Thorium Reactors
forbes.com
forbes.com
Is it just me, or is Forbes doing this a lot lately?
Nuclear power is the future. Ideally, the reactor should be a long ways from any valuable real estate, like at least 90,000,000 miles.
Fortunately, recievers that receive beamed power from the big fusion reactor are dropping in price at a rate of 30% per year. That fact makes VC funding of thorium reactor technology problematic.
Density of power is what matters in the long run. We need a solution that produces the most power for the given space it occupies. Hence, it's not a question of 'if' we use fission, it's a question of 'when'.
Think about the insane size of the inverters you would need to power the grid off of a DC battery.
Instead you use cheaper types of energy during the night, and avoid the natural gas. Then during peak usage you fire up your natural gas battery and run a turbine.
Don't confuse moving away from CO2 emitting fuel with energy storage, they are two different things.
We would need to pump water in all lakes about 408m high to have 7 day worth of reserves for USA.”
http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-bat...
So you actually only need to use 0.1% of all lakes.
http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
Efficiently moving power from one place to another is the big problem - the 'smart grid' is forever over the horizon - but storage only becomes a big problem after we have switched a massive amount of our energy production to solar and we're a long way off from that. Until then we just need to build a better system to move power from constant output plants to areas served by transient power sources.
Umm, no. They do that because of customers and "night is colder".
Agriculture, specifically pumping water, is an example that supports your argument.
> Energy usage at night is far smaller than during the day, so much so that we have an excess at night because of all the plants with constant output.
Until we start charging lots of electric cars then....
NY: http://www.nyseg.com/YourHome/pricingandrates/daynighrate.ht...
VT: https://www.burlingtonelectric.com/page.php?pid=49&name=...
The difference is almost 30%.
And that's only the tip of the iceberg. When you look at the area around most ski hills, the mountain is sucking more electricity during snowmaking season than everyone else in the area combined. When you are that big, the power company shows up and negotiates everything. Rates, times, usage caps, etc. The mountain can afford to buy its own generators (or diesel powered pumps/compressors) so the power company has a good reason to cut them a deal, but like every negotiation both sides want something and the power company is looking for someone to buy its excess constant capacity.
The relationship is so tight that the power company will call up the mountain and offer a lower daily rate based on usage elsewhere and the mountain will make snow accordingly.
http://www.usatoday.com/weather/news/2006-12-10-vermont-snow...
Fair enough.
> it's published on the power company website.
Hold it - those cites just say that night rates are lower. They don't say that lower rates are "the sole reason why they are not making snow 24/7", let alone the only reason why ski resorts run their snow machines at night (which was the original claim).
I don't know what fraction of a ski-resort's expenses go to power for snow-making. Do you?
The fraction that goes to power goes to the question whether day-time vs night time actually makes a difference that matters. For example, saving 100% of 1% is only 1%. I doubt that a ski resort would risk pissing off customers to save 1%.
For example, it may well be that day-time made snow is inferior, or that the transion layer from day-time made snow to night time made snow annoys skiiers. (IIRC, most natural snowfall is at night.)
$ per m² is important, too. Reason is that, the lower prices get, the greater the fraction of installation costs that are not due to the price of the solar cells themselves. Those costs scale with panel area, not with power output, and they do not sink.
Prices did go down 30%, but it took ten years, not one. http://gigaom.com/cleantech/solar-costs-dropped-30-over-last...
This is my problem with solar energy. It's getting better. It isn't price-competitive with coal yet. There are already lots of niche applications. But people can't maintain a healthy skepticism about it because it's such a feel-good technology.
To wit, the US government loaned $535 million to Solyndra at about the same time LBNL released that report. Now they're broke and the FBI raided their offices a few days ago. Where else could a company borrow half a billion dollars without ever showing a profit?
In comparison, the entire projected cost for the solar updraft tower that the Southern California Public Power Authority is building is under $30 million.
ETA - No replies yet, but plenty of downvotes. I hope to be corrected if I'm wrong, of course. I tried to find credible sources for what I've said here. I can't source my claim that solar power is an issue where people pay more attention to feelings than facts. You can't prove something like that. But people are downvoting, and they aren't answering...
links:
http://latimesblogs.latimes.com/washington/2011/02/solyndra-...
http://abcnews.go.com/Blotter/fbi-raids-connected-energy-fir...
on the updraft tower (which is an awesome piece of engineering):
http://www.scppa.org/pages/projects/lapaz_solartower.html
http://www.greentechmedia.com/articles/read/enviromission-se...
That works out of $3500/kW, which seems to be on par with construction costs for recent nuclear power plants (according to Wikipedia: http://en.wikipedia.org/wiki/Economics_of_new_nuclear_power_...)
Of course, limiting the comparison to construction costs is silly.
In response, you call me out for attacking solar power (pointing out bad parts), and being inconsistent about it (pointing out good parts).
So this reply looks like an example of the black-and-white thinking about solar power that I was complaining about above. I say "looks like" because I don't understand your second sentence. I agree with the all the facts you brought up, but I don't see the point of mentioning them. Please correct me if I'm missing something.
And an advantage of tidal compared to most (all?) other renewables is that it is completely predictable.
There are downsides, especially to do with ecological effects/damage during construction and operation.
You can't predict how great the 10th generation of a product will be without knowing how the other 9 were
Nice job picking out-of-date numbers.
Moore's law for solar:
http://blogs.scientificamerican.com/guest-blog/2011/03/16/sm...
If the 2010 and 2011 data was on the charts it would show an even steeper decline.
ETA:
This?
Averaged over 30 years, the trend is for an annual 7 percent reduction in the dollars per watt of solar photovoltaic cells. While in the earlier part of this decade prices flattened for a few years, the sharp decline in 2009 made up for that and put the price reduction back on track. Data from 2010 (not included above) shows at least a 30 percent further price reduction, putting solar prices ahead of this trend.
An average of seven percent per year for 30 years, then a breakthrough year in 2009 (which is well-documented). Then the author -- whose resume includes Microsoft, a company doing "nanotechnology research," and writing some books about transhumanism -- claims another good year in 2010, and you claim a third in 2011.
In other words, the author wants to extrapolate an exponential trend 10 or 20 years into the future based on (at best) 3 data points, while ignoring another trend that's been operating ten times longer.
And he could be right. Technologies do change growth regimes sometimes. But you don't make that argument by talking about the magic of exponential growth. You make it by talking about why all the rules are changing now.
Instead, he says "manufacturers are learning how to reduce the cost to fabricate solar." He doesn't say how, or how long they can keep it up. Then he throws out a paragraph about increasing efficiency ("in the lab," which could mean anything). Then he goes back to electricity prices in 2030.
Obviously, I hope he's right. But that article doesn't do much to refute my claim that solar power is over-hyped by people people who seem to think hype is OK for a good cause.
Also, I don't think this article does justice to just how far ahead India and China are in this field.
And all that isn't even accounting of the arcane crystals!
well played, sir!
From there it was a short step to naval reactors, and for the lessons of naval reactor design to disseminate into civil use.
1962: September 16. The Indian Point-1 nuclear reactor begins operating at Buchanan, New York. Designed and built by Babcock and Wilcox for Consolidated Edison, it is a pressurized water reactor designed to produce 275 MW of electricity. Unlike other pressurized-water reactors, the Indian Point-1 reactor uses highly-enriched uranium as a fuel and thorium as a fertile material. This combination has a superior conversion ratio in a thermal neutron spectrum than low-enrichment uranium (more thorium is bred to uranium-233 than uranium-238 is bred to plutonium-239). The uranium-233 generated in the Indian Point reactor is later processed into a tetrafluoride and used to fuel the Molten-Salt Reactor Experiment.(MSRE)
The MSRE program then successfully operated a reactor with a thorium blanket around the U-233 for the equivalent of an 18 month cycle (same as current reactors.
tl;dr - Read Dr. Alvin Weinberg's book from the late 1990s. Amazon link here: http://www.amazon.com/First-Nuclear-Era-Times-Technological/...
-Background- I discovered liquid fueled nuclear reactors, and the thorium subset thereof, as a consequence of the chemistry minor I undertook in grad school at Georgia Tech (my background is materials engineering). One of the classes I took was taught by Dr. Jiri Janata, and it was functionally a class in analytical radiochemistry. Dr. Janata's expertise is in chemical sensors, and he worked for an number of years at Pacific Northwest National Lab (PNNL) on methods to detect the spread of radiation in the environment. Dr. Janata exposed our class to the liquid fueled reactors.
-LFR- To read in Dr. Weinberg's book, Oak Ridge was left out in the cold when it came to reactor design. This despite the fact that Weinberg and Eugene Wigner wrote "The Physical Theory of Neutron Reactors," as the definitive first text on reactor physics. Wigner and Weinberg dreamed up many dozens of potential power reactor design concepts in the 40s.
Oak Ridge National Lab managed to procure funding to pursue reactors that might power airplanes. Weinberg is candid about how the concept of nuclear powered flight was nearly fiction, but any grant in a storm! Any grant in a storm is still alive and well, btw.
Out of that work came the liquid fueled reactors, of which thorium could be one of the fuels. The liquids were composed of multi-component molten halide salt solutions that had some partial solubility for certain radionuclide salts. Much of the molten salt chemistry details we have today come as consequence of the research into their behavior from Oak Ridge.
Liquid fuels for reactors have many advantages: 1. They operate at atmospheric pressure (1 atm), so there's no pressure vessel to worry about bursting in an accident. 2. Molten salts have very little vapor pressure, and therefore don't volatilize as readily. 3. The molten salts allow very high operational temperatures for better Carnot efficiency, in part because of 2. 4. The systems is single phase, liquid only. This is in contrast to 2-phase behavior of something like BWR reactors 5. Waste fission products (e.g. iodine) can be scrubbed from the molten fuel during operation. The fuel composition can be monitored and changed as needed during operation. 6. Neutron reflectors are needed to obtain criticality in the system. The molten salt with nuclear material in it is subcritical by nature.
For a liquid fuel reactor, there is no loss of coolant accident, as the fuel is in the working fluid. The amount of decay heat from fission products remaining in the fuel can be lower if there would be scrubbing in place. As the world sees now, decay heat is the tiger in the room for reactor safety.
-Brief Accident Scenario- If an accident occurs, and power is lost, the molten fuel drains back into a core sump vessel which then is cooled to deal with the decay heat. Because the fuel is dispersed, and there are no high pressures to deal with, passive cooling of the decay heat in the molten fuel sump is greatly simplified. Further, natural convection can be stimulated in the sump to help circulate the fuel and remove heat.
-Follow Up(?)- There are some downsides, of course, but this is already crazy long. If the OP is still around in the morning on the East Coast, I'll discuss some of the negatives in another comment.
-phil
Nuclear-powered aircraft are workable if you don't care about shielding. Who in their right mind would design a flying, unshielded nuclear reactor? A Cold War weapons designer who wanted to build:
... a locomotive-size missile that would travel at near-treetop level at three times the speed of sound, tossing out hydrogen bombs as it roared overhead.
The article at the other end of the link is the most tooth-curling engineer porn I've ever read. It's horrible. But also strangely awesome:
Pluto's designers calculated that its shock wave alone might kill people on the ground. Then there was the problem of fallout. In addition to gamma and neutron radiation from the unshielded reactor, Pluto's nuclear ramjet would spew fission fragments out in its exhaust as it flew by. (One enterprising weaponeer had a plan to turn an obvious peace-time liability into a wartime asset: he suggested flying the radioactive rocket back and forth over the Soviet Union after it had dropped its bombs.)
tl;dr - While the technology is solid, thorium reactor technology still has some practical kinks to work through, the kind that have already been addressed in large scale pwr/bwr commercial reactors.
-Drawbacks- 1. Thorium fueled reactors can still contribute towards the production of atomic devices, though not as readily, and most likely not the "classic" PU-239 based weapons. 2. The Oak Ridge reactor was built for a very specific purpose, with very high outlet temperatures and as little weight as feasible. It literally ran red hot. This is not the operating conditions under which a commercial power generating facility would operate. See the wikipedia article on the Oak Ridge reactors here: http://en.wikipedia.org/wiki/Aircraft_Reactor_Experiment http://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment 3. The handling of liquid fuels requires a complete paradigm shift in the regulation and methods of the existing nuclear industry 4. There were some hot corrosion issues of the Inconel alloys used in the piping of the MSRE. Evidently the Japanese solved these problems in the 1990s, but I have not been able to find the papers that talk about how. 5. In the US, at least, we will have to overturn Jimmy Carter's ban on nuclear fuel reprocessing to get the maximum benefit of the technology. This needs to happen independent of LFRs.
There are probably other downsides on the tip of my tongue, but I cannot tease them out at the moment. Folks who are interested in more can contact me off HN at the email address in my profile.
Not saying I was offended, at all, just thought it was interesting.
Moreover, I'd discount any claims to thorium, pebble bed, etc being safer because we have actual 50+ years of operational experience with light water reactors which swamps any marginal technical advantages wrt safety. Operational experience is a major unknown for new designs and a real factor in safety for current designs.
The current designs are safe enough, we need to start building reactors now, not 20 years from now.
http://www.paulgraham.com/ladder.html
"After all, projects within big companies were always getting cancelled as a result of arbitrary decisions from higher up. My father's entire industry (breeder reactors) disappeared that way."
My comment is that any Baby Boomer who read about physics as a kid (like me) heard about thorium DECADES ago, and is amazed that the blog writer has apparently never heard of anything that was written about before he was born.
A few hundred years is a helluvalot. It may all in all be better than fossil, but definitively not too good to be true.
you can't have your yellowcake and eat it too : if the propeller heads want to feed uranium-cycle waste to thorium reactors, there's an implicit WMD risk, both the risk of diversion for weapons production as well as providing a rationale for the ongoing operation of dual-use enrichment and reprocessing plants. Thorium fuelled reactors could also be used to irradiate uranium to produce weapon grade plutonium.
And the use of thorium as a nuclear fuel alone doesn't solve the WMD proliferation problem. Irradiation of thorium indirectly produces uranium-233, a fissile material which can be used in nuclear weapons. The US has successfully tested weapons using uranium-233. France is suspected of it. India's thorium program prolly has a WMD component - given they refuse to allow IAEA safeguards to apply.
but the worst threat of the thorium reactors is that we'll be fooled into judging the real threats and impacts currently posed by the uranium fuel cycle on the ambitious standards promised by the thorium advocates. The nuclear industry has been over-promising and under-performing for too long - we can't afford to allow their promises for tomorrow to deter focus from today's bitter realities.
I got news for ya bud. There's weapons everywhere, and governments have the resources to make them, thorium reactor or not. Extremists have the drive to source them, thorium or not. Hell, Brevik proved that. Should we ban fertilizer too?
I've been a Thorium advocate for a long time and have commented about it on HN.
You know what the single largest impediment to rapid adoption of Thorium to solve some of our energy problems? It's the existing nuclear power industry.
Since 2008, Sen. Orrin Hatch, R-Utah, and Sen. Harry Reid, D-Nevada., have introduced bills that would direct thorium research begin at the Idaho National Laboratory. We had prototype plants built in the fifties that ran as late as the seventies. There was even a Thorium powered jet fighter in the early fifties. They need $200 million to commercialize the technology and produce a sample pilot plant blueprint and have been met by a wall of lobbying by firms such as General Electric opposing the bill.