TC No. 6 • Kirk Sorensen: "Thorium - A Global Alternative" Part 2

but it's expensive to make nuclear fuel and i don't like the way we do it costs too much and it and it works too poorly we're only using a small amount of the potential energy in the nuclear fuel there's a number of reasons for that one of which is any nuclear efficient is going to make gaseous fission products xenon and krypton other products but xenon krypton are significant because they have as gases they have a huge amount of volume per unit mass and that leads to cracks and distortions and swelling in the fuel when the fuel swells to a certain point the clad can't hold it anymore and when the clad can't hold it anymore it's time to remove the fuel from the reactor at this point only a small amount of the energy has been consumed but if we had a fuel that was impervious to radiation damage in uranium fuel you're only able to burn up a small fraction because you cannot breed uranium to plutonium in the thermal spectrum you cannot breed that sustainably you can't achieve a conversion ratio of one thus the interest traditionally in fast spectrum reactors for uranium but with liquid fuel we can address most of these concerns fundamentally because the liquid fuel is ionically bonded not covalently bonded so it is impervious to radiation damage it will not be altered in its properties by the withering radiation environment inside the reactor it has a wonderful liquid range of about a thousand degrees c you have to get it to a certain temperature before it'll melt but once you get it to that point it will stay liquid for a tremendous range contrast that with water which is what we use which only has a hundred degrees c of liquid range at standard pressure we increase that liquid range by putting it under tremendous pressures but therein is is a risk that that all that i'll uh cover in just a moment and into these liquid fuels we can dissolve the fuels of the thorium fuel cycle or the uranium fuel cycle but we can put the uranium and the thorium in a true solution in these nuclear fuels and as many of you know lithium floyd beryllium fluoride if you rearrange the letters you get this funny word called flibe that we took is our our funny name of our company one of my favorite things though about the liquid fuel form is this safety feature that is inherently uh it is unique to liquid fuel and standard operating at atmospheric pressure the ability to drain the reactor into a passively safe configuration without operator intervention without uh anything active or mechanical or computer based needing to take place the the notion of having a small port at the bottom of the reactor that is kept blocked by a frozen plug of salt that when power is lost the reactor will drain itself passively into a configuration where decay heat can be rejected to the environment this is such a remarkable feature and it really is unique to having this liquid fuel form into having something to operate at standard pressure you can't do this in solid fuel if you do this in solid fuel it's called a meltdown that's bad for us it's no problem but this has been to my experience one of the key ways that we've reached out to the public is we're able to show them here's the simple and safe way this reactor is not going to harm you because the public is worried about am i going to be harmed by the use of nuclear power we've got to show them that within this approach there is an opportunity to drastically reduce that risk i can only contrast this with what happened uh in a solid fuel reactor at fukushima as as coolant levels drained in the reactor these ceramic fuel rods were not being cooled uh nearly as effectively as they were with the liquid water uh gas is a much poorer coolant than than liquid and without that removal of heat the the rods melted they failed and you had a radiation release and then that's that's not good we don't want that the entire pressurized water reactor as we know operates under tremendous pressure whether in the boiling water mode or or in the pressurized water mode that leads to every system needing to be of a very high quality of a very high grade because every penetration or valve or way for pressure to be released in this reactor is critical it's safety critical uh the loss of pressure can potentially lead to a meltdown all of our safety systems and existing reactors are built to mitigate this and i'm very impressed with how the nuclear industry has operated safely for so long but it comes with great complexity great carefulness and great cost and if we want to move into a world where nuclear is far more prevalent safer and cheaper we've got to change these fundamental principles and we've got to move away from high pressure operation that will also free us from having to build very very large containment buildings we can build containment buildings that are more close fitting to the reactor they're cheaper they're smaller we can build them in a factory i i talk to people about modular construction which is certainly one of our goals lots of people are talking about small modular reactors and factory construction and i think well how do you do this when you've got to build a big pressure vessel i mean i know it's possible but it's challenging this is a way to make it a lot less challenging by using a non-pressurized fluid so here's the basis of the lifter that we're working on at flab energy it's got a fuel salt which contains uranium-233 it flows through graphite moderator elements it's heated by fission and it heats a coolant salt in the primary heat exchanger all of this is contained inside a containment boundary then that coolant salt exits the containment boundary and heats a gas uh probably nitrogen or helium which in turn drives a gas turbine due to the temperatures at which the reactor is operating it's possible to achieve higher efficiencies higher thermal efficiencies with this configuration because the reactor is fundamentally delivering heat at a higher temperature with our water cooled reactors we can convert heat to electricity about 35 efficiency with salt and gas turbines we could potentially go a lot higher uh 45 coming up close to 50 percent that's really an impressive uh improvement in in thermal efficiency performance but one of the things that really excites me is this backing so you spin the turbine you make electricity the electricity goes out on the grid but then you cool the gas from the turbine and there's still a lot of heat energy in that gas in thermodynamics we call it enthalpy uh still a lot of enthalpy in that gas and that enthalpy can then be used to desalinate seawater using just waste heat this is something that a water-cooled steam turbine reactor can't do because it has to cool its steam at a very low temperature in order to achieve attractive efficiency they can use electricity to drive reverse osmosis or other processes but that's a penalty that's electricity you didn't sell to a customer or didn't use or shaft power that didn't go do work for you on on the on the grid or spinning a propeller or whatever it is this is energy that would otherwise go to waste that we can use productively in the gas turbine to desalinate seawater just visiting the the potential coolants that reactors can use i mean i like to try to boil down a space i go okay what's everything that could be done in nuclear reactors and i know there's a few others but i think this really captures the majority of the coolants that have been considered water is the one most commonly used it operates at relatively low temperatures and very high pressures that's exactly what we don't want we want to operate at low pressures and at high temperatures in order to achieve high thermal efficiency gas can operate at high temperatures but it has to go to high pressure only the salts appear to offer the potential to go to the high temperatures and at the low pressures and that's a unique combination in the in the potential space of nuclear coolants now let's talk a minute about thorium as a fuel and how thorium is enabled by the liquid fuel approach thorium's only got one isotope and a very long half-life it's much more common than natural uranium and if you think about all we're consuming now is that very very very small sliver of natural uranium that is uranium-235 that's what we're using up and we're not accessing the much larger amounts of uranium we need a fast reactor to do that on the other hand with thorium we can access the energies of thorium in a thermal spectrum reactor and thermal spectrums are much simpler safer reactors to build with the thorium approach we absorb a neutron causing thorium to decay through a chain to uranium-233 which is the fuel the absorption of another neutron leads to a fission in uranium-233 that releases more than two neutrons and that's very significant because you need more than two neutrons one to continue the fission reaction and the other to continue the conversion of thorium into new fuel uh all of these industrial processes they're radiation hard they don't require the fuel to be aged or or stored for some period of time and that's a real contrast with how people talk about doing existing nuclear fuel processing today the power of thorium in the liquid fluoride thorium reactor if used at these kinds of efficiencies becomes really mind-boggling and to try to put this in perspective i commissioned this animation the notion of a single cubic meter of regular earth anywhere on the planet by weight it will contain roughly two cubic centimeters of thorium metal so if you could extract all the thorium from regular piece of dirt anywhere you'd get about two cubic centimeters of thorium and about half a cubic centimeter of uranium if you were to consume that thorium at high efficiency which is the kind of thing you could potentially do in a lifter it would be as if that cubic meter of earth had the energy content of 30 cubic meters of crude oil so this is a remarkable potential capability the ability to take worthless dirt anywhere in the world and make it worth many multiples of crude oil i can't think of any industrialist who if you were to present him with an easily accessible huge pool of crude oil wouldn't say yes let me slurp that up and go sell it to somebody and make a lot of money you know here's a way to turn worthless dirt into something worth more than that but the key is to build a machine that has the ability to very efficiently convert thorium into energy part of the reason for this is because thorium starts so much lower on the on the chain of nuclear masses than uranium-235 and uranium-238 when we build an existing reactor it's mostly uranium-238 fuel and a few percent uranium-235 this is where the fissioning takes place and uranium-235 will fission about 85 percent of the time so about 15 of it will become uranium-236 and then ultimately neptunium-237 but 97 of it is only one neutron absorption away from being can't we see that's plutonium-239 so the formation of these transuranics that's really what drives a lot of the worry about long-lived nuclear waste we're making plutonium we're making americium curium these these higher forms why don't we make as much in the thorium cycle the reasons we start down here with thorium-232 which when it absorbs the neutron becomes uranium-233 that'll fission 90 percent of the time so only 10 percent of it makes it to become u-234 it absorbs another neutron and becomes uranium-235 which will fission 85 percent of the times now you're down to about one and a half percent of this material could potentially make it to neptunium-237 which is your first transuranic that then can be physically extracted from the salt if desired and you've arrested the formation of further transuranics or an alternative would be to retain it in the salt this is going to lead to some neutron loss and form plutonium-238 which at nasa we are just really really dying to get our hands on because we use plutonium-238 to explore the solar system lifters if operated in a particular manner would have the potential to make small quantities of this in fact uh i was at a meeting at nasa with some of my old friends there and and telling them about this potential they got really excited and they said can you make are you just going to make this stuff anyway and i said well no we have to choose to make it uh it's to our advantage to actually take it out at this stage so as not to make plutonium 238 he goes oh darn you know i said but under the right circumstances and and if there was a national need for this in a national interest uh there's the potential there to do this and he got kind of excited because we really are hurting for this we launched the curiosity rover to mars uh last year and it's got a large fraction of our remaining plutonium 238 on board it's going to be able to explore mars using that material which is really going to be cool getting back to some of the things we can we can make with a lifter with existing reactors we basically we make electricity that's that's about all we do we throw all the waste heat and we don't use uh the fission products with a lifter on the other hand we can not only convert to electrical uh energy and much higher efficiencies but we can also use the low temperature waste tea for desalinated water we can alternatively tap off some of the processed heat for a potential generation of hydrogen and my favorite product from hydrogen which is ammonia because ammonia leads to fertilizer and fertilizer leads to uh the green revolution that we've enjoyed as as inhabitants of this earth for the last few decades that's why uh seven billion of us can be fed on this planet when before we could only feed about 1 billion is because now we know how to make fertilizer and that's primarily driven by fossil fuels and then there's also great value potentially to the separated fission products this is a slide i believe i borrowed this from pear peterson about how high temperature heat from the gas cold reactor but the same principle applies because of the power conversion system how high temperature prop heat can be then converted to electricity and then the waste heat is used to cool seawater in order to lead to desalinization so let me talk about molybdenum for a moment uh molybdenum 99 will decay to technetium-99 a technetium-99 is used in more uh radioisotope procedures worldwide than anything about 30 million procedures worldwide use technetium 99 some of these other smaller radio isotopes iodine 131 also produced in a reactor like this xenon 133 also produced these guys no we don't make those but there's the potential there to make uh these medical radio isotopes and then technician 99 in turn is used in a variety of different diagnostic procedures uh primarily related to your heart how is your heart performing also your bones uh liver your lungs it's it's really a remarkable diagnostic tool it is combined with a variety of different compounds these are called cold kits in order to try to ascertain uh different performance gallbladder function or kidney scan or blood pool imaging each one of these is a compound that the molybdenum is is connected to in order to do that right now it's made in just a handful of research reactors that are scheduled to be shut down there's some great papers written about the market failure of not having uh the money that's being made in in technetium going back to operating these reactors they're going to be shut down this is the supply chain for one of these reactors it's in the netherlands the molybdenum is produced there it's extracted then it's shipped over to chicago right here into o'hare and it's trucked down to maryland heights in missouri to uh covidien's maryland heights facility where it is where it is made into uh what's called generators this is what they look like they've got this little uh column of silica and they lay the molybdenum on there and then they take it to the hospital and it is eluded they run a small saline lying through here and they extract the technician the technetium comes out in the saline the molybdenum doesn't and these run for about a week or two and they treat patients with this you know this is a really uh remarkable process unfortunately the ability to service the world's molybdenum needs is already very limited and it's on its way down which is which is bad for over 50 years we've been focused on the electricity that can be generated from fission but about five percent of fission leads to the formation of the molybdenum 99 the 99 mass decay chain and it could be that this is potentially worth even more than electricity what's unique about lifter is that we can extract this valuable product while making electrical power we do both at the same time our power reactors today that make lots and lots of molybdenum but it's not extractable if you want to get it out you'd have to shut the reactor down depressurize it cool it extract the fuel reprocess it by the time you did that the molybdenum is all gone it's only got a 66 hour half-life so you can't do it fast enough and these little research reactors where they do make the molybdenum they have to use targets and there's a lot of issues surrounding the use of targets here's a way where we can do both at the same time we can make electrical power and we can make this useful medical isotope i want to talk about another one that's somewhat related to thorium and uranium and that is uh the idea of targeted alpha therapy targeted alpha therapy is when you take an antibody and you attach an alpha emitting radioisotope and the one they're showing here is bismuth 213 which is probably the most promising the notion is the antibody then goes in the body it attaches to whatever you want to target typically a cancer cell but maybe other things and then when the bismuth decays it gives this knockout punch to the cancer cell and kills it and so this is an exciting technique and there's lots and lots of alpha emitting radioisotopes there's a four decay chains three of which occur naturally the thorium uranium and actinium decay chains occur naturally so you look at this and you think there's got to be a good alpha there's going to be lots of good alpha emitters well turns out there's not bismuth 213 which is the favored one exists on a decay chain that no longer exists in nature the neptunium decay chain we in the course of pursuing a thorium powered world recreated this decay chain about 50 years ago and we have an inventory of uranium-233 that has led to the formation of the precursors of bismuth-213 it's sitting up at oakridge right now it's slated for destruction many of you know about this and have tried to help fight against the destruction of that material but on the other decay chains there's not a lot of promising alternatives bismuth 212 this is on the same decay chain as thallium 208 which is a hard gamma emitter many of us in the thorium world are familiar with one of the ancestors uranium-232 that can lead to these hard gamma emissions so putting this stuff in the body is not a really great idea either and then over here on this decay chain they have to make acetene 211 in a particle accelerator that limits how much you can make so really it turns out that this neptunium decay chain is unique now golly wouldn't it be great if there was this stuff on earth and lots and lots of it and we could just go mine it and we can't because it it went extinct a long time ago it's the only one of the four decay chains that doesn't pass through radon on the way through its decay and that's significant because all the other decay chains as they pass through radon radons of gas and as you go through radon your stuff gets away it gets out of whatever you've got it in usually a liquid and so it's hard to retain and so not passing through a radon step is very very significant to starting out with a parent material and getting to this bismuth 213 which can be a real cancer killer we need to get this stuff in the hands of doctors so that they can use it to treat deadly diseases like acute myeloid leukemia and other cancers if we had this material extracted from this parent source i really think it would lead to a revolution in fighting cancer and we've talked about political challenges situations this is yet another one that's got a real political challenge situation attached okay so all these great benefits how do we know this can work uh quite simply because because we did it back at oak ridge in the 1950s and 1960s we built two reactors the aircraft reactor experiment and the molten salt reactor experiment i had the great pleasure uh last couple of days to talk with some of the pioneers of the molten salt reactor program and that was one of the things they kept emphasizing to me in my discussions with them we really did this we were trying to prove feasibility we felt like we proved that feasibility but it was a it was a pyrrhic victory because there were the forces of the atomic energy commission despite the success of the molten salt reactor program were very focused on building plutonium fast breeder reactors that was really the sole focus at the decision point at the time when when we needed to decide whether we were going to go forward with this technology uh the entire focus of the aec was was on the plutonium fast breeder and so it was set aside now when the plutonium fast breeder program foundered in the late 70s to the best of my knowledge nobody went back and revisited that decision nobody went back and asked you know should we have gone the other way should we have uh should we have used thorium i wish that i wish that question had been asked because maybe we would be having a very different conversation today if in the early 80s people had said let's go back and and revisit that we could have taken advantage of existing uh understanding the the men and women who were working on this and making it happen well nevertheless that's where we are here we are today in a world that desperately needs more energy at lower prices with a far lower impact on the environment and how are we going to do that well i remain convinced that thorium is the answer and i i've come to this belief because of learning about the technology of the liquid-fueled reactor and the potential to have a tremendous amount of energy that would quite literally be able to be held in the palm of your hand and it would cost a few cents and and jim would probably challenge that and tell me it would cost nothing right jim i i got curious how much thorium would it take to power all of north america for a year and and uh it would quite easily fit in this grain silo which i passed many on my drive up here from alabama yesterday so the good news is we've already got a four grain silos worth of thorium sitting out in a hole in nevada so it's not as if thorium is going to uh be something that somebody's going to go and corner the market on i'm often asked that question uh is is somebody gonna get the drop on us on this and i say i don't think it's gonna happen with regards to thorium supply i think it's much more likely to happen with regards to the technology to make that thorium worth something you know worth more than zero which is basically where we are right now this is a cartoon this is a notion of of what we're what we're striving towards this is kind of an aspirational goal of what we're striving towards at flyby energy with a small and minimally invasive thorium reactor installation so the reactor this would be the outer containment structure of the reactor inside would be the reactor vessel the drain tanks the primary heat exchangers and the pumps and what would be exiting the reactor you see here would be the coolant salt the the bare flibe or or fly knack or whatever we decided to use for the coolant so it's just carrying the heat from the nuclear reaction out to gas turbines the idea of saying let's go and be able to put in case a silo underground fill it with water both for radiation shielding and for seismic isolation and then go and place the reactor in it and connect it to uh gas turbines above grade what is our opportunity with with thorium in the and the liquid fluoride reactor uh trivial fuel costs that's actually not the biggest deal because fuel cost is still pretty low right now for existing reactors no carbon dioxide emissions very attractive uh in our in our carbon intense world very high availability factor that is a very distinguishing thing versus other low or zero carbon sources and the potential to be much simpler and safer than conventional uranium fuel reactors that operate at high pressure and with the two fluid design we also have the potential to be scalable to go up and go down i was talking with one of the gentlemen that was on the molten salt reactor program i was asking why the one fluid design they went to i said what about the scalability so well we weren't even thinking about scalable we were thinking about thousand megawatt units i said i said we're thinking about a 40 megawatt unit he goes oh well that size yeah that's probably not gonna be a real good idea you're gonna you're gonna want to take a different approach so again with the two fluid we have the potential for some great scaling we have political pressure to reduce greenhouse gas emissions we obviously have economic pressure to reduce the cost of energy most of the world considers these two pressures to be completely at odds with one another and and who's going to give you know what's more important the environment or economic growth you know different nations are making different decisions wouldn't it be good if we could have both and the public pressure to address concerns of current nuclear power this has really increased since fukushima fanned by the by unfortunately by the by the uh the poor way it has been described in the media but there is definitely a public pressure there and the military pressure to generate power reliably in remote locations as well as the aspect of secure redundancy which is needed on bases in the united states i think all of these point to lifter is a global energy solution well why go now why not wait a generation or as a a lot of people think they think technology develops without pushing on it um you know why not wait well there's a lot of proposals for small modular reactors right now but as rick said it's it's the same old uh here again and and i look at these smrs that are being proposed and i go there's not a lot of new here this is this is pretty much uh an existing reactor or package in a new smaller form only lifters will be able to manufacture the radioisotopes destalinated water and electrical power simultaneously you're not going to have to pick from one or the other you're going to be able to do them all at the same time i really think that the aftermath of fukushima will be that a lot of conventional reactors are going to be canceled and delayed um and and the real very real risk is that some societies will reject nuclear power altogether we're seeing this already we're seeing it in japan we're seeing in germany we're seeing in italy where it's just like no i'm not going to do it and and is that happening because they're just completely radiophobic is or is it happening because they don't know about a better alternative i hope there is and i'll turn that we can put an alternative in front of them make them go oh wait you know maybe we're being a little hasty remember throwing the baby out with the bathwater i think that revenues from medical sales of radioisotopes are going to be what gets this this operation out the gate initially rather than electricity electricity's still pretty cheap uh but these medical radioisotopes are extremely valuable and i think that's going to fund the global expansion of of energy from thorium and and finally uh this is a belief i have i think thorium will become the world's dominant energy source and that this is the most important development of this century you know we're still at the beginning of the centuries a lot of a lot of things still going to happen but i really think that by the time we get to the end thorium will be the dominant energy source and i want to leave you with a quote that i love from alvin weinberg during my life i've witnessed extraordinary feats of human ingenuity i believe that this struggling ingenuity will be equal to the task of creating the second nuclear era my only regret is i will not be here to witness a success thank you very much you

Channel: Keith Rodan

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Length: 29min 4sec (1744 seconds)

Published: Sun Nov 29 2020