Transatomic Power
transatomicpower.com
transatomicpower.com
The article glosses over a big issue - this type of reactor has to be hooked to a chemical plant which continually reprocesses the radioactive molten salt. Chemical plants for radioactive materials are historically a huge headache to operate. Many such plants are now toxic waste sites.
With BWR and PWR reactors, the radioactive portion of the system is simple, with few moving parts, and the working fluid is water. More complex large reactor designs have a poor track record. Sodium reactors have sodium fires (Monju, in Japan, was shut down after one in 1995), helium-cooled reactors leak helium (Ft. St. Vrain was a real disappointment), and pebble bed reactors have pebble jams (there's one in Germany so jammed it can't be dismantled.)
[1] http://www.world-nuclear.org/info/current-and-future-generat... [2] http://www.ornl.gov/ornl/news/news-releases/2015/ornl-and-sh...
Advantages include passive safety, no potential for hydrogen explosions, no high pressure containment, excellent nonproliferation, and reasonably high burnup. It's nowhere near what breeders are shooting for, but it's a good start.
What I think they're actually proposing (correct me if I'm wrong): a uranium molten salt fast breeder reactor that drives a steam turbine. So, much more ambitious than what's currently on the market, with better fuel utilization. As compared to, say, the Flibe Energy/Kirk Sorensen/LFTR crowd, it's mixed: it sounds like these folks have some new innovations around moderators and salts, and the stuff about consuming existing waste is compelling, but they're sticking with a uranium fuel cycle rather than thorium (though it sounds like they're getting proliferation resistance in other ways), and they're sticking with a steam turbine vs. proposed gas turbines that could yield some more efficiency and compactness in proposed thorium MSR designs.
EDIT: looks like I might have been wrong about the neutron temperature; their white paper says thermal, not fast.
EDIT 2: the white paper actually has all kinds of great stuff in it, now that I've read the rest: http://www.transatomicpower.com/wp-content/uploads/2015/04/t... ... In particular, it sounds like this is the first planned design, but they offer some potential future variations. They say this design could be adapted to Thorium fairly straightforwardly, but advocate uranium at least initially because of advantages in the existence of a supply chain around it and the availability of uranium spent nuclear fuel. They also mention Brayton cycle gas turbines as a possible future improvement, among others.
If the above statement is true, what happens to the remaining 4% of the energy in the uranium? Is it just not effective to have it in the molten salt, so the entire batch is replaced? Or does this happen 'on the fly' so to speak?
Of the 200 kilogram lanthanide mass removed by liquid metal
extraction, we estimate that approximately 20 kilograms will
be actinide contaminant with a longer half-life similar to
SNF. It may be most practical to leave such a small quantity
embedded in the ceramic granules, as it would be well
distributed and would not materially extend the time for the
overall waste form to reach background levels. If desired,
however, the actinides can be further separated offsite with
additional post-processing techniques.
The mass flow is 500 kg/year fuel in, and 500 kg/year waste out -- of which, 20 kg (4%) is unrecovered actinide fuel.
Edit: I posted that fuel handling is a batch process, not continuous – that might not be true for molten salt, not sure.
It amazes me that we don't have a better way to use the power generated by nuclear fission or fusion than heating water.
I've read the related wikipedia article about Molten Salt Reactors and I understand there are several problems about the technology: mostly corrosion and embrittlement.
So now I find myself asking this: did they fix those problems? The website copy suggests so. Can somebody explain how? I couldn't figure it out.
edit: clearly the team and company have quite legit credentials, MIT nuclear department etc... they must know what they're talking about. I just want to know if they've given details about the solution.
Kirk Sorensen has been a major advocate of molten-salt reactors and gave a great Google tech talk on the subject. https://www.youtube.com/watch?v=bbyr7jZOllI
The molten salt design is completely and utterly different. In a molten salt reactor the fuel itself is molten (in salt form), which turns out to offer a variety of benefits.
1: Seriously. Fukushima did everything wrong. Huge earthquake and tsunami. Older design. Then they tried to cover stuff up. And the repair crews showed up with wrong equipment. More denial. And all that with no loss of life. Just a bit of "lost" land for a while, and extra costs. So many people freak out about it, but that US carmaker with the stupid ignition killed more people and we aren't giving up cars. Fukushima screams "hey, wee couldn't fuck this up, even given perfect conditions and terrible management". But hey, why take a rational approach when you can " go green ".
Also having land uninhabitable for thousands of years weighs pretty heavily even if the risk of failure is low.
[1] http://www.theglobeandmail.com/news/world/area-around-cherno...
From what I've read, the estimates of cancer are really low. But you're right, there might be a few directly related deaths over the next several decades.
You'd think this would result in an attitude of wanting to push newer designs and so on, but running away is a more human reaction, it seems. :(
As if the fact that a very very large tsunami hit a densely populated area did not have an impact.
Of course, a lot of people were killed by Fukushima - due to the shutdown of other nuclear reactors, which necessitated reducing electricity consumption, i.e. turning off A/C in buildings, effectively killing lots of old and weak people.
People say these plants are all safe, and newer plants are safer, but the near catastrophic failures don't give one a warm feeling. The one that stands out to me was pin hole corrosion through the cladding on the top of a reactor vessel. That lead to a large cavity corroding unnoticed in the mild steel. Which which was discovered when someone noticed an odd budge in the top. if that had failed, you would have had total loss of cooling and a melt down.
That is why it makes sense to build the reactors slightly away from population centers. Not to protect the population, but to avoid annoying it with the presence of a huge energy factory.
BTW I find it somewhat scandalous that Russian gas companies can hire senior politicians (such as former German chancellor Gerhard Schröder and Finnish prime minister Paavo Lipponen) to assist the political approvals. Although these men are no longer in such official positions, it is obvious that they were given money to advance the interests of Северный поток through their connections in their respective social democratic parties.
There has never been an economic case for the breeder simply because the fuel cycle is such a small part of the cost of nuclear energy. When you have a factor of 5,000,000 you can afford to throw away a factor of 100.
The weapons material we do produce comes from specialized reactors, not civilian power plants.
aside: I think Greenpeace also has a lot to answer for with their campaign against nuclear power. Thanks to them my children can look forward to a world where a coal plant is build every week and fossil fuel fueled climate change is a certainty.
The smear campaign was accomplished by the companies and nations that built and maintained those shoddy, dangerous plants. Blaming Greenpeace makes as much sense as blaming them for climate change.
Considering that it would be illegal to build a Chernobyl style plant in any other country rather than the Soviet Union, it probably shouldn't be on your list.
>...The smear campaign was accomplished by the companies and nations that built and maintained those shoddy, dangerous plants.
But even including the deaths from Chernobyl, nuclear power has been safer over the last 60 years than all other types of mass energy production: coal, natural gas or hydroelectric.
>...Blaming Greenpeace makes as much sense as blaming them for climate change.
I think the point the OP was making was that by smearing nuclear (a power source that doesn't put CO2 into the atmosphere from generating power) the alternative has usually been to build a natural gas or coal plant that does put CO2 into the atmosphere when it generates power.
People die in installation and operational accidents for wind and solar at a higher rate relative to amount of electricity provided than all deaths attributable to nuclear.
And hydro has a quite horrible track record thanks to construction accidents and dam failures (even if you exclude the single worst incident - the Banqiao dam failure that killed an estimated 171,000 people).
at least your children can look using 2 eyes. If not for Greenpeace the expected value would be uniformly distributed anywhere between 0 and 4 or 5...
The deaths caused by Chernobyl is a tiny blip compared to coal no matter whose estimates you pick.
In 2010 alone, estimated deaths from US coal power plants alone was 13,000, with a huge number of other bad health effect (20,000 heart attacks for example) [1]
In the 3 decades from Chernobyl we can extrapolate to maybe ~350k-400k deaths from US coal plants alone.
The number of deaths due to Chernobyl on the other hand, is rarely estimated higher than the low tens of thousands. The number of cancer incidents attributable to Chernobyl is likely far higher. E.g. estimates of an excess 7k thyroid cancer incidents in Belarus, Ukraine and Russia by 2005. But only a small number of those have died of cancer so far (the number will likely increase, but the reduction in overall life expectancy is still modest).
In 2005, the UN predicted 4,000 deaths due to Chernobyl [2]. Greenpeace countered with a claim of up to ~300k deaths total[3] (based on a combination of an estimated 93k deaths in Belarus and 60k deaths in Russia due to cancers, and an additional estimate of potentially another 140k premature deaths in the following/coming years).
Even if we accepts the Greenpeace claims, as the upper boundary, more people have likely died due to US coal plants alone than due to Chernobyl in the years since Chernobyl.
And the US is not the biggest consumer of coal. Already well before 2000, China had surpassed US coal consumption. Tack on India and Russia, and the US coal consumption is only 1/3 of that used by the top 4 countries. Go to the top 10, and the US coal consumption made up ~25% by 2000, and as far as I know dropping as a percentage of overall consumption due to dramatic continued growth in places like China. So even just looking at the top 10, it would not be unreasonable to quadruple the estimates of excess deaths from coal from the above to 1.4-1.6 million in the 3 decades from Chernobyl.
But of course these plants were going for decades before that, and will continue for decades to come, and many of these countries have far more lax rules than the US when it comes to emissions. The reality is that worldwide deaths from coal likely are equivalent to Greenpeace's idea of Chernobyl every 2-5 years. On the other hand, if the UN predictions are right, US plants alone are as lethal as 3 Chernobyl's every year, and coal worldwide is equivalent to somewhere well above 12 Chernobyl's every year.
Now, it is reasonable to bring up that Chernobyl is only one plant, but the point is the difference is damage scenarios: Nuclear plants kill when something goes wrong, and something goes wrong exceedingly rarely, leaving us able to name the ones attributable to 90%+ of nuclear power related deaths.
Coal plants, on the other hand, silently kills every day, around the clock, during normal operation. Chernobyl, even accepting the worst case estimates, does not lift nuclear even into the same league. Even if we replaced coal with Chernobyl type reactors, with the same lax safety procedures as at Chernobyl, rather than opt for the much safer designs and processes that were the norm even back in 1986, we'd still kill far fewer people.
[1] http://www.rmi.org/RFGraph-health_effects_from_US_power_plan... [2] http://www.slate.com/articles/health_and_science/explainer/2... [3] http://www.greenpeace.org/international/en/news/features/che...
They do campaigning against nuclear power as well, for example open pit uranium mining and waste disposal processes, which might be the source of the confusion.
For those interested in MSR's this serves as a good starting point too[2].
[0] https://news.ycombinator.com/item?id=7922216
I know every time this molten salt vs light water reactor debate comes up, people much smarter than I talk about how the salt is corrosive and there are currently no viable solutions to deal with this. Is there anyone out there smarter than I that can explain whether this company is doing anything different, or if it is just sexy and VC backed?
Edit: There will likely be all sorts of materials issues. None of them damning. I'd worry more about FPs, tritium fluoride, etc. than the salt itself.
Other FPs in the salt are circulated out of the core and through a heat exchanger. Some ongoing actinide fission there too. Tiny defects in heat exchangers handling plain water currently cause reactors worth billions to be abandoned (e.g. SONGS).
Some FPs will plate out and you'll need to replace plumbing periodically. That has to be done by robots because the pipes will be ultra-hot and deadly within minutes to anyone nearby.
For what benefit? You improve the fuel cycle by a factor of 50. But the fuel cycle is < 10% of the costs and material flows of nuclear plant. So yes, online FP separation is something a mature fission-based civilization would have. But it is not clear how it helps us, other than to provide a focal point for a new culture to form (which may be a substantial if illegitimate benefit, admittedly).
ThorCon has an interesting approach for dealing with plating and so on: their design has reactor cores that can be easily swapped out. When one's ready for maintenance they just cart it away, let it cool for several years, then deal with it.
R. Buckminster Fuller
Now, a sales pitch is indeed a missing piece. Given the regulations, the nuclear industry is stuck with power plants whose designs date from decades back.
I didn't see anything about handling the waste heat though. Dumping it into rivers would be atrocious. Ingesting large amounts of water to use evaporation towers is also environmentally terrible. I hope they thought of that.
I am all for the responsible use of nuclear power. Greenpeace and the like made so much noise that the public is afraid of anything called "nuclear". The media doesn't help, either.
The result is far more deaths every year due to coal and other fossil burning. Let's do more solar and wind, sure, microgrids and other cool stuff. Nuclear can provide the baseline power and power for power-hungry industries, such as aluminium refineries.
On the surface, this seems kind of like launching an IaaS cloud service and claiming you're introducing something new and innovative.
Perhaps the NRC does require regular inspections for existing plants, but none of those existing plants are failsafe are they? If something starts to go wrong, it can snowball very quickly into a much worse situation.
With a MSR the worst-case scenario (short of terrorism) is that you empty into the dump tank until you sort the problem out and restart. If you make the entire facility's floor the dump tank then inspections are going to be rather redundant. Except perhaps to ensure that the dump tank is intact. But that can be made fairly easy I think.
See the quest for reusable launch systems like the space shuttle.
That is insane.
The best way to deal with waste is to recycle it.
And related, is transmutation of waste being worked on?
[1] https://en.wikipedia.org/wiki/Sodium_Reactor_Experiment
[2] Fukashima, ect
Oil/"green" lobbies made it to close: http://en.wikipedia.org/wiki/Superph%C3%A9nix
EDIT: And also terrorists and molten sodium.
http://www.ted.com/talks/taylor_wilson_my_radical_plan_for_s...
Edit: you're welcome to downvote the truth, but it won't change it.
Fast reactors make nuclear weapons as byproduct. Thats why we don't use them.
In the Integral Fast Reactor, for example, you end up with a mixture of the four isotopes of plutonium. It's impossible to use that mixture for weapons, and it's much harder to isolate the Pu239 than it is to enrich natural uranium.
In some thorium designs, the fissionable U233 (bred from thorium) is mixed with U232, which is also very hard to separate and makes the material unworkable for weapons. (However, this is not true of all thorium designs. Chemically separate the protactinium and it will decay to pure U233.)
If you had one of the nonproliferating designs and were silly enough to attempt using it for weapons production, you would need much larger and more sophisticated enrichment facilities than if you just enriched natural uranium. If you get your startup fuel from other countries, you can forgo enrichment facilities entirely, making it very clear that you don't have a weapons program.