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Fusion and Fission/LFTR: Let's Do Both, Smartly
TheRealHocusLocus writes: Disaster preppers have a saying, "two is one and one is none," which might also apply to 24x7 base load energy sources that could sustain us beyond the age of fossil fuel. I too was happy to see Skunkworks' Feb 2013 announcement and the recent "we're still making progress" reminder. I was moved by the reaction on Slashdot: a groundswell of "Finally!" and "We're saved!" However, fusion doesn't need to be the only solution, and it's not entirely without drawbacks.
All nuclear reactors will generate waste via activation as the materials of which they are constructed erode and become unstable under high neutron flux. I'm not pointing this out because I think it's a big deal — a few fusion advocates disingenuously tend to sell the process as if it were "100% clean." A low volume of non-recyclable waste from fusion reactors that is walk-away safe in ~100 years is doable. Let's do it. And likewise, the best comparable waste profile for fission is a two-fluid LFTR, a low volume of waste that is walk-away safe in ~300 years. Let's do it.
Why pursue both, with at least the same level of urgency? Because both could carry us indefinitely. LFTR is less complicated in theory and practice. It is closer to market. There is plenty of cross-over: LFTR's materials challenges and heat engine interface — and the necessity for waste management — are the same as they will be for commercial-scale fusion reactors. To get up to speed please see the 2006 fusion lecture by Dr. Robert Bussard on the Wiffle ball 6 plasma containment, likely the precursor to the Skunkworks approach. And see Thorium Remix 2011 which presents the case for LFTR.
All nuclear reactors will generate waste via activation as the materials of which they are constructed erode and become unstable under high neutron flux. I'm not pointing this out because I think it's a big deal — a few fusion advocates disingenuously tend to sell the process as if it were "100% clean." A low volume of non-recyclable waste from fusion reactors that is walk-away safe in ~100 years is doable. Let's do it. And likewise, the best comparable waste profile for fission is a two-fluid LFTR, a low volume of waste that is walk-away safe in ~300 years. Let's do it.
Why pursue both, with at least the same level of urgency? Because both could carry us indefinitely. LFTR is less complicated in theory and practice. It is closer to market. There is plenty of cross-over: LFTR's materials challenges and heat engine interface — and the necessity for waste management — are the same as they will be for commercial-scale fusion reactors. To get up to speed please see the 2006 fusion lecture by Dr. Robert Bussard on the Wiffle ball 6 plasma containment, likely the precursor to the Skunkworks approach. And see Thorium Remix 2011 which presents the case for LFTR.
It doesn't matter how safe modern fission designs are; the public fears it after several high profile disasters and that isn't likely to change.
What the hell am I reading?
>Disaster preppers have a saying, "two is one and one is none," which might also apply to 24x7 base load energy sources that could sustain us beyond the age of fossil fuel.
How does a non-nonsensical saying apply to energy? Explain yourself.
> I too was happy to see Skunkworks' Feb 2013 announcement and the recent "we're still making progress" reminder. I was moved by the reaction on Slashdot: a groundswell of "Finally!" and "We're saved!"
How did we move from crazy people sayings into nuclear energy? This is the worst written summary on /. in a very long time.
Also, learn what a comma is and how it's used. For the love of god, this reads like stream of consciousness passed through google-translate a few times.
If you've got a valid business plan, then get investors like any other business.
Nobody has built a large-scale reactor of this type. What we had and have is THTR300 and CANDU converting Thorium. What we figured was that is IS HARD, ENGINEERING-WISE. I am not saying we should not do it, quite the opposite. But -
Now we have a bunch of folks claiming that an unproven-in-reality concept is "easy". What year do we have ? 1317 ???
Better look at the record of CANDU and the Russian fast breeder. These things ACTUALLY WORK.
first, a fusion reactor can't "explode". It operates in a vacuum, and the amount of material fusing is less than a cup of deuterium gas (heavy hydrogen). If the fusing material does start to "explode", the fusion goes out and and the hydrogen dissipates in the vacuum.
Deuterium fusion has the lowest require startup energy, and produces the least amount of neutrons. The goal of fusion is the production of helium 4. The only stray neutrons come from making helium 3 - and that doesn't happen that often (it requires more energy to cause a deuterium nucleus to shed a neutron as it fuses with another deuterium nucleus).
Fission is only "super-dangerous" if you compare it with unicorn fairy energy sources. REAL ones badly compare to fission in terms of people killed/TWh. Just figure how many people fall off roofs installing solar panels and divide that by the funny leccy you get from that. Or better, dont get in rainy days and need coal backup. Or better Gazprom-based backup like we Germans idiots do it.
This is actually the point of LFTR. They operate at low pressure and are inherently unable to "meltdown". It's a design that has lots of promise if not for the fact that we no longer really need it.
We have 6 fission reactors under construction or licensed to begin construction. These are proven reactors designs and there is no shortage of fuel for them to burn. Thorium is more plentiful, but at present consumption levels we already have a worldwide supply of uranium to last another 230 years.
So who is going to invest in a new fission technology at this late stage? Sure, it's cleaner and safer, but it's not economically viable to develop it anymore.
Actually pretty interesting numbers
http://nextbigfuture.com/2011/...
How the hell did this get modded insightful? It's full of total BS.
First, as the summary even pointed out, fusion will produce waste due to the high neutron flux. You didn't even read the summary, nor do you have the faintest idea what you're talking about.
Second, LFTRs were designed to NOT meltdown. In fact, you need to heat the piping in order to have the salt not freeze. Again, your statement that all fission reactors melt down is proof of your ignorance. You're full of FUD.
Third, they tested them. They just walked away. And it shut down by itself. No special magic, no SCRAM. Then they walked away for 40 years. And it didn't melt down. Instead, it froze. Yes, there were problems discovered later, like the evolution of fluorine gas--but these are not even on the same scale of challenges as preventing an inherently meltdown-prone PBWR from going south for the winter. Also, you don't need to use water as your coolant. As we all know very well, water is dangerously prone to turning into a fuel-oxidizer mix and going off.
Also, what would make you think that solutions need to be expensive? Why is THAT your criteria for a safe design? See, PBWRs are bad because they're inherently unstable. I hope we never build another. However, I'm still pro-nuclear, and I think that a LFTR is the way to go for now, since the design is inherently walk-away safe. Yes, there are materials challenges. You need to use special piping doped with 1.1% niobium and so on. But these are things we've researched and can continue to refine. Solutions should be judged on technical merit, not simply on, "it's expensive, so it must be good!"
Also, why the hell would you suggest launching old nuclear reactor parts into space? Which orifice did you pull that out of?
You're so full of FUD that I can only wonder which energy conglomerate you're shilling for. Care to tell us?
I have always felt the problem of fission waste disposal has been overblown.
If the goal is "walk away safe", then fission fuel is walk away safe in about 300 years too. The high level radiation emitted by the fission products comes from cesium and strontium and in 300 years, it will all be gone. Leaving low level radioactives, Uranium and a tiny amount of plutonium. In 300 years, the used rods will emit the same level of radiation as the unused rods. Since plutonium is an alpha emitter, the used rod will effectively not emit any radiation from plutonium. You could store one under your couch and not suffer any ill effects.
Reason why the US doesn't reprocess nuclear fuel rods anymore is that the Dept of Energy realized that as long as the fuel pellets remain intact, the uranium and plutonium is entrapped in the metallurgical structure of the fuel pellets. For the uranium and plutonium to be released back into the environment they will have to be melted down. If the pellets are unchanged, we could probably recycle them back into a new reactor in 300 years even.
I love the idea of LFTR. Honestly. A thousand years of cheap and plentiful fuel, simplified nuclear design, smaller physical footprint, lower risk of cataclysmic meltdown & resulting fallout, waste having a much lower half-life, no CO2 emissions...
But it's still an idea. After Oak Ridge, there's been no government-led development of LFTR reactors in the states. Our only hopes at present are either with the Chinese or a private company called Flibe Energy that's trying to gather investment funds to build LFTE reactors for army bases.
Mining uranium is one of the dirtiest parts of the process. The idea that we should mine out all the easily accessible Uranium is just as foolish as to drill all the oil or mine all the coal.
With breeder reactors, either designs like the LFTR or more established designs like SFRs, we don't need to mine significant amounts of additional fissionables for a century. And with the SFRs there's not much left to develop - we can just deploy the existing designs more widely.
-- The act of censorship is always worse than whatever is being censored. Always.
The fusion "waste" isn't even in the same category. The fission reactor has the same problem with the neutron flux of the containment vessel and adds on a waste stream from the reaction. On top of that processing the fuel is not without it's own waste stream. It's that very processing which did in breeder reactors because it was dirtier and more polluting than the reactor.
Saying they generate approximately equivalent waste streams is an out and out lie. The fusion systems neutron enriched vessel and systems can be taken care of by leaving on site for 50 years then decommissioning and burying it in a conventional low level nuclear landfill or waiting 100 years and then melting it down and reusing it. The waste products generated from not only the fission reactor, the vessel, and the processing of the fuel are not even in the same category, the vessel alone might be close but even that will likely be contaminated beyond just neutron enrichment.
This is a total bullshit claim.
...fusion will produce waste due to the high neutron flux.
Not necessarily. The most viable fusion approach does not produce neutrons as a product of the reaction. In addition, they don't need to contain and stabilize the plasma which is the bane of most fusion programs. They intend to leverage the inherent instability of plasma to produce 200 small reactions or pulses per second. They won't need steam generators since most of the energy is released in the form of an ion beam.
There's almost zero reason we should put LFTR and Fusion into an adversarial relationship.
LFTR is closer to market right now, and fuel for it is ridiculously plentiful. It can easily power this planet for hundreds of years.
At the same time, Fusion is around the corner (though it's been "around the corner" for several decades).
Still, instead of dealing with:
* Nasty, polluting fossil fuel generation
* Solar/Wind/Hydro installs that fuck up the local ecology
* Dirty, ancient solid-fuel fission tech
Take the first step forward with LFTR and MSR fission.
Yes, we'll have waste still. But it's FAR easier to design storage/depletion facilities that last 100-300 years. Current fission plants are producing stuff that'll be hot for tens or hundreds of thousands of years. And, quite simply, we can't guarantee anything we engineer will last that long. The oldest (mostly intact) megastructures on this planet are the Egyptian pyramids. And they're only about 4500 years old. Mostly because they're just a giant pile of stone.
Still with LFTR/MSR, we can lower emissions and give ourselves time to grow and improve the grid while we get the kinks out of Fusion technology.
With portable, modular solutions like Boeing's fusion skunkworks project, we can put cheap, safe power generation capacity just about ANYWHERE.
When more power's needed? Just drop another unit next to the first and keep adding until your requirements are met.
And when it's time to decommission a unit? Simply truck it away!
And both of these technologies are engineered, from the get-go, to be inherently safe.
With LFTR/MSR fission. If power is cut, you don't get a runaway reaction. By design, the reactor dumps the medium into dump tanks, away from the reagent.
With fusion, you turn off power to a fusion reactor or change the dynamics inside the reactor, and the process shuts down naturally. Snuffed like a blown out candle.
But, will all the "nuclear = bombs" hysterics ever allow this to go through?
Hell no!
Chas - The one, the only.
THANK GOD!!!
What is really needed is a fusion/fission hybrid, which has been theorized for decades, but somehow never makes it past initial design phases. Gives a bridge to pure fusion, burns nuclear waste and/or thorium. Far fewer unknowns and engineering problems to overcome than pure fusion. What’s not to love?
Letter To Iran
Quoting S.R. Hadden (from Contact): "First rule in government spending: why build one when you can have two at twice the price?"
It must have been something you assimilated. . . .
... As I recall even thorium will only provide several centuries at 100%, though we could increase that by an order of magnitude by developing seawater extraction technology.
Good that you brought up seawater extraction technology. Using that we have enough uranium, even just using once-through burning, for something like a 10,000 year supply at current consumption rates. Increase nuclear power ten-fold (125% of current world electricity consumption) and it is still 1,000 years. If we implement breeding (we could get the bugs worked out in a few centuries I imagine) then we are back up 100,000 years or so.
Why does thorium need to enter the picture?
Second class citizen of the New Gilded Age
Here in Georgia we are having a heck of a time jumping through the political hoops to build two new much needed pressurized water nuclear (fission) plants in east Georgia. We also have a boiling water nuclear (fission) plant in south Georgia that probably needs to be decommissioned due to age and the problems of radioactive leaks in boiling water reactors inside the reactor containment bunker...er...building.
P.S. How can you call an airtight, air-locked, negative-pressured, yards thick of specially hardened reinforced concrete, enough to survive at least 2 9/11 style airplane crashes, "building" anything but an above ground bunker?
I have to say that where we built our nuclear plants geologically, population-wise, and climate-wise, are the best places to put such nuclear plants. Far better than in the crowded Northeast US or on the West Coast.
In Georgia we have no single "go-to" on alternative energy for base electric generation, no desserts for large scale solar projects, like Nevada, nor massive amounts of land for large scale wind farms, like the Plain states, and we lost much of our hydro capacity in the last 30 years or so. Natural Gas and Nuclear are our go-to for large scale base electric generation and our chance to break from coal. We use too way much coal here in Georgia our air quality has suffered immensely for it. At least nuclear plants do not create millions of tons of CO2 and makes our air cleaner.
I sincerely hope that the fusion plants can be built here.
> nor massive amounts of land for large scale wind farms
I had to look this up because I thought you were wrong. But you're not. Georgia has crap for wind:
http://apps2.eere.energy.gov/wind/windexchange/wind_resource_maps.asp?stateab=ga
What up with that?
> Look up "energy return on investment" if you want to know more.
I did:
https://en.wikipedia.org/wiki/Energy_returned_on_energy_invested#Economic_influence_of_EROEI
Wind outperforms nuclear, 180%. PV is 70% of nuclear.
So, you were saying?
Look at the three big reactor failures: Chernobyl, Three Mile Island, and Fukushima. All three were caused by human error. For Chernobyl, it was a dangerous design and running dangerous tests. For TMI, it was a less dangerous design, and they still screwed it up with bad procedures. For Fukushima, they made a series of globally bad design choices because they refused to consider realistic worst case external events. Plus they uncovered a flaw in the containment structure design that lead to the hydrogen explosions.
All of these are human error.
And it's not just reactors. The British Petroleum oil platform blowout in the Gulf of Mexico was human error. The sinking of the ferry Sewol in Korea was human error, as was the sinking of the Concordia off of Italy. BP also had a refinery blow up in Texas because of bad operations and ignoring a known problem with volatile fume leakage.
So no matter how secure a technology looks, it will still suffer a complete worst case failure. Assuming anything else is wishful thinking.
What's the worst case for LFTR? No one seems willing to even talk about it. It's remarkably like the head in the sand attitude that lead to the Fukshima disaster.
So here's a question: what happens when a molten salt containing fluorine, uranium, thorium and other miscellaneous radioactive elements comes in contact with water? Does it explode? Does it burn in air? How toxic are the substances entering the environment? (Trick question: both uranium and fluorine are very toxic elements. Fluorine forms many toxic compounds with carbon.) What is the equivilant explosive energy of tons of molten uranium salts?
If it is burning, how do you put it out? (Note: with fluorine compounds water is a bad idea. It's explosive.) How do you build a containment vessel that will withstand all of that? How will the cost of proper containment and emergency planning and equipment impact the economics of power generation?
A burning LFTR makes a burning graphite reactor seem like a campfire for a marshmallow roast. Good luck with that.
Why is Snark Required?
Because thorium might end up being cheaper and easier than uranium. The reason we were able to go from the speed of a horse to beyond the speed of sound is because we were able to find cheap and plentiful energy in coal and petroleum. As energy gets cheaper the more things become feasible.
Why is it that people don't have flying cars? We certainly have the technology for everyone to have their own personal aircraft. The limitation is the price of energy. It just costs too much to fly a helicopter for a person with an average income. But if energy were to be one tenth of what it is now then we'd be flying to get groceries instead of driving.
I believe we need to investigate every possible energy source. Solar power may last us for a billion years but I doubt it will ever be able to do so at a price as cheap as what thorium could do.
We don't burn coal because we want to live in a smog filled world. We burn coal because it gives us energy cheap enough that we can enjoy air conditioning while sitting in front of a computer. We are going to keep burning coal until something cheaper comes around. We do that because cold beer and hot pizza means more to us than some theoretical future where Florida is under water from melting the polar ice caps.
So, why thorium? Because beer, pizza, and Miami.
I am armed because I am free. I am free because I am armed.
I sincerely hope that the fusion plants can be built here.
Congratulations on achieving ~22% nuclear electricity in July 2014.
My state of no-nuke Oklahoma is powered by natural gas and coal (which arrives by train), considers itself a nexus of wind power but after decades of investment, hundreds of turbines and probably much more money spent --- net generation of mostly-wind ~809GWh for July is still less than the ~855GWh that would have been generated that month by the single two-reactor Black Fox Nuclear Power Plant. That is... if it had not been the only nuclear plant in the United States cancelled after construction began, in 1982.
Oklahoma sits on the border of the three North American grid interconnects. I have been trying to convince the powers that be and Halliburton Corporate to embrace molten salt research, to no avail so far.
<blink>down the rabbit hole</blink>
If it is burning, how do you put it out?
You are confusing fluorine with fluoride. A fluoride will not burn because it has already reached a state with a potential lower than that it would have with water or air.
With that said most every LFTR design I've seen does have fluorine as a gas at some point in the process but that is in the chemical processing of the fuel while outside the reactor. There is little to no fluorine in the reactor vessel.
There would not be a fire because the stuff in a LFTR does not burn. If there were things burning then the answer is to use water.
both uranium and fluorine are very toxic elements.
Uranium tetrafluoride is an insoluble salt, no more toxic than sand. Saying uranium and fluorine are very toxic is like saying sodium and chlorine are very toxic. Sodium and chlorine alone are very bad but combined they create a substance vital to life. I suppose you think we should ban the use of table salt because of the toxic materials it is made of.
What's the worst case for LFTR?
The worst case is you douse it with water for hours, maybe days, until it cools off. After it's cool you send in people with jackhammers and tractors to haul away the pieces for recycling. The mangled mess would no doubt contain radioactive material but since fission would have been stopped for days at this point the pile of scrap would be about as radioactive as a typical granite counter top. The workers would have to wear protective gear for the dust because heavy metal poisoning is a risk, just like for people that mine for gold or coal.
Perhaps I am mistaken, perhaps I exaggerated a bit, but regardless a LFTR simply cannot burn or react with water like you describe.
I am armed because I am free. I am free because I am armed.