The Complete Case FOR Nuclear

[Jay McKinsey + 1,489]

On 11/2/2020 at 10:24 AM, Jan van Eck said:

Sorry, Jay, not true.  Look, everybody here knows that you are the most ardent proponent of your wind machines on the face of the planet.  Your enamoration of that technology does not mean that other technologies are stagnant.  

Nope.  There are two reactors on a sub and four on a carrier.  They are all the same, built by General Atomics in their plant near Albany, New York.  They are based on the rather primitive design used in the Nautilus, lots and lots have been built, they all work flawlessly, and due to the commonality of design the cost per unit drops. 

And that is "old" technology.  Much newer designs are being proved out, specifically the thorium reactor that runs on a molten salt.  The machine has a plug in the bottom and if it overheats then the plug melts, around 800 C, and all the salt that supports the reaction simply drains out and spreads out into a basin below the reactor core.  Without the salt volume in close proximity, the reaction chain stops.  When the salt cools, then it can be scooped up and put back into the reactor and the machine re-started.  Because there is no high-pressure water for cooling, there is no need for a containment dome and all the other expensive hardware that the hysterical have demanded that the regulators insist be built, of the plant operators.  Do you seriously maintain that technology will never advance?  Come on, now. 

Look, Jay, you can go convince yourself of anything you like, I certainly don't mind.  Your infernal wind machines have been banned here in Vermont.  Absolute prohibition; the downsides are just not tolerable.  And if you put one up, you can bet that the locals will go there some night and drag along some acetylene torches and cut it up for scrap.  Timberrrrr!  Crash goes that tower. 

 If the cost for navy ship reactors has been significantly dropping then why did the navy discontinue their use in cruisers and start using only fossil fuels? I'm sure you will come up with all the usual excuses except the most obvious - that they are actually quite expensive to operate. 

The fact that the market for simple cheap reactors has not grown tells the story. Remember you have to account for capex and opex.

Of course technology advances but that doesn't mean the problem gets solved in an economically viable manner. Thorium reactors are a long way from proving economic viability at large scale let alone at small scale. Let me emphasize - there are two hurdles - technical viability and economic viability at scale, whether in big plants or small ones. 

Vermont will be powered by off shore wind before another nuclear reactor.

 

Edited April 7, 2021 by Jay McKinsey

[Rasmus Jorgensen + 1,169]

13 hours ago, Jay McKinsey said:

 If the cost for navy ship reactors has been significantly dropping then why did the navy discontinue there use in cruisers and start using only fossil fuels? I'm sure you will come up with all the usual excuses except the most obvious - that they are actually quite expensive to operate. 

The fact that the market for simple cheap reactors has not grown tells the story. Remember you have to account for capex and opex.

Of course technology advances but that doesn't mean the problem gets solved in an economically viable manner. Thorium reactors are a long way from proving economic viability at large scale let alone at small scale. Let me emphasize - there are two hurdles - technical viability and economic viability at scale, whether in big plants or small ones. 

Vermont will be powered by off shore wind before another nuclear reactor.

Jay, 

I generally like and agree with your posts. And I agree re electricity production. But when it comes to transportation then MSR reactors have real potential. The reason being that engines and tanks takes up a lot space and "freigth capacity" on big bulkcarriers and container ships. If you can increase the cargo capacity with a different propulsion technology this changes the game. 

I doubt we will see retrofits, but on newbuild orders a few years from now I wouldn't rule it out if they overcome the secuity hurdles. 

Edited November 3, 2020 by Rasmus Jorgensen

[Rob Plant + 2,608]

On 10/31/2020 at 9:09 PM, Marcin2 said:

I will believe in smaller reactors once anybody invests dollars in this technology, gets all the approvals  and later builts at least 1 specimen

Its certainly possible, and I think this will get off the ground

https://www.rolls-royce.com/products-and-services/nuclear/small-modular-reactors.aspx#/

[Dan Warnick + 6,100]

1 hour ago, Rob Plant said:

Its certainly possible, and I think this will get off the ground

https://www.rolls-royce.com/products-and-services/nuclear/small-modular-reactors.aspx#/

I find that inspirational.  Thanks for sharing.

[Rob Plant + 2,608]

On 11/2/2020 at 7:38 AM, Jay McKinsey said:

Sadly, the nuclear industry continues to practice selective remembrance and to push ideas that haven’t worked. Once again, we see history repeating itself in today’s claims for small reactors—that the demand will be large, that they will be cheap and quick to construct.

But nothing in the history of small nuclear reactors suggests that they would be more economical than full-size ones. In fact, the record is pretty clear: Without exception, small reactors cost too much for the little electricity they produced, the result of both their low output and their poor performance. In the end, as an analyst for General Electric pronounced in 1966, “Nuclear power is a big-plant business: it is most competitive in the large plant sizes.” And if large nuclear reactors are not competitive, it is unlikely that small reactors will do any better. Worse, attempts to make them cheaper might end up exacerbating nuclear power’s other problems: production of long-lived radioactive waste, linkage with nuclear weapons, and the occasional catastrophic accident.

https://spectrum.ieee.org/tech-history/heroic-failures/the-forgotten-history-of-small-nuclear-reactors

Haha Jay, for someone who is constantly telling us that technology and economies of scale will make renewables the most cost effective source of energy in the next 10-15 years why do you reference a quote from 1966 when referring to the nuclear industry??  That "analyst" has probably died of old age by now!

Don't you think newer tech is possible in the nuclear industry also?? Making it more and more cost effective with economies of scale and more importantly safe??

You are looking backwards 50 odd years not looking forwards.

There are many companies like RR investing in SMR's right now

[Dan Warnick + 6,100]

7 minutes ago, Rob Plant said:

Haha Jay, for someone who is constantly telling us that technology and economies of scale will make renewables the most cost effective source of energy in the next 10-15 years why do you reference a quote from 1966 when referring to the nuclear industry??  That "analyst" has probably died of old age by now!

Don't you think newer tech is possible in the nuclear industry also?? Making it more and more cost effective with economies of scale and more importantly safe??

You are looking backwards 50 odd years not looking forwards.

There are many companies like RR investing in SMR's right now

 

8 minutes ago, Rob Plant said:

Haha Jay, for someone who is constantly telling us that technology and economies of scale will make renewables the most cost effective source of energy in the next 10-15 years why do you reference a quote from 1966 when referring to the nuclear industry??  That "analyst" has probably died of old age by now!

Don't you think newer tech is possible in the nuclear industry also?? Making it more and more cost effective with economies of scale and more importantly safe??

You are looking backwards 50 odd years not looking forwards.

There are many companies like RR investing in SMR's right now

I have to say, after reading that the SMR can be, or will be, installed in a short time, that I was a bit surprised when I read the following entry on the page:

Perhaps they mean relative to the amount of time to build a regular plant?  Maybe, but it would be logical that by the time they get full approval and go into production, and after the first, say, 15-20 builds, that they will be able to further reduce that installation time by half at least?

[Marcin2 + 724]

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Edited November 3, 2020 by Marcin2
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[Jay McKinsey + 1,489]

6 hours ago, Rob Plant said:

Haha Jay, for someone who is constantly telling us that technology and economies of scale will make renewables the most cost effective source of energy in the next 10-15 years why do you reference a quote from 1966 when referring to the nuclear industry??  That "analyst" has probably died of old age by now!

Don't you think newer tech is possible in the nuclear industry also?? Making it more and more cost effective with economies of scale and more importantly safe??

You are looking backwards 50 odd years not looking forwards.

There are many companies like RR investing in SMR's right now

Precisely because nothing has changed for nuclear in the past 54 years.

The difference is that renewables have a proven history of exponentially decreasing cost curves due to economies of scale and technical advances. Nuclear has exactly the opposite. Nuclear costs have gone up not down as more were built using either old or new tech, whether big or small. If renewables didn't have a proven history of decreasing costs then I would not be touting them either. 

Of course it is possible that there will be some breakthrough that will allow fission to start on a decreasing cost curve and I support continued funding to find it but as of today it does not exist. But even if that is found it is going to start out expensive and have to decrease costs through continued investment and scaling. Here is the huge second problem. Renewables are way ahead. It is going to be very difficult to feed the investment function if a utility has to choose between $30MWh solar battery or $60MWh MSR. They will choose the less expensive option and feed its investment function driving its costs down more and leave the more expensive option stranded.

The place where SMR have a place are as @Rasmus Jorgensen points out are in unique applications where renewables don't work so well such as shipping because of either weight or space concerns. That is why I support continued research. But as of today there is not a singe working prototype known that does this in a cost effective manner.

Critical to this discussion is that you guys keep conflating two different things: SMR and MSR (thorium, gen IV, etc) The SMR designs that I know of such as those from RR and NuScale are old technology PWR. These have been under construction for 70 years in both big and small implementations and have not decreased costs, costs have gone up. So now we have yet another plan to try and make the design economically viable, and you guys call big renewable projects boondoggles. RR has a plan to have their first commercial reactor online in 2030, 10 years from now! (and what do you think the odds are of them meeting that date?) Consider how much further renewable costs will have dropped by then. 

MSR hasn't gotten anywhere yet, let alone in a small reactor. They have been worked on since the 1960's and yet there is not a single economically viable plant in operation. No one has proven a workable economic design. It is very much stuck in the lab with a hundred competing designs.

Do you see the difference? Renewables are on a proven decreasing cost curve in operation today. Nuclear doesn't even have a full size working prototype of something that is claimed to be economically scalable. With renewables one can project the cost curve into the future and make reasonable decisions. With nuclear you are just hoping and guessing that some breakthrough will be made. Maybe it will or maybe it won't. 

[Gerry Maddoux + 3,627]

Nice explanation. 

Still, when I extrapolate energy needs to solar and wind farms, I get millions of acres covered with expendable and fragile production units. 

I'm no wizard in this, and I am an unrepentant oil and gas enthusiast, so I'll believe it when I see it. 

I suppose it helps if you really believe global warming is secondary to fossil fuel expenditure. I am on my fourth reading of John McPhee's "Annals of the Former World." About fifty climate changes of extraordinary degree are written into the rocks of geology, yet the burning of fossil fuels didn't account for any of them. 

It seems that we're throwing away a perfectly good, inexpensive, readily available fossil fuel source in natural gas for a mechanism that may or may not cause harm on a worldwide level. But then I'm a fossil. 

[Ward Smith + 6,615]

New news on Fusion reactor testing. A 10x reduction in containment power is a huge plus, if it can be scaled. We'll see. 

[Jay McKinsey + 1,489]

28 minutes ago, Gerry Maddoux said:

Nice explanation. 

Still, when I extrapolate energy needs to solar and wind farms, I get millions of acres covered with expendable and fragile production units. 

I'm no wizard in this, and I am an unrepentant oil and gas enthusiast, so I'll believe it when I see it. 

I suppose it helps if you really believe global warming is secondary to fossil fuel expenditure. I am on my fourth reading of John McPhee's "Annals of the Former World." About fifty climate changes of extraordinary degree are written into the rocks of geology, yet the burning of fossil fuels didn't account for any of them. 

It seems that we're throwing away a perfectly good, inexpensive, readily available fossil fuel source in natural gas for a mechanism that may or may not cause harm on a worldwide level. But then I'm a fossil. 

Thanks.

I'm not sure why you think solar panels and wind turbines are fragile. They are designed to handle hurricane winds and horrific hail. Off shore wind isn't up to the very strongest hurricanes yet but those don't happen everywhere and even then the damage is caused by sudden wind shifts that are highly localized. A few damaged turbines after a once in 20 year storm is not economically impractical.

https://www.energy.gov/eere/articles/hail-no-national-labs-solar-panels-survive-severe-storm

And even better there is research showing that off shore wind actually takes the power out of hurricanes thus decreasing the damage on land fall. https://www.scientificamerican.com/article/offshore-wind-farms-could-knock-down-hurricanes1/

Otherwise this thread is about nuclear so I'll stop with that.

 

 

[Jay McKinsey + 1,489]

The delays and cost over runs for the SMR boondoggle begin;

Plans to build an innovative new nuclear power plant—and thus revitalize the struggling U.S. nuclear industry—have taken a hit as in recent weeks: Eight of the 36 public utilities that had signed on to help build the plant have backed out of the deal. The withdrawals come just months after the Utah Associated Municipal Power Systems (UAMPS), which intends to buy the plant containing 12 small modular reactors from NuScale Power, announced that completion of the project would be delayed by 3 years to 2030. It also estimates the cost would climb from $4.2 billion to $6.1 billion.

Before construction can start, however, UAMPS still has to line up customers to buy the full 720-megawatt output of the plant, Webb says. So far, UAMPS members involved in the project have agreed to take only a relatively small fraction of that output. So UAMPS may have to convince plenty of other folks that it’s a good deal.

 

https://www.sciencemag.org/news/2020/11/several-us-utilities-back-out-deal-build-novel-nuclear-power-plant

[Rasmus Jorgensen + 1,169]

On 11/3/2020 at 10:17 PM, Jay McKinsey said:

The place where SMR have a place are as @Rasmus Jorgensen points out are in unique applications where renewables don't work so well such as shipping because of either weight or space concerns. That is why I support continued research. But as of today there is not a singe working prototype known that does this in a cost effective manner.

I would like to add that if MSRs get working with proper safety etc there can be other applications such as microgrids in remote areas etc. But basically I believe that you are rigth on renewables downward cost-curve. 

It is my understanding that a large part of the cost to nuclear is waste disposal and safety compliance. I further understand that MSR / thorium could overcome this. It won't happen tomorrow, but if it happens it will kill nat-gas for electricity production. 

[Sebastian Meana + 278]

On 11/3/2020 at 6:17 PM, Jay McKinsey said:

 

 

On 11/5/2020 at 9:00 PM, Jay McKinsey said:

The delays and cost over runs for the SMR boondoggle begin;

Plans to build an innovative new nuclear power plant—and thus revitalize the struggling U.S. nuclear industry—have taken a hit as in recent weeks: Eight of the 36 public utilities that had signed on to help build the plant have backed out of the deal. The withdrawals come just months after the Utah Associated Municipal Power Systems (UAMPS), which intends to buy the plant containing 12 small modular reactors from NuScale Power, announced that completion of the project would be delayed by 3 years to 2030. It also estimates the cost would climb from $4.2 billion to $6.1 billion.

Before construction can start, however, UAMPS still has to line up customers to buy the full 720-megawatt output of the plant, Webb says. So far, UAMPS members involved in the project have agreed to take only a relatively small fraction of that output. So UAMPS may have to convince plenty of other folks that it’s a good deal.

 

https://www.sciencemag.org/news/2020/11/several-us-utilities-back-out-deal-build-novel-nuclear-power-plant

I'm just going to do a simple, quick, shitpost, Nuclear is the only clean, scalable , cheap, reliable, energy source, period, just is not compatbile with all political/economic/social systems Nuclear power energy will get cheaper , is just that is incompatible with liberal democracies, and it will become a big trend, just not in the western liberal democracies, Because nuclear energy is done best under state commitment, even more under state enterprise (low interest long term loans, large economies of scale, pre-established supply lines, standardization of everything, vertical integration of different areas)

State owned enterprises are just not compatible with politics and the useless opinions that tend to get inside a country, that's what prevents the US to restart the construction of massive hydropower dams and getting another 500GWe of clean super cheap electricity, Framatome will start doing reactors for the cheap once the 5th french republic dies and they decide to make a 6th French republic, give it 10 years

The VVER-TOI units at Kursk-2 , both units will cost 3.6 BIllion U$D to generate 2600MWe, 1400U$D/KWe compared with the 1800U$D/KWe of the VVER-TOI units previously built at Novovoreznezh, Ohi 1&2 were built in Japan in the 90s for 1900U$D/KWe adjusted per inflation

If there's development in the third world it will be fueled by fossil fuels, nuclear requires the stability that the third world lacks, and wind and solar, not gonna work, the next big thing will be southeast asia, go to Indonesia, look to the sky, what you see? clouds, the sun doesnt shine in the tropics, therefore Solar power is out of the question, and the wind potential of Vietnam or Bangladesh, or Malasyia or Indonesia is negible, and that's without counting climate change

For each 1°C in global warming wind speeds are reduced by 35%, if the earth becomes 5°C warmer the average wind power potential will be 23% of what currently is, if the earth becomes warmer you will get higher precipitation than you currently have, the subtropical regions that currently are perfect for solar power could have some serious challenges
 

[Dan Warnick + 6,100]

There!  You are in the right place @turbguy and @footeab@yahoo.com.  Do continue.  I'm enthralled.  Seriously.

1. Why is it called a "partial breeder"?
2. Doesn't encasing something like that end up being like a pressure cooker, and it's got to go somewhere eventually?
3. "fertile to fissile"?  Does that mean it is good to produce plutonium?
4. The breeder producing plutonium, yet also the (very positive?) breeder somehow "ate the other long lived poisons" is fascinating.  I guess I should have taken more Chemistry.

Anyway, sorry to ask so many questions.  I just found you guys' conversation on this fascinating.

DW

  8 hours ago, footeab@yahoo.com said:

Erm, not what I wrote bud.  Fermi was same half way design as a near standard Pressure water reactor.  Only addition was that it was also a partial breeder reactor.

Liquid salt, breeder... any kind of problem, the reactants pour via gravity into their own containers which are not large enough for continuous reaction or outgasing.  Last two portions were done in the late 70's at Oak Ridge same with liquid salt.  Breeder, portion is partially done but did not get all the poisons out of(Namely Tritium).  What is poignant was that breeder, while it made plutonium, ate it an ate the other long lived poisons.  I believe it left Iodine/cesium and I forget which one of them has an 800 year half life. 

Well, Fermi 1 did breed some fertile to fissile, the reactor coolant did not require pressurization, avoided the potential for hydrogen generation, and operated at a much higher temperature to increasing the thermodynamic efficiency on the rankine cycle.  And it did work, even after the partial meltdown was repaired.

Molten salt has similar advantages, including enhanced safety issues as you point out.  Hopefully the fluoride salts don't end up attacking the pressure parts.

Lots of room for improvement.  If Washington was not so interested in easy naval reactors and getting material to make bombs, we'd probably have some LFTR's in service instead of LWR's.

But, we are off topic again, sorry...

Edited 14 minutes ago by turbguy

 

[Dan Warnick + 6,100]

On 11/1/2020 at 10:45 PM, Gerry Maddoux said:

Not to be too argumentative here, but you want to see a mess go up to Lithium Valley and see for yourself the giant gouges made into the earth in order to get the several hundred tons of rock and soil moved for one lithium-ion battery. Or to The Congo and peer at the orange-red pits of cobalt mining. Or visit a nickel smelter and take a sample of the ambient air filled with sulfurous gases that cause acid rain. More and more lithium is going to be needed: massive amounts of it. I haven't seen the mining operations of Abelmarle or China but I'll bet they're a mess.

That's all I was trying to point out, that energy does not come cheap, or without collateral damage. It's the ringing voices of confidence that fossil fuels were evil, and that change is so urgent that bothers me. Nuclear will claim its own victims, not to mention absolutely gargantuan volumes of water and electricity. Everyone is so cocksure that EV's are "carbon-neutral" or have "zero-emissions," which is insane. Like Big Oil, the lithium mines are hiding their "messes" and we haven't even begun to see the collateral damage from giant wind and solar farms--but we will. We will. 

Albermarle is huge, and growing rapidly.  They claim they are in all 50 states, and their international operations are big deals wherever they go.  I'm with you, I'll bet the behind the scenes scenes are sickening.  How should they be handling them?  Are they (operations such as these) that necessary?  Should it be considered as being managed as best as is currently possible, but of course should do better as better practices become known and implemented?  Or is it too much for the ROI and should rather be scaled back or shut down?

My questions are serious.  I am curious to know what damage and what scale of damage these places are producing, and whether or not it's a problem in the grand scale of things.

[Dan Warnick + 6,100]

On 11/2/2020 at 2:15 AM, Jan van Eck said:

Readers should note that this is rubbish, basically a political cant.  In the USA, probabluy one hundred (100) or more small nuclear reactors have been built, and their operating record is totallty flawless.  The standard size is 100 MW.  These are of the (rather primitive) light-water pressurized reactors, to develop high-pressure steam that will drive a turbine.  The design is that of the very earliest nuke reactors, going back 75 years, and all have had a perfect record - zero failures.  

Readers should note that, at least in the USA and probably also in Germany, the push against reactors was made by the Malthusians, whose mantra is that there are "too many people on the planet."  Oil & gas will support many billions in a reasonably comfortable lifestyle once the price points and distribution are sorted out equitably.  It is those billions that the Malthusians rail against - they would prefer those people to be dead.  Along comes nuclear power and the billions numbers can become permanent; that really upsets the Malthusians.   So the political tactic was to create fear of "explosion," which is ridiculous.   A standard pressurized water reactor, which today would be considered antique, is cheap enough to build, to the point where you can go to flat-rate metering and not even charge for the electricity itself, only a fee for maintaining the wires that bring it to you. Ironically, the slogan "too cheap to meter" is actually true.

What the "anti" crowd then did was convince politicians, who control the permitting process, to require plant operators to have very expensive add-ons, including a full-time fire department, a police department, and all manner of massive containment domes in hardened concrete.  All of that is unnecessary, and the Malthusians knew it, but did it anyway so as to make nuke power cost-prohibitive.  Faced with these massive add-on costs, the nuke operators responded by making the plants as big as possible - not because that was desireable, but because then overhead costs could be spread anomg lots more production. 

Remember this: the Malthusians believe that the world population should be no more than 200 million.  That is the goal.  Forcing down the population by denying the fruits of engineering, by removing power and all that that power promises, including clean water, sanitation, raods, heat, buildings, jobs, food, everything, is their goal.  

Of couse, in this Brave New World, the Malthusians will run everything and control all lives, including your reproduction  (and especially your reproduction), and in that Brave New World they will be the dictators and you will obey or be executed, discarded as "surplus population."  Don't have any illusions about those people, they are nasty, brutish, and evil. Your life means nothing to them; only their vision of how the planet should look.  This is what happens when ideology overtakes reason.

Another post, (above) from back on Nov. 2nd, that bears repeating.  It is an interesting one, that I suppose it doesn't hurt to be aware of?

[Dan Warnick + 6,100]

On 11/2/2020 at 9:34 PM, Rasmus Jorgensen said:

https://splash247.com/bill-gates-joins-nuclear-powered-shipping-push/

This is a really interesting experiment... I know some of the people in CORE-POWER and this really has the potential to be a game-changer.

Fascinating article at the above link.  Thanks.  And the further reading at the links in that article is captivating as well.  Very interesting developments.

[turbguy + 1,398]

2 hours ago, Dan Warnick said:

There!  You are in the right place @turbguy and @footeab@yahoo.com.  Do continue.  I'm enthralled.  Seriously.

1. Why is it called a "partial breeder"?
2. Doesn't encasing something like that end up being like a pressure cooker, and it's got to go somewhere eventually?
3. "fertile to fissile"?  Does that mean it is good to produce plutonium?
4. The breeder producing plutonium, yet also the (very positive?) breeder somehow "ate the other long lived poisons" is fascinating.  I guess I should have taken more Chemistry.

Anyway, sorry to ask so many questions.  I just found you guys' conversation on this fascinating.

DW

  8 hours ago, footeab@yahoo.com said:

 

Liquid sodium does not boil (vaporize) until something like 1600 degree F at atmospheric sea level pressure.  The reactor core must run cooler, of course, to stay within reasonable material properties.  No "pressurization" of liquid sodium is required.  You are just handing molten liquids with no vapors. 

To get light water "saturated with heat" at atmospheric sea level pressure, you only get to 212 degrees F.  That's really lousy for thermodynamic efficiency. Add any more heat to the water and some of it begins to turn to gas  If you want to raise the water's saturation temperature, you must raise the pressure on the water.

If the vessel containing that "saturated water" inventory ever releases pressure (pipe break or similar pressure boundary fault), the saturated water within immediately begins to turn to gas (steam) in a rather violent manner...

So it's simply a matter of transferring the heat contained in the liquid sodium to pressurized water in a (series of) heat exchangers. You can then not only saturate that pressurized water with heat, but even SUPERHEAT THE RESULTING GAS to higher temperatures.  VERY good for heat engine efficiencies!

Typically you use TWO heat exchangers, as the liquid sodium exposed to the core becomes radioactive (with a short half life), so you heat another intermediate loop of liquid sodium that heats water.

Molten salt reactors operate with similar "dynamics".   No pressure required in the reactor vessel.   High temperatures achieved in the heat engine's working fluid.

Edited February 28, 2021 by turbguy

[Dan Warnick + 6,100]

34 minutes ago, turbguy said:

Liquid sodium does not boil (vaporize) until something like 1600 degree F at atmospheric sea level pressure.  The reactor core must run cooler, of course, to stay within reasonable material properties.  No "pressurization" of liquid sodium is required.  You are just handing molten liquids with no vapors. 

To get light water "saturated with heat" at atmospheric sea level pressure, you only get to 212 degrees F.  That's really lousy for thermodynamic efficiency. Add any more heat to the water and some of it begins to turn to gas  If you want to raise the water's saturation temperature, you must raise the pressure on the water.

If the vessel containing that "saturated water" inventory ever releases pressure (pipe break or similar pressure boundary fault), the saturated water within immediately begins to turn to gas (steam) in a rather violent manner...

So it's simply a matter of transferring the heat contained in the liquid sodium to water in a (series of) heat exchangers. You can then not only saturate that water with heat, but even SUPERHEAT THE RESULTING GAS to higher temperatures.  VERY good for heat engine efficiencies!

Typically you use TWO heat exchangers, as the liquid sodium exposed to the core becomes radioactive (with a short half life), so you heat another intermediate loop of liquid sodium that heats water.

Molten salt reactors operate with similar "dynamics".   No pressure required in the reactor vessel.   High temperatures achieved in the heat engine's working fluid.

That's awesome.  I can picture the process.  Good writing.

[Dan Warnick + 6,100]

Just a note to the (obvious) forum members:  I have thoroughly enjoyed the reading on various topics tonight, including this one, and have subsequently stayed up well past a reasonable bedtime because of it.  Thanks everybody.  It is refreshing and I look forward to more of it.  (No pressure! {pun intended}).  Catch you all tomorrow.

[footeab@yahoo.com + 2,131]

5 hours ago, turbguy said:

Liquid sodium does not boil (vaporize) until something like 1600 degree F at atmospheric sea level pressure.  The reactor core must run cooler, of course, to stay within reasonable material properties.  No "pressurization" of liquid sodium is required.  You are just handing molten liquids with no vapors. 

...

Molten salt reactors operate with similar "dynamics".   No pressure required in the reactor vessel.   High temperatures achieved in the heat engine's working fluid.

 

NIT: No one will ever use Sodium as a medium again.  Rather they are all in on Floride salts with MUCH higher temperatures allowed. 

Here is @Dan Warnick an excellent START place for all things advanced nuclear reactor design, not just what we are discussing.  https://www.youtube.com/user/gordonmcdowell  

Start about 9 years ago

Full disclosure I did a cup of coffee in the industry about 15 years ago now on the MASLWR design which has as you might note, since been scrapped. 

[turbguy + 1,398]

3 hours ago, footeab@yahoo.com said:

NIT: No one will ever use Sodium as a medium again.  Rather they are all in on Floride salts with MUCH higher temperatures allowed. 

Here is @Dan Warnick an excellent START place for all things advanced nuclear reactor design, not just what we are discussing.  https://www.youtube.com/user/gordonmcdowell  

Start about 9 years ago

Full disclosure I did a cup of coffee in the industry about 15 years ago now on the MASLWR design which has as you might note, since been scrapped. 

While MUCH higher temperatures are desirable,  you must have the metallurgy to support high working fluid temperatures.  Even the most advanced steam cycles (advanced ultra-supercritical steam) stop at 1250 degrees F or so. 

Of course, you can heat a gas instead instead of water, and then use a gas turbine. That will permit somewhat higher working fluid temperatures, potentially high enough to reach 50% thermal efficiency. I think there were some reactor designs proposed, or even prototyped  or in operating states, that used helium as a coolant and working fluid, no?  Helium would be a great working fluid, as it's a noble gas (non-corrosive).

That said, I have no issues with considering a molten fluoride salt as a reactor coolant.  You can push them up to about, what, 1400 degrees, maybe even more?  I DO have issues with the potential for fluoride salt corrosion of structural metallurgy (water is bad enough, but it forms a thin protective film on structural alloys, the film makes a great barrier to continued attack).  Fluoride salts tend dissolve these films.  Again, metallurgy rears it's ugly head.

Your gonna need some really exotic alloys, the ones where iron is considered a "tramp" element.

Condensate chemistry in steam plants is monitored by plant chemists,  politely called "water doctors".

Now your gonna have to add "fluoride doctors".

Edited March 1, 2021 by turbguy

[Dan Warnick + 6,100]

16 hours ago, footeab@yahoo.com said:

NIT: No one will ever use Sodium as a medium again.  Rather they are all in on Floride salts with MUCH higher temperatures allowed. 

Here is @Dan Warnick an excellent START place for all things advanced nuclear reactor design, not just what we are discussing.  https://www.youtube.com/user/gordonmcdowell  

Start about 9 years ago

Full disclosure I did a cup of coffee in the industry about 15 years ago now on the MASLWR design which has as you might note, since been scrapped. 

Thanks for the link.  I've just spent a few hours learning.  Fascinating.

[footeab@yahoo.com + 2,131]

18 hours ago, turbguy said:

While MUCH higher temperatures are desirable,  you must have the metallurgy to support high working fluid temperatures.  Even the most advanced steam cycles (advanced ultra-supercritical steam) stop at 1250 degrees F or so. 

 Again, metallurgy rears it's ugly head.

Your gonna need some really exotic alloys, the ones where iron is considered a "tramp" element.

 

Actually, no.  SS works just fine.  Not plain jane SS, but Hastelloy, so slightly more expensive, but much easier to work/weld actually than "plain jane" SS.  Several videos where Gordon, or one of his colleagues talks about this issue.  The original salt reactor guys went through the same process of finding correct alloys for long term corrsion and wear properties.  Had it done in the 70's.

The T limit IS only true if you do not place insulation on the INSIDE of the piping with a lining and cooling on the outside. Can be done because in effect, we are talking LOW pressure, high volume(just enough to pump the liquid salt around) Once this is done, then the Temperature limit is in effect ~1200C, but is limited by gas phase outgassing of the salt in question is my understanding or it was outgassing of the nuclear fuel is what it actually was I think???  Then add it is always possible to add NG at this point for a combined cycle and boost Temps even higher via another heat exchanger.  (My pet project assuming I ever dip a toe back into that field, which is looking less likely every day.)

Frankly, it is pathetic that current nuclear reactors do not have a NG boost to T hot for much higher efficiency.  True, complexity goes up, but so does efficiency, by a massive margin.  Try upwards of 50% increase so... Plenty of room for improvement even on ancient tech, just no one is willing to play the Regulatory game of the NRC bumbling fools political hacks and their pack of slavering anti science, anti progress NIMBY's who hate humanity supporters. 

Edited March 1, 2021 by footeab@yahoo.com