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

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.

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?

Space is an endless storage unit.

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.

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?

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.

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.

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.

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.

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).

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.

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.

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.

Please note: to view any linked PDF files in this comment, you must first download the Acrobat Reader plug-in for your browser.

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.

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.

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.

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.

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.

Breed plutonium and burn that as fuel.

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.

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.

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.

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.

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.

This is something the world is waiting for.

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.

Cheers,
Magnus

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?