Prospects for Process Heat & "Advanced" Nuclear

00:00:19:02 - 00:00:38:19

Chris Keefer

All right. Let's jump into what we are here to do, my friend. The 3, 2, 1. Welcome back to Decouple. Noah Rettberg. Everyone knows who you are, although it's been a long time since you've been with us, Noah. The reason I've brought you back. Well, I've lots of things I'd like to talk to you about, so it's hard to narrow it down.

00:00:38:19 - 00:01:04:15

Chris Keefer

But, you know, I was over in Dubai. There was a great talk by Stefan Quist, and I'm blanking on his co-presenter, but they were talking a lot about decarbonization. Difficult to abate sectors and nuclear. One of the selling points that advocates will point to is that there's more than just electricity. It can provide heat, which is something that, you know, other low carbon options struggle with.

00:01:04:17 - 00:01:32:04

Chris Keefer

So I wanted to explore that. Today, we're going to call this episode prospects for Process Heat. And I guess this is sort of by necessity going to be a talk that's far ranging and looking at a few different reactor designs and what the what the prospects are for them coming through and this tricky, tricky area of decarbonization. So now, again, welcome back to the participants who are it?

00:01:32:06 - 00:01:49:14

Noah Rettberg

Yes, it's it's nice to to to be here again. You had to get along without me. Don't know how that went, but but I'm glad to be here again. It's ah, I always like. Like our chats.

00:01:49:14 - 00:02:00:14

Chris Keefer

So wonderful. Wonderful. Yes. Our our Germany coverage is has lapsed. You are, you are our German correspondent. But we'll talk about that another time. How do you want to tackle?

00:02:00:14 - 00:02:08:08

Noah Rettberg

Well, at some point that that's that's boring to me it would be like yet not worth addressing and so.

00:02:08:10 - 00:02:27:18

Chris Keefer

Right right okay well let's let's jump into the the matter at hand prospects for process heat and talk about some nuclear process heat applications. You know I guess part of part of this is, you know, if this is such a exciting possibility, why why is it not happening or why has it not happened? But I might be unaware.

00:02:27:18 - 00:02:36:21

Chris Keefer

Maybe it has happened. So let's let's maybe dive in historically, but I'll I'll let you pick sort of our our starting point.

00:02:36:23 - 00:03:17:22

Noah Rettberg

So let's let's start with what process heat is. And and let's make one clear distinction, because where we use heat, where we use thermal energy in our world, most cases we use the heat to drive a heat engine and generate work for mobile applications for stationary applications. Power generate work generation is done by electricity. In our times the past it used to be also done with thermal heat and also for like heating for buildings, because if the building is cold, this makes us uncomfortable and sick.

00:03:18:00 - 00:04:00:14

Noah Rettberg

And also just when a building just does is not constantly heated at the time. The thermal expansion and contraction, as the building heats up and stone cyclically can damage a building. So but processes as distinct from that process heat is the heat that we use to drive production processes. And when we talk about these production process, we usually talk about heat that we use to modify that We used to work on something which we modify thermally this could be home cooking or industrial cooking when we made food or and we bake bread.

00:04:00:16 - 00:04:37:18

Noah Rettberg

These are processed heat applications where we like use the heat to drive chemical reactions like the myatt reaction. Browning caramelized in flavors and such, but also just evaporate steam to evaporate water, to cook our food, and also process heat is used in metalworking. Processes like casting or forging come easily to mind when we talk about this. But what should not be ignored is also annealing and hardening.

00:04:37:20 - 00:05:27:07

Noah Rettberg

So where we use heat application to a to work piece, not to make it malleable, but to rearrange its crystalline structure to make it more or less hard in order to make a hard tool or make and yield metal that can bend into the shape we need. So but also in chemical, it industry, in the oil and gas sector generally to use heat to evaporate or melt stuff, especially for the purpose of separating either separating water ethanol out of water if you want to make spirits or be that separate in gasoline out of oil, if we want to make fuels, these are thermal processes.

00:05:27:09 - 00:06:11:04

Noah Rettberg

Similarly, when we want to dry out stuff, we news, we just process heat. When we when we have, for example, in the papermaking industry, we use process heat to dry out the paper pulp to make solid sheets of paper or cardboard and in interest. And in one other aspect is also to use processes to drive chemical reactions. When we, for example, made concrete or when we prepare metal or we deal with carbonate salts, essentially with concrete, it's or cement, it's calcium carbonate and which needs to be turned into calcium oxide to make cement.

00:06:11:06 - 00:06:42:18

Noah Rettberg

Either it's Portland or simple Portland cement or simple mortar. We first need to drive the process of putting the carbon dioxide, carbon and salt. And this is an endothermic reaction. So we need to put a lot of heat into it to make the it's the we also when we have like iron ore of these are often carbonate source so we need to roast the iron ore to break down the carbonate salts in there so we can separate over or so there.

00:06:42:18 - 00:07:17:01

Noah Rettberg

Basically when we look at the process, it can be used for like evaporation of liquid, for changing the material structure of a work piece directly to to a liquid phase. If we talk about melting or just making it more malleable or just rearranging the crystalline structure and hardening or annealing, or to drive a chemical endothermic chemical reactions so or a process, heat applications essentially boil down to these processes.

00:07:17:03 - 00:07:38:08

Chris Keefer

Know that that's that's okay that's that's a very you know even rich my understanding already remarkably you know we hear about different temperatures that are required to do these different processes you mentioned and I love just tying it into something we do so mundane every single day, cooking our food for instance. But we hear that that is a potential limitation right now.

00:07:38:08 - 00:08:01:05

Chris Keefer

I think conventional water cooled water moderated plants, nuclear plants produce waste heat or process heat that's insufficient to do a lot of these reactions. You talk about the different grades of heat required to do each of these things and how high we can go conceptually with with some of the nuclear designs being considered.

00:08:01:07 - 00:08:22:19

Noah Rettberg

So generally, one thing that we need to get familiar with when we talk about processing application is that we need to get our heat from where it is generated into where we wanted. And this can be very as simple as put in like a piece of iron or steel if we want to forge directly into the burning coal.

00:08:22:21 - 00:09:07:19

Noah Rettberg

So there the heat transfer is very simple and very obvious to us, or just difficult at home. The heat transfer from our stove, it or electric into our food is also clearly understandable to us through either connectivity or through just the the gaseous release of the combustion directly heating our piece. But in many case in industry, the heat transfer process is very complex and and many of these complex pieces, it is done with usually with thermal oils or with steam and but there are limits to where we can use steam or thermal oils as a heat transfer system.

00:09:07:19 - 00:09:31:11

Noah Rettberg

So I talked about limits after that. So where we are limited with our steam, where the steam cannot reach us, we either heat directly with the heat release from our combustion gases. So in most metalworking processes, you use the combustion gases to heat either your metal directly or to heat light the vessel in which your metal is contained.

00:09:31:13 - 00:10:02:03

Noah Rettberg

But if you have a ceramic, if you have a ceramic pot where you have your molten metal and you heat that with the combustion gases. But even this, if you are talking about metals, which need to get really hot, well exceeding 1000, approaching the 2000 degrees Celsius range, you can also not reach this with cotton, with the conventional conduction by exhaust gases or your vessel anymore.

00:10:02:05 - 00:10:39:04

Noah Rettberg

So in this range you either need electric art generating plasma, which can exceed the 3000 degrees Celsius range and or what you would need is inductive heating, which only works with conductive scenes or metal and inductive heating. You generate you apply a oscillating magnetic field at the outside of your metal and then anti currents will form inside will be generated by the oscillating magnetic field inside the metal and heat the metal from inside.

00:10:39:06 - 00:11:12:06

Noah Rettberg

So this also inductive heating is used for hardening processes at work. In the workshop where I work, I have layers which for example, have inductively hardened batteries. So where just the electrons are used to heat up the cast iron and then the cross iron is drenched in the crystalline structure. It's a cross I need. So inductive heating, so inductive heating is not just something that is very useful when you cook food.

00:11:12:07 - 00:11:37:14

Noah Rettberg

It is essential for many modern process heat applications because you can't just we can reach temperatures, exhaust gases could not reach and it is in many cases much more, much more easily a pliable can, for example, directly heat just the top off the better days of my life rather than just heating up the entire bed wave. So you can use it also to apply heat.

00:11:37:14 - 00:11:59:19

Noah Rettberg

Precisely. You can use it to apply heat in very hot temperatures. And you can also, if you want to reach very hot temperatures, you can also use electric arch out furnaces, which are essentially unlimited and where they go. But we use them for applications in industry, where we go beyond the 2000 degrees Celsius mentioned or also for a mountain steel.

00:11:59:21 - 00:12:15:02

Chris Keefer

So it sounds like, you know, any any sort of power source that can generate like sorry, it sounds like any power source that can generate electricity is capable of electric arc. And I'm not sure if induction is an electrically driven process, but what are the.

00:12:15:02 - 00:12:20:22

Noah Rettberg

Fundamental challenges that it feels?

00:12:21:00 - 00:12:41:07

Chris Keefer

So what if we're trying to eliminate carbon based, carbon based fuels out of the equation? What are the areas that are that are sort of most difficult? The temperature ranges that are most difficult to get into, not just in terms of getting to that temperature, but in terms of volume of processes that that need to run. Again. I've heard, you know, nuclear can be excellent for things like district heating.

00:12:41:07 - 00:12:59:21

Chris Keefer

Again, that is not for us process heating. But in terms of the vast majority of the world's processes that that require heat, what's the not the lowest hanging fruit but the the largest areas that need to be addressed if we were to stop using again carbon based fuels for for process heat.

00:12:59:23 - 00:13:33:00

Noah Rettberg

so process heat consumption makes up around a third of our energy consumption. depends on the country. Here in Germany, it's a bit less than a third, but roughly a third and lower. Now, all for the process. The feeders that I know are a bit dated, so could be and end of that of a process heat around half sits a temperatures below 500 degrees Celsius.

00:13:33:02 - 00:14:16:14

Noah Rettberg

And these are the temperatures where usually steam is used as the heat transfer fluid using steam as a heat transfer fluid beyond these 500 degrees is not very practical. Modern steam generators struggle with getting steam much hotter than 650 degrees Celsius. So even the most modern coal plant usually don't have steam generators which go beyond these temperatures. Just at these temperatures and the high pressures of the steam, just the heat, these impacts in the steam generators are stretched to the limit and are not as robust as at low temperatures.

00:14:16:19 - 00:14:47:17

Noah Rettberg

So you can't really get beyond that. And so the steam can only be generated to temperatures of around 650 degrees Celsius. So this limits you to a point. But then you have to consider that what you are heating with your steam is of a lower temperature than your steam. And so above the 500 Celsius range, steam is no longer really useful as a heat transfer fluid.

00:14:47:18 - 00:15:36:16

Noah Rettberg

And this this is like half of the process heat applications, which are essentially never going to be reached by nuclear energy because while you can make a nuclear reactor where you have the coolant, which is hotter than 650 degrees Celsius, you can't just pipe the coolant directly from the reactor to where your process heat is used. When you do that, you essentially make fire your entire industrial plant to be monitored for radiation, which essentially a big reason why many utilities don't lose or don't want to use boiling water reactors is in the boiling water reactor is the primary circuit runs to the turbine.

00:15:36:18 - 00:16:02:21

Noah Rettberg

So the turbine has to be monitored for radiation and you have to treat the turbine building similarly to how you treat the reactor building and the pressurized water reactor. It tends to be its own thing. It doesn't need the intensive radiation protection monitoring. And similarly for an industrial plant, you would not want to run the or the reactor coolant directly into your industrial plant.

00:16:02:23 - 00:16:38:21

Noah Rettberg

You would want a second medium to bridge, to pass the energy on the heat, on before you make the heat, leave your nuclear island. And you would do this usually with steam. And there are and the steam is limited to 650 degrees Celsius. So we could simply say, I would say that half of all processed heat applications will never be reached with nuclear ever unless you lose electricity to for your heat.

00:16:38:23 - 00:16:50:17

Chris Keefer

How how energy intensive are electric arc furnaces? How do they compare, say, to in steel production? How would that compared to just using traditional methods?

00:16:50:18 - 00:17:23:01

Noah Rettberg

I've read an old paper from eighties German paper which comes to the conclusion that using an electric arc furnace to re melt scrap steel is about 40% more efficient than using coal directly to melt down the steel because the electric arc furnaces can you apply their heat that they generate much more directly into the material compared to the traditional warfare method?

00:17:23:03 - 00:17:56:02

Noah Rettberg

But keep in mind, the study from the time used just a state of the art eighties era coal power plants and compared it compared to to how the coal power plants running the electric furnaces to a state of the art conventional coal fired steel making. So the electric arc furnaces are very efficient and there have an economic case to there's an economic case to run electric arc furnaces to melt down steel.

00:17:56:04 - 00:18:29:05

Noah Rettberg

Even in a world where both your plant in the world where both your electric art furnace and your conventional melt in would be powered entirely by coal. So, so I think one should kind of lose the understanding that using electricity to power process heat is inherently inefficient because in many cases using combustion to power. This process also brings with it itself.

00:18:29:07 - 00:19:02:22

Noah Rettberg

A certain inefficiencies can apply the heat much more indirectly cannot. You have transfer losses there? And you also use a much more complicated process to heat up what you want to heat up. Many electric application like induction or resistive or electric out furnaces, can put their heat much more directly onto where you want it, and they can also make it and use a much less complex system, which was often put the electric heater where it needs to be.

00:19:02:22 - 00:19:24:02

Noah Rettberg

You can put the induction coil where it needs to be. You can, for example, with my leaf, can just put the induction of the induction quotes above the waste directly. And you does not not heat need to heat up the entire body of the leaf. So one should not underestimate the efficiencies of the electric process.

00:19:24:05 - 00:19:45:20

Chris Keefer

So. So I mean, there's a difference between, you know, energy analysis of efficiencies and obviously economic efficiencies. And, you know, this is a criticism I hear a lot of criticism about slops mills work or people talking about primary energy. A lot of folks, particularly on the, you know, alt energy, I'm forgetting the exact term that people use now.

00:19:45:20 - 00:20:09:05

Chris Keefer

Right. But clean tech, they say, well, listen, it's actually not such a challenge to replace fossil fuels because you're talking primary energy. Electric motors are much more efficient. For instance, we only need to replace about one third of primary energy. But obviously it's it's fairly easy to dig something out of the ground and burn it, even if you are wasting, you know, 70% of of that heat as as waste heat, for instance.

00:20:09:07 - 00:20:18:04

Chris Keefer

So how does that work? I mean, there's a reason why the majority of the world's steel mills are not electric. Obviously, it takes a lot of juice, I'm guessing, to run an electric arc furnace have.

00:20:18:04 - 00:20:21:05

Noah Rettberg

A global centricity shortage, as simple as that.

00:20:21:07 - 00:20:21:18

Chris Keefer

Okay.

00:20:21:23 - 00:20:24:18

Noah Rettberg

So what's the one major reason?

00:20:24:20 - 00:20:36:15

Chris Keefer

Expand on the kind of. Yeah, the energy economics versus the you know, the the monetary economics of of electric arc furnaces.

00:20:36:17 - 00:21:06:08

Noah Rettberg

Is the the energy economics. So using a coal power plan, what I know what I've read though that is work from the late eighties down here in Germany is that the arc furnaces are 40% more efficient. If we talk not just about furnaces but the economy in general. A friend of mine, Rosenbluth, which has a very fantastic plot, but most of your audience can't read him because it's in German.

00:21:06:10 - 00:21:43:05

Noah Rettberg

He basically did a calculation how much it was in these processes he would which energy you would need to decarbonize Germany with electricity only in a manner that would not lead to any loss of living standard or any loss of industrial output in Germany. So essentially decarbonize the entire German economy itself. I think to use 2019 2019 as a baseline without any loss of industry, without any loss of quality of life.

00:21:43:07 - 00:22:20:06

Noah Rettberg

And then Germany used around 3500 terawatt hours of primary energy, I think 90% or 90% of it, which was either fossil or nuclear, 50% was nuclear back then. And then he he used he looked into which processes you would need to drive these. He said that for most automotive application, you wouldn't use battery electric for a few applications, you would use synthetic fuels made from hydrogen.

00:22:20:08 - 00:23:01:20

Noah Rettberg

You would also use synthetic fuels for in his assumption, you would use synthetic fuels for some power heating and you would use for processing it almost entirely electric, directly electrically powered, and for home heating you would use heat pumps backed up by synthetic fuels just for peak demand. And in his assumption, where he used electric only for basically processing it, he got around 70% of the primary energy consumption that we do now have.

00:23:01:22 - 00:23:38:21

Noah Rettberg

So Germany would go down from a 3500 terawatt hours of primary energy consumption, and you would then get 2500 terawatt hours of electricity consumption to decarbonize the entire German economy with it using 2019 as a baseline and the methodology that he used. I tend to agree with you. I mean, he excluded nuclear energy. It's sort of nuclear process heat from, from the U.S. also excluded the nuclear the strategic.

00:23:39:03 - 00:24:08:11

Noah Rettberg

But if you would, you would just electricity only then you would get to similar numbers. So for for a very industrialized modern economy that has not seen a lot of industrialization like other Western countries, Germany. 2019 you would probably you can probably reduce your energy. You can have like 70% of your primary energy consumption, but just as electricity.

00:24:08:11 - 00:25:08:09

Noah Rettberg

So you get a little bit more efficiently, certainly. But many of the clean tide advocates drastically overestimate the efficiency gains that they can get with going electricity only, which comes from using basically electric vehicles as a comparative. They they compare some a little bit unrealistic, efficiencies of of modern electric vehicles. They usually take 80%. It's more like 70% well two wheel and they put that against outdated combustion engines, which are at around 20% modern combustion engines tend go from 30%, well above well above 30%, up to 40% thermal efficiency and from comparing these 80% efficiency to 20% efficiency, they get the idea that they can decarbonize the economy with it.

00:25:08:11 - 00:25:47:05

Noah Rettberg

They tend to talk to China's economy with just a third of the energy that we use now in electricity. You will overall probably end up more with around 70% of the energy that we use now. using the methodology of, of Mr. Blume and I tend to agree with Mr. Newman. I think either he should translate this article or I should do it because it's it's very worth reading to understand the different decarbonization processes that you would use in an electricity only scenario and the standard if you some efficiencies, but not as much as most people think.

00:25:47:07 - 00:26:13:03

Chris Keefer

So suffice it to say, you know, a lot of these process heat applications would benefit from a baseload generator because we're trying to run them efficiently around the clock. So I mean, that's just kind of obvious. If you wanted to electrify process heats, probably would have been good to keep those nuclear plants running. I don't think need to belabor that point and I want to move into some of the technologies that are being discussed that may be more ideal to process heat.

00:26:13:03 - 00:26:29:12

Chris Keefer

And in my simplistic understanding, that'd be things like high temperature, gas reactors, sodium fast reactors, and if they have to be fast, but sodium reactors and molten salt reactors might missing anything. And can we maybe take a turn on each of these to try and understand.

00:26:29:14 - 00:27:06:12

Noah Rettberg

Their I would like to get like cooled and erectus cooled with supercritical water. Okay. Which is your Canadians especially did some very interesting research into water reactors tend toward with supercritical water where you would have supercritical water at temperatures exceeding 500 degrees inside your candu reactors. And according to what I've read, you even intended to use special saw chromium alloys, inside your reactor, which is very important because it's not like you can make water reactor.

00:27:06:13 - 00:27:34:09

Noah Rettberg

It's not led to ten very much made water reactors hotter than we currently do. But you would usually in order to do that, put the in inner off the reactor would make them out of many of them would be made of steel. Steel is absorbs much more neutrons. So if you would make director hotter and you would make the director more of the fuel cladding out of steel, you would make the vector more thermally efficient but less than totally efficient.

00:27:34:09 - 00:28:09:01

Noah Rettberg

And this is why it has never been done, because there is no reason to go. More thermally efficient fuel is plenty enough and this erector is less neutrons, totally efficient. You don't even gain anything from it. But there was research in Canada, I think up until 2006 by atomic energy of Canada limited to into zirconium alloys which tend to sustain these higher temperatures and especially trans sustained, supercritical water, which is much more aggressive than either hot water or old steam.

00:28:09:03 - 00:28:35:23

Noah Rettberg

And I'm not sure how much they got with this research. I know that it has been done. I would really love to see whether this can work. There hasn't been a lot of research into supercritical water cooled reactors where the supercritical refers to the water, not just the reactor. I want to amend that, but sadly there has not been happening a lot in this field lately.

00:28:35:23 - 00:28:38:07

Noah Rettberg

But I think we should.

00:28:38:09 - 00:29:12:00

Chris Keefer

Mention I don't want to yeah, I don't want to get lost into. I know because of your technical expertise, we could spend hours on each of these. So I want to make sure that we don't bite off more than we can chew in the in the kind of. But around half an hour we have left, maybe. Why don't we go through a few of these technologies anyway, in what you consider to be the highest likelihood of success or the best demonstrated track record, or especially the most likely to fill this this gap for, I guess, both high temperature steam with that caveat that it's kind of limited for processes about five 600 C, I guess

00:29:12:00 - 00:29:24:07

Chris Keefer

we're focusing on that, right, because, you know, any old power reactor can make electricity.

00:29:24:09 - 00:29:51:06

Noah Rettberg

The first high temperature reactors which were built in any significant quality, that there is really another type of high temperature reactors that has been built in significant quantity. And these were the advanced gas reactors by the British. And usually when we say advanced vector, we think of like some modern paper reactors. But these were reactors which were designed in the sixties and built in the seventies and eighties in Britain.

00:29:51:08 - 00:30:22:10

Noah Rettberg

So this is very much an established technology, but also a technology where we can kind of see some of the promises by the hot temperature falling apart. The British wanted to build these advanced best world reactors as an improvement upon their earlier generation Magnox reactors, which cooled, which were crude with all sort of CO2 or CO2, but couldn't generate steam significantly hotter than waterproof reactors.

00:30:22:12 - 00:30:57:05

Noah Rettberg

And the advanced reactors were planned to generate steam exceeding the temperatures which coal power plants back in the sixties would reach much more into the temperatures. Modern coal power plants can reach in the 600 degree range, and I think the steam that they generate is more than 550 of them, not one, but the reactor. The CO2 insight director gets up to 750 degrees, so they generate superheated steam and they therefore can run much more efficient turbines.

00:30:57:07 - 00:31:20:22

Noah Rettberg

And there has been a it has been looked into whether the using the advanced cooled reactors might be interesting as a source of Prosit in Britain for both industry and for generation of hydrogen. The hydrogen was never really put in Britain and most of the British nuclear power plants are too far away from industry to really be useful for this purpose.

00:31:21:00 - 00:31:56:20

Noah Rettberg

So this has not has never been done. Also, there are other problems of the advanced reactors. Basically, almost all of them were overbudget and over this over schedule. So you can say that this might be a feasible issue. There have been light water reactors which have been overbudget and behind schedule as well, but unluckily almost all of them were they had never really rate to capacity factor, even as the technology matured as.

00:31:56:20 - 00:32:00:01

Chris Keefer

The reason why.

00:32:00:03 - 00:32:31:22

Noah Rettberg

Essentially they because they they did use steel cladding for their fuel elements. The fuel element, the they the burn up in the elements is not as great. So they need to change fuel elements much more often. They were tried and in some of them they used on online refueling, but in many of them this was not achieved. So they use a very time consuming offline refueling.

00:32:31:22 - 00:33:03:15

Noah Rettberg

So they are offline for for a lot of time for building maintenance. And also, as they did older, there were material issues inside the power plants and many of them had to be rated and now run on significantly reduced power, whereas in almost in almost all light water reactors we have driven power, operates some very crazy Swedish nuclear power plants, which has seen almost a third 30% increase of power and operates.

00:33:03:17 - 00:33:40:05

Noah Rettberg

The British had to direct their reactors. Also these reactors, especially when you consider them of over all of their lifetime, these have been costly to build. They will be costly to decommission. Also, the fuel handling and fuel disposal is much more costly than light water reactors. So you can generate process with the out design, You can generate the very hot steam that you would need to fulfill the entire half of processing demand that you can meet with very hot steam.

00:33:40:07 - 00:34:02:00

Noah Rettberg

But these reactors, the steam would be much more costly than probably using electricity from a light water reactor directly. And there are and these reactors are not not as reliable as light water reactors are. So they will probably end. And also the British completed is up the design, so we will not see them in the future.

00:34:02:05 - 00:34:16:12

Chris Keefer

How how do the egos compare to like a watts, you know, X energy or a high temperature gas reactor. I think that's a German technology. The pebble bed, our choice of fuel. I'm out of my water here. Help me understand the difference.

00:34:16:14 - 00:34:51:16

Noah Rettberg

I'm I think price of fuel was first done first Euston or first came up with were actually also the Brit. The Brits had like a 40 year master plan of master industrial reactor, including where the fourth tier for that gas world fast reactors and the second tier were the year. And the third tier would have they would have envisioned to be twice the reactors just as its energy tries to do the first reactors using helium as a coolant and the price of fuel.

00:34:51:18 - 00:35:15:01

Noah Rettberg

They had a demonstration reactor. The it that they have to do in reactor at demonstration reactor which had no turbine, just heat output which they used to research tries to fuel reactors but they gave it up, especially when the air became a much more troubled reactor. And then in the late eighties, they looked into building light water reactors instead.

00:35:15:03 - 00:35:37:03

Noah Rettberg

So with the Brits canceling, they're tired gas reactor program so out the British twice throughout the program, there has also been an American and a German endeavor until this the American one used to of fuel interest met fuel elements at the nuclear power plant at MIT.

00:35:37:04 - 00:36:06:23

Chris Keefer

Rain was a prismatic fuel element like, I'm understanding, high temperature gas reactors, or at least the maybe pebble bed is the wrong word. I guess the trace of fuel is kind of like a bubblegum machine and the gases are moving up through these balls essentially that are all, you know, lying together. And I guess they get shifted and moved in terms of not so they refueling, but just fuel management, which is very, very different from the AGR I visited and B and that was an R, and they just had these insane fuel elements that the graphite core you were talking about was just massive.

00:36:06:23 - 00:36:16:06

Chris Keefer

I mean, these are like seven, eight story buildings plus three stories for the refueling machine. So I'm trying to get a sense of how they differ physically as well. And just for our listeners that aren't aware of, you know, prismatic photons.

00:36:16:11 - 00:36:43:17

Noah Rettberg

So so the prismatic fuel just means it's more like a traditional fuel element made up of. Right. Okay. That that's the external shape. And then when you, when you extend a polygonal surface, you get a press muscle. It's just a general shape. So imagine it more like a traditional that very much like a traditional reactor. And the the bubble gum design is the tri reactor design that came from Germany.

00:36:43:19 - 00:37:27:08

Noah Rettberg

It was real ice and two reactors here in Germany. First the AVR in the in the sixties and then the HDR in the eighties. The these these this were envisioned as to simplify the refueling processes because refueling a non water cooled reactor is not trivial. In a water cooled reactor, you can basically open the reactor, step down into the reactor because you have water on top of it and the water shield and you can then move the fuel element under, the hot fuel element under the water in a non water cooled reactor.

00:37:27:10 - 00:38:01:21

Noah Rettberg

You need to use much more complicated fuel handling systems. Be that sodium gastruloids or whatever. It's not it's trivial. So in order to make the refueling much more easier, they envisioned a design where you would just load the cold nuclear fuel. The unused nuclear fuel on the top is fierce, and then the fuze would like fall down. And on the bottom you remove the you remove the fuze and the fuze drop dropped right into the storage container to have a much longer span.

00:38:01:21 - 00:38:40:05

Noah Rettberg

Simple refueling process which was envisioned to make these reactors much more economical and much more and much more reliable. Since the simplified fueling process as they envisioned, would also increase downtime when refueling allow for actually for online refueling. But these bubblegum type reactors, as we try it here in Germany, it's energy wants to try as the Chinese have built to reactors which they are currently operating though they are not operating them quite as well as they hope to.

00:38:40:06 - 00:39:11:04

Noah Rettberg

So these fossil fuel reactors also have a problem with these spherical fuel elements. You don't have like a very clearly defined flow for your gas through the reactor inside with like what the AVR or the prismatic, if you will try. So reactors since you have traditional fuel elements which are always at the same place, you always know where your fuel is, where their coolant is flowing in very straight, very direct and controllable lines.

00:39:11:06 - 00:39:41:12

Noah Rettberg

This is not the case inside your petrol reactor. You have a chaotic sea of fuze and the coolant tries to move around there. Also in these pebble beds, the coolant also the sea is also up against each other. So they fall down. And as it turns to director, also, when you want to insert control what's inside the reactor, this becomes an issue.

00:39:41:13 - 00:40:19:11

Noah Rettberg

These tablets are not like water. If you can control what in there you get a lot of friction. And this became a huge problem at. The border one of the German pebble bed reactors. This control what brought the fuel elements. Also the fuel elements broke as they wrapped each other and transferred through the down to director. So this this reactor had a large amount of fuel element failures and a large amount of radioactivity release coming from this design of reactor.

00:40:19:11 - 00:40:50:04

Noah Rettberg

And this design of fuel element. One has to mention that the fuel design, the the fuel is used in the fuel in the German reactors is certainly of a lesser quality than the price of fuel the tri so so twice Ostend for a price to try structural fuel. So the essential fuel pellet inside is coated three times by a ceramic and in the German one they had to try to just a two times.

00:40:50:06 - 00:41:12:11

Noah Rettberg

So you can say that the fuel that its energy is going to use in the reactor certainly offer much more quality, better quality than what the German reactor used in the 80. And also since they use a smaller reactor's motor water and power output, they use a somewhat different design than the bit reactor that we had here in Germany.

00:41:12:12 - 00:41:43:10

Noah Rettberg

They use a design where they have rather than control watch which ram directly into the fuel elements. They have control what's at the outside of the battery vessel, which they can turn and just they can they can control how much neutrons escape the reactor vessel and therefore change control direction from the outside. This way of reactor control, this is much less damaging to the fuel, but it has also drawbacks.

00:41:43:10 - 00:42:07:05

Noah Rettberg

It is much less powerful. It's control authority over the nuclear reactor. In this smaller and reactors larger than a certain size ten, It can no longer be controlled by this, by this type of control. What's in these small try of fuel Talbot reactor, which we had here in Germany in the sixties, The AVR, the also used the external control.

00:42:07:05 - 00:42:35:08

Noah Rettberg

What which would not be inside the vessel, but outside of it. This, this reactor had not enough control authority with the external control. What's over? It's over its reactor. They struggled to shut the reactor down on several occasions rather than whether control rods did not have enough authority to properly throttle down. Director So the the design was feared.

00:42:35:08 - 00:43:01:00

Noah Rettberg

Control was at the outside at the problem that attention to it much, much less power than the one with the control it's ramming inside the vessel. And also it might not have enough control authority at all. This has been a problem at the German reactors, whether it's energy has addressed this issue, I cannot say I'm there is not enough for me to know about their design.

00:43:01:01 - 00:43:28:20

Noah Rettberg

But this has been a problem that that its energy certainly needs to overcome and it limits their reactor to a certain size. The German reactor was 17 megawatts electric and it still had the problems that it had not enough control authority. I wonder whether the 100 100 megawatt can do this and whether they want to go above the 100 megawatts.

00:43:28:22 - 00:43:44:01

Noah Rettberg

They either need a prismatic fuel or they need to have the design where they control what's inside the sea of pebbles. And hopefully this time the pebbles won't break.

00:43:44:03 - 00:44:10:21

Chris Keefer

So it's probably quite simplistic analysis. But in terms of assessing the commercial and operational maturity of a technology, it does seem useful to look at sort of the number of reactor years of operation. And I think our light water and pressurized heavy water fleets are up in the 17,000 reactor years of operation, and that's meant that we've worked through a lot of kinks, we've identified a lot of problems, we've innovated based upon operational experience and gotten to the exceptional capacity factors.

00:44:10:21 - 00:44:29:00

Chris Keefer

We now have a part of what makes economic a nuclear economical, you know, in terms of getting a sense of these other technologies. And I think for today's show, I think we should just focus on on gas reactors just for the limit of time that we have the hard stuff have what's what's the number of sort of reactors of operational experience we have?

00:44:29:00 - 00:44:46:23

Chris Keefer

I think molten salt reactors is about three. It's all in national labs and sodium reactors. So fast reactors run to several hundreds. What about the the gas director technologies? The advanced gas reactors in the UK are going to give us a lot, but these pebble bed reactors, these are the bubblegum machine reactors.

00:44:47:01 - 00:45:15:16

Noah Rettberg

With the British reactors, we're probably talking around 600, 700 reactor use of operation, though one might argue that with the large downtime that this reactor had where the one could actually counteract or you're saying where you can't light water reactor, you with the with the pebble bed reactor it is much worse. And one reactor in Britain, which was never a power plant, was a demonstration reactor only gives you a couple of years.

00:45:15:18 - 00:45:49:05

Noah Rettberg

The AVR in Germany only gives you a couple of years before the American one, which wasn't even one of the pebble but reactor, well, it used twice as fuel but didn't have the pelvis, only have a couple of years. And the really big German one, the THG air didn't get to use and in over this it really only was built in 13 years no German nuclear reactor was ever this expensive in relation to its power and took this long to build.

00:45:49:06 - 00:46:20:17

Noah Rettberg

And after all this long build time, the reactor ran terribly. It basically needed to go offline every three days and had that 20% capacity factor over the time it ran for a good 500 days and then it was shut down because of the the project partners, which candidates saw the design failing. And then they dropped out and then the program had to be shut down.

00:46:20:18 - 00:46:50:04

Noah Rettberg

So from the air you only get like 500 operational days probably. And what these operational days give you, they indicate a lot of problems. They don't give a lot of practical experience. It's more like you ran it for 500 days, all of which were miserable, all of which show you the problems, but don't really show you the solutions to the problems.

00:46:50:06 - 00:47:24:03

Noah Rettberg

And after the FDR in Germany shut down in 89, after that, we never had another one until the Chinese opened this year ago. And from these two, we now have four more operational years and hopefully these two will provide a significant amount of operational years. But when we talk about total operational use of the try so high temperature reactor, we are barely in the double digits.

00:47:24:05 - 00:47:53:12

Chris Keefer

So this leads me to propose a new definition of advanced nuclear. Advanced nuclear is the nuclear that advanced the kind of nuclear that survived that proved itself operational and and commercial. And that is essentially the nuclear that we have with us today. And then we have non advanced nuclear, which is nuclear that has yet to advance, that has only made it, you know, a few, you know, single digit, double digit reactor years of operation.

00:47:53:12 - 00:48:13:09

Chris Keefer

Because I just see this incredible hubris and the the kind of promotional materials, they look amazing. Right. And to a policymaker who has not got the kind of in-depth background knowledge that you have or that many of my other guests have, they see a promotional PowerPoints. It looks great. This looks brand spanking new, shiny. Okay. It's going to deliver on X, Y, and Z promise.

00:48:13:09 - 00:48:31:01

Chris Keefer

But I think what policymakers are lacking is the history. And that was why I was amazing to have Nick Saran on the other day to give us some context. You know, many, many concepts have been tried from the fifties onwards and the advanced ones advanced and those that did not advance did not. And That doesn't mean that we shouldn't develop that those technologies more.

00:48:31:01 - 00:48:53:10

Chris Keefer

But I think it does probably suggest that there needs to be a lot less hubris in terms of just saying, you know, this is going to be commercially mature. We're going to have, you know, X energy reactors distilling petrochemicals, Dow Chemical and, you know, five, ten years and doing so commercially and economically. Diatribe over. But I think you get my point.

00:48:53:12 - 00:49:24:00

Noah Rettberg

So can I just say I would think it would be really funny if in all your future appearances nowadays you get invited to a lot of them refer to these reactors as the yet to advance reactors rather than the advanced reactors. I think this is a nice thing, just like with like the summers and I am quite sympathetic to to the people with the hubris.

00:49:24:02 - 00:50:07:12

Noah Rettberg

I am unlike you, I am not a pessimist. I'm actually an optimist. But I don't know. I cannot have my hope. I don't have the maybe I don't have the enough cognitive dissonance that I can like keep my optimism whenever I whenever people point out the flaws that I have in my reason for my optimism. So other than other people who need to have the chronic problem after a cognitive dissonance, I'm sorry I worked a lot other than the people have a lot of dissonance.

00:50:07:14 - 00:50:39:03

Noah Rettberg

I tend not just stand with what my I need to reframe them and I need to change them because I don't like it how I feel when I'm not an optimist. So whenever my optimistic vision that's challenged, I get much more motivated to find out light another way. So every time it was pointed out to me that my reasons for an optimism were flawed, I adjusted it and found reason to find a better way.

00:50:39:08 - 00:51:18:18

Noah Rettberg

So when I was pointed out to me that my reason to be more optimistic about renewables was I thought I changed there. And when I realized that my reason to be optimistic about the yet to advance reactors was flawed, I needed to change my outlook from there. I am not a pessimist. I am quite optimistic that with the reactors that we have, which are actually mature first and foremost pressurized and boiling water reactors and set and sodium cooled reactors, I'm very confident and very optimistic that we can completely decarbonize with these.

00:51:18:20 - 00:51:54:20

Noah Rettberg

And this is the foundation of my optimism and I am therefore critical of people who just who are less gung ho on the get to advanced reactors, because I, I don't want to be gloomy. I want to have a well-founded optimism so I can sleep well at night. And if I would need to put my hope on something where I'm not certain enough that it can actually work, that would not make me sleep well at night.

00:51:54:20 - 00:52:18:15

Noah Rettberg

So I need to be I need to have my optimism grounded in reality. But I'm sympathetic to people who strive for a lot of things and who say, let my conservative optimism is not good enough for them. They want more and I cheer on them. But and I really hope that its energy achieves what it set out to achieve.

00:52:18:17 - 00:52:57:03

Noah Rettberg

Proof that maybe the the German engineers, which did the high temperature gas reactors in the eighties, were not maybe the best quality of engineers. And personally what I have found out, the nuclear engineers in Germany which went into how into high temperature reactors were not made from the same wood as the nuclear their engineers that went into that water reactors were not competent, that most people maybe that energy people are much more competent and they can use much more modern tools to fulfill their vision.

00:52:57:05 - 00:53:29:19

Noah Rettberg

I still think that operational experience, both in cumulative reactor use and in how many reactor use the oldest reactor has put on a stomach. I think this is really important if you have a proper and well researched, mature, sure design and this cannot this this operational experience cannot be replaced by having better cam and test software and having better milling machines and forgers than we had in the eighties in better material sciences was the fuel.

00:53:30:01 - 00:53:53:22

Noah Rettberg

There needs to be the operational experience for a mature design. I really hope it's energy proofs new. On if it's energy sets out what it achieves. I can sleep very well at night. I would be very happy about that. I would gladly buy nuclear synthetic fuels from them and put them in my car and have fun driving over the hash and countryside.

00:53:54:00 - 00:54:25:13

Noah Rettberg

But I do not expect that and I don't want to base my optimism, my positive outlook on these dreams that its energy have. And therefore I don't want that our energy policy is based on these. I want our energy policy based on reliable, mature technology so that we can be certain that we can sustainably for the long term, have a supply of energy that's plentiful enough, sure enough.

00:54:25:13 - 00:55:07:13

Noah Rettberg

And that's cheap enough that I can sleep well for my future and for the future of the children that I plan on having in the future. So all so I cheer for it. Energy When they have success, I will really do that. But when they go around and promoting their reactor is the solution to all of our energy problems, which will lead to less resources and capital and political goodwill being allocated to pressurized and sodium, pressurized water, a boiling water and sodium cooled reactors, which definitely tend solve our energy problems.

00:55:07:15 - 00:55:12:18

Noah Rettberg

I am not. I do not like that. Sorry.

00:55:12:20 - 00:55:44:09

Chris Keefer

So we're going to have to leave it here in the next couple of minutes. So I'm going to kind of take the mic and do one last reflection here. I've been reading a fair amount about nuclear history recently, mostly on the Canadian side, and it's just leading me to realize that with this unique moment of scientific and technical mobilization in the form of the Manhattan Project and what I call the Manhattan Project, North original Canadian nuclear research facilities were very much pursuing the same goals as the nuclear research south of the border, which was weapons technology.

00:55:44:11 - 00:56:16:18

Chris Keefer

This led to massive wartime spending and an incredible accumulation of human and institutional capacity. And when the war was over, and particularly Canada was not interested in being nuclear armed, we devoted those resources towards research and engineering to develop this lineage of the precious heavy water reactor. And we iterated, iterated, iterated. We went through three or four different research reactor designs, culminating in the National Power Demonstration reactor, a 20 megawatt candu precursor that we went to 200 megawatts at Douglas Point, 500 megawatts at Pickering, 800 at Bruce, 900 at Darlington.

00:56:16:18 - 00:56:34:07

Chris Keefer

Now we're hopefully heading for a gigawatt, but iteratively we've run into all kinds of problems. We've trouble shot them. But at the nucleus of that is an incredible investment and I hope it's not a one time investment, but you can see sort of why it was, you know, Turing starts around the Manhattan Project consuming like six or 7% of U.S. electricity.

00:56:34:09 - 00:56:59:06

Chris Keefer

This gives you a sense just of one element of the resources poured into this project had that spillover effect of leading to the design moving through the valley of death on certain reactor technologies and the ones that advanced advanced. So I just want to give that context. And I think for a lot of these other concepts to advance, I'm I'm a little pessimistic because I think that they need a similar mobilization of scientific resources.

00:56:59:06 - 00:57:18:05

Chris Keefer

And I'm not sure that we have that at the present moment. I am not even going to let you respond to that. We're going to leave that as a pregnant pause. We're going to have you just before interest of time, hard stuff. I've got to go and I got to go talk about Pickering and national media. But I do want to have you back because we didn't pull on that sodium cooled reactor thread.

00:57:18:07 - 00:57:33:18

Chris Keefer

And I'd like to finish this excellent conversation about processed seeds. You know, I've even heard people say that's a reason to be profusion is because we could use processed heat from fusion. I'm very interested to hear your perspective on that, but I'm not going to let you shirt right now. I know. Richard, great to have you back on the podcast.

00:57:33:18 - 00:57:54:13

Chris Keefer

I'm sure this is going to earn you some lovers and haters, but thank you for doing what you do and being able to offer a perspective. I think because you don't work in the industry, you're able to say a lot. Maybe because there's no German industry anymore, you're able to be very free with your thoughts. And that's what we love on Decouple is people that can come and offer offer opinions freely.

00:57:54:13 - 00:57:59:00

Noah Rettberg

It's a nice way of saying I have questionable qualifications.

00:57:59:02 - 00:58:06:12

Chris Keefer

All right. Well, let let the audience judge. No, awesome to have you back. And we'll talk again soon.

00:58:06:14 - 00:58:06:22

Noah Rettberg

Bye.