Speak, Muse! And tell me of the pros and cons of molten salt reactors, such as the Peoples’ Republic of China plan to create:
Chinese energy demand is growing rapidly, and despite the world’s largest campaign of new nuclear construction, the vast majority of Chinese power generation still comes from fossil fuels. China has abundant supplies of coal, but their combustion has led to some of the worst air quality in the world. The ability of thorium MSRs to operate at atmospheric pressure and with simplified safety systems means that these reactors could be built in factories and mass-produced. They could then be shipped to operational sites with standard transportation. Their thorium fuel is compact and inexpensive. Chinese rare-earth miners have been rumored to have been stockpiling thorium from rare-earth mining for years, and if this is true, the Chinese will have hundreds of thousands of years of thorium already mined and available for use. The Chinese now have the largest national effort to develop thorium molten-salt reactors. Whether other nations will follow is an open question.
They never spent any time with ADM Rickover. That’s all I have.
Mark, that “all” ain’t nothing.
Well, they’re going to have a few problems:
1) Getting DoE approvals
2) Writing an environmental impact for each reactor and getting approvals
3) Fighting the NIMBY lawsuits for each one for years.
4) Facing all the protests and lawsuits over transporting the fuel.
Oh, wait ….
O.K., O.K., so there are SOME advantages to a dictatorial, repressive regime.
Funny how the same class of people that lauds this aspect of the Chinese regime is the same one that have erected the hurdles here. Hmmmmmm …
Plus what bank is going to front the money w.o. an EPA approved study, DOE cert., etc? And, given current financial conditions, what corp. is going to have the kind of a balance-sheet that banks would look upon favorably? “Chicago Boyz” had an excellent article on this subj about a year ago whose conclusion was that under current conditions the likely-hood of ANY new reactor building starts is almost nil given all the financial & regulatory pitfalls/roadblocks unless a) MAJOR changes are made in the permitting and regulatory area and b) ditto for the financial in terms of banks being willing to do a 180 in their present lending guide-lines.
My employer is planning to build two new PWRs (AP100s) in the next five or so years (online 2015 & 2016). We are currently conducting site construction.
The licensing process has been improved and utilities have gotten smarter. In the good old days, a utility would submit a custom design plant for construction approval. When construction was complete (5-10 years), the utility would then go back for approval to operate the plant. Nowadays, we use a standard design that has been already been reviewed and approved by the NRC, and the licensing process is one step: apply for construction & operating license.
The toughest nut is the upfront financial risk. US govt is providing loan guarantees.
Several other US utilities are doing the same.
Butch, what Public Utility Company had EVER not made money over the long-run; assuming that the company conducted its operations in a reasonably competent manner?
Guess I am a bit slow, but where is an example of this financial risk you speak of?
Lots of upfront money needed? Sure, but you also have a guaranteed long-term (perpetual really) revenue stream.
Concur to an extent, Ron. The reality has been that investors have been reluctant to loan funds to build nuke plants because of the possibility of the plant being canceled after great expenditure and the Public Utility Commission disallowing the recovery of those sunk funds.
As a capitalist, I am highly uncomfortable with USG providing loan guarantees. However, that decision was made several levels above my paygrade.
BTW, last week the NRC Advisory Committee on Reactor Safeguards (ACRS) has recommended that the Plant Vogtle 3&4 Combined License (COL) should be issued. The next step in the process will be the finalization of the safety evaluation report and the mandatory hearing process which will occur later summer 2011. This also allows subsequent utility COL applicants referencing the AP1000 design to move forward in their respective NRC reviews since Vogtle is serving as the AP1000 Reference COL.
Ron, here is the answer.
In 1983, Energy Northwest became infamous for defaulting on $2.25 billion USD worth of bonds after construction on two of its nuclear power plants, WNP-4 and 5, was halted. The default remains the largest municipal bond default in the history of the United States
http://en.wikipedia.org/wiki/Energy_Northwest
http://en.wikipedia.org/wiki/WNP-3_and_WNP-5
http://en.wikipedia.org/wiki/WNP-1_and_WNP-4
Spencer, interesting, and with the tree huggers gives some background on why the NW is so anti-nuke. That company fully deserved to be known as “Whoops” and I can see why they changed their name to EN.
I have to stand by my caveat of “….the company conducted its operations in a reasonably competent manner.” Incurring four-fold cost increases primarily due to mismanagement is not especially competent. Plus, Whoops had no expertise in building this type of facility.
Monopoly (or at most an oligopoly), essentially a guaranteed rate of return -I have to stick with my statement of virtually no risk to the investors if the company is competently run and the unions aren’t hosing them (unlike the GM/UAW BHO crooks).
So China is going to build its electrical generation infrastructure on reactor technology that has been implemented maybe 10-20 times ever. Maybe they can do it…
Molten salt reactors operate at low pressure, which makes plant fabrication easier and serious reactor accidents less likely. The first part is key because there are very few companies that can fabricate the components needed for high-pressure reactor plants. Unfortunately, molten salt working fluids also make plant maintenance/refueling really, really difficult, which is why the Navy cut research after building one sub with a liquid sodium reactor.
Who knows, maybe they’ll figure it out. Then we could do some IP appropriation of our own when the politicians/DoE decide to pull the trigger on restarting nuclear plant construction.
Thorium-232 was used for breeding nuclear fuel – uranium (233), for example, in the molten-salt reactor experiment (MSR) conducted in the United States from 1964 to 1969. After most of the initial test reactors were closed down, Russia, India and other countries are reconsidering the use of thorium fuel cycle for the production of nuclear power.
This is a good way to make uranium out of thorium. There are some technical challenges from the Oak-Ridge Experiments, but I suspect we stopped because RonF gets it in 1. The Idaho National Laboratory does have the MSR up as an advanced design.
OBTW – The NRC – The most effective anti-nuclear organization in the US.
we’ve already done that thorium thing. But US does have estimated 25% of world supply, and it is considerably cheaper than uranium to produce.
We will just cover all of Texas and Oklahoma with wind turbines to produce the necessary GW required for all of this “green” energy. But wait, what about when the wind don’t comes sweeping o’er the plains?
“…simplified safety systems…”
o.O That’s not going to end well.
It means that the reactors are self regulating and have negative reactivity as temperature increases. So if the guy on the switch freezes up, the thing does not run away.
As long as they don’t use lead-based paint…
Thorium reactors are the real future of nuke power. Lots of it available, the reaction is naturally stable. I wish we’d get off the dime and get on with building them ourselves.
Worth a visit to the wiki page.
http://en.wikipedia.org/wiki/Molten_salt_reactor
http://en.wikipedia.org/wiki/Thorium_fuel_cycle
Wouldn’t net usable power fusion power be the future Taxi1?
I’m going to blame sticky keys, only one power please.
Well, given the well documented history of quality control and environmental concern of the Chinese, what could possibly go wrong?
As I recall General Atomics Co (yes, the people that brought us the Predator) had the thorium fuel cycle in mind with the Gas Cooled Fast Breeder, and I believe the High Temperature Gas Cooled reactor as built at Ft Saint Vrain. I don’t believe they actually used the thorium cycle in production but could be mistaken on that. As far as liquid sodium cooled reactors, that’s old had – they Navy played with them and decided that having a coolant that reacted violently with water might not be a good idea on a submarine. Commercially, Fermi 1 was a liquid metal fast breeder, though they had some significant mechanical issues.
Chalk up another one for Robert Heinlein – - use of thorium as a desirable reactor fuel featured prominently in his “Rocket Ship Galileo,” published in 1947.
Academy man, he was.
Energy From Thorium is actually probably where you’re going to wind up getting most of your useful information on LFTRs from. They’ve been promoting the technology for quite some time, often nearly alone.
Personally, I view LFTRs as the single best potential energy source on the planet… short of one of the new fusion concepts (polywell, focus fusion, NIF) actually working out, in which case LFTR likely becomes overpriced and redundant, with few advantages and many disadvantages compared to a good proton-boron fusion reactor.
That said, none of those concepts have proven themselves yet, and fusion has a history of always being fifty years out, so I would strongly recommend that if the government is going to insist on doing things not technically permitted under its charter, it should encourage and support the development of LFTRs. Heck, they could even justify it under the excuse of developing new power plants for our warships (which is exactly how polywell has been funded).
For those laypeople that don’t know what LFTR is all about (like myself), I found this video to be quite informative.
Full disclosure, I’m not a nuclear engineer, though I did play one in college until my junior year when I noticed the lack of new plants, the lack of new students in the program, and bailed into a major that might have a job at the end of it. It’s actually not until your junior and senior years that you get into the real reactor design stuff, so take this as second-hand and from memory over 20 years ago during lectures.
The advantages of a liquid metal reactor is the higher boiling temp of the working fluid, which would be sodium or similar period-1 element, and thus the lower pressure inside the reactor, and you’ve only one state to design for which simplifies much of the cooling. As an added advantage, since your fuel is also a metal you’ve working fluid and fuel in the same state.
Let me explain. Use water as an example, cooling your car. Water is a solid below 32F, and a gas (for purposes of discussion) above 212F. Gives us 180 degrees to work within. Your engine is made of aluminum and steel, which expand at different rates so at their optimum size at 190F (where your car thermostat is set to operate) they work pretty good, but at 33 or 211 tolerances are sort of off. Then there’s the additives we need to keep water liquid below 32F, and the high pressure we run to keep it liquid above 212F, all of which place extra strain on things like radiators and water pumps and hoses. Kind of a square peg in a round hole, we’re using water which does things we don’t want at temps we commonly see, but we’ve plenty of water so what the heck.
Now apply to a reactor. If you fill it with sodium, design so it can be air-cooled, and use a fuel that’s also a metal you’ve a number of problems overcome.
First, as the fuel expands due to heat the fuel rods have less coolant and moderating material between them, so there are fewer thermal neutrons to continue the chain reaction. Translation: it has a rev-limiter, a built-in governor, set up by God at the factory and it can’t run away from you. As it cools from making steam for your power plant it adjusts its throttle up, as it heats from doing nothing it throttles back. Wonderful for power plants. It’s like a car with an automatic transmission — you can’t stall it and you can’t over-rev it.
Second, remember this thing can be air-cooled, or cooled with water, or geo-thermal, or whatever happens to float your boat. You don’t need to have to consider the ideal temperature that some fish down-stream of your cooling tower needs for spawning, you don’t need a bunch of reactor operators and staff monitoring it every minute as the electrical grid load changes. Designs from Westinghouse, GE, and Toshiba back in the early 80′s were for a stand-alone unit in the 1000KW range, pretty much a stand-alone neighborhood power plant.
Finally, these things can scale down, and up, via the same physics that make them self-regulating. You can power a neighborhood or plug a few together and power a city. You could even power Al Gore’s house if you were so inclined.
They have disadvantages that come from that liquid metal working fluid. Period 1 elements (metals) tend to react well with anything else they can come in contact with. Sodium is a good example. Place sodium in contact with water and you’ll have a bar-b-q you can’t put out. Lithium is another good one, it pretty much exists to start fires while bonding with anything else it can find. (And it powers your laptop batteries, so if you happen to break that battery pack open don’t wash it in the sink. Just saying…) We can add other elements, common salt is sodium and chlorine, but you’ll notice salt doesn’t catch fire in water nor is it liquid. Clearly we have to accept some chemical instability to get the benefits we want.
Which is what makes refueling and general maintenance the problem for a LFTR that it isn’t for a LWR (light water reactor). There have been various ideas from shoving fuel pellets into a mail slot and letting robotics handle it to setting up a tent filled with a noble gas over the thing and having people in Apollo Astronaut suits do the work. The coolant, which has the benefit that it won’t flash into steam and make the reactor core melt, is now the hazard.
To go back to the car analogy, you’ve a beautiful car with plenty of power, but to change the oil you need to put on a space-suit and park it in a garage filled with argon. It’s not going to do a China Syndrome, or a Three Mile Island Melt (sounds like a sandwich, doesn’t it?), but you can’t fix it if it breaks and changing the pre-sets on the radio requires a week at the dealer’s shop. In fact, an oil change is only needed at 50,000 miles but they have to erect a garage over it, have astronauts change the oil and filter, and then the whole car has to be inspected and certified safe.
Some people look at that and opt for the less-perfect car and changing their oil at Jiffy Lube. If you’re a public utility, you’re looking at natural gas to fire a turbine. Nobody ever sued you to stop a billion-dollar project that amounts to a hundred kitchen stoves. People have been known to sue to stop fish from feeling warm and sodium fires in their yards.
The LMR takes away the worst fear of nuclear energy and replaces it with the worst
fear of high-school chemistry. For people who need something to be afraid of, either
one will do.
– Max
Max,
Thanks for a good description of the pros and cons of liquid metal cooled reactors.
However, the Molten Salt Reactor is not a metal cooled reactor.
The MSR does not use fuel rods, so your oil change analogy doesn’t work.
Let me try to draw a word picture of a MSR. Imagine a pipe that is bent into a circle. On the right side of the circle we insert a heat exchanger. On the left side of the circle we have the reaction chamber. The working fluid in the pipe is a mixture of Lithium Fluoride salt and Uranium Fluoride salt. The operating temperature is around 600C so the salt mixture is liquid.
The liquid salt mixture circulates around the pipe from heat exchanger to reactor to heat exchanger. As the fluid goes through the reactor, the U235 in the mixture fissions and creates heat in the working fluid. As the fluid goes through the heat exchanger the fluid gives up the heat to whatever you want to heat.
The working fluid is at atmospheric pressure and needless to say, it cannot melt down because it is already melted down.
To go back to your car analogy; you have a car with plenty of power that will go 50,000 miles on a single tank of fuel. When you have burnt up the first tank of fuel (U235), you open the cap and add a pound of salt (Uranium Fluoride).
By the way, the waste products from normal reactors (fuel rods) that have to be stored for so long due to the half life remain in the system and are burnt up with the excess neutrons in the reactor.
What happens when a pump breaks in the MSR and you need to do maintenance? Changing the oil is hard if it turns into a solid block of metal when not running through the engine. Of course you can store it in a separate heated chamber, but that is a whole other system. Hence the point about maintenance being really difficult.
Takeaways from all this:
Metal reacts with stuff, so MSRs introduce a large set of known and unknown operational challenges (strong vote for proven water-cooled reactors)
Fuel for MSRs is abundant , cheap (moderate vote for MSRs because fuel is a small part of reactor plant lifetime operating cost)
MSRs can be engineered for greater passive safety than a typical water cooled reactor due to low operating pressure and absence of a traditional fuel core(Moderate vote for MSRs because current and future envisioned water cooled reactors are very, very safe)
I’d say let someone else take the risk – we have proven technology and the MSR really doesn’t offer revolutionary advantages over current technology paths in terms of plant capacity, cost, or safety.
Joe
The dump tank is a feature of the MSR, not a bug. Any maintenance on a reactor circuit will be complicated by the radiation. With a MSR you can move all the reactive material to a safe place while maintenance takes place. Think for a minute of all the valves and pumps necessary to maintain the water in a current reactor. With a MSR the pumps circulate the fluid at atmospheric pressure. The system can be much simpler and therefore more reliable mechanically.
MSR stands for Molten Salt Reactor. These are fluoride salts not metals. Metal does react, so you take the sodium metal (Na) and react it with fluorine (F) to get a very stable salt NaF that does not react with anything. Mix it with water and you get salt water. It might rust stuff but it will not react violently.
Oak Ridge developed the MSR technology to the point of having working test reactors. The physics, the materials and the designs exist in reports from the 1960’s. Why weren’t they developed then? My opinion from extensive reading is the MSR did not provide the two things that were popular at that time. The ability to produce weapon grade plutonium and a low breeding ratio compared to the IFR’s.
Advantages?
The MSR represents a scalable reactor. The reactor can go from a few Mwatts to multiple Gwatts. The technology is a good candidate for independent military base power and for ship power. The ability to put capacity where it is needed and add it as needed.
The massive pressure vessels and containment vessels are not needed, so there is a material savings. The components can be factory produced for economy of scale. Maintenance is reduced because there is no need to shut down to refuel.
The MSR is self regulating and cannot melt down. Passive safety design means fewer opportunities for human mistakes. Minimum waste products with a shorter half life.
So China is really not taking any risk, they will just do the engineering that needs to be done to turn this into a source of cheap electricity for their population. The USA on the other hand is developing the most expensive forms of electrical generation while driving up the cost of conventional generation and regulating nuclear out of existence.
“The USA on the other hand is developing the most expensive forms of electrical generation while driving up the cost of conventional generation and regulating nuclear out of existence.”
Regulation has driven the cost. The EPA is now working on shutting down our Coal Fired Plants. We can’t build any more coal or nukes due to the cost of regulatory burden (yes I know there are new license applications, but talk to utility people and the delays they are having for the dollars to line up) NRC regulations require each change in reactivity be supervised by a licensed Senior Reactor Operator. A neighborhood nuke ain’t gonna happen in the US.
We are doing this to ourselves. California is instructional-we are regulating ourselves into a corner and driving costs up to ensure employment of thousands of bureaucrats have a job.