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Author: Subject: Does nuclear fusion really solve problems ?
metalresearcher
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[*] posted on 28-12-2020 at 12:23
Does nuclear fusion really solve problems ?


Since the 1950s it is said that nuclear fustion will be feasible 'within thirty years'. At that time is was 1980. now it is 2050. And projects like ITER claim they will make it running with Q > 1 (even 10) by 2025. And even when they make it, it will not become commercial before 2040. The same applies to other attempts.
Well and then ? Are all climate change related problems solved then ?
I am afraid of not. Energy (mainly electricity) will be so plentiful, that the price will be one cent or less per kilowatthour, so all incentives to save energy (which are now already very low) are completely gone. Even when all use of fossil fuel is phased out, energy waste is becoming common, resulting in cheaper steel, concrete, plastics with all adverse effects on nature and environment.

Is this true ?


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[*] posted on 28-12-2020 at 16:00


Despite its superficial appeal, I doubt anything will ever come of fusion for energy production.
An enormous amount of energy is required just to get the thing up and running: deuterium isolation, superconductor cooling, maintaining an enormous magnetic field, and plasma initiation are just some of the energy demands. This means that there are large energy costs before any electricity is produced and the break-even point is a long way out.
Maintaining plasma stability is tricky: akin to balancing a unicycle on top of a unicycle. Similarly, converting the energy output from neutrons into electrical energy is not straightfirward. Both can probably be done with clever design, but that increases the cost significantly.
Then there are material issues. Many materials would need to function in extreme temperature conditions and maintain structural integrity in the face of high neutron bombardment. And if these are highly engineered components and have to be replaced regularly, then again costs may skyrocket.
In short, if net positive energy is ever attained then it is likely to be at astronomic cost.

The immediate future seems to belong to small scale modular fission reactors.
And if we were truly worried about safety or waste then we would be developing thorium technologies.

The truth is that nuclear energy as an industry is very conservative in the same way that the aircraft industry is. It is bound up by red tape and safety regulation. This means that adapting existing technology is a far more attractive proposition than developing new ones. (Aint no one building a titanium plane. Aint no one building a liquid salt thorium reactor.)
Additionally, the nuclear energy industry experiences extreme political and social pressure that prohibits development. Much of this is based on fear and misinformation. (When was the last time you heard an environmentalist laud nuclear energy on the basis that it is the only industry on the planet that contains 100% of the waste produced?)
Nothing new is happening here until the winds of political anc popular opinion change. And fusion will be the last tech out of the starting blocks by virtue of its complexity and expense and the mountains of red tape needed to incorporate a completely new and different technology.

[Edit: typos]

[Edited on 29-12-2020 by j_sum1]
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[*] posted on 28-12-2020 at 16:38


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[*] posted on 28-12-2020 at 18:48


j_sum, you meant to say small scale modular fission reactors? They are looking promising. I keep waiting to hear they aren't fulfilling promises but chugging along nonetheless.

Everything I've read about thorium salt reactors sounds positive but yeah red tape. I think most of the world's future prosperity lies in fission technology but how will we ever get there.




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[*] posted on 28-12-2020 at 19:13


Quote: Originally posted by roXefeller  
j_sum, you meant to say small scale modular fission reactors? They are looking promising. I keep waiting to hear they aren't fulfilling promises but chugging along nonetheless.

Everything I've read about thorium salt reactors sounds positive but yeah red tape. I think most of the world's future prosperity lies in fission technology but how will we ever get there.

Of course you are right. I will edit that.
Remember that the small scale fission reactors gave a proven history in ships and submarines. (And a sub is the last place you want uncontrolled dangerous radioactive waste.)
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[*] posted on 29-12-2020 at 06:49


Quote: Originally posted by roXefeller  

Everything I've read about thorium salt reactors sounds positive


There are two main issues:
1. Molten, radioactive fluoride salts are ridiculously corrosive. And the consequences of a leak due to corrosion would be quite bad.

2. In order for the reactor to work, thorium-232 must be bred into U-233. But the intermediate isotope in this process is protactinium-233, which has a relatively long half life. In order to prevent further neutron absorption (which would ruin the cycle) the protactinium must be continually separated from the fuel, allowed to decay, and then the U-233 must be returned to the reactor. This requires additional equipment. It's also why you don't hear about solid-fuel thorium reactors (because this would be completely impossible, instead of just difficult).




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[*] posted on 29-12-2020 at 07:46


Metacelsus, thanks for that. I'm going to go read. Every salesman gives you the selling points, none of the detractions.



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[*] posted on 29-12-2020 at 08:58


Quote: Originally posted by j_sum1  
Remember that the small scale fission reactors gave a proven history in ships and submarines.


I think that's because these 1.gen naval reactors were designed from scratch. The design was then scaled up adapted to other uses, and this caused some issues. Some of the inherent safety was lost, so extra safety measures was "bolted on" afterwards with less than perfect results.





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[*] posted on 29-12-2020 at 13:07


As for fusion I share your doubt. It's been "any day now" since the beginning, which kinda suggests its not very viable using current physics. In nukes they need to compress the fusion fuel between two nuclear explosions, it's not exactly trivial to do controlled. By comparison the first fission reactor was a pile of graphite and guys with ropes.

I think fission is the obvious choice right now. Imagine a world that committed fully to fission at the earliest possible moment. What would that world be like? A few more wild life sanctuaries perhaps? So what? Neither Chernobyl nor Fukushima are disaster areas for anybody beside us.




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[*] posted on 29-12-2020 at 14:45


Quote: Originally posted by roXefeller  
Metacelsus, thanks for that. I'm going to go read. Every salesman gives you the selling points, none of the detractions.


Most of what I know of thorium comes from watching yt videos featuring Kirk Sorensen. He does give a detailed but understandable layman's overview of the technology. Particularly telling is his speil where he lists safety cost and waste issues with uranium and compares these to thorium. He does sell it well - at least well enough that we should be asking some serious questions and doing some feasibility studies.

I understand that corrosion issues are solvable. Oak Ridge laboratories had a working model in the 60s that ran for five years continuously.

I believe the most complex part of the system is what is called "the kidney" which chemically processes and enriches the fuel as part of its cycle. I forget the details and I am sure that Kirk glossed over some of this.

I would provide a link but I forget which of the dozens of presentations available I have watched. If you are interested in Th then probably a couple of the longer videos would be an excellent prelude to some deep reading.

I believe there is currently some Chinese research in this field, but otherwise, the world is pretty much ignoring this avenue. In my mind, it is far more promising than fusion. And also makes better design sense than uranium. However, at this stage, it pretty much seeks to solve problems that modern U designs have already solved. And in a red-taped-up industry, the incentive for development seems not to be there.
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[*] posted on 29-12-2020 at 14:51


Directly addressing the OP, here is a recent video on the current state of the fusion problem. https://youtu.be/FrUWoywZRt8

It seems that India too is investigating thorium. I have not taken a critical look though.
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[*] posted on 29-12-2020 at 16:46


Considering the corrosion, water at elevated temperatures isn't very nice either for corrosion. Even back in the 40's the nuclear industry was dealing with corrosion. The EBR II reactor was already dealing with liquid NaK coolant. We've probably got enough goodness in the superalloys to deal with salt corrosion. Steam turbine have been making headway on that for decades. Problems that can be engineered aren't so much problems. The insurmountable ones like red-tape are probably more the problems.

I was talking to someone the other day about thorium. It's so fringe still. I hope someone picks it up, India, China, whoever doesn't have the red-tape. For a nation like the US, it solves a problem we don't have, sitting on most of the world's refined U235. Other nations that don't have that luxury may just usher in the next nuclear spring. Anyway back to that discussion with the nuke, the complication does seem to lie in the kidney. Though I was thinking a centrifuge cascade could do a lot for that, given the fission products, like U235's Cs&Zr, are so very different from Th233 mass-wise to efficiently be extracted. There are other isotopes that may need removed though, poisons like Xe&Cd, or elements that won't play nicely chemically with the salt or materials (I'm only postulating their existence, I have no idea). I'll have a look at the Sorensen videos. I've only read energyfromthorium.com so far and chatted with people. But like I said, its fringe.




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[*] posted on 30-12-2020 at 09:33


Quote: Originally posted by j_sum1  
Directly addressing the OP, here is a recent video on the current state of the fusion problem. https://youtu.be/FrUWoywZRt8

It seems that India too is investigating thorium. I have not taken a critical look though.

I watched this video with the Indian girl telling the story.
What I wonder is that we try to harness "the process in the Sun and the stars", but that is not true.

The Sun fuses two normal hydrogen to deuterium and then to helium 4 at 'only' 15 million K, unlike the tenfold temperature in D-T fusion reactors.
https://en.wikipedia.org/wiki/Proton%E2%80%93proton_chain_re...

So why can this proton-proton reaction not be mimicked ?
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[*] posted on 30-12-2020 at 09:45


Remember that p-p fusion is ridiculously hard to get going. The rate of energy production in the Sun's core, per volume, is roughly equivalent to that of a compost heap. See: https://en.wikipedia.org/wiki/Solar_core#Energy_conversion

@j_sum1: I haven't watched the videos but I'd imagine that the "kidney" is the Pa-233 extraction apparatus.

[Edited on 2020-12-30 by Metacelsus]




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[*] posted on 30-12-2020 at 09:46


http://en.wikipedia.org/wiki/Jevons_paradox

Bottom line is that if fusion does make electricity a lot cheaper then yes you will see an increase in usage.

But the thing is that electricity currently ranks way behind gas (price-wise) in various heating processes. These thermal processes -- heating, manufacturing, cooking -- collectively account for up to 40% of emissions. Replacing that fuel usage with electricity was always going to require an increase in electricity generation and usage, even if we develop more efficient heating methods. Some chemical manufacturing might use solar thermal but geography is a powerful limiter here.

Overall I'd say that the outlook for fusion is bright mostly because of innovations in superconductor manufacturing. With a durable enough superconductor ribbon, many current reactors would already be large enough to achieve net power! New reactors use ReBCO ribbons instead of NbTi and achieve corresponding improvements in density and cost efficiency. ReBCO ribbon is a huge improvement for every possible fusion reactor design, and arguably the biggest "breakthrough" since the '50s.

The great thing about fusion is that reactors can be built in the developing world with little IAEA oversight. Intermittent renewables probably won't satisfy paranoid military strategists who want reliable electricity. Fusion slots into this hole better than anything else, even though it would likely take a few decades even after net power is achieved.




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[*] posted on 30-12-2020 at 09:52


Quote: Originally posted by metalresearcher  
What I wonder is that we try to harness "the process in the Sun and the stars", but that is not true.


Just can't let them have their science porn? Most people watching videos nowadays do it pop-culture style, with little critical training. Cause the audience wants to have faux arguments in the cafeteria and flex. If they get views from some 12 y/o, they get ad money, doesn't matter if the 12 y/o understands the deeper questions like proton-proton feasibility.




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[*] posted on 30-12-2020 at 09:56


@cna: Fair point, while the development of superconductors have been slow it is inching forwards.



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[*] posted on 30-12-2020 at 13:36


Fusion does have promise.
It has been inching closer for decades .. in the 70s it was 30 years away.
Now it is 10 at the most. Once a success can be demonstrated governments will be falling all over themselves.
Fusion does not produce the quantity of highly radioactive waste that fission does.

As for global warming and water purification, those can be solved by raw energy.
You can literally sequester the CO2 and return it to carbon and oxygen given enough energy.
Distilling water is again energy intensive. Reverse osmosis is less energy intensive but it is still substantial.
Soils remediation is also energy intensive.

We now have the technology to turn CO2 and water into ethanol with much lower energy cost.

Every bit of energy we use today started as either fission or fusion and even fission started with fusion

fusion -> light -> plants -> sometimes animals -> fossil fuels
fusion -> light -> solar power
fusion -> light -> atmospheric heating -> wind power
also atmospheric heating -> water evaporation -> fresh water/hydro power
fusion -> supernova -> heavy elements -> radioactive heat -> geothermal
also heavy elements -> fission power
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[*] posted on 30-12-2020 at 14:19


I'm not holding my breath...

As for the initial premise, no and yes. No, it's not about the energy spending per se. We could be spending 10 times the energy we do now as long as it was clean (enough). But in the end, yes. We do tend to expand to and beyond our resources. This time it's tricky since we refuse to use our best technology while we wait for progress to save us.




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[*] posted on 1-1-2021 at 21:48


As usual in the real world things are messy. Fusion, fission, and renewables all fit different usages. There's a lot of activity in new fusion and renewable technology and engineering. Nations are betting their futures on success.
I see fusion and renewables complementing each other - fusion is a large centralized source and renewables are distributed. I think fission will exist in small niches where renewables are scarce and a fusion plant isn't feasible - very remote areas etc.

Fusion is definitely creeping towards sustained break-even. At this point it looks like a soluble but nasty pile of engineering problems.

Stability is the biggest problem. If the plasma touches or even gets near something solid it quenches (possibly melting the offending object). Contamination is next. Materials are getting better. Modern supercomputers make it possible to understand plasma stability a lot better than even 10 years ago. Computation has revealed geometries that need merely very intense (but still enormous) magnets.

IIRC one recent project briefly reached a point where instantaneous local energy out was greater than instantaneous local energy in. Output needs to be about 10x higher and run time has to be about 100x longer to produce usable power. 20 years ago the ratios were about 1000x output and 10000x run time. Converting the neutron output to steam energy has gotten well past hand-waving and whiteboards. For some value of easy capturing neutrons and converting kinetic energy to steam is easy. I don't know details.

Britain is planning a commercial fusion reactor to be on-line by 2030. One proposal is to build it on the site of a decommisioned fossil fuel plant to re-use the existing turbines, generators and distribution network. They're betting billions that the reactor will succeed.

There is more solar and wind than you might think. Right now there is so much excess installed solar capacity in the US Southwest to power 1/3 of the country during high sun. In Hawai'i HELCO won't accept more than 50% solar on any branch. Some states in the US require solar panels on all new residential construction.

Solar and wind are intermittent now. Inexpensive storage changes everything. Sections of Australia run using a huge Li battery farm now. There are V flow batteries installed.

I read an article about a different new chemistry (Na, Ca, Mg, Al) replacing Li at lower cost and higher energy density or new electrode compositions for Li weekly. Using current battery technology renewables are cost-effective where fuel costs are very high or infrastructure is very bad. Electric vehicle engineering is quickly pushing the price of Li batteries down and capacity up. In the last 5 years Li-Ion capacity in the standard 16550 cell has tripled.

Supercapacitors are getting insanely large. Chinese companies are advertising >>100,000 Farad<< graphene capacitors with low internal resistance and high surge capability for $100. If I haven't dropped a decimal point that's about 60WH. It would be quite expensive but one could run a house using fully electric heat, cooking, lighting & cooling with solar now with storage for a week without sun. The capacitors don't wear out.

U fission will always stumble on the disposal problem. The Russian submarine in the Baltic, Hanford in the US etc are examples of what happens when organizations make stupid mistakes or just don't care about consequences. Given human nature that will always happen sooner or later. Then there's Chernobyl and Three Mile Island...

Th fission is much better but still leaves long half-life radionucleides in quantity. Small reactors distribute the problem but don't solve it.

Fusion does leave radioactive material. It's orders of magnitude less mass than fission because there's no spent fuel. Most of the metals irradiated have low atomic number so the resulting waste has short half-lives.
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[*] posted on 1-1-2021 at 23:50


One problem fusion research solves even now is it helps to keep a pool of nuclear specialists, scientists and engineers, in employment and helps their education and pure research. We don't know when or what we may need them for in the future.

Its a bit like going to the Moon or Mars. There may be no foreseeable benefits now apart from satisfying our curiosity. As in all research we never now how useful it will be until much later. Fusion power generation my be essential when our population has grow an other ten fold.




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[*] posted on 1-1-2021 at 23:56


You have overstated the Australian Li battery.
It was at the time of construction the world's largest. And it powers nothing. It simply smooths out the bumps in an intermittent power supply that is the result of over-reliance on wind and solar. South Australia is still heavily reliant on neighbouring states when demand is high. Occasionally power is exported. But usually, when SA has surplus from solar, so do surrounding regions. And supply drops to zero when it gets dark. IIRC, the battery can power the state for 20 minutes.

King Island, another Aussie location, has vanadium flow batteries. I personally live the tech and they are well suited where they are. The supply is a combination of wind, solar and diesel generator. It is a small remote region. Diesel is now somewhere around 20% of the supply compaed to the 80 previous.
But, it was not cheap. And despite being scalable in concept, it is probably unsuitable for anything much larger. It probably has niche uses, but large scale grid storage probably is not it.

In your analysis of fusion, I believe you have oversimplified the plasma stability issue. Last time I looked at this in detail, it was anything but solved. And the complex manipulation of the magnetic field to twist the plasma into something more stable was an enormous feat in mathematics, physics and engineering with still significant shortcomings. I am a bit skeptical that a bigger magnet will fix it all.
You also leave something out of the waste equation: all of the irradiated components. And there are containment issues mentioned in the video I linked above that would make ITER no more attractive than fission.

When it comes to grud storage, there are some good udeas under development. Liquified air may be a good replacement for pumped hydro. And there is a liquid calcium antimony battery under development that looks like it will be good for deep cycles and high cycle iterations. Unfortunately it needs to operate at 500C snd so expends 20% to keep itself hot. That makes efficiency 80% which is still in line with pumped hydro at 70%. And it won't have the same kind of land-use problems.

If the Australian (and I believe Californian) experiment has told us anything, then it is that wind and solar remain immature technologies until there is a viable grid storage solution to mitigate against intermittency. And even then, lifespan studies indicate that they are nowhere near as green as they are being marketed as. Moreover, they seem to need continual subsidies and incentives to make them economically viable; which suggests that renewables are not as cheap as us often claimed.

To address the OP's concern about supply and demand, it probably is true up to a point. Cheap electricity may lead to some wasteful use. But other lifestyle factors such as home size and design, and travel patterns, will likely have more effect as these put a ceiling on the amount of energy an individual uses. Similar things can be said for industry where electrical supply us not the only factor in play.

Whatever the situation, there is no indication that fusion will bring a breakthrough in cheap supply in the forseeable future. Also, I have serious doubts with aspects of the climate change narrative which may render moot some of the motivational factors of the OP's argument.
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[*] posted on 2-1-2021 at 02:12


The EROI of oil used to be 100:1, and nowadays it's between 20:1 to 5:1. So, using large amount of energy to keep up the production is not anything unordinary.
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[*] posted on 5-1-2021 at 16:34


Everytime I see an article about the progress of fusion research I think of comic book fan fiction sucking valuable money away from legitimate energy research. The more spectacular the gains sound, the more poorly informed billionaires throw at it.

I was reading today the EPRI report from their review of the current thorium salt proposal. If you haven't read it yet, you should. It goes into a lot of detail beyond youtube. The attached file is an excerpt from it, detailing the process of separating fertile streams from fissile streams to split between the blanket salt and the reactor salt. Reductive and oxidative chemistry with the benefit that fluorine reacts with everything. Honestly they have a "proven" concept (based on 1960's development) but need testing to satisfy safety requirements because, unlike fusion where people get to play in bathtubs, activities utilizing special nuclear material like U233 or U235 has an extra hurdle. Reading through, there is the outstanding uncertainty of long-term effects from fluoride salts.

I also listened to the Power Hour episode with Kirk Sorensen, about an hour. I think he made a convincing argument that a lot of fission development came from military use and expediency. For instance the nuclear navy specialized in a reactor that was uber-safe and could afford the extra weight from a PWR, having plentiful water nearby. Early on they couldn't afford the danger of untested materials, leading to the use of safe, proven, rankine systems of well known material. The air force wanted to develop something special for air using different schemes, like the Brayton cycle. However after the SL1 accident in Idaho, the military got sober on nuclear energy. So it was left to the navy, who had a very ballsy and powerful Admiral, so many friends in DC. Is the naval PWR the best design for land-based reactors? Kirk says no. I agree partly too. The military makes trade-offs for rock solid items with war-time reliability, and they spend dearly for it. Commercial plants can't do that, and they are suffering the ridicule of subsidy-hawks for having the nerve to ask for funding. When natural gas shale produces so cheaply, who wants to throw money at the sinking nuclear industry. Based on Kirk, at this point they may only be sinking because they are so tied to early PWR/BWR development, and unable to get a fresh start.

The small modular reactors are passing a lot of hurdles. I was looking at the wikipedia page on those. I hadn't realized that russia had some online. The main benefit to them, they don't get tied up in siting litigation. They have spent so much time getting smaller that environmentalists can't effectively take them to court over disaster planning. Their zone of emergency planning is the size of their physical boundaries. To get there, they seem to have taken the standard nuclear designs of PWR, natural circulation, fail-safe (similar to the navy) and shrunk them. They've also spent a fair amount designing and testing things like low head heat exchangers, enough to satisfy commercial regulators. Not so much innovative as much as smart engineering. But still, they're too much like other commercials and will suffer similar fates. Low enrichment for instance, means much of the "waste" was mostly inert. Structural items or U238 that will only activate and become liabilities for disposal. I'd be willing to listen to the cost-benefit analysis of enrichments beyond the 3 percents, spending more on enrichment to get more kWh's. Enrichment to 6% could halve the waste volume in theory. Imagine 50%. You've have hot turds, but far less of them. Perhaps that is GE's and Westinghouse's punishment for such low enrichment - nobody wants to deal with the low density waste. Thorium salt reactors have that improvement, the fission waste is much denser, and has a shorter life since they lack the transuranics. You can say that all the nuclear waste can be stacked on a football field, but we haven't used it long, and I've never seen it stored densely, always spread out. As we scale up, it will start taking larger areas, not as much as the stupid solar/wind farms, but larger than football fields.

I'm a real proponent of nuclear energy the world over. Anyone concerned with fossil fuels or carbon footprints should be likewise. I've told my son for years, if there wasn't a fear of malefactors around the world, we might get nuclear everywhere and bring prosperity to all. Instead, proliferation is the boogeyman and the US can't share the goodness, cuz soMeoNe BaD mIghT dO soMetHing neFarIoUs. If the nonproliferation case for thorium is true, it could be a breakthrough.

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[*] posted on 6-1-2021 at 12:45


The marine reactors are designed for very specific conditions, few of which apply to civil power production. And I honestly think all the current designs are good enough, so all talk about better designs can only slow the process. Almost all major incidents involved design flaws, but it still took almost deliberate effort to cause them. And waiting for a completely idiot-proof design is the same as saying never. That's the most infuriating thing about fusion. Sure it'll be nice. If or when someone solves it... And it's not like it's some missing "Eureka-moment" or secret formula that will magically crack it, with dozens of plants just waiting to fire up. Implementation will be slow.

If there is one thing I dislike about the classic PWR/BWR designs it's the core fuel excess. When shit hits the fan the size of the incident is ultimately limited by the amount of fuel present.




We're not banging rocks together here. We know how to put a man back together.
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