radioactive materials. Please do NOT attempt to recreate any part of these experiments for the following reasons:

You will most likely poison yourself and/or others

Nobody really needs an unsafe homemade reactor (especially one made of duct tape and foil)

If enough people try these dangerous experiments, the government will try to outlaw any sort of legitimate private experiments with radioactivity or possession of any radioactive minerals or materials (thus spoiling all of our fun).

What happened when a teenager tried a dangerous experiment in his back yard

Tale of the Radioactive Boy Scout.

FROM HARPER'S MAGAZINE BY KEN SILVERSTEIN

Golf Manor, a subdivision in Commerce Township, Mich., some 25 miles outside of Detroit, is the kind of place where nothing unusual is supposed to happen, where the only thing lurking around the corner is an ice-cream truck. But June 26, 1995, was not a typical day.

Ask Dottie Pease. Cruising down Pinto Drive, Pease saw half a dozen men crossing her neighbor's lawn. Three, in respirators and white moon suits, were dismantling her next-door neighbor's shed with electric saws, stuffing the pieces into large steel drums emblazoned with radioactive warning signs.

Huddled with a group of neighbors, Pease was nervous. "I was pretty disturbed," she recalls. Publicly, the employees of the Environmental Protection Agency (EPA) that day said there was nothing to fear. The truth is far more bizarre: the shed was dangerously irradiated and, according to the EPA, up to 40,000 residents of the area could be at risk.

The cleanup was provoked by the boy next door, David Hahn. He had attempted to build a nuclear reactor in his mother's shed following a Boy Scout merit-badge project.

Grander Ambitions



David Hahn's early years were seemingly ordinary. The blond, gangly boy played baseball and soccer, and joined the Boy Scouts. His parents, Ken and Patty, had divorced, and David lived with his father and stepmother, Kathy, in nearby Clinton Township. He spent weekends in Golf Manor with his mother and her boyfriend, Michael Polasek.

An abrupt change came at age ten, when Kathy's father gave David The Golden Book of Chemistry Experiments. David became immersed. By age 12 he had digested his father's college chemistry textbooks; by 14 he had made nitroglycerin.

One night his house in Clinton Township was rocked by an explosion in the basement. Ken and Kathy found David semiconscious on the floor. He had been pounding some substance with a screwdriver and ignited it. He was rushed to the hospital to have his eyes flushed.

Kathy then forbade David from experimenting in her home. So he shifted his operations to his mother's shed in Golf Manor. Neither Patty nor Michael had any idea what the shy teenager was up to, although they thought it was odd that David often wore a mask in the shed, and would sometimes discard his clothing after working there until two in the morning. They chalked it up to their own limited education.

Michael does, however, remember David saying, "One of these days we're gonna run out of oil."

Convinced he needed discipline, David's father, Ken, felt the solution lay in a goal that he didn't himself achieve, Eagle Scout, which requires 21 merit badges. David earned a merit badge in Atomic Energy in May 1991, five months shy of his 15th birthday. By now, though, he had grander ambitions.

Concocted identity



He was determined to irradiate anything he could, and decided to build a neutron "gun." To obtain radioactive materials, David used a number of cover stories and concocted a new identity.

He wrote to the Nuclear Regulatory Commission (NRC), claiming to be a physics instructor at Chippewa Valley High School. The agency's director of isotope production and distribution, Donald Erb, offered him tips on isolating and obtaining radioactive elements, and explained the characteristics of some isotopes, which, when bombarded with neutrons, can sustain a chain reaction.

When David asked about the risks, Erb assured him that the "dangers are very slight," since "possession of any radioactive materials in quantities and forms sufficient to pose any hazard is subject to Nuclear Regulatory Commission (or equivalent) licensing."

David learned that a tiny amount of the radioactive isotope americium-241 could be found in smoke detectors. he contacted smoke-detector companies and claimed that he needed a large number for a school project. One company sold him about a hundred broken detectors for a dollar apiece.

Not sure where the americium was located, he wrote to an electronics firm in Illinois. A customer-service representative wrote back to say she'd be happy to help out with "your report." Thanks to her help, David extracted the material. He put the americium inside a hollow block of lead with a tiny hole pricked in one side so that alpha rays would stream out. In front of the block he placed a sheet of aluminum, its atoms absorb alpha rays and kick out neutrons. His neutron gun was ready.

The mantle in gas lanterns, the small cloth pouch over the flame, is coated with a compound containing thorium-232. When bombarded with neutrons it produces uranium-233, which is fissionable. David bought thousands of lantern mantles from surplus stores and blowtorched them into a pile of ash.

To isolate the thorium from the ash, he purchased $1000 worth of lithium batteries and cut them in half with wire cutters. He placed the lithium and thorium ash together in a ball of aluminum foil and heated the ball with a Bunsen burner. This purified the thorium to at least 9000 times the level found in nature, and up to 170 times the level that requires NRC licensing. But David's americium gun wasn't strong enough to transform thorium into uranium.

More Help From the NRC



David held a series of after-school jobs at fast-food joints, grocery stores and furniture warehouses, but work was merely a means of financing his experiments. Never an enthusiastic student, he fell behind in school, scoring poorly on state math and reading tests (he did, however, ace the test in science).

Wanting radium for a new gun, David began visiting junkyards and antique stores in search of radium-coated clocks. He'd chip paint from them and collect it.

It was slow going until one day, while driving through Clinton Township, he says he came across an old table clock in an antique shop. In the hack of the clock he discovered a vial of radium paint. He bought the clock for $10.

Next he concentrated the the radium and dried it into a salt form. Whether he fully realized it or not, he was putting himself in danger.

The NRC's Erb had told him that "nothing produces neutrons from alpha reactions as well as beryllium." David says he had a friend swipe a strip of beryllium from a chemistry lab, then placed it in front of the lead block that held the radium. His cute little americium gun was now a more powerful radium gun.

David had located some pitchblende, an ore containing tiny amounts of uranium, and pulverized it with a hammer. He aimed the gun at the powder, hoping to produce at least some fissionable atoms. It didn't work. The neutron particles, the bullets in his gun, were moving too fast.

To slow them down, he added a filter, then targeted his gun again. This time the uranium powder appeared to grow more radioactive by the day.

"Imminent Danger"

Now 17, David hit on the idea of building a model breeder reactor, a nuclear reactor that not only generates electricity, but also produces new fuel. His model would use the actual radioactive elements and produce real reactions. His blueprint was a schematic in one of his father's textbooks.

Ignoring safety, David mixed his radium and americium with beryllium and aluminum, all of which he wrapped in aluminum foil, forming a makeshift reactor core. He surrounded this radioactive ball with a blanket of small foil-wrapped cubes of thorium ash and uranium powder, tenuously held together with duct tape.

"It was radioactive as heck," David says, "far greater than at the time of assembly." Then he began to realize that he could be putting himself and others in danger.

When David's Geiger counter began picking up radiation five doors from his mom's house, he decided that he had "too much radioactive stuff in one place" and began to disassemble the reactor. He hid some of the material in his mother's house, left some in the shed, and packed most of the rest into the trunk of his Pontiac.

At 2:40 a.m. on August 31, 1994, Clinton Township police responded to a call concerning a young man who had been apparently stealing tires from a car. When the police arrived, David told them he was meeting a friend. Unconvinced, officers decided to search his car.

They opened the trunk and discovered a toolbox shut with a padlock and sealed with duct tape. The trunk also contained foil-wrapped cubes of mysterious gray powder, small disks and cylindrical metal objects, and mercury switches. The police were especially alarmed by the toolbox, which David said was radioactive and which they feared was an atomic bomb.

The discovery eventually triggered the Federal Radiological Emergency Response Plan, and state officials would become involved in consultations with the EPA and NRC.

At the shed, radiological experts found an aluminum pie pan, a Pyrex cup, a milk crate and other materials strewn about, contaminated at up to 1000 times the normal levels of background radiation. Because some of this could be moved around by wind and rain, conditions at the site, according to an EPA memo, "present an imminent endangerment to public health."

After the moon-suited workers dismantled the shed, they loaded the remains into 39 sealed barrels that were trucked to the Great Salt Lake Desert. There, the remains of David's experiments were entombed with other radioactive debris.

"These are conditions that regulations never envision," says Dave Minnaar, radiological expert with Michigan's Department of Environmental Quality. "It's simply presumed that the average person wouldn't have the technology or materials required to experiment in these areas."

David Hahn is now in the Navy, where he reads about steroids, melanin, genetic codes, prototype reactors, amino acids and criminal law. "I wanted to make a scratch in life," he explains now. "I've still got time." Of his exposure to radioactivity he says, "I don't believe I took more than five years off my life."

[Mousehound]

Good info Shalym!

[Mousehound]

The thick hardbound volume was sitting on a shelf in a colleague’s office when Kirk Sorensen spotted it. A rookie NASA engineer at the Marshall Space Flight Center, Sorensen was researching nuclear-powered propulsion, and the book’s title — Fluid Fuel Reactors — jumped out at him. He picked it up and thumbed through it. Hours later, he was still reading, enchanted by the ideas but struggling with the arcane writing. “I took it home that night, but I didn’t understand all the nuclear terminology,” Sorensen says. He pored over it in the coming months, ultimately deciding that he held in his hands the key to the world’s energy future. Published in 1958 under the auspices of the Atomic Energy Commission as part of its Atoms for Peace program, Fluid Fuel Reactors is a book only an engineer could love: a dense, 978-page account of research conducted at Oak Ridge National Lab, most of it under former director Alvin Weinberg. What caught Sorensen’s eye was the description of Weinberg’s experiments producing nuclear power with an element called thorium. At the time, in 2000, Sorensen was just 25, engaged to be married and thrilled to be employed at his first serious job as a real aerospace engineer. A devout Mormon with a linebacker’s build and a marine’s crew cut, Sorensen made an unlikely iconoclast. But the book inspired him to pursue an intense study of nuclear energy over the next few years, during which he became convinced that thorium could solve the nuclear power industry’s most intractable problems. After it has been used as fuel for power plants, the element leaves behind minuscule amounts of waste. And that waste needs to be stored for only a few hundred years, not a few hundred thousand like other nuclear byproducts. Because it’s so plentiful in nature, it’s virtually inexhaustible. It’s also one of only a few substances that acts as a thermal breeder, in theory creating enough new fuel as it breaks down to sustain a high-temperature chain reaction indefinitely. And it would be virtually impossible for the byproducts of a thorium reactor to be used by terrorists or anyone else to make nuclear weapons. Weinberg and his men proved the efficacy of thorium reactors in hundreds of tests at Oak Ridge from the ’50s through the early ’70s. But thorium hit a dead end. Locked in a struggle with a nuclear- armed Soviet Union, the US government in the ’60s chose to build uranium-fueled reactors — in part because they produce plutonium that can be refined into weapons-grade material. The course of the nuclear industry was set for the next four decades, and thorium power became one of the great what-if technologies of the 20th century. Today, however, Sorensen spearheads a cadre of outsiders dedicated to sparking a thorium revival. When he’s not at his day job as an aerospace engineer at Marshall Space Flight Center in Huntsville, Alabama — or wrapping up the master’s in nuclear engineering he is soon to earn from the University of Tennessee — he runs a popular blog called Energy From Thorium. A community of engineers, amateur nuclear power geeks, and researchers has gathered around the site’s forum, ardently discussing the future of thorium. The site even links to PDFs of the Oak Ridge archives, which Sorensen helped get scanned. Energy From Thorium has become a sort of open source project aimed at resurrecting long-lost energy technology using modern techniques. And the online upstarts aren’t alone. Industry players are looking into thorium, and governments from Dubai to Beijing are funding research. India is betting heavily on the element. The concept of nuclear power without waste or proliferation has obvious political appeal in the US, as well. The threat of climate change has created an urgent demand for carbon-free electricity, and the 52,000 tons of spent, toxic material that has piled up around the country makes traditional nuclear power less attractive. President Obama and his energy secretary, Steven Chu, have expressed general support for a nuclear renaissance. Utilities are investigating several next-gen alternatives, including scaled-down conventional plants and “pebble bed” reactors, in which the nuclear fuel is inserted into small graphite balls in a way that reduces the risk of meltdown. Those technologies are still based on uranium, however, and will be beset by the same problems that have dogged the nuclear industry since the 1960s. It is only thorium, Sorensen and his band of revolutionaries argue, that can move the country toward a new era of safe, clean, affordable energy. Named for the Norse god of thunder, thorium is a lustrous silvery-white metal. It’s only slightly radioactive; you could carry a lump of it in your pocket without harm. On the periodic table of elements, it’s found in the bottom row, along with other dense, radioactive substances — including uranium and plutonium — known as actinides. Actinides are dense because their nuclei contain large numbers of neutrons and protons. But it’s the strange behavior of those nuclei that has long made actinides the stuff of wonder. At intervals that can vary from every millisecond to every hundred thousand years, actinides spin off particles and decay into more stable elements. And if you pack together enough of certain actinide atoms, their nuclei will erupt in a powerful release of energy. To understand the magic and terror of those two processes working in concert, think of a game of pool played in 3-D. The nucleus of the atom is a group of balls, or particles, racked at the center. Shoot the cue ball — a stray neutron — and the cluster breaks apart, or fissions. Now imagine the same game played with trillions of racked nuclei. Balls propelled by the first collision crash into nearby clusters, which fly apart, their stray neutrons colliding with yet more clusters. Voilè0: a nuclear chain reaction. Actinides are the only materials that split apart this way, and if the collisions are uncontrolled, you unleash hell: a nuclear explosion. But if you can control the conditions in which these reactions happen — by both controlling the number of stray neutrons and regulating the temperature, as is done in the core of a nuclear reactor — you get useful energy. Racks of these nuclei crash together, creating a hot glowing pile of radioactive material. If you pump water past the material, the water turns to steam, which can spin a turbine to make electricity. Uranium is currently the actinide of choice for the industry, used (sometimes with a little plutonium) in 100 percent of the world’s commercial reactors. But it’s a problematic fuel. In most reactors, sustaining a chain reaction requires extremely rare uranium-235, which must be purified, or enriched, from far more common U-238. The reactors also leave behind plutonium-239, itself radioactive (and useful to technologically sophisticated organizations bent on making bombs). And conventional uranium-fueled reactors require lots of engineering, including neutron-absorbing control rods to damp the reaction and gargantuan pressurized vessels to move water through the reactor core. If something goes kerflooey, the surrounding countryside gets blanketed with radioactivity (think Chernobyl). Even if things go well, toxic waste is left over. When he took over as head of Oak Ridge in 1955, Alvin Weinberg realized that thorium by itself could start to solve these problems. It’s abundant — the US has at least 175,000 tons of the stuff — and doesn’t require costly processing. It is also extraordinarily efficient as a nuclear fuel. As it decays in a reactor core, its byproducts produce more neutrons per collision than conventional fuel. The more neutrons per collision, the more energy generated, the less total fuel consumed, and the less radioactive nastiness left behind. Even better, Weinberg realized that you could use thorium in an entirely new kind of reactor, one that would have zero risk of meltdown. The design is based on the lab’s finding that thorium dissolves in hot liquid fluoride salts. This fission soup is poured into tubes in the core of the reactor, where the nuclear chain reaction — the billiard balls colliding — happens. The system makes the reactor self-regulating: When the soup gets too hot it expands and flows out of the tubes — slowing fission and eliminating the possibility of another Chernobyl. Any actinide can work in this method, but thorium is particularly well suited because it is so efficient at the high temperatures at which fission occurs in the soup. In 1965, Weinberg and his team built a working reactor, one that suspended the byproducts of thorium in a molten salt bath, and he spent the rest of his 18-year tenure trying to make thorium the heart of the nation’s atomic power effort. He failed. Uranium reactors had already been established, and Hyman Rickover, de facto head of the US nuclear program, wanted the plutonium from uranium-powered nuclear plants to make bombs. Increasingly shunted aside, Weinberg was finally forced out in 1973. That proved to be “the most pivotal year in energy history,” according to the US Energy Information Administration. It was the year the Arab states cut off oil supplies to the West, setting in motion the petroleum-fueled conflicts that roil the world to this day. The same year, the US nuclear industry signed contracts to build a record 41 nuke plants, all of which used uranium. And 1973 was the year that thorium R&D faded away — and with it the realistic prospect for a golden nuclear age when electricity would be too cheap to meter and clean, safe nuclear plants would dot the green countryside. When Sorensen and his pals began delving into this history, they discovered not only an alternative fuel but also the design for the alternative reactor. Using that template, the Energy From Thorium team helped produce a design for a new liquid fluoride thorium reactor, or LFTR (pronounced “lifter”), which, according to estimates by Sorensen and others, would be some 50 percent more efficient than today’s light-water uranium reactors. If the US reactor fleet could be converted to LFTRs overnight, existing thorium reserves would power the US for a thousand years. Overseas, the nuclear power establishment is getting the message. In France, which already generates more than 75 percent of its electricity from nuclear power, the Laboratoire de Physique Subatomique et de Cosmologie has been building models of variations of Weinberg’s design for molten salt reactors to see if they can be made to work efficiently. The real action, though, is in India and China, both of which need to satisfy an immense and growing demand for electricity. The world’s largest source of thorium, India, doesn’t have any commercial thorium reactors yet. But it has announced plans to increase its nuclear power capacity: Nuclear energy now accounts for 9 percent of India’s total energy; the government expects that by 2050 it will be 25 percent, with thorium generating a large part of that. China plans to build dozens of nuclear reactors in the coming decade, and it hosted a major thorium conference last October. The People’s Republic recently ordered mineral refiners to reserve the thorium they produce so it can be used to generate nuclear power. In the United States, the LFTR concept is gaining momentum, if more slowly. Sorensen and others promote it regularly at energy conferences. Renowned climatologist James Hansen specifically cited thorium as a potential fuel source in an “Open Letter to Obama” after the election. And legislators are acting, too. At least three thorium-related bills are making their way through the Capitol, including the Senate’s Thorium Energy Independence and Security Act, cosponsored by Orrin Hatch of Utah and Harry Reid of Nevada, which would provide $250 million for research at the Department of Energy. “I don’t know of anything more beneficial to the country, as far as environmentally sound power, than nuclear energy powered by thorium,” Hatch says. (Both senators have long opposed nuclear waste dumps in their home states.) Unfortunately, $250 million won’t solve the problem. The best available estimates for building even one molten salt reactor run much higher than that. And there will need to be lots of startup capital if thorium is to become financially efficient enough to persuade nuclear power executives to scrap an installed base of conventional reactors. “What we have now works pretty well,” says John Rowe, CEO of Exelon, a power company that owns the country’s largest portfolio of nuclear reactors, “and it will for the foreseeable future.” Critics point out that thorium’s biggest advantage — its high efficiency — actually presents challenges. Since the reaction is sustained for a very long time, the fuel needs special containers that are extremely durable and can stand up to corrosive salts. The combination of certain kinds of corrosion-resistant alloys and graphite could meet these requirements. But such a system has yet to be proven over decades. And LFTRs face more than engineering problems; they’ve also got serious perception problems. To some nuclear engineers, a LFTR is a little … unsettling. It’s a chaotic system without any of the closely monitored control rods and cooling towers on which the nuclear industry stakes its claim to safety. A conventional reactor, on the other hand, is as tightly engineered as a jet fighter. And more important, Americans have come to regard anything that’s in any way nuclear with profound skepticism. So, if US utilities are unlikely to embrace a new generation of thorium reactors, a more viable strategy would be to put thorium into existing nuclear plants. In fact, work in that direction is starting to happen — thanks to a US company operating in Russia. Located outside Moscow, the Kurchatov Institute is known as the Los Alamos of Russia. Much of the work on the Soviet nuclear arsenal took place here. In the late ’80s, as the Soviet economy buckled, Kurchatov scientists found themselves wearing mittens to work in unheated laboratories. Then, in the mid-’90s, a savior appeared: a Virginia company called Thorium Power. Founded by another Alvin — American nuclear physicist Alvin Radkowsky — Thorium Power, since renamed Lightbridge, is attempting to commercialize technology that will replace uranium with thorium in conventional reactors. From 1950 to 1972, Radkowsky headed the team that designed reactors to power Navy ships and submarines, and in 1977 Westinghouse opened a reactor he had drawn up — with a uranium thorium core. The reactor ran efficiently for five years until the experiment was ended. Radkowsky formed his company in 1992 with millions of dollars from the Initiative for Proliferation Prevention Program, essentially a federal make-work effort to keep those chilly former Soviet weapons scientists from joining another team. The reactor design that Lightbridge created is known as seed-and-blanket. Its core consists of a seed of enriched uranium rods surrounded by a blanket of rods made of thorium oxide mixed with uranium oxide. This yields a safer, longer-lived reaction than uranium rods alone. It also produces less waste, and the little bit it does leave behind is unsuitable for use in weapons. CEO Seth Grae thinks it’s better business to convert existing reactors than it is to build new ones. “We’re just trying to replace leaded fuel with unleaded,” he says. “You don’t have to replace engines or build new gas stations.” Grae is speaking from Abu Dhabi, where he has multimillion-dollar contracts to advise the United Arab Emirates on its plans for nuclear power. In August 2009, Lightbridge signed a deal with the French firm Areva, the world’s largest nuclear power producer, to investigate alternative nuclear fuel assemblies. Until developing the consulting side of its business, Lightbridge struggled to build a convincing business model. Now, Grae says, the company has enough revenue to commercialize its seed-and-blanket system. It needs approval from the US Nuclear Regulatory Commission — which could be difficult given that the design was originally developed and tested in Russian reactors. Then there’s the nontrivial matter of winning over American nuclear utilities. Seed-and-blanket doesn’t just have to work — it has to deliver a significant economic edge. For Sorensen, putting thorium into a conventional reactor is a half measure, like putting biofuel in a Hummer. But he acknowledges that the seed-and-blanket design has potential to get the country on its way to a greener, safer nuclear future. “The real enemy is coal,” he says. “I want to fight it with LFTRs — which are like machine guns — instead of with light-water reactors, which are like bayonets. But when the enemy is spilling into the trench, you affix bayonets and go to work.” The thorium battalion is small, but — as nuclear physics demonstrates — tiny forces can yield powerful effects.

Richard Martin (rmartin@newwest.net)
http://www.wired.com/magazine/2009/12/ff_new_nukes/

Be sure to check out the comparrison between Ur, Ur+Th, and Th plants on the second page of that article!
http://www.wired.com/magazine/2009/12/ff_new_nukes/2/