The Nuclear Power Thread

[berkeman]

I never heard of NR-1 before.

Yoiks...

A book about NR-1 by a crewmember, states that it was "unsafe" to go aft of the sail on the surface on the NR-1 when the reactor was operating.

 

[anorlunda]

Yoiks...

Yeah, the same article I linked earlier said.

The reactor compartment had to be a certain size to provide for space and shielding to reduce radiation levels. Shielding posed a special problem; it was not only heavy, but its weight was concentrated in a small area.

The propulsion motors were already outside the hull. I wondered if anyone back then considered moving the reactor away from the inhabited spaces, as in the movie 2001. Water makes a good radiation shield.

 

[Astronuc]

It is also worth mentioning that the NR-1 reactor design was 10-15 years after the Army small reactor design. And of course, land is not sea.

According the AEC booklet, ALCO was the manufacturer of PM-2A (criticality in October 1960), and design was probably done ~1958-1959. ALCO was struggling at the time as their locomotive business cratered in the 1960s. One of the main suppliers of generators and motors, GE, decided to enter the locomotive business as a competitor. Prior to that GE had manufactured custom electric locomotives.

NR-1 was done by the Navy with their BAPL and KAPL laboratories. Their program was generally of higher quality than those of the Army. The limited information indicates the reactor was operational in 1969, so was probably designed ~1967-1968 and constructed ~1968-1969.

 

[Astronuc]

16 August 2021 - Turbine tests completed at China's HTR-PM
https://www.world-nuclear-news.org/Articles/Turbine-tests-completed-at-Chinas-HTR-PM

Testing of the steam turbine using non-nuclear steam has been completed at the demonstration high-temperature gas-cooled reactor plant (HTR-PM) at Shidaowan, in China's Shandong province. The twin-unit HTR-PM is scheduled to start operations later this year.

Non-nuclear steam flushing is an important test for nuclear power projects to check the operating quality of steam turbine units and conventional island systems prior to start up. The test verifies the design, manufacturing and installation quality of the steam turbine set.

The steam turbine of the HTR-PM reached operational speed using non-nuclear steam at 8.30pm on 14 August, China Huaneng announced today. It said all parameters, such as power and temperature, attained good standards; the main protection parameters were normal; and the auxiliary engine system operated stably.

Construction of the demonstration HTR-PM plant - which features two small reactors that will drive a single 210 MWe turbine - began in December 2012. Helium gas will be used as the primary circuit coolant. China Huaneng is the lead organisation in the consortium to build the demonstration units (with a 47.5% stake), together with China National Nuclear Corporation subsidiary China Nuclear Engineering Corporation (CNEC) (32.5%) and Tsinghua University's Institute of Nuclear and New Energy Technology (20%), which is the research and development leader. Chinergy, a joint venture of Tsinghua and CNEC, is the main contractor for the nuclear island.

 

[Astronuc]

Interesting statement: https://www.royce.ac.uk/collaborate/roadmapping-landscaping/fusion/

The UK is a world leader in fusion technology and has an ambitious programme for a net positive energy spherical tokamak by 2040. The programme is at the concept stage and major opportunities exist to identify, select and develop materials systems for structural and functional requirements which will then be used in the prototype and commercial reactors.

Royce worked with the UK Atomic Energy Authority to develop a focused technology roadmap for baseline and value-add materials for fusion. The output is a clear commentary on the current strengths and opportunities, technology gaps, and investment requirements.

Since there exists an ITER Materials Property Handbook, I'm wondering what we have been doing the last 50 years that we still need to identify materials to accomplish CTRs.

 

[anorlunda]

Interesting statement: https://www.royce.ac.uk/collaborate/roadmapping-landscaping/fusion/Since there exists an ITER Materials Property Handbook, I'm wondering what we have been doing the last 50 years that we still need to identify materials to accomplish CTRs.

It sounds like, "Fund me for (at least) the next 29 years before judging my success."

 

[etudiant]

Cruel, but true.

 

[Astronuc]

Meanwhile, back at MIT

In 2015, a group of physicists at MIT did some calculations to rethink how we're approaching the problem of fusion power. High-temperature, nonmetallic superconductors were finally commercially available and could allow the generation of stronger magnetic fields, enabling a simpler, more compact fusion reactor. But the physicists behind the work didn't stop when the calculating was done; instead, they formed a company, Commonwealth Fusion Systems, and set out to put their calculations to the test.

On Tuesday, Commonwealth Fusion Systems announced that it hit a key milestone on its quest to bring a demonstration fusion plant online in 2025. The company used commercial high-temperature superconductors to build a three-meter-tall magnet that could operate stably at a 20-tesla magnetic field strength. The magnet is identical in design to the ones that will contain the plasma at the core of the company's planned reactor.

https://arstechnica.com/science/202...ts-key-milestone-big-superconducting-magnets/

Let's see where we are 4 years from now.
https://news.mit.edu/2021/MIT-CFS-major-advance-toward-fusion-energy-0908

Commonwealth Fusion Systems - https://cfs.energy/
https://cfs.energy/technology

Commonwealth Fusion Systems is collaborating with MIT’s Plasma Science and Fusion Center to build SPARC, the world’s first fusion device that produces plasmas which generate more energy than they consume, becoming the first net-energy fusion machine. SPARC will pave the way for carbon-free, safe, limitless, fusion power. This compact, high-field tokamak will be built with HTS magnets, allowing for a smaller device than previous magnet technology. SPARC is an important step to accelerate the development of commercial fusion energy.

Three and one-half months, or 114 days, left in 2021
https://www.psfc.mit.edu/sparc

The MIT Plasma Science & Fusion Center in collaboration with private fusion startup Commonwealth Fusion Systems (CFS). is developing a conceptual design for SPARC, a compact, high-field, net fusion energy experiment. SPARC would be the size of existing mid-sized fusion devices, but with a much stronger magnetic field. Based on established physics, the device is predicted to produce 50-100 MW of fusion power, achieving fusion gain, Q, greater than 2. Such an experiment would be the first demonstration of net energy gain and would validate the promise of high-field devices built with new superconducting technology. SPARC fits into an overall strategy of speeding up fusion development by using new high-field, high-temperature superconducting (HTS) magnets.

The first step in this roadmap will be to carry out research leading to development of the large, superconducting magnets needed for fusion applications. Once the basic engineering of HTS fusion magnets is established, the next step will be to use that technology to build SPARC. Preliminary analysis has led to a conceptual design with a 1.65m major radius and 0.5m minor radius operating at a toroidal field of 12 T and plasma current of 7.5 MA, producing 50-100 MW of fusion power. Its mission will be to demonstrate break-even fusion production and to demonstrate the integrated engineering of fusion-relevant HTS magnets at scale. While audacious in its goals, SPARC leverages decades of international experience with tokamak physics and is a logical follow-on to the series of high-field fusion experiments built and operated at MIT.

 

[artis]

From what I understand SPARC is just "another" tokamak which suffers/benefits from most of the features of tokamaks in general, namely the pulsed operation due to plasma induced currents via transformer action, need for a blanket to breed tritium as well as absorb neutrons etc.

Also @Astronuc from your quoted text , I don't understand how SPARC benefits in the toroidal field direction , it says 12 T toroidal field , Iter also has such field strength toroidally, but Iter has a larger size so the curvature bending is less, I can't find the plasma current for Iter so can't compare on that note.
Maybe you can comment on where the potential "upshot" is for SPARC as compared to Iter purely performance wise not considering time/cost etc.?

 

[Astronuc]

Also @Astronuc from your quoted text , I don't understand how SPARC benefits in the toroidal field direction , it says 12 T toroidal field , Iter also has such field strength toroidally, but Iter has a larger size so the curvature bending is less,

Of hand, I don't know. I'd have to look at the dimensions, but my initial guess would be that SPARC should have lower Surface/Volume ratio, so losses should be less. I'd have to look at the plasma temperatures as well in order to determine the confinement pressure which is limited by the mechanical strength of the structure supporting the magnet(s). I recall that 70 atms pressure was a typical limit, but it might have been increased during the last 35 years.

 

[green slime]

As was fleetingly mentioned much earlier in the thread, I'm wondering if the enormous amount of effort (money, materials, research, energy) spent on chasing Nuclear fusion, wouldn't be better employed utilising currently available technologies to solve the energy issues... We are literally talking trillions of USD, man-centuries of research, and exotic materials. Yes, Fusion research is nice. But if the technology is still decades away, is this really a good way to be spending these sums of money now?

 

[Astronuc]

We are literally talking trillions of USD, man-centuries of research, and exotic materials.

Since 1954 through early 2021, the US has spent about $17.1 billion on fusion, or ~$34.1 billion adjusted for inflation. I believe ITER is included in the total funding, but one must peruse the cited references to figure out if that is the case.
http://large.stanford.edu/courses/2021/ph241/margraf1/

But if the technology is still decades away, is this really a good way to be spending these sums of money now?

Previous posts indicate a goal of 4 to 5 years. We'll see in 4 or 5 years.

As for exotic materials, same can be said for fission systems. Many are not so exotic, but the US, UK, EU and Japan, South Korea, and Russia and China, have spent considerable sums on variations of stainless steels and Ni-based alloys (and related alloys), a variety of ceramics, carbon-composites, graphite, and various reactive metal and refractory metal alloys for exotic fission systems, but also for fossil fuel systems. There is a huge array of Ni-based and Co-based alloys for aero-derivative combustion turbines.

Many of the alloys used in nuclear power systems (LWR, CANDU and Gas-cooled reactors) evolved for fossil fuel technology, e.g., austentic and ferritic/martensitic stainless steels. Each of the Gen-IV reactor designs requires some 'exotic' materials.

Ni-based alloys evolved from aerospace technology, e.g., Inconel for the X-plane program. Zirconium-based alloys (e.g., Zircaloys and their successors) are unique to the nuclear industry, although analogs of Zircaloys (Zircadynes) with natural levels of Hf still intact are used in certain applications in the chemical process industry. Similar, Nb, Ta, Mo, W and Re alloys have special applications in a variety of process industries other than nuclear power.

What is unique about nuclear applications is the presence of neutrons and gamma radiation in the operating environment. The radiation, in addition to temperature, affects the alloy microstructure over the course of years, or decades. Neutrons transmute elements (nuclei), sometimes in a beneficial way, but also in deleterious ways. Gammas influence the chemical potentials of atoms in an alloy, and this is an area that is not well-understood.

 

[bhobba]

I'm wondering if the enormous amount of effort (money, materials, research, energy) spent on chasing Nuclear fusion, wouldn't be better employed utilising currently available technologies to solve the energy issues... We are literally talking trillions of USD, man-centuries of research, and exotic materials. Yes, Fusion research is nice.

If Fusion is achieved, the payoff is staggering. It is without a doubt a transformative technology like driverless cars will be when finally perfected. Everything is risk/reward. With such a vast reward, the risk for many looks worth it. For me, it is. But of course, opinions will vary. That's the thing about science/technology/engineering - probably best expressed by this amusing video by Sabine Hossenfelder on Climate Change:


It gives us knowledge and tools. What we do with it is up to us.

Thanks
Bill

 

[green slime]

If Fusion is achieved, the payoff is staggering.

It gives us knowledge and tools. What we do with it is up to us.

Thanks
Bill

If... Undoubtedly. And yet... Research is all fine and dandy. When is it time to have the discussion on the consequences for our society? Researchers gladly fob off morality discussions onto the wider audience, which is gladly ignoring everything but the latest entertainment buzz. Politicians wait until it is a fact. Corporations lobby for their own profiteering.

Once the cat is out of the bag, you cannot put it back. So postponing the discussion until the research is achieved get's us nowhere. If ever achieved, it will be implemented. It will be too late to have the discussion.

What has cheap energy in the form of fossil fuels really meant for life on the planet? If we look beyond the obvious benefits for mankind (for example, increased agricultural output, increased wealth and trade, etc): We see accelerated extinction rates across all wild species, global warming, increased pollution, etc.

Given Joven's paradox, is commercial nuclear fusion really an ambition worth striving for?
https://en.wikipedia.org/wiki/Jevons_paradox

 

[Dale]

When is it time to have the discussion on the consequences for our society? Researchers gladly fob off morality discussions onto the wider audience, which is gladly ignoring everything but the latest entertainment buzz. Politicians wait until it is a fact. Corporations lobby for their own profiteering.

Frankly, I think this is nonsense. The consequences are always part of the discussion, from the beginning. Pretending like such discussions are not happening all the time is ridiculous. How do you think researchers get funding? The consequences are always part of that discussion

What has cheap energy in the form of fossil fuels really meant for life on the planet?

This is not a particularly relevant question in discussing cheap energy in the form of nuclear fusion.

 

[green slime]

Frankly, I think this is nonsense. The consequences are always part of the discussion, from the beginning. Pretending like such discussions are not happening all the time is ridiculous. How do you think researchers get funding? The consequences are always part of that discussion

This is not a particularly relevant question in discussing cheap energy in the form of nuclear fusion.

I see. So where could a layperson read about these discussions?

I'd disagree, with your final statement, but that is your prerogative.

 

[Dale]

So where could a layperson read about these discussions?

For those specific discussions it depends on the granting agency. If it is a government grant in the USA then those are a matter of public record. You can search the agency’s website for a grant of interest and either directly download the information or get the grant number and ask the agency for the grant application. Under the freedom of information act anyone is entitled to get that information.

I'd disagree, with your final statement, but that is your prerogative.

Sure, you can shrug it off that way, but that is hardly persuasive. You tried to make a "guilt by association" argument, which is a logical fallacy. Your argument, as presented above, is that both fossil fuels and nuclear fusion are "cheap energy", so since fossil fuels do all of these bad things then nuclear fusion is guilty of the same bad things by association. This is a logical fallacy.

Of course, as you say, it is your prerogative to hold a fallacious opinion and to simply disagree with people who find your fallacious opinion to be irrelevant. That doesn't mean that your fallacious opinion represents a valid or persuasive argument.

 

[artis]

@green slime I have to say that I don't think you are looking at this from a perspective. Researching fusion doesn't hold us back from implementing fission nor any other source.
Second if we look just for example at the military spending for example the money spent in Afghanistan which is trillions then on that background fusion is like a poor kid's birthday party.

Not to mention there are countless far more useless projects out there taking up more money.

Also one could argue which is more cost efficient in the long time, to not have CO2 neutral energy sources and invest billions more like trillions in various CO2 limiting techniques (carbon filtration from atmosphere, cloud seeding etc) or forget about CO2 filtration and simply lower it's production in the first place to a level which is manageable. If we wish to attain the second we need to invest those trillions into finding new energy sources, one of them might be fusion.

Truth be told we will spend trillions either way , whether for climate crisis and CO2 mitigation or start now and invest them into new energy sources.

 

[russ_watters]

If Fusion is achieved, the payoff is staggering. It is without a doubt a transformative technology like driverless cars will be when finally perfected. Everything is risk/reward. With such a vast reward, the risk for many looks worth it. For me, it is. But of course, opinions will vary.

Well, yeah, in my opinion the "vast reward"/"staggering payoff" is very much in doubt. I really don't understand why people think the payoff is a given. To me it seems more likely at this point that even if fusion can be made to work it will still be a bust.

So can you explain what this "vast reward" is and on what basis you are so confident in it?

 

[Dale]

To me it seems more likely at this point that even if fusion can be made to work it will still be a bust.

Interesting. Why do you think that?

 

[russ_watters]

Interesting. Why do you think that?

I think it will be expensive.

 

[Dale]

I think it will be expensive.

I don’t know for sure the arguments on the other side, but I think that the idea is that your fixed costs will indeed be high but your variable costs will be low.

 

[Astronuc]

Interesting. Why do you think that?

I'm not answering for Russ, but with respect to "To me it seems more likely at this point that even if fusion can be made to work it will still be a bust," 1) one would have to define what "to work" means, and 2) even if it made to work, there is the matter of the supply chain infrastructure.

Unless "made to work" means beyond a marginal net energy generation, the process may be uneconomical, and in the case of point 2), the fuel supply (copious quantities of deuterium and/or tritium) may render the process uneconomical. I can't find the price for D₂ gas, which is probably more than $1000/kg, and T₂ is considerably more expensive.

Pricing from one supplier, a 10 or 25 l, would cost about $158K/kg for 10L to $134 K/kg for 25 L. Buying in bulk, e.g., railroad tank car, would be considerably less expensive. Pricing such fuels for fusion systems will attract attention.

Edit/update: I corrected the first work in the second paragraph from 'If' to 'Unless'. A marginal gain in net energy over input would most likely uneconomical.

 

[russ_watters]

I don’t know for sure the arguments on the other side, but I think that the idea is that your fixed costs will indeed be high but your variable costs will be low.

Sure. And for fission, hydro, solar and wind too. The question is, how high?

Fusion is really difficult to make work. Difficult typically means expensive. And over the past 50 years we've found out it is more difficult than expected. More difficult typically means more expensive.

A secondary issue is that fusion will not play a role in the upcoming climate change fight unless we lose. If we win the climate change fight, fusion will be an additional energy transition that no longer has an urgent need. If we lose, and fusion becomes viable then, then fusion I will be an awesome, transformative technology that arrived too late to save New York.

 

[gmax137]

I don't recall ever seeing a full-plant design concept. I mean aside from the particle physics and magnets. How do you get the heat out? Do you boil water and use a Rankine steam plant to turn the generator?

Unlike a fission plant, it seems to me you wouldn't need the containment, or all of the core-flooding and decay heat removing safety systems (and their supporting systems, emergency diesels, safety grade ultimate heat sink, redundant controls, on and on). Not only avoiding those construction costs, but also the monthly surveillance testing on all that stuff throughout the plant life.

With no fissionable materials on site, you don't need a huge security staff.

I can't find the price for D2 gas, which is probably more than $100/kg, and T2 is considerably more expensive.

What does that translate into in $/MW-hr? And how much energy does it take to create the "fuel grade" D2?

 

[bhobba]

So can you explain what this "vast reward" is and on what basis you are so confident in it?

The fuel is virtually limitless here on earth, with little or no pollution.

But I take your point. Engineers, economists, actuaries etc., would need to do a detailed cost-benefit study comparing it to other energy sources available when and if it eventually happens. So a better way of expressing it would be that many people think it can be a transformative technology.

On second thought, it is good you raised it. I am critical of aspirations like carbon neutral by 2030 without a detailed cost-benefit analysis. Only in that way can an informed decision be made by the citizens in a democracy. Further comment would be political. All I will say is I have seen elections lost here in Aus because politicians did not do that.

Thanks
Bill

 

[russ_watters]

I don't recall ever seeing a full-plant design concept. I mean aside from the particle physics and magnets. How do you get the heat out? Do you boil water and use a Rankine steam plant to turn the generator?

Well it hasn't been invented yet, but there are some speculative schematics out there about how it might work:
https://en.wikipedia.org/wiki/DEMOnstration_Power_Plant#Technical_considerations

Ultimately, yes, it'll spin steam turbines.

Unlike a fission plant, it seems to me you wouldn't need the containment, or all of the core-flooding and decay heat removing safety systems (and their supporting systems, emergency diesels, safety grade ultimate heat sink, redundant controls, on and on).

It wouldn't need those systems per se, but given the exceptionally extreme, difficult to maintain conditions of the reactor, the extra systems required for fusion may be more complex than for fission. It also points to a potential for fusion power to be dangerous and unreliable.

 

[russ_watters]

The fuel is virtually limitless here on earth, with little or no pollution.

That's nice, but the same can be said for solar and wind. And, depending on your framing criteria, fission too.

But I take your point. Engineers, economists, actuaries etc., would need to do a detailed cost-benefit study comparing it to other energy sources available when and if it eventually happens. So a better way of expressing it would be that many people think it can be a transformative technology.

On second thought, it is good you raised it. I am critical of aspirations like carbon neutral by 2030 without a detailed cost-benefit analysis.

Yes, and it's really hard to accurately estimate the cost of something that hasn't been invented yet. Aspirational technologies are always championed by optimists. Sometimes they are right, often they are not.

 

[PeterDonis]

I think that the idea is that your fixed costs will indeed be high but your variable costs will be low.

That is my understanding as well. For fission power, fuel costs are a much smaller percentage of total life cycle costs, and initial capital investment is a much larger percentage, as compared with chemical fuels. This would be expected to be even more extreme in the case of fusion since the energy yield per unit mass of fuel is larger for fusion than for fission. So even if the cost per unit mass of fuel is several orders of magnitude higher than for chemical fuels, the impact of fuel costs on total life cycle cost can still be competitive. Also, fuel costs would be expected to decrease if fusion power became widespread and there was a large economic incentive to find more efficient ways of obtaining fusion fuels. (The same can be said for fission fuels, of course.)

That high initial capital investment, of course, is what has made fission power much less attractive in countries like the US, where there is a high risk of not recovering that investment for various reasons that are too long to fit into the margin of this post. But if those risks were lower, the economic case for making that high initial investment would be stronger. At least if appropriate attention is paid to the fact that the time horizon of the investment is so long--the plant would be expected to operate for many decades and the net present value of the investment would have to be assessed accordingly. One of the major risks with that is that we humans in general don't seem to be very good at properly evaluating investments with such long time horizons.

 

[Astronuc]

I don't recall ever seeing a full-plant design concept. I mean aside from the particle physics and magnets. How do you get the heat out? Do you boil water and use a Rankine steam plant to turn the generator?

Once upon a time (late 1970s, early 1980s), there was a STARFIRE commercial fusion reactor concept.

STARFIRE reference commercial tokamak fusion power reactor design​

https://www.osti.gov/biblio/6187212...ommercial-tokamak-fusion-power-reactor-design

STARFIRE: a commercial tokamak fusion power plant study​

Volume I, Chapter 1-11, ANL/FPP-80-1 - https://www.osti.gov/biblio/6679109-starfire-commercial-tokamak-fusion-power-plant-study
Volume II, Chapter 12-23 and Appendices - https://www.osti.gov/biblio/6633213-starfire-commercial-tokamak-fusion-power-plant-study

From Volume I, 2.3.1 Reactor Configuration (page 46 of 875 in pdf).

The reactor delivers 1200 MWe to the grid in addition to providing 240 MWe for recirculating power requirements. The reactor operates with a continuous plasma burn and develops 4000 MW of useful thermal power.

A lot of wishful thinking went into that.

And there is this - https://fti.neep.wisc.edu/fti.neep.wisc.edu/ncoe/timeline/mfe/US22b1.html

and more recently - https://www.engr.wisc.edu/news/uw-m...or-fusion-energy-research-at-wendelstein-7-x/

And that is just one university. There are other university programs, e.g., Princeton, MIT, . . . .

A lot has happened since then, and the funding situation for fusion research is considered volatile for any given institution. U of Wisconsin was kind of a leader until they weren't, and it was not unique to UW.
Archived site for U of Wisconsin, Fusion Technology Institute.
https://fti.neep.wisc.edu/fti.neep.wisc.edu/index.html
from: https://energy.wisc.edu/research/uw...versity-wisconsin-fusion-technology-institute

Since then, the cost of raw materials has increased. I attended separate meetings with AREVA/Framatome, GE (GEH) and Westinghouse back around 2000 during which presentations were made on their next generation (Gen-III+) LWRs. An estimated cost was about $1 billion per unity. A few years later it was about $2 billion per unit, then by the end of the decade about $5 billion to $7 billion, and that is with government guarantees and subsidies. As of about 2019/2020, "Units 1–2: $8.87 billion (1989 USD) ($16.2 billion in 2019 dollars) Units 3–4: $25 billion (estimated)", or about $12.5 billion per unit, and they are not quite finished. Similarly, the costs for the EPR in Europe, Olkiluoto 3 and Flamanville 3, were WAY over budget. Both Westinghouse and AREVA were driven into bankruptcy (for these plants and other problems) and were restructured. Ref: https://en.wikipedia.org/wiki/Vogtle_Electric_Generating_Plant

Unlike a fission plant, it seems to me you wouldn't need the containment, or all of the core-flooding and decay heat removing safety systems (and their supporting systems, emergency diesels, safety grade ultimate heat sink, redundant controls, on and on). Not only avoiding those construction costs, but also the monthly surveillance testing on all that stuff throughout the plant life.

With no fissionable materials on site, you don't need a huge security staff.

There is no fission, unless they put a breeding blanket of ²³⁸U on the periphery. There have been fusion-fission hybrid concepts. Even without fission, one may have large quantities of tritium both as a fuel and as a product. For d+d -> t + p, roughly about 50% of the time. That has to be contained somehow. They could also breed T in blankets of Li, which requires a secured facility.

The containment building has to withstand any hypothetical accident, e.g., a magnet quench, or other fault. For example, Superconducting Magnet Explosion
https://ehs.berkeley.edu/news/superconducting-magnet-explosion

A 9.4 Tesla superconducting magnet, used for mass spectroscopy in a campus laboratory recently suffered a catastrophic failure. The incident was apparently caused by over-pressurization and failure of the liquid helium (LHe) chamber. Although there were no injuries because the incident occurred during off-hours, the potential for significant injury due to the venting of LHe into the facility was present. There was also significant damage to equipment associated with the magnet.

A magnet achieves superconductivity (zero resistance to electrical current) when it is bathed in LHe. If for some reason the magnetic coil starts to resist the electrical current, it heats up, causing an explosive expansion of the LHe. This expansion of gas is vented through a large bore vent, sealed by a membrane called a "rupture disk". This process of explosive venting is known as a "quench".

It is a concern but on a larger scale for a power reactor system.

What does that translate into in $/MW-hr? And how much energy does it take to create the "fuel grade" D2?

I think I was editing my post when you quoted. I had raised my cost estimate for D₂ to more than $1000/kg.

I'll have to do some calculations, and look into the second question. Obviously, the Canadians produce copious amounts of deuterium for the heavy water CANDU reactors.

As an undergrad and graduate student, I was keen on fusion and fast reactor technologies. Professionally, I ended up working mostly in LWR technology (fuel and core components, and materials) and some special nuclear applications.

 

[artis]

As an undergrad and graduate student, I was keen on fusion and fast reactor technologies. Professionally, I ended up working mostly in LWR technology (fuel and core components, and materials) and some special nuclear applications.

I guess it's like that old saying "if your not a socialist in your 20's you have no heart but if your not a capitalist by the time you are 30 you have no brain..."
Fusion has that dream like attraction to it much like many alternative energy ideas have, in reality I would tend to agree with what has been said here by @russ_watters and others that the high cost and complexity might mean fusion instead of being the "workhorse" of energy will be just "another horse" or "another brick in the wall".

My personal thoughts are that while the most popular Soviet derived design "tokamak" is rather simple in it's basic idea, the complexity of the auxiliary equipment needed to keep things in working order is very high.
The need for cryostats and shielding, RF heating, a giant transformer etc makes everything expensive and huge.
Not to mention the energy out VS energy in, unless you get more than twice out I fail to see how one can have a return on investment if for example you get 1.2...something out vs having to put exactly 1 back in.
Also the lifetime of the equipment is in question due to the high neutron flux. I don't know how long they estimate the tokamak to survive but I myself would think it would be shorter than the lifetime of a mature fission reactor like the PWR.

 

[green slime]

Awesome thanks to Russ_watters for articulating better than I could, some of my concerns.

 

[Astronuc]

The UK Atomic Energy Authority (UKAEA) has opened its new nuclear Fusion Technology Facility at the Advanced Manufacturing Park in Rotherham, South Yorkshire.
https://www.world-nuclear-news.org/Articles/UKAEA-opens-new-fusion-research-centre

The Fusion Technology Facility will house a range of test rigs, including the Combined Heating and Magnetic Research Apparatus (CHIMERA) device, which is being designed and built by Jacobs and Tesla Engineering Limited. The CHIMERA test rig is said to be the only device in the world that has the ability to test prototype components in an environment that simulates the conditions inside a fusion power plant. Within the UKAEA facility, component prototypes will be subjected to a combination of high heat and magnetic field within a vacuum environment, as well as thermal cycling.

Meanwhile, Tokamak Energy of the UK announced it has demonstrated a transformative magnet protection technology that improves the commercial viability of fusion power plants, delivering higher performance than alternative magnet systems. It said results from the latest tests validate a revolutionary approach to scaling up high-temperature superconducting (HTS) magnets, which are highly resilient to plasma disruptions.

https://www.world-nuclear-news.org/Articles/Tokamak-Energy-develops-new-magnet-protection-tech

 

[Astronuc]

Completion of unit 4 of the Khmelnitsky nuclear power plant in Ukraine will be accelerated by the use of major plant components in storage since the construction of new reactors at VC Summer in the USA was cancelled. The head of Energoatom toured Westinghouse warehouses to inspect the condition of the AP1000 components.

https://www.world-nuclear-news.org/Articles/Components-for-Summer-headed-to-Ukraine

That's one way to recover some of the cost.

 

[artis]

https://en.wikipedia.org/wiki/Khmelnytskyi_Nuclear_Power_Plant

It seems the backbone to that station are two VVER 1000 units built back in the USSR, two more VVER blocks were intended but never finished after the dissolution of the USSR, apparently they wanted to finish the original unfinished VVER's but for some reason terminated the deal with the Russians. So I guess they are now pursuing to finish the blocks with the help of a Korean firm. What I don't understand is which type of reactor are they trying to finish there?
Given they have started VVER are they now fitting an AP1000 in that frame?
It seems so

 

[Astronuc]

Given they have started VVER are they now fitting an AP1000 in that frame?

Outside of the core, PWR components are fairly generic, except for key dimensions, e.g., main/primary piping dimensions. Otherwise, there can be some adaptation. The balance of plant is essentially agnostic with respect to the core geometry. The steam generators do not care from where the heat originates, but one would try to match the heat flux and change in enthalpy in primary and secondary systems - within reasonable tolerances.

On the other hand, the pressure vessel head, with control elements, and core internals are very specific to the core/fuel assembly designs.

 

[gmax137]

What I don't understand is which type of reactor are they trying to finish there?

From the link
https://www.world-nuclear-news.org/Articles/Components-for-Summer-headed-to-Ukraine

Kotin signed a Memorandum of Cooperation with Patrick Fragman, Westinghouse president and CEO, last week which foresaw the completion of Khmelnitsky 4 "using AP1000 technology." The reactor started out as a VVER design in 1987 but construction stalled at 28% completion.

I'd like to know more about this too.

 

[artis]

Well given the 4th block was only 28% completed maybe they will buy the whole AP1000 auxiliary as well as the core vessel. I understand the plant in US was canceled so everything is up for grabs including reactor vessel.
But I guess we need more information to say for sure
https://www.foronuclear.org/en/updates/news/ukraine-will-build-westinghouse-reactors/

Based on this and other sources I suspect that they will finish the 3, 4 blocks with VVER and use some AP1000 parts while then they will go and build additional reactors on the site which will then be solely AP1000 by design.

 

[Rive]

Third and fourth block 'completion' a few years ago:

source

Top view
Some more pictures here

The pictures are from the time of the previous attempt of project revival.

I would say there is nothing there yet in the fourth block other than some concrete. I won't even think about 'mixing it up' - just adjust the building and go on with a complete AP1000

The status of the third block might suggest the possibility of some tweaking, but even there it might be better to wait for some components (for completing the VVER) or cutting it back first (and then go on with AP).

The building clearly requires some 'cutting back', though...

 

[green slime]

"How close is nuclear fusion power?"

 

[Astronuc]

"How close is nuclear fusion power?"

She is correct. If I recall correctly, back when I studied fusion, we were looking for a Q ≥ 20 to have plant produce net power. The power conversion (plasma energy to useful electrical energy) part was critical.

 

[bhobba]

She is correct. If I recall correctly, back when I studied fusion, we were looking for a Q ≥ 20 to have plant produce net power. The power conversion (plasma energy to useful electrical energy) part was critical.

I saw it yesterday and thought, of course. It is easy to get carried away with the potential of fusion and 'forget' things like that.

Thanks
Bill

 

[Astronuc]

The power conversion (plasma energy to useful electrical energy) part was critical.

The three methods for transformer the plasma (thermal) energy to electric current are:
1) traditional approach of transforming thermal (heat) energy to mechanical (e.g., steam or gas turbine) to electrical (generator)
2) induction, in which the plasma expands against the magnetic field to induce a current
3) direct energy conversion through charge separation, where the electrons flow through the load to recombine with the positive charges (H or He nuclei).

Each has it's set of technical challenges.

 

[artis]

The three methods for transformer the plasma (thermal) energy to electric current are:
1) traditional approach of transforming thermal (heat) energy to mechanical (e.g., steam or gas turbine) to electrical (generator)
2) induction, in which the plasma expands against the magnetic field to induce a current
3) direct energy conversion through charge separation, where the electrons flow through the load to recombine with the positive charges (H or He nuclei).

Each has it's set of technical challenges.

Wouldn't there also be the option for a fourth way if some of the designs were to ever gain net energy , like converting produced heat to steam/gas turbine/generator + taking the plasma exhaust in the form of hot gas and introducing that directly to a turbine.
Like if for example anyone of the fusion ramjets worked as they were researched in the decades ago I could see that this would be a design capable of producing both heat as well as exhaust gas directly from fusion plasma as it recombines back to gas.
Somewhat similar to direct energy conversion only instead of catching the still hot plasma separated charges onto electrodes one allows for it to cool to recombination and uses the hot gas phase to drive a turbine.

 

[Astronuc]

taking the plasma exhaust in the form of hot gas and introducing that directly to a turbine.

No, the plasma operates in a near vacuum, with very low atomic density (~10¹⁴ /cm³). The high pressure, due to the high temperature, is accommodated by the confining magnetic field. Allowing for 'plasma exhaust' mean loss of fuel and heat, which then has to be made up through more heat input and injecting more fuel.

For energy transport, one also needs mass and momentum flow.

 

[Astronuc]

Germans asked to keep reactors in operation
15 October 2021
https://www.world-nuclear-news.org/Articles/Germans-asked-to-keep-reactors-in-operation

Germany's phase-out of nuclear energy will only lead to the country missing its 2030 carbon emissions target, 25 leading foreign and German environmentalists, journalists and academics have written in an open letter to the German public. They call on German politicians to be "brave enough" to change legislation to at least postpone the shutdown of the country's reactors.

PWRs Unterweser, Brokdorf, Grohnde and Phillipsburg 2 and BWRs Gundremmingen B & C are among the most efficient NPPs (LWRs) in the world.

 

[anorlunda]

Germans asked to keep reactors in operation
15 October 2021
https://www.world-nuclear-news.org/Articles/Germans-asked-to-keep-reactors-in-operation

PWRs Unterweser, Brokdorf, Grohnde and Phillipsburg 2 and BWRs Gundremmingen B & C are among the most efficient NPPs (LWRs) in the world.

I recall an earlier thread where someone said that Germany was also paying money to coal plants to prevent them from shutting down and the coal companies from going out of business. But I can't find the link.

 

[Rive]

That was me I think.
link

 

[artis]

Following the accident at the Fukushima Daiichi plant in Japan in March 2011, the government of Chancellor Angela Merkel decided it would phase out its use of nuclear power by the end of 2022 at the latest. Prior to the accident, Germany was obtaining around one-quarter of its electricity from nuclear power.

Ehh fear, where would we be without you... better off I'd say!

 

[Astronuc]

I don't want to go offroad with my rambling here but EU is also to blame, their scare from nuclear began even before Fukushima. Back in the early 2000, they literally pushed Lithuania to abandon their two Ignalina 1500MWe reactors which were operational and had years to go.
That was part of their deal with joining the EU, closing the two RBMK 1500 blocks. The simple reasoning was something like this - they were afraid of anything Russian and Chernobyl related, a very unscientific stance.
Even though the RBMK's after Chernobyl were retrofitted and monitored more closely than a top security federal prison. The Lithuanian reactors were operating without flaws, they were good to go.
When they operated they provided some 98% of all energy for that country, they were the greenest on planet topping France. My country was second after neighboring Lithuania but only thanks to our huge reliance on Hydro.

The effort to shutdown RBMKs and VVER-440s began mid-1990s after the breakup of the Soviet Union and dissolution of Warsaw Pact. It was driven by US and EU policy. In the US, the DOE established the International Nuclear Safety Program (https://insp.pnnl.gov/ ), which was basically finished by around 2003/2004. DOE stopped supporting the website in 2004.

The main concern of US and EU authorities with respect to RBMKs and VVER-440s was the lack of a containment structure and the inability to contain the consequences of a loss of coolant accident (LOCA) or reactivity insertion accident (RIA), i.e., a core disruptive accident. Vessel embrittlement (somewhat related to LOCA) is another concern.

Another concern with respect to the RBMK is the positive void coefficient, which was a critical factor in the Chernobyl accident. "Reactors cooled by boiling water will contain a certain amount of steam in the core. Because water is both a more efficient coolant and a more effective neutron absorber than steam, a change in the proportion of steam bubbles, or 'voids', in the coolant will result in a change in core reactivity. The ratio of these changes is termed the void coefficient of reactivity. When the void coefficient is negative, an increase in steam will lead to a decrease in reactivity."
https://www.world-nuclear.org/infor...-power-reactors/appendices/rbmk-reactors.aspx

Preparations for the construction began in 1974. Field work began four years later. Unit 1 came online in December 1983, and was closed on December 31, 2004. Unit 2 came online in August 1987 and was closed on December 31, 2009 . . .

https://en.wikipedia.org/wiki/Ignalina_Nuclear_Power_Plant

NPPs were designed for 40-year lifetimes. Many operating NPPs (mostly LWRs) have had their operating licenses extended, but some have been shutdown prematurely for a policy (including regulatory) and/or economic reasons.