Is there a new nuclear option that Permaculture can endorse?

I thought I would go ahead and revive an old thread that was initially started about 10 years ago. I had revived it over a year ago after studying the topic for a while, the discussion started to get a bit rowdy, and it was suggested the topic was an important one and could be revived in the cider press.  I did not see where it was revived, so here goes..

My main interest in the topic comes from an ancient history (high school) predisposition to nuclear physics generally, and curiosity after viewing some of the commentary around this lost molten salt technology that was being revived.

It appeared as if the new/old thorium technology  (Briefly described in the link above) might offer a way to solve some immediate problems with a  much safer form of nuclear energy (while we are energy intensive setting up the systems for our new world order inspired by Permaculture thinking) and reduce (by burning up) the large amount of nuclear waste and armaments that we will want to remove from our systems.

I read through some of the quite lengthy critiques of the thorium promise, and it is true that there are  still some issues to work through, and lots of testing that needs to happen   but both India and China are proceeding quickly to test and develop the technology, Canada is even a refuge for American investors and scientists who want to move these projects forward, while the United States is bringing up the rear.

Without trying to automatically dismiss all the criticism, I do see some bogus hype around some of the issues that I think is undeserved.

I also believe the idea of a star trek type system where there is so much cheap abundant energy that all problems are automatically solved is a bit over simplified.

To give any single element that much influence over what needs to be a naturally complex interdependent system is opening the possibility of complete collapse if anything happens to that one element.

The idea of having a net, not just a fishing line  is always assumed to be in the background of the discussion. Not just nuclear, not just solar, not just ...

I have a hard time endorsing aquaponics/hydroponics. So radioactive waste that is 1,000,000x worse than CO2 coal-power-plant waste is a hard sell.

Solar Panel or Solar induced Wind power in the Gobi-desert just sounds alot better to me.


I could get behind Nuclear Fusion where we combine H2 to make Helium. So no radioactive waste. The fusion process, can however make the actual (metal) device become radioactive. But they decay to safe level in 30yrs.

Bob,

I really hope I don’t offend anyone here or lose apples or anything like that, but I think the short answer to your basic question is yes, there is a much safer alternative form of nuclear energy that at present is almost completely undeveloped.


I want to start here by saying that this is my informed opinion based in part on my masters research.  If anyone wants to challenge my position, feel free to do so, but please bear in mind that I am looking at a form of energy that is emission free, highly efficient and produces a pittance the waste of current reactors.
 
The technology is called the Molten Salt Reactor (MSR).  The concept is different from a “conventional” Pressurized Water Reactor (PWR) in almost every respect.  MSRs dissolve uranium into a salt that is then mixed with other salts to get a eutectic mixture, or a mixture whose melting point is lower than any of the components.  The salt mixture (colloquially known as flibe) is placed in a reaction chamber with graphite rods serving as a neutron moderator.  Moderators are typically misunderstood devices.  A moderator is called such because it slows down or moderates neutrons.  Neutrons that have been slowed down or moderated have a much higher likelihood of bonding to atomic nuclei and causing fission.  In effect, a neutron moderator is actually a nuclear reaction accelerator.  In most reactors, nuclear fission can not take place without a moderator being present.

So what does this all mean?  It means that the flibe is used as both fuel and coolant.  In the reactor chamber, the flibe undergoes fission and heats up to about 650 degrees C as opposed to a PWR that heats up to about 300 degrees C.  The flibe is then pumped outside the reaction chamber where it carries away the intense heat (and stops fissioning because of the lack of moderator), runs through a heat exchanger and generates electricity.  It is then pumped back into the reaction chamber where it fissions again.

At the same time, a tiny stream of flibe is pumped into a chemical processing unit that pulls out certain decay products.  Some of these decay products are medical isotopes which can then be sold.  Another benefit of the chemical processing is to reduce to almost but not quite zero time the long half-life nuclear waste.  It has been estimated that a 1 gigawatt plant would produce a coffee can size volume of long lived waste and this waste is dangerous for 300 years as opposed to 10,000 years or more from a PWR.

Even better from a waste issue is that with a little reprocessing, existing nuclear “waste” can be almost 100% burned up in a MSR.  In a PWR with solid fuel, certain fission products build up in each fuel pellet that end the effective life of the pellet when LESS THAN 1% OF THE NUCLEAR FUEL HAS BEEN CONSUMED!!  That means that the vast majority of long lived nuclear waste is actually nuclear fuel.  Configured properly, a MSR could burn through much of our existing stockpiles of nuclear waste.  I can think of few technologies that are more green than taking high level waste, turning into medical isotopes and much lower levels of waste that is dangerous for a much shorter time all while making emission free electricity.

I have drastically simplified the process for brevity in this description, but to reiterate, yes, a MSR is essentially a green form of nuclear energy and I think we ignore this possibility at our own peril.

And again to reiterate, I know that there are some people who are completely anti-nuclear.  If you disagree with me, I understand.  But please be specific in your criticism.  I will try to respond specifically and respectfully.

Thank you for bringing up this topic.  I find it fascinating and very important.

Eric

Eric, you say this MSR technology is almost completely undeveloped—does this mean all the kinks are worked out in actual reality, if on a small scale, and they have built a working unit, they just haven’t built it out on a larger scale yet; or is it more theoretical at this point—like, we’ve thought about it a lot and detailed plans are drawn up and the engineers have looked at it and it should absolutely work, no reason why it shouldn’t, but we haven’t actually built one yet? Or is it more like, we know there has to be a way to do this thing, we just gotta figure it out?

Hi Eric, thanks for being a bit more specific, did you look at the short video link I posted, it was a short summation of the thorium technology.

Strictly from the view that governments are not acting in the interest of the people, I like the idea that the scientist behind the current nuclear design- the light water reactor never thought it should be in widespread use. it was specifically designed for nuclear submarines, and he thought it was much too prone to possible disastrous failures.

So our government in it's warlike posturing decided to use it anyway to build a stockpile of nuclear weapons, and deprive us of cheaper, safer nuclear alternatives that they already had working, immediately stopping all research on the molten salt reactor.  The president responsible for those decisions was Nixon, kind of ironic how in the future we may see  the most criminal thing he did while in office might have been the decision to pursue the wrong nuclear path.

Another decision based on politics and greed against the advice of science.

Also, I appreciate that you are more an expert than I on some of the finer points, I have not been keeping up with the thorium issue for a year or so, and it looks like the Chinese may have pushed through some major material improvements to resist corrosion of the molten salt.

And Jennifer, all the kinks aren't worked out, but there was a functional reactor operated for about 4 years and that research and data is free on the internet and provided a jump start to the other nations using it.

Jennifer,

I know that at least two MSRs were developed, ran and produced power (but not electricity as both were proof of concept plants).

The first MSR was specifically designed to power a nuclear powered bomber.  Basically, the Navy had nuclear powered subs so the Air Force wanted a nuclear bomber.  A PWR was never going to work as it was far too heavy.  The MSR was developed to produce a very high power output from a small reactor.  The reactor was designed to fit in the rear bomb bay of a B 36 bomber.  That first MSR did operate and even produced the highest working temperature of any known nuclear reactor.  Ultimately the project failed for a number of reasons not related to the reactor itself.  Firstly, while the reactor worked, the AF could not get a radiation shield that would protect the crew and stay within weight limits.  Secondly, air to air refueling was developed that drastically improved the effective range of the bombers without having a nuke power plant in the rear.  Finally, the shear liability of flying around a nuclear reactor in a plane was just plain ridiculous.  I am all for the MSR, but a nuclear powered bomber was a terrible idea.

A second MSR was built at Oak Ridge TN.  This one was called the Molten Salt Reactor Experiment or MSRE.  The MSRE ran for about 4 years in the late 60’s & early 70’s when funding was cancelled in favor of what is called a fast neutron Reactor that was specifically designed to produce plutonium for nuclear bombs.  Ironically, one of the reasons for shutting down the MSRE was that it could not be easily be adapted (though there is debate on this issue) to make nuclear weapons.

One interesting quality of the MSRE was its ability to simply and safely shut off completely.  There was neither funding nor desire for staffing the reactor over weekends.  One feature of all MSR designs is the drain tank.  The reaction chamber is connected to a drain tank directly below by a small pipe.  A fan blows on the pipe and cools it to the point that the salt freeze.  If there is a loss of power accident (like at Fukushima) then the fan stops, the frozen salt melts and the flibe drains into the tank that has no moderator.  The reaction stops immediately and the salt freezes safely in place.  At Oak Ridge, on Friday afternoon, the team would turn off the power to the fan and let the core drain into the drain tank, effectively shutting off the reactor safely over the weekend.  On Monday, the flibe would be electrically heated up and pumped back into the core where the reactor would start up again.  This feature makes the reactor walk-away safe.  If things go to pieces and nobody does anything, the reactor will shut itself down by itself.

Sadly, we have not had an MSR since Oak Ridge and there are a few technicalities to overcome, but certainly nothing insurmountable.  The biggest obstacle is regulation.  The design is just so different that it does not correspond to anything that the NRC would commission.  There is some lobbying going on to make the MSR easier to authorize, but I fear it will not happen soon enough.

Jennifer, I hope this answers your question and if you have more, I will gladly try to answer them.

Eric

I believe there is a new thorium reactor being built in holland now. Maybe it's already online

Bob,

I took a look at the video and for a 4 minute video, It is not bad.  My biggest issue with the video is a minor one, referring to the corrosive nature of the salt.  Actually, one of the qualities of flibe is that it’s specific chemistry is relatively non-corrosive, and the reactor vessel will likely be constructed of a material such as hasteloy N which is essentially nuclear grade stainless steel.  The short version is that corrosion was not a problem even in the MSRE.

I know that China is researching a possible MSR but I don’t think that they have built one.  On a side note, there have been attempts to make thorium fueled PWRs and I think that is being developed in Europe.  Sadly though, this just swaps out a fuel without really changing the reactor design.

Eric

Personally I prefer coal powered electricity with all it's waste problems over nuclear. But luckily we have natural gas, which I think is an improvement, but even better is hydro/wind/geothermal. They all have their negative points, so nothing is perfect.

But I wouldn't say that I endorse natural gas power plants just because they are better than coal powered. And I for sure would not say that I prefer Thorium nuclear reactors just because they might be safer than Uranium/Plutonium Reactors.

All that said. If someone told me nuclear waste is sitting 30miles from my house and it will be a level 200 waste for the next 300,000yrs or the could 'COMPOST' all the existing nuclear waste in this 'new reactor' while also cutting CO2 pollution and planting trees, reducing mining and deforestation. Then yes I am all about tapping into the waste stream.

But if we are not going to do that then I prefer if we dump money and brain capital on.

Yes, I understand most of the issues with corrosion are less problematic than many people might imagine. They equate the rust that happens near ocean salt with the inside of a reactor, which is a totally different chemical environment than the iron/oxygen/water/salt  of the ocean environs. The pure salts are chemically quite stable, and the corrosion concerns mostly arise in parts of  the "kidney" of the reactor, where fission by products are removed from the molten salt.

I'm actually quite glad to have the discussion around thorium, since it looks very promising, and we may be on the edge of a revolution, where people wholly reject fossil fuel and totally embrace the nuclear thorium option (at least until we burn up all the waste and warheads and have sufficient batteries and renewables in place.)



We will still need to do our energy efficient houses, gardens, reforestation, etc. and the main issue I see is what will we do with all the extra energy, and how long will we want to run these reactors.

Another piece that gets left out of discussions whenever a cheap (or free) and abundant energy source is posited is what to do with the waste heat that is an unavoidable byproduct of exploiting any high order energy source to do work. Basically, if we had unlimited free energy (even something with no carbon emissions) and a way to harness it, we'd cook ourselves if we attempted to maintain any semblance of a modern middle-class consumer lifestyle and even modest economic growth (which is an unfortunate requirement of our financial system).

This guy explains it beautifully. If you've got some time and inclination, read as many of his blog posts as you can.

bob day wrote: the main issue I see is what will we do with all the extra energy, and how long will we want to run these reactors.

Wouldn't the "extra energy" be used to replace all the fossil fuel plants during this transition period?

If the thorium plants are meant to run on waste and warheads, wouldn't they only be run until those sources are exhausted?

S Bengi,

Not trying to be rude here, so please understand that what I am about to say is an actual question and not a sarcastic statement.  What exactly do you mean by saying that radioactive waste is 1,000,000 times worse than CO2?  Are you saying that there is an actual measurement in which case the waste is 1,000,000 times worse or do you mean that radioactive waste is just simply vastly worse than CO2 in general?

For the purpose of waste, high level waste is actually the one waste that is treated seriously and stored properly (though there is considerable room for improvement).  CO2 on the other hand is simply exhausted straight into the atmosphere.  Additionally, what about the use of waste as fuel that would further reduce stockpiles of existing waste.  I would think this would be nothing but a good thing.

I do understand and am sympathetic towards those that are concerned with the issue of nuclear waste, but the MSR actually produces less radioactive waste in one year of operation than a similar sized coal plant as coal contains uranium.

Again, I am not trying to be argumentative as I know that this is a very sensitive topic.  But I do see promise in the MSR that I don’t see in a PWR.

Eric

I would like to see nuclear discussed without comparing it to coal.  Comparing a bad thing to another bad thing is not a great endorsement of the thing, in my opinion.

Except for the express purpose of deactivating existing nuclear waste, I see no benefit in atomic power, at this point in my life.  

S Bengi wrote: I have a hard time endorsing aquaponics/hydroponics. So radioactive waste that is 1,000,000x worse than CO2 coal-power-plant waste is a hard sell.

I could get behind Nuclear Fusion where we combine H2 to make Helium. So no radioactive waste. The fusion process, can however make the actual (metal) device become radioactive. But they decay to safe level in 30yrs.
Personally I prefer coal powered electricity with all it's waste problems over nuclear. But luckily we have natural gas, which I think is an improvement, but even better is hydro/wind/geothermal. They all have their negative points, so nothing is perfect.

But I wouldn't say that I endorse natural gas power plants just because they are better than coal powered. And I for sure would not say that I prefer Thorium nuclear reactors just because they might be safer than Uranium/Plutonium Reactors.

All that said. If someone told me nuclear waste is sitting 30miles from my house and it will be a level 200 waste for the next 300,000yrs or the could 'COMPOST' all the existing nuclear waste in this 'new reactor' while also cutting CO2 pollution and planting trees, reducing mining and deforestation. Then yes I am all about tapping into the waste stream.

But if we are not going to do that then I prefer if we dump money and brain capital on.

The quick answer is that I was being figurative vs literal similar when I said "COMPOSTING/deactivating' nuclear waste and when I said that to me track record nuclear is a million times worse than than coal (per 1000 plants/GW/etc).

I also understand that you might not have read all the post I made before you commented but I did list nuclear fusion, what do you think about this type of nuclear reactor. I also stated that I would be okay with 'reducing our current nuclear waste and if that can give us energy in the process, I am okay with it but it would be secondary. We also have similar views in that thorium-based nuclear might be safer/better than uranium/plutonium reactor. And I thing that most of us also agree that reducing consumption is the best 1st step and after that we keep on trying to improve on other things, and that if I/we did have money and research to invest that I prefer it going to renewable.

Also as others have hinted the primary reason for nuclear reactors was to 'secretly' build weapons to destroy, kill, deter. It was not to wean us off fossil fuel. I think it was 'great' that we were able to stack function by providing a bit of energy while making weapon grade raw material for national security purposes. I do hope that we stop making weapon grade material now, that the need is over, that is if we ever needed it in the 1st place.

The comparison to coal was introduced because of Germany's recent build of a  coal fired plant and deactivating an existing nuclear plant which had been running without incident. Environmental activists claimed a victory, but the CO2 sure jumped because of their "victory".


Of course one might theorize they have the coal plant as a backup and only run it part time, using it less and less as the renewable energy matures, but it sure looks counter productive.

I think my main transition to   support of MSR would primarily depend on it's ability to reduce waste stockpiles and weapons.

I have not been as involved studying this stuff for about a year, but I think the initial offerings will be primarily thorium based, and not waste incinerators. Although there may be some that will burn uranium which could conceivably use reprocessed weapons as fuel.

What actually ends up as the model for a plant is up for grabs at this point. Some of the nicer designs feature factory built small reactors transported (unfueled) by truck and lowered into a prepared concrete bunker below grade.

The sites are set up to have one active unit, and one that is cooling off and being replaced with a new unit.

This design lessens the expected life of the core, but enables the plant to continuously produce power.

By far the largest part of the site is the turbines, and there are ambitions to use hot air turbines  which are said to be wildly more efficient than steam

Interchangeability could also allow a reactor to transition from one fuel type to another when the units are switched out adding a versatility to the design..

I think the main thing for this thread is not to make decisions, but to become aware of what is going on. In our country (USA) regulations favor the status quo and these guys would rather build unsafe, inefficient  nuclear plants forever. They have lots of design stuff that has become industry standard, lots of investments would become obsolete overnight. About as bad as fossil fuel, and the regulators don't even know anything about the MSR reactors Schools stopped teaching about it  and trying to retrain the regulators may be more difficult than changing out obsolete engineering. Certainly getting a new set of regulations in place is going to be a major hurdle.

In the US, coal plants are too expensive to build and operate these days, and few people want them.  Nuke plants have always been too expensive to build and operate, and few people want them.  I think it will be difficult to persuade people that atomic power is appropriate at this time in history.  I don't see permaculturists in general endorsing atomic energy.  I'm a Mollisonian permaculturist myself, and Mollison believed atomic power was insane (he put super highways and large buildings in the insane category also).

Yes, I like Bill also, currently listening to his 1983 course.

Remember the course (Texas I think) where he talks about digging taro  with a wooden spade, and he said the natives would never let steel touch their food. Then he commented on how he always thought that was just superstition but he had seen some new study about the different effect of steel on food and how he had an  open mind ...?

S Bengi,

Thanks for the specific reply.  

Regarding fusion reactors:  I would LOVE to get behind those—if only they worked!  At present we can just barely make an energy profit only under really, really ideal conditions.  It gets worse.  The best version of fusion reactors we have today involve superconducting magnets cooled by liquid helium (which boils at barely a degree above absolute zero) directly adjacent to plasma streams that approach the temperature of the core of the sun!  This is the greatest temperature diffential in the known universe!  Also the reactors are absolutely huge, containing underground loops that run for miles.  One of the problems with the fusion reactor in France was developing an internal transportation system into the design and then re-designing bathrooms into the design as the initial design was optimized for fusion and not people.

But fusion is no doubt the energy solution of the future—and always will be!  I actually hope this pessimistic outlook proves false, but fusion has been 30 years away for about 70 years.  Maybe some day fusion will be tackled and we can get reasonable sized fusion reactors that run on water, but at present we simply are not there.

Regarding running MSRs on waste:  as I have read, MSRs could produce the worlds electricity needs for several years running solely on waste assuming that tomorrow all coal plants and PWR reactors were replaced 1 for 1 with MSRs.  After that, they would have to run on the thorium cycle.  To simplify a bit, thorium itself is a lousy nuclear fuel.  But if it absorbs a neutron (and it likes to do this), it will turn into U233 which is an excellent fuel, better than the U235 we use today in PWRs.  Thorium is 4x more abundant than all isotopes of uranium combined and only consists of 1 isotope in nature, meaning all of it can eventually be consumed in a reactor.  Uranium ore on the other hand consists of two isotopes: U235 which is a good nuclear fuel and U238 which is useless as a nuclear fuel.  Natural uranium ore consists of 0.7% U235 (the fuel portion), while the remaining 99% is useless for fuel.  Compare that meager figure to the abundance of thorium and one will realize that we have a truly vast supply of thorium at our disposal.

As  I have mentioned before, I am sensitive to the very real concerns about waste, but thorium shines again, producing “long lived” waste that is dangerous for 300 years as opposed to over 10000 for PWRs.  Also, this long lived waste is only a small fraction of the waste of a PWR.

I wrote this to respond to earlier posts and to be informative, not to be persuasive.  I am completely understanding of those who are highly concerned about nuclear fission.  If you just don’t like nuclear energy, I understand, but if you are curious about nuclear energy, I hope this has helped.

Eric

Eric, thanks for your reply! It was very detailed and helpful, and I was pleased to hear that the tech was past the theoretical stage. My position on nuclear energy is generally that no amount of energy or CO2 savings is worth the production of highly dangerous wastes which need to be contained without mistakes for periods of time the length of which seem rather daunting in light of the track record of our species for long term social/governmental stability and the operation of technologies without major human error. I just don’t think it’s worth it. On the other hand, if the option you’re discussing can actually consume those wastes and reduce the length of time for which the remainder persists, it seems worth it to build them as a sort of remediation strategy, regardless of energy output or profitability. My preference would then be to have them shut down, but maybe I could be convinced in the meantime, if there is a record of them operating safely and the waste really is minimal and short-lived, that they were an acceptable option. This all sounds rather nice from what you say, but I honestly don’t have the knowledge to evaluate it critically, so I’ve no idea how feasible it actually is. What do you think is the biggest obstacle to getting a plant like this in operation?

If one of the first principles of permaculture is to take responsibility for ourselves and our children, then it seems like leaving a problem this toxic for even one generation down the line is irresponsible. The 24,000yr half life of uranium is 20+ times the lifespan of any known civilization and is in my opinion obviously sociopathic. I do not know enough about thorium or other alternative nuclear methods to uranium or plutonium to speak educatedly about them. However, what better place than an internet forum to talk about stuff I am not an expert in?  Given what is stated above about degradation periods of between 30-300yrs, I still wonder what the worst case scenario is in the timeframe. Looking at it as I try to develop food forests that I would like to outlive me, especially with the NW CA native one where we have a 300yr wait for maturation of the keystone coast redwoods, this seems like a difficult enough multigenerational challenge without throwing in elements that could make the Earth uninhabitable for 99% of life. I cannot design something that only I can manage and expect it to last. That was the failure of Justinian in Byzantium and many other great builders over history. We could make analogous arguments about massive dam projects and their catastrophic longterm impact on their watersheds's ecology for many millenia, but that is just one watershed.

Ultimately, I see claims of sustainable inexhaustible nuclear power as a similar pipe dream to interplanetary human exploration. It becomes an excuse or rationalization for an economic model of perpetual growth dependent on ever increasing energy use and resource exploitation. We can probably manage 10billion people on Earth with Sepp Holzer and other permaculture techniques if people can be happy with a reasonable amount of luxury like great food, comfortable homes and resource security that these design methods can provide. Nuclear energy is only necessary if we get greedy.

Jennifer,

There is a parallel MSR technology called the fast spectrum MSR (FMSR).  The FMSR has no moderator and requires more initial fuel loading and is based on simple chloride salts.  The FMSR has a couple of advantages over the MSR.  Firstly, and perhaps most importantly, a FMSR by nature of having fast neutrons does not produce any significant degree of transuranic waste as it tends to fission every radioactive fuel it comes in contact with.  This has the ability to reduce waste to almost nothing.

Secondly, the FMSRs will run on a vast array of nuclear fuels, so it can run on waste or on thorium.  Thirdly, the basic salt loading is simpler, cheaper and melts at a lower temperature which means it has better thermodynamic properties.

Fourthly, it needs no online chemical processing.  This is both a plus and a minus.  It is a plus because it simplifies the operation.  Unfortunately, it will produce no medical isotopes.

Finally, by its very nature, a FMSR needs no moderator in the reaction chamber.  In fact, the reaction chamber is simply a hollow sphere with a couple of entry and exit points for cycling hot salts and a drain tank.  Fission is accomplished based on the mass of salts and geometry of the chamber.  In a regular MSR, graphite is used as a moderator.  This must be periodically replaced.  This is considered low level nuclear waste, is not particularly dangerous and only needs isolation for about 30 years.  This is about the same as hospital waste.

So the FMSR appears on the surface to have numerous advantages over the MSR which has even more advantages over a PWR.  The main reason that there is not a huge push for the FMSR (though this concept does have some serious adherents) is that to the best of my knowledge, we have never actually built even a test reactor in the past whereas the MSR was built and operated twice, so there is a corpus of knowledge around the MSR design.  There are even plans to build reactors in clusters (a common practice) where say 4 MSRs would operate and send their waste to a on-site FMSR.  

From what I gather (and I want to confirm this) is that a MSR extracts more energy per kg than a FMSR, but the FMSR can really reduce the waste stream to almost nothing so long as it is in operation.  The main waste left over from a FMSR (again, as I understand) would be the fuel load left over once the reactor is decommissioned.  If this were to truly work out, I personally could really get behind MSRs and FMSRs working together to produce emissions free electricity and really obliterate its own waste.

Once again I have rambled on, but I hope this illustrates the enormity of difference between MSR/FMSRs and PWRs operating today.  I hate the idea of nuclear waste, and I hate carbon pollution.  I can’t help but wonder if this is a technology that can take care of both.

To everyone who has read/responded, thanks so much for the civility of discussion.  At first I was a bit afraid that this topic would turn into a caustic insult slinging contest.  It has been anything but.  This is a highly controversial topic but every one has been mentioned extremely open minded.  Thank you all.

Eric

Ben,

You posted your reply while I was responding to Jennifer.  Regarding your permieness, I could not possibly agree more that I want to leave the world better than I found it.  This is the very reason I am a land owner in the first place.  I wanted to own/be steward to a piece of land so that it would not get commercially developed.  In this regard, I think I see absolutely eye to eye with you.

Regarding waste, I cannot tolerate the idea of vast quantities of spent nuclear fuel sitting around for a time longer than the present age of humanity.  And therefore I just love the idea of actually consuming this waste, making useable energy from it, offsetting and possibly even replacing fossil fuel consumption and vastly reducing the actual quantity of the waste (and what little waste is left is only dangerous for 300 years as opposed to tens if not hundreds of thousands of years) all in one step.

Like you, not long ago I was fundamentally opposed to all things nuclear, but having discovered MSR technology, I look at nuclear entirely differently now.

I hope you (and others) can see that I am favoring solutions that leave our planet better than we left it.  This is ultimately a compromise:  how do you provide a humane and reasonable amount of energy to 10 billion or more inhabitants on Earth?

And as I stated earlier in my last post, thank you for the very civil discussion.  As you point out, what better forum for this discussion than at Permies?

Again, I truly want what is best for both people and the planet at the same time and I look forward to yours and others responses in this surprisingly productive discourse.

Eric

Hi Eric, I want to thank you for carrying so much of the technical end of this. I have seen several different designs for reactors, but am really not up on the last year or so of development. (plus I've forgotten a lot of what I thought I knew)

I do plan to look it up, but it sounded like you were saying that the FMSR did not need online purification, which doesn't make much sense to my understanding. Fission produces by products, some escape as gas, some need to be chemically separated, doesn't seem to me to make much difference what the neutron speed is, or whether it's transuranic fuel or thorium.

If you feel like a little detail on how they avoid a kidney for this thing --or a link if you have one, I'll try and catch up.

Hi again Eric,

never mind , I think I see what you are saying, the actual reactor life is shortened, and while it is creating  some " internal pollution" it is able to process significantly more(most) of the semi enriched fuel --and evidently the emphasis today is on developing the simplest reactor possible while the kidney technology is perfected.

The nomenclature I saw was labeled MSFR (Molten Salt Fast Reactor)  Trying to look up FMSR didn't get me anywhere.

Bob,  

Sorry about the nomenclature.  To be honest, I did make up that abbreviation as I was going to simplify for readers, but apparently it complicated for you.  So for the future, I will use MSFR to reference fast spectrum MSRs.

Just to expand for others, I think the point you were wondering about was xenon 135.  Xe135 is something of a troublemaker in a moderated or thermal spectrum reactor.  Xe135 is a very common by product of fission reactors, and Xe 135 just loves to suck up a stray neutron.  In fact, in thermal spectrum reactors, Xe135 has such a propensity to eat up neutrons that it can actually shut down a reactor.  This phenomenon is called xenon poisoning and was actually a contributing factor to the Chernobyl disaster.

In a regular, solid fueled moderated reactor, Xe135 is a real problem.  It is a short lived element as it will decay with a 9 hour half-life, but during that time it will drastically lower reactor output unless more neutrons are brought to the party (which will then produce more Xe135).  Modern reactors try to run as close as possible to a steady state in order to keep Xe135 manageable.  In reactors used for submarines, where output can change drastically over short time spans, the Navy partially gets around this issue by having highly enriched uranium to always have even more neutrons to bring to the party in an emergency.

In a MSR, since the core is a liquid, when Xe135 forms, being a gas it simply bubbles out of the fuel and is pulled over offsite for some time to decay at which point the fission products are flushed back into the reactor to add to the fuel supply.

In a fast spectrum reactor, this step is not necessary.  In fast fission, the neutrons are moving so fast that they produce fission almost every time they strike another fertile nucleus whereas with thermal fission, about 1/3 of the time (depends widely based on the exact element) the slowed neutron strikes the nucleus and bonds on, making a new element.  In the case of Xenon 135, in the thermal spectrum, the neutron sticks and bonds almost 100% of the time.  In fast fission, the neutron causes a fission event almost 100% of the time, meaning the trouble-making Xe135 is just another element to cleave in half and not a neutron sponge with a half-life of 9 hours.  Also, because of fast fission’s tendency to always cause a fission event, a fast spectrum reactor has almost no potential to make any plutonium or other extremely long lived waste components.  The fast fission cleaves them all up into smaller elements, almost completely eliminating the whole trans-uranics (TU) class of waste and significantly reducing the quantity of fission product (FP) waste.

So why not make all reactors fast fission reactors?  These sound great at first—nuclear energy with a mere pittance the nuclear waste.  The main trouble historically has been cooling the (which is also how you remove the heat to do something useful like generate electricity).  Fast fission (FF) coolant must be almost completely transparent to neutrons and not moderate them at all.  That means you can’t use water as the hydrogen atoms in the water are pretty awesome moderators.

Historically the most commonly used FF coolant was liquid sodium which melts just above room temperature, or NaK, a eutectic of sodium and potassium that melts below room temperature.  Actually, either of these make pretty awesome coolants.  They melt low (so they don’t freeze in the heat exchangers—that’s bad), are very heat conductive, boil at high temperature so they carry a LOT of heat and are indifferent to neutrons (almost).  So far they sound like great coolants.  But anyone who has taken high school chemistry knows that sodium and potassium are wickedly chemically reactive (spectacularly in water) and to boot are fairly corrosive in most metals.  This is not to say that they can’t be used, they have, but the reactor itself needs a fair amount of maintenance.  Another benefit (sarcasm here), you can find your coolant leaks quite easily!

Another FF coolant is lead or lead-bismuth eutectic (expensive stuff here).  It also does not care about neutrons, carries a LOT of heat, and does not react like sodium.  The Russians used a lead cooled FF reactor for their Alfa class submarine, a sub known for being very small and very, very fast.  Another plus for lead coolant, you can actually get away with less shielding because the coolant IS shielding.

So what happened to these subs?  The Soviets had a series of nuclear meltdowns from an ironic cause—they surfaced their submarines through Arctic ice pack into air that was more than-20F.  The lead froze in the heat exchanger and plugged it up.  The reactors overheated and partially melted down because they could not circulate the lead coolant.  Ouch.  Ironic—they melted down because they froze!

This is not to say that FF is inherently bad.  In MSFR, the mechanics are entirely different.  In an overheating situation, there is room at the top (in some designs a little pipe that extends up) for overheating salt to expand.  Expanding salt reduces the fissile mass in the reaction chamber and fission reduces.  In extreme events, the freeze plug melts at the bottom of the reactor and the fuel drains out.  

FF reactors have two big but not insurmountable strikes against them.  Firstly, FF needs a much larger fuel load.  Secondly, we just have so much experience with moderated/thermal fission that we know how it behaves.  We have built two thermal MSRs, but no MSFRs.  The potential is there,  but it is just more of an unknown.

I hope this helps a bit and thanks again for everyone being so civil.  It really makes this a great place to exchange ideas.

Eric

The article I read seemed to indicate current US focus is on the MSFR, since it avoids the need for a breeder blanket (also I think there is a fair amount of interest in using up spent fuel and warheads)

Most of the things I read would suggest regulations may be the biggest challenge to implementing these. The research and development still has a way to go, but  what I read mentioned the russians had worked with MSFR s back in the 70s testing them with plutonium.

Bob,

Absolutely no doubt whatsoever, the biggest obstacle to developing ANY MSR is the regulatory environment.  MSRs are just so different that do not correspond to current legislation.  For example, in order to be licensed, your design must show how you will get coolant water on the core in high, medium and low pressure environments.  MSRs just don’t use water as coolant so right there they fail an important piece of safety regulation. It is good to know that the NRC takes these things seriously, but absurd that it can’t get around water coolant!

As far as Russian MSRs, I just don’t know what they have done and I don’t trust their reports.  As far as I am a aware, there were only two MSRs, the Aircraft Reactor Experiment and the MSRE.  Maybe the Russians did have a MSR type experiment, but I have no direct evidence as such.

Regarding the status of the MSFR, there is a big schism in the MSR community, dividing along the fast/thermal lines.  The biggest voice in the MSR community is Kirk Sorensen, an advocate of the thermal spectrum, more or less brought the MSR concept back to life after it was abandoned in the 70s.  Others understandably favor the fast spectrum for its ability to obliterate waste.

Eric

Eric,

I was not meaning to condemn your even bringing up the topic, and of course it seems like a great idea to get value out of "spent" nuclear fuel given that its already here, while also reducing its toxicity and half life. I mainly just think that the 1930's-40's saw the most insanely short term thinking I could imagine, even if it was for a lot of largely understandable reasons given the Depression and the World Wars those decision makers lived through. I just hate the idea of our finding a way to mitigate the catastrophic toxicity of nuclear waste being seen as an excuse to create more of it. I know that even with my permie values I rationalized gardening under plastic film because at the time I bought it my local recycler accepted it. Now, while it definitely paid itself off for me financially and I reuse it however I can, I cannot recycle it and will not use it again, as its still a long term problem for many living things around me and will outlive me.

Ben,

I do understand your concerns.  I really do.  You are absolutely correct about the short sighted nature of the events around mid-century (personally I think the worst was the 900 or so above ground nuclear tests done in 50’s.).  And by no means do I want to generate more waste.  My interest is that can generate electricity with many orders of magnitude less waste than what has been produced each year since the 1950s.

And while I don’t like waste, I really, really don’t, I have seen some basic numbers.  Any coal power plant of even modest size releases more radioactive waste than any nuclear plant as coal contains uranium and it is simply released into the atmosphere.  I find this absolutely unacceptable.  I realize that you like coal no more than I, but I think it irresponsible to not use energy when the waste can massively reduced, easily contained and is now dangerous for only a mere fraction the time of current waste.

Ben,  I sincerely appreciate your extremely civil tone with me on a topic where I am sure we have differing opinions.  I did not form this perspective lightly, and I only do so because I think of the amount of CO2 we would not be sending into the atmosphere.  Previously on this thread it was stated that no amount of CO2 reductions would be worth any new radioactive waste.  I have to wonder though, if we could eliminate all of our carbon debt with one additional ounce of waste would that be worth it?  In my mind it would, so the salient question then would be how much would it be worth?  What if we could completely eliminate all waste that will be dangerous for 10000 years or longer and replace it with a vastly smaller amount dangerous for only 300?  Would that also not be worth it?

To most respectfully reiterate, no, I don’t like waste, but neither do I like out-of-control carbon being released into our atmosphere.  I know that we may disagree on this point, but My informed perspective is that MSRs are a powerful tool to reduce both CO2 and nuclear waste at the same time.

I hope I have not offended and I thank you for your polite civility.

Eric

I agree with you Ben,

finding uses for these "waste" streams is important,    Eric hasn't posted it, and I forget, but just running on the nuclear waste alone we could supply the country's electrical needs for a hundred years (I made that up, I don't really remember the number, but it is huge)

Add to that war heads and then go to thorium (the earth burns this at it's core, it keeps our magnetic fields going and helps heat us.   This technology holds the promise of more than just cheap electricity, and the temptation will be to over use and create problems where there were none.

Honestly, when I got involved in studying this stuff it made me giddy with hope, and afraid of it all at the same time. Of course I'm just a bystander, this field is major leagues and I'm not close to being a contender, so I do the things I know to do, and if democratically I'm asked to select, i just hope I have the wisdom to know which button to push.

Bob,

Thanks for bringing up the run time of waste alone.  At present we have some pretty massive stockpiles of waste, most of which are fuel pellets with well over 90% the fissionable uranium left inside.  At present it is just sitting around at a bunch of different sites.  This alone would produce electricity for a very long time.  

Getting fuel from warheads would be much more difficult politically so for the moment I am not even going to go there.  Burning our waste would substitute a tiny amount of waste for a huge amount.  Each year a 1 gigawatt sized plant produces several tons of waste in the form of spent fuel.  A similar sized MSR will produce a coffee can sized amount of waste.  That coffee can can be reduced further in a fast spectrum MSR.

The way I see things, we have the potential to really cut down on our stockpile of waste.

Eric

“Any coal power plant of even modest size releases more radioactive waste than any nuclear plant as coal contains uranium and it is simply released into the atmosphere”

Eric,

This was very surprising to me. I did a bit of reading to try to understand this better. From the articles I read, it sounded like the coal plants released more radioactive waste into the surrounding environment than a nuclear plant that produced the same amount of energy. That is worrisome. But it sounded like this was because the radioactive waste from the nuclear plants was contained, while the coal plants simply released it into the air. But it did not sound like the absolute amount of radioactive waste produced was lower for the nuclear plant. In other words, nuke plants PRODUCE more radioactive waste, but coal plants RELEASE more. Do you agree with that assessment?

Thank you for the time and thought you are putting into this discussion!

Guys,

Been reading all day. Wonderful!!! THIS IS WHAT LIFE SHOULD BE!!!

Hard topic with vivid and important issues discussed fervently and respectfully. I love it!

Eric, I have been staying off here, but I am excited to have someone who is recently involved. It has been over 20 years since I was involved in some of this. I had let it go, there was no bridge to the future at that time. I am excited that we are considering a waste stream enterprise that can make a profound difference. The little waste streams I am involved in are peanuts, this has real potential.

What people may or may not know is that nuclear weapons need to be reprocessed. Often it generates even more waste, a lot more, like train cars more. Most were built during the cold war, and are aging out. This is true for >two countries. There are other considerations I won't go into, but suffice to say electricity is a better byproduct than some other waste streams.  It is far easier to repurpose some of these isotopes (shall we say) than to utilize them. And there are hundreds of tons of nasty stuff out there. The Russians are often just dumping them in the ocean. There is every possibility that that is true for other nations including the US. Waste streams tend to be disposed of by organized crime. This seems constructive in a couple ways.

The thermal issue is a factor, but in four plus generations. Let tomorrow's problems be dealt with tomorrow. Lets solve today's problems. If tuberculosis isn't the main problem by them something else will be.

Jennifer,

You have a very good point here and I am glad you took the time to look it up.  Also, thanks for fact checking me.  I really do try as best as possible to as much as possible use objective fact and sound reasoning, especially for inherently controversial and emotionally charged topics like this.

But back to your question.  I think it is fair to say that a coal plant does not produce any new radioactive waste as it is not a nuclear reactor in the first place.  But this is a really incomplete picture.  Making waste really is not a problem.  Releasing waste is.  For example, let’s say we have some incredibly wicked nasty reactor that produces the most awful waste (both radioactive and chemical—an overlooked aspect) —and the loaded all of it onto a rocket and shot it into the sun.  We would have no problem whatsoever then right?  And if the same waste was alternatively tucked into some hard-as-diamond and otherwise impervious structure and placed right back into the same uranium mine it came from, would there be any problem there?

Alternatively, CO2 is generally not considered dangerous waste because it is not toxic unless it is in extreme amounts so we let it go into the air where it does significantly contribute to climate change, so which is worse?  Is the contained waste really more dangerous that a completely uncontained greenhouse gas?  In my opinion, a thing is not dangerous, it is what we do with the thing that is dangerous.  Further, it is my opinion that controlled radioactive waste, no matter how radioactive, is safer if controlled than a completely uncontrolled “benign” gas like CO2 which has is clearly detrimental to the environment.

But I have strayed a bit in my answer, but the principle still applies.  A nuclear power plant is fueled by uranium that occurs naturally.  It then creates a bunch of new materials, most of which also occur naturally, but mostly in far lesser concentrations.  But regardless, these waste materials are contained.  Don’t get me wrong, these materials should be contained much better than they presently are, but they are contained.

A coal fired power plant on the other hand not only released vast amounts of CO2, but also completely uncontained and uncontrolled uranium which is not only radioactive, but is also chemically toxic (and strange at it may seem, the chemical toxicity might actually be worse than the radioactivity.  Just imagine if that uranium were lead instead)

So in the end, and to answer your question more directly, it is my opinion that burning coal and releasing uranium wily-nily is worse than having even high level nuclear waste but kept in a contained form.

Now even better would be to take this waste we have kept secure and vastly reduce it so that any potential accident will reduce the spread of contamination further.

On a personal note, I grew up 20 miles from a power plant and never feared the radiation.  I did not look forward to it being released, nor did take it lightly, but I did not fear it.  Presently I live not terribly far Paducah and the associated gaseous diffusion plant.  The surrounding area is no radioactive wasteland, but rather a beautiful national forest that I personally treasure.  The radioactively associated with these associated industries simply does not enter the environment.

As I have said before, I do not like the idea of the radioactive waste, but I am concerned with uncontrolled release of CO2.

Jennifer, thanks again for bringing this up.

Eric

TJ Jefferson,

Thanks for chiming in here and really, I greatly appreciate having someone out there who can see the potential for the MSR.  I am curious as to your thoughts on fast vs thermal spectrum reactors and curious as to your background.  Mine is from studying the history of energy for my masters degree in history (I am a high school history and psychology teacher).

Eric

Eric,

My background is that I was a big nerd, trying to figure out how to put bread on the table. I was planning on working at the Columbia University HBT-ET (tokomak), where I had a good friend in the lab. But as you have mentioned, a couple lifetimes, maybe. The new patent for room air superconductor if it works out is a big deal. Not one person I knew in that industry stuck with it, there just wasn't a future. We all went into something different.

Anyhow, I aged out. Went to work for the Man. I was an electrical engineer. Then system engineering in chemical byproducts. Then burnout and international work. Then other stuff making my family think I was in the Mossad or something. I made and lost money. I feel like Dr Evil So basically from an engineering background but with an extreme appreciation for how freaking smart people were back in the day. I have a picture of myself (with a BAC of close to toxic) outside the Cavendish labs after a big party. They were giants. I am not.

Anyhow I recommend anyone who wants to get the bug to read "In Search of Schroedinger's Cat". And the read Feinman's lectures. If that doesn't make your little heart just beat with enthusiasm, you just aren't going to be an engineer.

Eric,

I agree with you in principle. My main concern is that I feel it is pretty inevitable for the storage to fail, considering human nature and the history of human civilization vs. the enormously long (in human terms) half-lives of some of this waste. The MSR really appeals to me as a way to reduce some of this stockpiled waste. I do have some reservations aside from storage:

Transport. Transporting these wastes for reuse is a major point of vulnerability and potential for uncontrolled release. I don’t know if the MSR plants would/could be built on/near existing nuclear plant sites to reduce this danger, but that would make me feel better.

Psychology. If people feel like their energy use is/will be “free” or even beneficial as a way to reduce these wastes via the MSR technology, I fear that they will be less inclined to conserve. I think we could eliminate coal and nuclear plants tomorrow if people had the personal and political will to take basic conservation measures. This depresses me sometimes.

Population, demographics, and social organization. It seems that high energy availability per capita correlates with an increase in human population as well as with the complexity (and speciazilation and alienation, IMO) of our social arrangements, both things I would like to see reduced due to adverse impacts on people and the rest of the biosphere independent of our means of energy production. So honestly, even if we could somehow produce non-polluting, limitless, highly concentrated energy, that wouldn’t necessarily be an unmitigated win in my book (although, very tempting).

Cost. I’m not sure if such an operation would be profitable or to what degree taxpayers would need to subsidize it, and how that would compare to other forms of energy production or the costs of climate change, but my understanding is that nuclear energy doesn’t really pay for itself, and I don’t know if MSR would be an exception.

The possibility of meltdown. Rare, but catastrophic.

Not saying any of these is necessarily a deal-breaker when compared with other methods (except conservation, which I think wins hands-down), but they do temper my enthusiasm.

I would honestly like to see virtually all non-home- or village-scale energy generation go the way of the dodo, but I will confess that nuclear worries me most.

CO2 I know how to sequester, and while I am convinced that anthropogenic carbon emissions do contribute to climate change and that this is dangerous, I do feel that we can probably mitigate the effects, especially if we decide to really care, and individuals can do a lot. Radioactive waste is not something I think we have the ability to mitigate or remediate once it is realeased, and individuals can do absolutely nada on the home scale, so I assign it more of a fear factor.

I have the dubious privilege of having both a coal and a nuclear plant quite near. We used to get acid rain that stripped the skin off our baby calves from the coal plant. Horrific. I will say that they have cleaned up their act, relatively speaking, at least—although only at regulatory gunpoint.

I absolutely don’t want to seem as if I’m arguing in favor of coal or wanton CO2 production! And I will say that based on this discussion (pending further research), I’d tentatively vote in favor of building an MSR, whereas I was categorically anti-nuclear before. But I still don’t think I’d like to see them relied on into the far future or as an alternative to conservation.

I am so glad we are having this conversation! It has given me tons to think about already.

TJ Jefferson,

So I have no formal engineering background.  I have always had an interest in energy and history, though the two did not intersect until graduate school.  I did a BA in psychology and then a BS in history and as chance would have it, I got a job teaching high school history and psychology.  In graduate school (which I did while teaching full time—6 1/2 grueling years) I took an interest in environmental history with a further focus on history of energy.  Initially I had naive hopes that biofuels and renewables would save us from our own destructive tendencies.  It did not take much time for me to have my hopes utterly dashed.  

I really held out hope that efficiency could save use from energy disaster.  Then I read about the Jevon’s Paradox.  The Jevon’ Paradox states that increasing efficiency actually increases consumption rather than decreasing it.  If you are curious about the Jevon’s Paradox, I could do another thread dedicated to it, but if you own a Prius, it is pretty depressing.  I can recommend an author Vaclav Smil.  He writes about energy, the environment and population dynamics (among other things).  He was born in Czechoslovakia, educated in England, started his academic career in the United States and finished his career and retired in Canada.  He has something to offend almost everyone, so therefore I like him.  He made me pretty depressed.

Eventually I found a YouTube video about the Molten Salt Reactor and I was hooked.  Nothing about it violated anything from my previous education and I fact checked it to see if this was legitimate or someone’s fantasy.  As far as I can tell, it is completely legitimate.  

I had to educate myself on some basic nuclear physics.  I learned the difference between a moderator and a control rod.  I learned that short half-life radioactive materials are more dangerous than long half-life radioactive materials (if anyone wants that clarified I will gladly do so).  So basically I self-taught myself most of my energy background.  I am back in grad school again and am considering getting a PhD in the history of energy, but that will be a tough row to hoe.

That’s basically my energy background for anyone curious.  If you are still curious, feel free to ask.

Eric

Jennifer,

I too am extremely pleased we are having this discussion.  Also I too share your concerns/skepticism about human nature.  Believe it or not, it is this skepticism that led me to being favorable to MSRs.  Truly, I did at one point really try to power my life with renewables.  I built my house with Southern exposure.  I paid extra for really good insulation and I put in energy efficient everything.  Then I went the extra mile and went to install solar panels on a roof designed for optimal solar exposure.  What I got was an extremely painful slap of reality.  I got quoted a system that would replace 1/2 my electrical bill for $30000—with a rebate!  I was shocked.  The payback time was about 25 years with panels that had a 20 year warranty.  

I was more than a little jaded by this experience and I am certainly not opposed to renewables, but I started (painfully) to see their limitations and context in which they can work (or for me, won’t work).

I am perpetually interested in clean energy, I am just wondering/discovering what that may look like.

At any rate, this is my personal journey.  I have my own ideas and I am pleased we have Permies as a forum to exchange these ideas.

Thanks so much for contributing and fact checking for me.  I hope our conversation can continue.

Eric