Nuclear Fusion-Fission Hybrid Could Destroy Nuclear Waste and Contribute to Carbon-Free Energy Future

Jan. 27, 2009

AUSTIN, Texas — Physicists at The University of Texas at Austin have designed a new system that, when fully developed, would use fusion to eliminate most of the transuranic waste produced by nuclear power plants.

The invention could help combat global warming by making nuclear power cleaner and thus a more viable replacement of carbon-heavy energy sources, such as coal.

Fusion-Fission Hybrid
The idea behind the compact Fusion-Fission Hybrid is that fusion can be used to burn nuclear waste, producing energy and getting rid of much of the long-lived waste generated by nuclear reactors.

View the complete illustration of the new nuclear waste destruction system, demonstrating how a fusion-fission hybrid, made possible by the Super X Divertor invented by University of Texas at Austin physicists, could integrate into the nuclear fuel cycle. (Large image opens in a new window.)Illustration: Angela Wong

"We have created a way to use fusion to relatively inexpensively destroy the waste from nuclear fission," says Mike Kotschenreuther, senior research scientist with the Institute for Fusion Studies (IFS) and Department of Physics. "Our waste destruction system, we believe, will allow nuclear power—a low carbon source of energy—to take its place in helping us combat global warming."

Toxic nuclear waste is stored at sites around the U.S. Debate surrounds the construction of a large-scale geological storage site at Yucca Mountain in Nevada, which many maintain is costly and dangerous. The storage capacity of Yucca Mountain, which is not expected to open until 2020, is set at 77,000 tons. The amount of nuclear waste generated by the U.S. will exceed this amount by 2010.

The physicists' new invention could drastically decrease the need for any additional or expanded geological repositories.

"Most people cite nuclear waste as the main reason they oppose nuclear fission as a source of power," says Swadesh Mahajan, senior research scientist.

The scientists propose destroying the waste using a fusion-fission hybrid reactor, the centerpiece of which is a high power Compact Fusion Neutron Source (CFNS) made possible by a crucial invention.

The CFNS would provide abundant neutrons through fusion to a surrounding fission blanket that uses transuranic waste as nuclear fuel. The fusion-produced neutrons augment the fission reaction, imparting efficiency and stability to the waste incineration process.

Kotschenreuther, Mahajan and Prashant Valanju, of the IFS, and Erich Schneider of the Department of Mechanical Engineering report their new system for nuclear waste destruction in the journal Fusion Engineering and Design.

There are more than 100 fission reactors, called "light water reactors" (LWRs), producing power in the United States. The nuclear waste from these reactors is stored and not reprocessed. (Some other countries, such as France and Japan, do reprocess the waste.)

The scientists' waste destruction system would work in two major steps.

First, 75 percent of the original reactor waste is destroyed in standard, relatively inexpensive LWRs. This step produces energy, but it does not destroy highly radiotoxic, transuranic, long-lived waste, what the scientists call "sludge."

In the second step, the sludge would be destroyed in a CFNS-based fusion-fission hybrid. The hybrid's potential lies in its ability to burn this hazardous sludge, which cannot be stably burnt in conventional systems.

"To burn this really hard to burn sludge, you really need to hit it with a sledgehammer, and that's what we have invented here," says Kotschenreuther.

One hybrid would be needed to destroy the waste produced by 10 to 15 LWRs.

The process would ultimately reduce the transuranic waste from the original fission reactors by up to 99 percent. Burning that waste also produces energy.

The CFNS is designed to be no larger than a small room, and much fewer of the devices would be needed compared to other schemes that are being investigated for similar processes. In combination with the substantial decrease in the need for geological storage, the CFNS-enabled waste-destruction system would be much cheaper and faster than other routes, say the scientists.

The CFNS is based on a tokamak, which is a machine with a "magnetic bottle" that is highly successful in confining high temperature (more than 100 million degrees Celsius) fusion plasmas for sufficiently long times.

The crucial invention that would pave the way for a CFNS is called the Super X Divertor. The Super X Divertor is designed to handle the enormous heat and particle fluxes peculiar to compact devices; it would enable the CFNS to safely produce large amounts of neutrons without destroying the system.

"The intense heat generated in a nuclear fusion device can literally destroy the walls of the machine," says research scientist Valanju, "and that is the thing that has been holding back a highly compact source of nuclear fusion."

Valanju says a fusion-fission hybrid reactor has been an idea in the physics community for a long time.

"It's always been known that fusion is good at producing neutrons and fission is good at making energy," he says. "Now, we have shown that we can get fusion to produce a lot of neutrons in a small space."

Producing an abundant and clean source of "pure fusion energy" continues to be a goal for fusion researchers. But the physicists say that harnessing the other product of fusion—neutrons—can be achieved in the near term.

In moving their hybrid from concept into production, the scientists hope to make nuclear energy a more viable alternative to coal and oil while waiting for renewables like solar and pure fusion to ramp up.

"The hybrid we designed should be viewed as a bridge technology," says Mahajan. "Through the hybrid, we can bring fusion via neutrons to the service of the energy sector today. We can hopefully make a major contribution to the carbon-free mix dictated by the 2050 time scale set by global warming scientists."

The scientists say their Super X Divertor invention has already gained acceptance in the fusion community. Several groups are considering implemented the Super X Divertor on their machines, including the MAST tokamak in the United Kingdom, and the DIIID (General Atomics) and NSTX (Princeton University) in the U.S. Next steps will include performing extended simulations, transforming the concept into an engineering project, and seeking funding for building a prototype.

For more information, contact: Lee Clippard, Lady Bird Johnson Wildflower Center, 512-232-0104; Dr. Mike Kotschenreuther, 512-471-1322; Dr. Swadesh Mahajan, 512-471-4376.

69 Comments to "Nuclear Fusion-Fission Hybrid Could Destroy Nuclear Waste and Contribute to Carbon-Free Energy Future"

1.  Ryan said on Jan. 28, 2009

I assume this technology still does nothing to address the horrendous environmental and health consequences associated with the mining and enrichment of nuclear fuel? Though the radioactive waste from the plants themselves is a grave concern, it is only one of the numerous deadly problems associated with nuclear power. No nuclear plants should be permitted or allowed to operate until these threats are addressed and resolved.

2.  qraal said on Jan. 28, 2009

Turn off the nukes and what do people do for electricity then? Burn coal? What kind of unrealistic picture of the world is that? Most of the supposed environmental issues from mine tailings have been exaggerated by Greens for political reasons, but it is still an issue and can only be improved by higher-efficiency use of fission fuels. We need to be able to burn all the U238 as well as the bit of U235 we focus our efforts on now.

3.  Tony Turpn said on Jan. 29, 2009

We need to give everything a chance in our energy needs. What can be more deadly is waiting for the "perfect" solution to come along. I applaud these scientists for trying to solve problems instead of waiting and hoping someone else will solve the problem for them. If they wait, we can always burn more coal, right?

4.  Brad said on Jan. 29, 2009

It's a step in the right direction. Having worked with the movement of radioactive waste, I like the idea of reducing the amount that we stuff into holes in the ground.

5.  tyler said on Jan. 29, 2009

Space is an endless storage unit.

6.  David said on Jan. 29, 2009

I first saw the TOKAMAK magnetic bottle experiment as a visiting high school student in the summer of 1968, in the basement of the PMA (now called the RLM). It's gratifying to know that the work continues.

7.  Bart said on Jan. 29, 2009

In response to Ryan: Are you of the belief that coal mining is both environmentally sound and safe to those who mine it? Almost anything is a better option. Nuclear plants were preferable before this technology. Now that fact is far truer.

8.  Elliot said on Jan. 29, 2009

One of the big reasons I've been against expansion of nuclear power is for the waste issues. It just doesn't seem that smart to leave the waste laying around where it remains radioactive for thousands of years. If this device works and can get rid of the waste that's already built up in addition to the future waste, then that's a breakthrough in my book.

Now if there was a way to separate the energy generation from the weaponization process to the point that there's no mistaking one for the other, or using similar tools or elements for both, then even unfriendly nations could have clean electricity without endangering the rest of us. One step at a time I suppose, and this is a big one.

9.  Daniel Encina said on Jan. 29, 2009

This early stage of nuclear waste control needs the technology management teams to collaborate, sound financial backing from government sources and technology interest, precisely along with interstate, regional, pan-American and international policy on global warming and security caveats. Is this invention info conclusive enough for inclusion/approval in STS curriculum or cross-listed courses?

10.  Marshall Eubanks said on Jan. 30, 2009

This idea was (in some sense) around in the 1960s, believe it or not.

The high neutron flux produced means that the CFNS would itself become radioactive, and the steel of its construction weakened by neutron irradiation. I would like to see a life-cycle analysis to make sure that the total waste consumed was more than that produced by the CFNS itself.

This general issue is why I would like to see a lot more emphasis places on He3 fusion and also on linear fusion devices.

11.  argosian said on Jan. 30, 2009

To Ryan: Are you aware that coal contains radioactive uranium, barium, thorium and potassium? Additionally, the strata in which coal is often found frequently contains even higher concentrations of these and other radio-isotopes. Mining and burning coal release these contaminants into the atmosphere and the "fly ash" left over from burning has much higher concentrations of radioactive elements and heavy metals. Finally, ever heard of miner's lung? What about incidence of cancers and birth defects in coal mining towns? Coal mining and processing is implicated in vastly more health problems than uranium mining and processing. Neither activity is going away any time soon, but I would say on the whole that nuclear-derived energy production is safer and cleaner than coal, and finding ways of making it even cleaner and safer makes it all the more attractive.

12.  Alhazred said on Jan. 30, 2009

It is an interesting technology, but let's be realistic here.

Building an existing 'off the shelf' LWR design requires roughly 10 years. Turning this technology into a standardized design which can be used by industry will require some amount of time, probably 10 to 20 years by the time all the safety engineering is complete and a prototype reactor is built, run for several years and the bugs are worked out of it.

So we're talking about optimistacally 2028 and possibly 2038 to 2048 before the first one of these reactors would come online. By every indication solar PV and solar thermal power systems will be highly mature and widely deployed by that time. Why at that point is there a need for more nuclear reactors?

Nuclear power's time has come and gone. Regardless of any debate about its safety and efficacy as a power generation technology, the time frames are just wrong. Had we made these advances 20 or 30 years ago it would maybe be a different story, but at this point nuclear power is irrelevant. The only thing nuclear power can do now is suck up investments which would be better made perfecting solar, wind and dry geothermal power solutions, as well as the buildout of the power grid which they will require.

So, with all due respect to nuclear power enthusiasts, please stop wasting our time and money on a dead technology which has relegated itself to irrelevance long ago.

13.  James said on Jan. 30, 2009

It's a great idea to solve our current stored waste problems, but honestly why would you want more nuclear production when it involves so much risk? Using nuclear energy requires too much technology, environmental risk and safeguards when we have so many other alternatives such as wind, solar and geothermal. All of which are ready today, not 50 years from now.

14.  phil said on Jan. 30, 2009

I understand the idea of fission and fusion, but at the end of the day what are the waste products that would come out of such a process?

15.  Al said on Jan. 30, 2009

Ryan: If your concern is the mining, then maybe we should not allow coal. Lots of people die and/or get sick in coal mines. Maybe we should not allow oil drilling; lots of people die over the fight of oil. OK, so now we eliminated two other primary forms of energy. Solar, wind and water are not there yet. We will improve tech, but we gotta do with what we have.

16.  quixote said on Jan. 30, 2009

As the scientists themselves say, this should be a bridge technology to allow us to move away from nuclear power. It would be great if the reactors we've been saddled with could be used and decommissioned without running up tens of thousands of years' worth of bills.

The first commenter is right in noting the front-end problems. They're still there. And there's the little problem that uranium itself is a finite resource. We'd run out of the *practically* recoverable mineral within 50 to 100 years if enough was mined to make much of a dent in our energy needs.

The problem with nuclear has always been like the old joke: the operation is a complete success, but the patient dies.

We need to get off that treadmill, and this research is a big contribution because it would make that easier.

17.  DMFH said on Jan. 30, 2009

Unfortunately the many comments we see world-wide about "no nukes" reflect the world's continual lack of understanding about nuclear energy, and the fear that results from that lack of knowledge. People can focus on nuclear power as a negative because of its attachment to global warfare, and the fact that badly managed nuclear resources result in damage and destruction one can readily perceive in a short amount of time--also within a human lifetime.

If people understood and acknowledged the long-term, more-than-a-human-lifetime impact of fossil-fuel usage, which we're only coming to terms with now some 150 years or so after the U.S. Industrial Revolution, there would be less objections to nuclear power.

Steps forward like this bring us ahead towards cleaner and more abundant forms of raw power to move humanity ahead instead of being stuck inside the pseudo-sciences of uneducated fear-mongering.

18.  Tom said on Jan. 30, 2009

If the CFNS facility becomes radioactive, perhaps its materials could somehow be disposed of by another CFNS.

19.  jeff said on Jan. 30, 2009

Eighty percent of the 'waste' stored at nuclear plants right now could be burned with reprocessing (technology established during the Manhattan Project and banned by Jimmy Carter) and using fast breeder reactors (also existing technology, tested, proven and mothballed at the INL).

20.  Winston said on Jan. 30, 2009

Marshall: I'd rather not wait 'til we have a viable moon base to send us the He3! As I understand it (based on the JET reactor in the UK), although the reactor walls will be irradiated by the neutron bombardment, it should be able to run for significant periods (not that JET has!) between any reactor-wall refittings.

As for linear fusion, it was my understanding that these were long ago abandoned as a viable power source due to the impracticalities of downsizing them enough to produce a manageable amount of power?

21.  Bud Aaron said on Jan. 30, 2009

It will never cease to amaze me how many self-made nuclear experts we have in the world. I'm 81-years-old and worked testing devices in the Pacific. A friend of mine and I walked to ground zero three days after a 20 KT blast to kick the slag around. We wore coveralls and a mask but aside from that, nothing. I'm still healthy as a horse. My point is: Way too much is made of the danger of atomic waste, and I just don't believe it's a problem.

22.  Cellar said on Jan. 30, 2009

The mere fact that we haven't so far built non-nuclear large scale solutions that in this or that way aren't hazards to the environment either doesn't mean they can't exist. Heavy industries have a long, active life, so most technology powering our grids today isn't the very latest, nuclear or not.

I think this, if viable and without unforeseen snags, is a wonderful advancement for nuclear technology. It doesn't magically make it safe and fit for children's toys.

Realistically large parts of the world are still burning coal or wood, petrol, gas, what-have-you, often enough right next to nuclear reactors. We will need advancement in those areas, too.

23.  maxxotic said on Jan. 30, 2009

It is commonly believed that fission is a low-carbon source of power. However, if you consider (and you must) the full life-cycle of fission power (including the tremendous amount of energy--thus carbon--required to mine/refine/transport/dispose of the fuel) it is a fact that fission power produces more carbon dioxide than solar or wind power. The main argument in favor of nuclear power is the cost of power-generated. However if you figure in 'externalized' costs, nuclear power is not competitive with other sources of power. The work of these scientists can be thought of as helping to fix a problem that should not be created in the first place. Though their work is to be commended for its use in reducing existing waste, it should not be used to support the expanded use of fission power. Not mentioned is the huge water requirements for fission power plants. In 2008 several nuclear plants were in danger of being shut down because the water needed to cool them down was in critical shortage. We will be forced, in the near future, to choose between using water for power or for human consumption (for drinking or agriculture). Power will lose in that choice, especially when we have many alternatives to nuclear power that require no water at all.

24.  kbt999 said on Jan. 30, 2009

Life isn't perfect, and there's no perfect solution to energy production. We need to use what we have and this kind of invention is on the right track. Hats off to these guys at UT.

25.  Jim said on Jan. 30, 2009

Sounds like a step in the wrong direction to me. We need to transition to burning U-238 and Th-232, not just the tiny amount of U-235 nature has provided. For that, we need breeder reactors, which need substantial amounts of transuranics to get started. So we should be preserving them, instead of destroying them.

On the other hand you can burn thorium (Th-232) if you have neutrons. Usually you would get those from uranium, but there's a proposal to get the neutrons from an accelerator (PDF). That could give you a power reactor with no plutonium, and so no proliferation risk. Maybe this CFNS would be an even better source.

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26.  MattB said on Jan. 30, 2009

Have to start somewhere. Doing nothing accomplishes nothing. Well done. 2050 is a long time from now though.

27.  Matt Hunter said on Jan. 30, 2009

Not only would this technology be great in reducing nuclear waste, it would be a perfect superheated steam generator, a potential for creating clean power from destroying waste.

28.  Bob said on Jan. 30, 2009

If you want more info on pure fusion energy generation, Google ITER--the timeline points to 2040-2050 before commercial plants possibly come online. This is a near-term solution that gets the public aware of fusion power and comfortable with a flame 100 times hotter than the sun in a building that looks like a warehouse made of aluminum siding. It's safe, but you have to get the public on your side before people let a thermonuclear reaction happen across the river in town.

29.  Jon Carr said on Jan. 30, 2009

I am all for research, but my concern is that the neutron-producing fusion takes a lot of energy and as we all know no fusion system to date is net positive. So my question is: What is the net energy produced and what is the ultimate price per kilowatt when we are all said and done? It may address the waste issue, but not the cost issue. Nuclear power is still one of the most expensive ways to produce electricity.

30.  Brian said on Jan. 30, 2009

Qraal: Do you have any idea how much radiation a coal-fired power plant releases into the air?

31.  Austin said on Jan. 30, 2009

I'm a nuclear engineering student at the University of Tennessee - Knoxville. While this whole idea is nice, it's nothing more than a standard fusion reactor with fission plants' waste forming the wall of the reactor. This is a great way to reduce waste. However, the problems with this process aren't just sticking the fission waste on the walls, it's getting a sizable fusion reactor to work consistently, which people have been working on for more than 50 years and which will take at least several more decades. There are problems with starting the plasma-generating pulse, maintaining the pulse, handling the fuel, which materials can just hold something with such an incredible neutron barrage as a fusion reactor. There are so many engineering problems requiring incredibly expensive research that it's going to be a while before fusion.

Natural uranium isn't excessively radioactive. In fact, you probably get more from the radon daughters from digging a few feet into the ground. That's where the vast majority of the radiation you'll receive in your lifetime comes from. The biggest problem with U mining is that miners inhale it, and the type of radiation U-238 (>99 percent of U) gives off is only bad if you breathe it in, which is what miners do. Most of the U mining I would imagine is legitimate. Enrichment, or spinning the U in a giant tube or other complicated machinery, doesn't hurt anyone. And enriched U is, if anything, taken too seriously. The cap on most commercial enrichment is 5 percent U-235, the good stuff, and that's not remotely enough to make a bomb for anyone.

The waste issue just plain stinks, I know. There really isn't that much of it, probably about tens of thousands of tons. Sounds like a lot, but compare those numbers to how much hydrochloric acid is made commercially, it's almost negligible. The biggest problem is that all radioactive waste has to be stored on-site in containers that were not originally built for that amount of waste, since the original guys figured we'd have figured out a place to stick it all, completely out of the way, by now.

Political problem: No one wants it in their backyard, and so it doesn't go anywhere. If, not when, we just pick a place in the middle of nowhere, this would be much less of a problem.

Also, we would burn our U-238 to turn it into Plutonium-239 that we can put in fission reactors, but Plutonium is such a taboo in politics that we'd have to be in dire straits to reconsider it. It's really not any worse than U235.

32.  james said on Jan. 30, 2009

Isn't there also something to be said about the limited nature of our global uranium reserves? No one likes to talk about this, but uranium itself is rare and non-renewable.

33.  Stuart McCracken said on Jan. 30, 2009

It is naive to assume that there are forms of generating electricity on the Earth's surface with no environmental impact. Even something as "benign" as a photovoltaic cell has environmental cost from the growing silicon and production of silicon wafers/cells. The bottom line is that we are wrecking our planet by burning various materials in atmosphere. Here is a news flash for environmental groups: we breathe the atmosphere. The suspended particulates and chemical vapors from combustion are brought down onto the surface and into water tables by precipitation. The air we breathe and the water we drink are being polluted by the junk we are burning while we are debating the worth of nuclear energy. Why are environmental groups so blind to this fact? Why accept coal and gasoline as safe just because they've been around for 100 more years? Familiarity is not an assurance of safety.

The volumes of raw materials required to generate energy from fission are far less than coal. By nature, our fear of radioactivity has prompted very tight regulations on radioactive material and fission byproducts. As a result, fission plants can't just "pump out" clouds of waste gas into the environment as coal plants do; we have to store the nuclear "waste." If this waste can be "burned" to produce energy, where the byproducts are relatively harmless, then fission would be a decent choice for "on demand" power to supplement alternative energy sources.

For the case of environmental impact of uranium mining, consider Northern Saskatchewan (home to a large world uranium supply). The small volumes of ore processed mean even smaller tailings ponds when compared to the tar sands of Alberta. High-energy density of fission fuel and sub-surface mining of ore mean no barren fields of strip mines and square-kilometer tailings ponds. Mining nuclear ores does have an environmental impact, but in comparison it is much less than something like surface coal mining. In comparison, the effect per kWh is far less.

If you want to see environmental disasters, look at coal mining, tar sand mining, phosphoric acid production or any large-scale mineral extraction. The fact that nuclear power deals in such small quantities of ore, fuel and waste mean that it is possible for greater (ultimately more cost-effective) control over environmental impact. Read the facts before you indulge in the drivel of "environmental" groups.

34.  jon said on Jan. 30, 2009

No one has ever been killed in a nuclear power plant in the U.S. Russia, yes, but not here. It is far safer than coal or gas plants. Reducing the waste output will only make it safer yet. The designs of the reactors have evolved to the point that they are virtually foolproof. Even Homer Simpson could not mess them up.

35.  Jed said on Jan. 30, 2009

Uranium can be reclaimed from our nuclear waste (depleted uranium), which is still something like 98 percent good, but the process produces plutonium, which is extremely dangerous and not environmentally friendly.

36.  Wayne said on Jan. 30, 2009

One percent of 77,000 tons is 1.5 million pounds. It will still need to be stored safely somewhere. That is only a little more than 300 space shuttle flights. It could work?

37.  gibbie said on Jan. 30, 2009

Breed plutonium and burn that as fuel.

38.  Osama said on Jan. 30, 2009

@ Stuart McCracken: You don't die from CO2, and other particles of a coal-based power plant can be filtered. But you can die from radioactive particles through cancer.

39.  Sherwood Botsford said on Jan. 31, 2009

If this works, and if the size is correct (room-sized) could this be a more local way to generate power:

Bypass the LWR. Use a fusion source of neutrons and a subcritical reactor mass. Control is much easier. Output depends on how many neutrons you generate. No moving parts inside the core.

40.  Jim said on Jan. 31, 2009

I wouldn't go so far as to say no one has ever been killed in a nuke plant in the U.S. That would, in fact, be wrong. Several incidents have occurred, but all were industrial accidents as opposed to "nuclear" accidents. Some were radiological in nature, but nothing of the scale of what happened at Chernobyl plant 3.

As a nuclear worker, I see the inherent benefit to operating nuclear power on a daily basis. However, even to my own family and friends, no one truly understands anything more than what the media and Hollywood have shown them. To them, a reactor being "critical" still sounds like it's a bad thing as opposed to normal operation.

As evidenced in the media over the last couple of years, general acceptance of nuclear power is growing and in time, the media and the movies will sway public opinion to a more favorable light. People want to be told how the feel about things and it seems that nuclear power being "bad" is not in style any more.

41.  TheMage said on Feb. 1, 2009

Jed: Plutonium is burnable in fission reactors. Even if we just used the current reprocessing technology (currently used by the Japanese and French and outlawed by Carter), the current amount of waste generated by a family of four over their lifetimes is about one cup.

By the way, photovoltaics generate huge amounts of toxins in their production, and commercial windmills take a lot of precious space and still require maintenance and occasional replacement.

Largest PV solar plant ~60 megawatts (on a good sunny day)
Largest thermal solar plant 350 megawatts (and huge)
Largest planned thermal solar plant 1,000 megawatts

Largest existing nuclear plant 8,212 megawatts running at an average of 70 percent power 24 hours a day, seven days a week, 365 days a year.

42.  UnSub said on Feb. 2, 2009

Every time someone comes up with an extension for using non-renewable fuels--this solution for nuclear waste, "clean" coal--it's really used to justify that we keep going as we have been because we'll have a fix in place...eventually.

Give renewables the same time line--2050, in this case--and they'll also be a lot more effective. The thing is if we start ramping up our renewable energy sources today, we'll be in a lot better position in 2050 as well, rather than continually damaging the environment until our non-renewable energy fix is in place.

And I agree with Jon Carr's assessment - if we are using all this energy to destroy nuclear waste, how much is actually going into power grid at the overall level?

43.  Mike D said on Feb. 2, 2009

As a supporter of renewable energy sources I want to remind all of my compatriots that solar and wind power is not ‘clean’ energy. They, too, have their environmental and ecological side effects. Both solar and wind require efficient geospatial placement and both require huge swaths of land. Both solar and wind installations have significant local environmental impacts. Both types are generally situated far from urban centers and hence require extensive new transmission lines which require the mining, smelting and transportation of massive amounts of copper and steel, and both systems require environmentally hazardous processes and products in their production. Neither wind nor solar nor geothermal are reliable 24 hours a day, seven days a week, and at least wind and solar are susceptible to weather-related damage.

The point is even in the best case solar and wind are only a part of the answer. Nuke power is tremendously efficient in land use and power produced and it's reliable 24/7. It has its problems but let’s not throw the baby out with the bath water. Nuke power still needs to be researched to see if it can be safer, even more efficient and worthy of long-term investment. I'll agree that most of the anti-nuke posters are at heart swayed by their emotional beliefs and not facts. The same thing that creates NIMBYism. But in the end you have to remember regardless of your expertise or your beliefs what you personally want is irrelevant. The decisions will be made by the power brokers, the cold and ‘invisible hand’ of the market, and maybe even by “the will of the people” as occasionally happens. Not by individuals holding their cherished beliefs close to their bosom, decrying all dissenters.

44.  Mike Kotschenreuther said on Feb. 3, 2009

Hello to all, we are the scientists who did the research on the hybrid waste burner (Mike Kotschenreuther, Swadesh Mahajan, Prashant Valanju and Eric Schneider). We thank you all for your interest and expressions of support. It really makes our work seem more worthwhile. We've been too busy to answer questions 'til now. Many of you had great questions and comments:

1) To Alhazred, James, Al, DMFH, maxxotic, UnSub: We are big supporters of wind and solar, too, but studies show it is very difficult to make very deep replacements of baseload electricity plants (coal and nuclear) with these intermittent sources. We agree with renowned climate scientist James E. Hansen (truly a scientist-hero in the battle to stop climate change, fighting since 1988) that eliminating coal emissions is the single most important part of preventing global warming. And we think this will require nuclear power, especially since we have a deadline to solve the problem quickly. To quote Dr. Hansen: "However, the greatest threat to the planet may be the potential gap between that presumption (100 percent "soft” energy) and reality, with the gap being filled by continued use of coal-fired power. Therefore we should undertake urgent focused R&D programs in both next generation nuclear power and carbon capture and sequestration." You can read his entire letter to Barack Obama online (PDF).

2) To Marshall Eubanks, phil, Tom, Jeff, Winston: The nuclear waste destroyed by the CFNS has far more long-lived biohazard than the new waste produced as a result of our process--by about a factor of a hundred.

3) To jeff, Jim, Matt, Jon Carr, Stuart McCracken: The hybrid is a definite net energy producer, not a consumer, mainly because burning the fission transuranic waste creates enormous energy. The CFNS produces about 100 MW of pure fusion power, and requires a bit more than 100 MW of electricity, but the fission waste (burned by the CFNS) produces about 1200 MW of electricity. Almost all of this electricity can be sold to the grid, while a little bit is used internally to keep the CFNS going. A little bit of fusion power makes a big difference to the neutron chain reaction of transuranics with much higher power, since a certain amount of fusion energy gives roughly an order of magnitude more NEUTRONS than the same amount of fission energy.

4) To Alhazred, quixote, Bob, Austin: The CFNS is much easier than a pure fusion reactor. A pure fusion reactor (by itself without fission boost) has to produce many times more electricity than it consumes--in order to be an economically viable energy source. But the CFNS only needs to produce about as much fusion energy as the electricity used to keep it going. This is much easier to achieve, and we believe is nearer term.

5) To qraal, Elliot, quixote, Jim, Austin, james, Jed, gibbie: We think it would be possible to generate electricity from relatively abundant Thorium--232 using a CFNS, and with a much lower proliferation concern than existing fission technology, and this is something we are already working on.

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45.  An Aggie said on Feb. 8, 2009

UnSub: Actually not much power is used at all to destroy the waste. Typical first and second generation fusion (until we would get to a p-B11 fusion) will produce an excess of neutrons. In essence, this is mostly 'free' energy.

Let me speak to waste as an issue to begin with. Most of the nasty stuff is gone within the first few hundred years. By 10,000 years, it is no more radioactive than the dirt it originally came from. If we don't change our reprocessing laws (no thanks to Jimmy Carter), we lose a lot of potential energy still in Pu and U. Nevertheless, even with the long lived transuranics, most of the really nasty stuff is gone very quickly and the overall level of activity in spent fuel declines essentially to background in a few thousand years. Now, if we reporcessed, it would take about a thousand years to reach background. And we would be able to extract some potentially useful radionuclides. It is not necessary to contain waste for millions of years, but could we engineer a containment for a thousand years? Well, I would like to think that if Egyptians could build structures to last 5,000 years ago, we might be able to follow today. Those nice steel and concrete storage casks that can take a train hit seem they might be able to do the job if stored in a dry environment (say, a desert).

Hats off to UT for the effort. Besides, when we are all driving our plug-in hybrids and charging up at night, what are we going to use to make the go-juice on that chilly (or hot), windless night in Texas? Wind, solar, hydro? Probably not. Coal, gas or nuclear. It's probably a whole lot less expensive to sequester compact radwaste than high volume (gas phase) combustion carbon byproduct.

46.  Kyle said on March 8, 2009

This is all interesting, but what about using nano-fabric or some other technology to use even the small remaining waste as fuel. If it's radioactive, it's giving off energy. That energy can become electricity. Why not use it in a waste disposal setting like landfill to electricity generation? If it seems like we have the technology, it may not be economical, but who cares. Let's just employ the technology to make it possible. I would like someone with more in-depth knowledge of this to give me a reason besides economics why we can't do this or even if it is possible.

47.  Brian Park said on March 15, 2009

Could you explain in more detail how this process works? Normally when you irradiate matter with neutrons, you cause some nuclides to fission (U235, Pu239, U233), others capture the neutrons (U235 can capture a neutron and become U236, which builds up in an "ordinary" fission reactor). So this process "scrambles everything" turning non-radioactive substances into radioactive substances and vice-versa. How are you going to control the process to modify those nuclides that are radioactive, and leave the stable ones alone? The only way I know to do this is to continuously reprocess the material, remove the stable nuclides, and send the unstable ones back in for more bombardment. But if this separation could be readily done, we would do it to the materials from conventional reactors, and have at worst pounds of waste instead of tons (a typical reactor consumes about 20 pounds of fissile fuel per year and makes a similar amount of radioactive waste. But that waste is mixed in with tons of "inert material" that is not practical to separate. You irradiate that with neutrons, you turn more of the inert material into radioactive than you destroy initially radioactive material (there is more of the inert material in the mix). The uranium that fails to fission just keeps capturing neutrons and gaining mass number (which is radioactive with long half-lives).

The only solution I know that is practical is the "magic filter" of time. Wait long enough, and the radioactive nuclides go away.

The only thing I see that your process offers is to enable 'burning" fuel that is so contaminated with fission products that it will not "burn" in an ordinary reactor. (Normally only about 1 percent of the fuel in a "charge" is fissionable in an "ordinary" reactor.) So your neutron source would enable an existing reactor to burn the "charge" of fuel longer, not "destroy" dangerous nuclear waste.

48.  Bob Overman said on March 28, 2009

When you consider getting rid of fission products (FP) look at what the Savannah RiverLab has done for the weaons program. They are taking the FP out of the storage tanks, most of the solid material is aluminium, from the fuel rods. The solids are mixed with sand, put into an electric furnace and the molten glass is poured into lead casks. The glass 'logs' are stored until a permanent place is found. Very little decay heat is generated because the long half-lived actinides, plutonium, uranium, Americium, etc. were chemically separated. The glass will keep the FP from migrating for several thousand years.

The plutonium and uranium will be mixed with 5 percent enriched uranium and made into more fuel rods for power reactors. We are getting rid of weapons grade plutonium. The plutonium from power reactors is difficult to fission due to the lack of Pu-239. It is not a proliferation hazard.

I question whether the FP needs to be "burned". What will the composition of the burned FP be? What half-lives and what will be the specific activity of the products? These might be of academic interest, but you might produce a material which is much more radioactive for a longer time than what you have now.

49.  Robert Groutars said on April 7, 2009

This is something the world is waiting for.

50.  Niki said on April 17, 2009

In response to Alhazred: I am sorry, but I believe you are off-track. Sure, nuclear energy has been around for quite some time, but there is no reason to assume that it is outdated or that is has outlived any hope of being useful. If anything, this will at least get rid of any nuclear waste we have left by the time it is actually created, which is sure to be an impossibly large amount if your estimated time line is true. In my opinion, as we discover new ways to produce and use safe nuclear energy in place of fossil fuels, nuclear energy will remain as a top power source. No matter how widespread solar and wind power become, there are still plenty of places that would not be able to harness these energy sources. In those cases, nuclear energy will remain to be an important form of power. And if they do create a machine that is capable of what has been described above, it will definitely have a widespread impact on energy, no matter how advanced we may be at the time.

51.  Magnus Hasselqvist said on May 14, 2009

If we add some "heat-storage materials" (water, stone, concrete, bricks, mud, lightweight concrete, preferably produced without too much CO2) at strategic places in our houses, the houses only need to be heated or cooled against the average outside temperature.

If we had laws which forced buses and trains to allow people to take their bicycles with them, more people would find it useful to commute or otherwise travel not using their cars (and thus avoid the traffic jams, which, by the way, would be less severe).

Higher fuel prices and less taxation on other stuff would result in people and working places rearranging such that the commuting times were reduced, and thus the quality of life increased.

While most of the classical industrial world has had the same, or reduced, level of fossil fuel usage during the last 20 years, the U.S. has nearly doubled its use despite the possibilities for fuel savings offered by the revolution in IT and control technology. Maybe this is why the economy is melting?

I like the idea of reducing the amount of nuclear waste, but the truth is that the U.S. uses about twice as much fossil stuff per capita than the average for the highly industrial world (and therefore decades more than for the developing world), and that the best replacement for a lot of the current oil, coal and nuclear energy is by energy savings.

If the rest of the industrial world knows how to do it, why can't it be done in the U.S.? And the ways to save energy are easy to implement, and well tried. In addition, improving houses, etc. creates good U.S. jobs, whereas coal mining is awful, and the alternative is to provide a lot of dollars to people we have no reason to give our money to.


52.  Michaelc said on May 25, 2009

There is no country in the world where nuclear power is able to support itself without government subsidies ($70 billion in the U.S. alone since 1950). The technology has been in use commercially for more than half a century. If it was a viable commercial proposition, wouldn't it be a non-subsidized success somewhere?

On the other hand, with probably less than $5 billion in subsidies since 1950, wind and solar are very close to being competitive with coal and nuclear but without the long construction time or toxic leftovers. If you include the externals of site cleanup, waste remediation and health costs, wind and solar are probably actually significantly cheaper (and likely to get more so since the fuel is free).

53.  Mad Jack said on July 14, 2009

Wow! I worked on fission-fusion hybrid concepts in the '70s and thought the idea was shelved and forgotten. I think it's a great idea when put into the appropriate overall energy strategy. Using co-location techniques and treating today's energy crisis like a "Manhattan Project," realistic timelines for "parks" of fission-fusion hybrids and reprocessing facilities and fission power plants could be measured in election cycles rather than decades. Unfortunately, we’d have to make it secret like the "Manhattan Project" because the public reaction would be riotous.

Yes, there are positives and negatives to such a concept as there are with any highly concentrated energy generation-distribution schema, but--other than the fusion candlestick--the technology is ready TODAY! And the laser scheme seems to be improving as does the rest of the plasma physics work.

I’m ready to start work! Where do we sign up?

54.  Harold l. Alger Ii said on Aug. 2, 2009

How about the waste we already have? Is it going to go away magically in 10 years, 20 years or This technology is a good thing to dispose of existing nuclear waste and get a value for it and distance ourselves from danger. It is stored all over the country now and has been for many, many years. There are many well-developed countries to benefit from this technology and the advances that are referred to even in this article. We need a safe and clean disposal method and get it to pay for itself in the mean time. We need to think in broader terms than just one generation and cleanup has fallen to us. It will take many technologies to fill the void and we need them all. So, let's advance the use of a cleanup technology and dispose of nuclear waste as a fuel and realize that this is a waste to energy solution of the highest order. We will and do use nuclear power, and it's in service today and not leaving.

55.  Laurinda Cole said on Dec. 2, 2009

How much would it cost to construct this so that it could provide electricity? How much electricity could be produced? How much land would you need to construct a plant? What kind of staff would you need to operate this on a daily basis?

56.  Brandon Ellis said on Dec. 11, 2009

There is a lot of criticism on this post and that won't get us anywhere. I think that any effort to reduce waste and help with carbon emissions is a valiant one. Alas, there seems to be much greater minds than mine on this subject here, but I plan on writing about this issue on my blog. I have been looking into magnetic energy to help the earth through using it as power. But the F-F Hybrid could be a game changer. I am going to share this with my circle of influence. Thanks.

P.S. Nuclear power will be leaving quicker than you think in response to that last comment.

57.  Stuart said on Jan. 25, 2010

Ryan said on January 28, 2009:

I assume this technology still does nothing to address the horrendous environmental and health consequences associated with the mining and enrichment of nuclear fuel? Though the radioactive waste from the plants themselves is a grave concern, it is only one of the numerous deadly problems associated with nuclear power. No nuclear plants should be permitted or allowed to operate until these threats are addressed and resolved.

Mining is not a problem. There is enough naturally occurring uranium in the earth's oceans.

Uranium enrichment is a problem? How? It is one of the cleanest processes in the world. The enriched nuclear fuel is the size of a pellet -- and then assembled into a rod the size of a pencil.

How much would it cost to construct this so that it could provide electricity? How much electricity could be produced? How much land would you need to construct a plant? What kind of staff would you need to operate this on a daily basis?

It would cost about 10 billion in today's dollars for a hybrid plant or for an 1100 MWe nuclear power plant.

Electricity? Ask the researchers. A very good question.

Land use -- about the same as a modern nuclear power plant. Use existing sites in order to minimize environmental impact. Each plant would probably be the size of a football stadium and its adjacent parking lot.

Staff -- about the same as a modern nuclear power plant. I would say 1,000 personnel nearly full time. 2,000 to 3,000 for initial construction and start-up.

Michaelc said on May 25, 2009:

There is no country in the world where nuclear power is able to support itself without government subsidies ($70 billion in the U.S. alone since 1950). The technology has been in use commercially for more than half a century. If it was a viable commercial proposition, wouldn't it be a non-subsidized success somewhere?

On the other hand, with probably less than $5 billion in subsidies since 1950, wind and solar are very close to being competitive with coal and nuclear but without the long construction time or toxic leftovers. If you include the externals of site cleanup, waste remediation and health costs, wind and solar are probably actually significantly cheaper (and likely to get more so since the fuel is free).

This is not true. VC Summer nuclear power plant did not take any funds from the U.S. government and has been saving for years in order to build two AP 1000 reactors. This is one of the few utilities that had some long term vision.

If anybody is interested in knowing more -- please e-mail me.


58.  Leonel Nava said on Feb. 2, 2010

Hi to all. I was reading the pros and cons of all the energy sources you are mentioning here and in some sense all have part of the truth. In simple terms, renewable energy does not have the punch to provide the energy density our societies are demanding right now, and will demand in the future.

So here are several questions I would like to post for discussion. In the last 150 years our energy source demand - supply profile has grown like yeast grows in a sugar broth, exponentially (see reference 1). After a certain time there is no more sugar and they suddenly simply stop existing. If we use this analogy to our energy debate today: Are we going to be held back and not grow, so we can live a little longer? What are we going to do when there is no more conventional "fossil fuels”? Are we going to adapt to the new lack of energy punch systems? Are we going to kill all animal species because of our stubbornness of not considering other more competitive and cleaner sources of energy? Is a dollar more important than clean air? This is a fact: Societies grow because they have energy (see reference 2).

There is no way back. We have to move forward in a clean, sustainable and high-energy-punching way. We have to invest in nuclear, in order to build what will be the new base line generation. Renewables have their place, but let’s go to the facts, they are not for baseline generation. Let’s be realistic, they simply do not have the punch. We’ll have to either keep on burning fossil fuels or stay in the dark. It is our call. We are in a transition time right now. It is the right time to invest in nuke plants and if there are ways to get rid of HWL and fission, why not?

Reference 1 -
Reference 2 -

59.  Christine Mazzola said on Feb. 26, 2010

To a comment made earlier about clean, 'efficient' energy: Nuclear power (consisting of fusion and fission) is the future, as we must consider the numbers here. No disrespect to solar, wind, water and geothermal power, but their time will never come. Unless, of course, you'd like to live on Mercury and collect the sun rays there.

To address safety, the dangers involved in the mining are diminished to the public because we've been mining them for years. Does that make them any safer? Of course not! The possibility of an incident with nuclear power is unlikely with existing technology, not to mention with further funding.

And to consider whether they achieve their purpose efficiently, our current 'ideal' forms of clean energy barely produce enough to sustain a single house, depending on the location, and aren't constant. Admittedly, efforts to improve this technology are being made, and are coming to some fruition. The advancements are not comparable to the capability of nuclear power now, though. Telling someone to collect power themselves (look--its right in front of you! You just need to spend money on inefficient technology to harness it) then I'd like an explanation if there are two better, highly expandable forms of energy production available for discussion.

60.  bob said on March 9, 2010

Do you know how much money it is to make a single wind turbine? Think of the costs of a single wind turbine, a 50-120 foot tower of steel, placing it into the ground. You can't have a wind turbine too close to a city because of room, so you need to be able to get it to the city, also when electricity is transferred that far most of it will be lost, and finally you need to have it checked. Windmills don't even produce that much energy because even if you put one windmill for every house in America we still would need more power. We need energy, and we are running out of coal. Solar and wind won't produce enough power. We need nuclear energy. If you don't want it then you try living one week without power and then tell me if you want nuclear power or not.

61.  Sean Holt said on March 25, 2010

What an unmitigated bunch of nonsense!

Sure, let's waste money and resources postulating some new and untested technology for false reasons! Science solved the waste fuel issue 30 years ago! If you want to use all that can be usable in a fission reaction and burn all the resulting actinides and leave no waste, you simply breed fuel and close the fuel cycle. These reactors left the blackboard 60 years ago! It is called an INTEGRAL FAST REACTOR. (Google it!) Unlike the proposed fusion garbage, fast reactors have been used commercially in several countries since FERMI 1 went online near Detroit in 1957. Stop with the stupidity and use the technology we already have. This already proven and existing technology can supply all of humanity with all of the energy we will ever need for all of eternity. All actinides have the same fission probability in a fast neutron spectrum. We do not now nor will we ever need fusion. Wake up, people!

It’s the narrow-minded stupidity of some scientists that make me embarrassed to be human! I’m incredulous!

Sean Holt

62.  Max said on April 9, 2010

I understand the idea of fission and fusion, but at the end of the day what are the waste products that would come out of such a process?

63.  Charlie said on May 17, 2010

With regards to the first comment, there are CANDU reactors that use heavy water which eliminates the Uranium refinement step. And in response to Max, everything that is used in the process (including gloves and coveralls to feeder pipes and fuel bundles) are stored as nuclear waste if they exceed the designated dose requirements.

64.  alex said on May 24, 2010

It is a very interesting way how you can destroy radioactive waste.

65.  fivegalaxies said on June 24, 2010

With all due respect to non-engineering minded environmentalists, solar is not a mature technology, as it costs seven times what fossil fuels do, (and that number is extremely unlikely to ever go down) and is not a portable energy source. Wind power kills migratory birds, which are an absolutely vital part of the ecosystem. Nuclear technology can, if scaled up to greater industrial levels, be too cheap to meter. It simply comes in conflict with highly entrenched political forces, who play shell games with your badly informed and poorly educated minds.The safety issues are not nearly what they were 50 years ago, and if properly regulated, could be a boon to us both environmentally and economically.

66.  Erin Keet said on July 14, 2010

Fusion disposal sounds all right in practice but it's terribly hard to manage. This process doesn't have enough mental energy invested in it. It is too rational and not logical enough. It lacks the necessary dynamism. Maybe in time it will develop into something better.

Nuclear power is absolutely the worst way to go due to the fright factor for the vast majority of the population, which encourages a chest-puffing, 'I ain't scared a nothin' bravado on the part of many who are literally scared out of their minds by the stuff, including some posters here. The use of nuclear energy is virtually the same as trying to bring a piece of the sun to the earth and then manage it successfully. Disposing of all nuclear materials is the only way to cease scaring the lights out of what some deem ignorant billions of people. If we continue to have such a cattle-farming approach to other human beings, we're going to have so much war that I'd like to see whether anybody has time to maintain the power plants at all.

Of course many human beings currently find the idea of war quite a pleasant one. This is because we need to stop growing in numbers and irritating each other endlessly. Since we adopted agriculture many thousands of years ago, we've increasingly frightened and poisoned ourselves.

Those who stop breeding have my wholehearted approval. Those who breed like rabbits have my withering scorn. Those who make an attempt at extricating us from the current overdeveloped state of agriculture get my cheers.

You can't manage nuclear waste like agriculture.

67.  Vito Buonomano III said on Aug. 24, 2010

The amount of energy in this Country that is wasted every day is hard for any one to imagine and is killing our GDP and job growth. Your average American is left on his own to manage energy and most are incapable. Most Americans feel the need to put in a new hardwood floor and granite counter top before properly insulating and up grading their boiler or furnace in their home. Companies are just as bad by hiring incompetent maintenance crews to manage tens of thousands of dollars of energy.
From cars to light bulbs we as a nation have not even scratched the surface in terms of energy conservation and efficiency. The DOE and EPA knows how to get the job done if we keep politics out of the equation.
So lets gets down to reality when we talk about building more crazy expensive nuclear power plants in this country to power us into the 21st century. The bottom line is nuclear power needs to slowly be phased out in this Country and replaced with renewable energy. Nuclear power around the world is also feeding the nuclear arms race and needs to be stopped dead in its tracks.

68.  Kevin said on Feb. 6, 2012

@Vito Buonomano III, I'm the owner of Chicago Heating Repair I couldn't agree with you more. For example, all the little lights on our electronics (think about it, computers, home phones phones, microwaves, TV's, DVD players, cable boxes, ovens, toasters, coffee makers, CD players, modems, WIFI, power strips, night lights, alarm clocks, electric toothbrushes, computer monitors, music amplifiers, VCR's, furnace circuit boards, T-stats, home security systems etc. actually use more energy than our appliances like heating and cooling systems or washers and driers. These little lights are on 24 hours a day 365 days a year and the irony is that all these little gadgets are certified as energy star compliant. I agree, insulation is probably one of the biggest energy saving tips here. In addition to insulation there are some excellent developments in green building technologies like solar power, geothermal, building materials and even landscaping can play a significant roll in energy savings. In most hvac applications nowadays you can reduce your indoor blower motor energy consumption by decreasing your HVAC systems duct size and use a variable speed motor which creates a high velocity energy efficient air distribution system. Fan motors use the most energy in an indoor comfort system because that thing is running almost all year round. Anyhow, I've rambled on long enough. If you can find a copy I suggest watching the full version of Into Eternity a scary documentary about the building of a nuclear waste repository called Onkalo. We've got Chernobyl, now Fukushima and over 300,000 tons of toxic "kill you in minutes" nuclear waste that will stay taxic for hundreds of thousand of years. I don't consider that clean or efficient energy. Perhaps one day you guys will figure out deal with 100% of the waste. Maybe you will develop reactors that are Tsunami proof and earthquake proof. But it still seems like madness trying to control something like that. This planet is fragile and what gives us the right to determine it's fate with such an absolute power of destruction that can never be undone?

69.  Sagetim said on April 21, 2012

At the very least, this technology would provide us with a means to use up that nuclear waste that has already been accumulated. Certainly burning that off instead of keeping it buried in facilities for the next x hundred/thousand years is a good idea? Sure, it won't replace a good geothermal plant, a proper solar farm, or a good wind farm, but when people are doing things so bone headed as frakking, this is at least a step in the right direction. If this could be implemented and used (whatever the time frame) it would at least enable us to get rid of so much stored nuclear waste, and the now irradiated component parts of the devices could then be stored in the locations where the waste was formerly located. Would it be necessary to meet our power needs? probably not if it was implemented in 2048, but what if we could get it going in 2028? or 2020? All other concerns aside, we already have nuclear waste being stored, so having a means of eliminating 99% of it is better than keeping that in storage and shutting down this project because it doesn't conform to your idea of clean or productive.