# The Nuclear Power Thread

berkeman
Mentor
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
anorlunda
Staff Emeritus
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
Staff Emeritus
Science Advisor
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
Staff Emeritus
Science Advisor
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.

bhobba
Astronuc
Staff Emeritus
Science Advisor
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
Staff Emeritus
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."

bhobba, etudiant, artis and 1 other person
etudiant
Gold Member
Cruel, but true.

bhobba
Astronuc
Staff Emeritus
Science Advisor
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.

bhobba and PeterDonis
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
Staff Emeritus
Science Advisor
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.

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
Staff Emeritus
Science Advisor
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.

green slime, Imager, bhobba and 3 others
bhobba
Mentor
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 and Astronuc
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
Mentor
2020 Award
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.

bhobba and russ_watters
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
Mentor
2020 Award
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.

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bhobba and Astronuc
@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.

bhobba and Astronuc
Mentor
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?

bhobba, Dale and Bystander
Dale
Mentor
2020 Award
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?

Mentor
Interesting. Why do you think that?
I think it will be expensive.

Dale
Mentor
2020 Award
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
Staff Emeritus
Science Advisor
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. Last edited: bhobba, Dale and russ_watters Mentor 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. bhobba and Dale gmax137 Science Advisor 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?