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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.
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 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.
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
... 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.
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.
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