The Nuclear Power Thread

[russ_watters]

Seems like China has accelerated its Nuclear energy program, planning 150 new reactors

https://asiatimes.com/2021/11/china-goes-big-uk-goes-small-on-nuclear-power/

China gets it, and they don't have to worry about pesky things like public opinion and lawsuits.

Last night I accidentally watched a ted talk by a professional environmentalist who gradually over a decade+ of his career came around to recognizing that renewables alone can't save the planet and nuclear needs to be a significant part of the solution. But if it took him that long, with that much effort invested, what hope is there for the general public, who puts much less effort into it, to come around?

 

[BWV]

well perhaps the timeline is the same - the technological advances in batteries and materials that would allow an all solar / wind grid vs. getting through the politics of building enough new nuclear plants

although I do think that gas + solar + wind combined with electric light vehicles is good enough

 

[Astronuc]

Executive Summary of the eVinciTM Micro-Reactor Deployment in Mining and Remote Canadian Communities Feasibility Study

https://www.brucepower.com/wp-conte...houseBPMicroReactor_ExecutiveSummary_R000.pdf

Micro-Reactor Deployment in Remote Communities is under serious consideration in many area.

https://www.nrcan.gc.ca/our-natural.../small-modular-reactors-smrs-for-mining/22698

 

[BWV]

Executive Summary of the eVinciTM Micro-Reactor Deployment in Mining and Remote Canadian Communities Feasibility Study

https://www.brucepower.com/wp-conte...houseBPMicroReactor_ExecutiveSummary_R000.pdf

Micro-Reactor Deployment in Remote Communities is under serious consideration in many area.

https://www.nrcan.gc.ca/our-natural.../small-modular-reactors-smrs-for-mining/22698

How long until these are on the market?

Rolls Royce is also developing small reactors
https://www.rolls-royce-smr.com/press/rolls-royce-smr-shortlists-locations-for-first-factory

 

[Astronuc]

How long until these are on the market?

Hard to say. It could be 5+ years for a demo system. I'm not sure how far along the licensing process has progressed. I know of some demo plants being designed, and I know of one in the planning stage, with request for proposal coming out within the year.

 

[anorlunda]

US regulators will certify first small nuclear reactor design​

https://arstechnica.com/science/202...l-certify-first-small-nuclear-reactor-design/

Wow, I was not expecting that. Congratulations NuScale,

Edit: I looked up some details.

https://mc-67443a0a-0a3b-4888-8568-...136b81c&hash=665C75BFFFD9E0D06D1FEAFD100BDB48

There are several key features of the NuScale plant that collectively distinguish it from the many other SMRs being developed today and contribute to its simplicity and flexibility.
• Compact size. The nuclear steam supply system, including containment, can be entirely prefabricated off site and shipped by rail, truck or barge to the site. This reduces construction time due to parallel fabrication considerations and reduces overall schedule uncertainty due to the reduced amount of on-site construction activities.
• Natural circulation cooling. Natural circulation operation and integral design eliminates pumps, pipes, and valves in the primary system and hence the maintenance and potential failures associated with those components, while also reducing house load.
• Triple Crown of Safety. The NuScale plant, with its innovative design is able to safely shut down and self-cool with no operator action, no AC or DC power, and no additional water for an unlimited period of time.
• Dedicated power trains. Because each power module, including the power conversion system, is independent of other modules, each module can be shut down while other modules continue to operate. This feature allows for continuous plant output and greatly enhances the overall reliability of output power.

 

[russ_watters]

US regulators will certify first small nuclear reactor design​

https://arstechnica.com/science/202...l-certify-first-small-nuclear-reactor-design/

Wow, I was not expecting that. Congratulations NuScale,

Edit: I looked up some details.

I've heard their reactors aren't going to be cheap, but hopefully they get cheaper as they produce more. Still, reduced "schedule uncertainty" and shorter construction timeliness is still an economic advantage. It means they start making money sooner and pay back faster.

 

[anorlunda]

I've heard their reactors aren't going to be cheap, but hopefully they get cheaper as they produce more.

In coming years, our standard of what is cheap is likely to change a lot.

I just bought gas for $4.50, thinking that was cheap.

I was surprised because I just expected NRC to sit on their hands and never approve anything ever again.

 

[gmax137]

It means they start making money sooner and pay back faster.

I think this is the selling point. Each 77 MWe module can be operating (ie, selling power) while the subsequent modules are being built/installed.

 

[anorlunda]

They probably don't do this, but it would be neat if all initial fueling and refueling could happen in the factory under controlled conditions. Refueling could be combined with inspection.

But the cost and risks of transporting those modules back and forth with fresh or spent fuel would probably shoot that idea down.

EDIT: OTOH, with 12 modules per site, an automated refueling/inspection machine could be kept busy handling one module every 2 months.

 

[artis]

I wonder how do small cores compare in neutron efficiency with larger cores. In terms of minimum necessary enrichment and fuel burnup.

Control of small cores might be easier though.

 

[anorlunda]

I wonder how do small cores compare in neutron efficiency with larger cores. In terms of minimum necessary enrichment and fuel burnup.

Control of small cores might be easier though.

I don't know that answer. But small cores must also have fewer opportunities to control shape by placement of old/new/high enrichment/low at different radial positions. I don't know if all bundles are replaced at refueling.

I also wonder if fuel costs as a percent of total costs are higher/lower/same compared to other reactors.

I also wonder about load following, and about the manpower and training for operations.

I also wonder about finding multiple sources for fuel bundles.

Modular reactors would be a new ball game, there may be many secondary factors that influence total competitiveness.

 

[Astronuc]

They probably don't do this, but it would be neat if all initial fueling and refueling could happen in the factory under controlled conditions.

I believe that there was some consideration on delivering the reactors with the initial fuel loading intact, but I don't know of that is currently the plan. One concern in transporting fuel horizontally (on its side) is the loading on the bottom fuel assemblies and the control systems. The route would have to be carefully planned to avoid bumps and shocks. When fuel is shipped, there are accelerometers on inner and outer containers, but they would only establish a threshold (go/no-go), since they are set to trigger at a given acceleration. There may be more sophisticated systems that allow a load/acceleration spectrum to be developed.

Shipping irradiated fuel would be more problematic. NuScale plants have a refueling station. I'm not sure the current fuel cycle strategy, but one would expect between 1/3 to 1/2 of the core to be exchanged. One operating plan was based on 24-month cycles (700-730 EFPD), so that every other month, one unit would be taken our of service while the other 11 modules would continue to operate. Everything is fine until one or more fuel rods leak, in which case, the reactor system would have to be flushed prior to opening the reactor vessel and removing the fuel to be discharged.

Refueling could be combined with inspection.

That is typically the case.

I've heard their reactors aren't going to be cheap, but hopefully they get cheaper as they produce more. Still, reduced "schedule uncertainty" and shorter construction timeliness is still an economic advantage. It means they start making money sooner and pay back faster.

In theory, the plant is smaller than a comparable single unit with the same output, but each of 12 modules requires a steam generator, turbine and electrical generator. The plant might use less steel and concrete, but it uses more components in the power conversion system.

On the other hand, a small issue with one reactor should not affect the output of the others, and in theory, the plant capacity factor (CF) should be greater with 11 of 12 modules continuing to operate.

They have increased the generation capacity of the modules since the initial design.

 

[Astronuc]

I wonder how do small cores compare in neutron efficiency with larger cores. In terms of minimum necessary enrichment and fuel burnup.

Small cores tend to be less efficient neutronically, due to leakage from the ends and circumferential surface. I know of one design that leaked neutrons to the extent that the steam generators and containment structure became radioactive.

Neutron leakage may be partly alleviated with neutron reflectors, usually stainless steel, or natural or depleted fuel assemblies, and axial blankets.

 

[anorlunda]

each of 12 modules requires a steam generator, turbine and electrical generator.

I read that, but I don't see why that is necessary. Historically, it was common to have many boilers feeding a common steam header.

Turbines and generators have no problems running at any fraction of rated power. Of course, it is true that availability is higher with multiple independent components, but costs are higher too. Any power plant with any source of steam generation, could have n smaller independent turbine/generators, but the designers haven't chosen to do that.

 

[Dale]

I read that, but I don't see why that is necessary. Historically, it was common to have many boilers feeding a common steam header.

I don’t think that it is necessary, but it is in keeping with their “redundant array” design philosophy. I think that is why they recommend it

 

[anorlunda]

I don’t think that it is necessary, but it is in keeping with their “redundant array” design philosophy. I think that is why they recommend it

You may be correct. But that is a very expensive way to purchase more reliability. As this table shows, cost in $/kW is a strong function of unit size. Twelve 60 MW turbine generators may cost 3-4 times as much as one 720 MW turbine generator.

 

[Astronuc]

I read that, but I don't see why that is necessary. Historically, it was common to have many boilers feeding a common steam header.

Turbines and generators have no problems running at any fraction of rated power. Of course, it is true that availability is higher with multiple independent components, but costs are higher too. Any power plant with any source of steam generation, could have n smaller independent turbine/generators, but the designers haven't chosen to do that.

Putting two or more 'modules' on one steam generator could be problematic when taking one module off-line. One would have to isolate the feed from one module, and the steam turbine would operating below optimal capacity.

I don't believe one would want to connect two modules to one turbine, which if one module was offline, the turbine would have 50% reduction in thermal input. So then does one connect 3, 4, or 6 modules of 12, which would mean 4, 3 or 2 turbines. There are some PWRs that have twin turbine trains, but most have a single turbine.

The idea of fully separate modules is that they generate fully independent through to the generator output.

 

[gmax137]

Does NuScale have a contract-signed customer yet? It would be really interesting to see the bid evaluation between a NuScale twelve-pack and a conventional 900-1100 MWe nuclear plant. Of course, the chances of such an eval being public are slim.

 

[Astronuc]

Does NuScale have a contract-signed customer yet? It would be really interesting to see the bid evaluation between a NuScale twelve-pack and a conventional 900-1100 MWe nuclear plant. Of course, the chances of such an eval being public are slim.

01 February 2022 - Field activities at the Carbon Free Power Project (CFPP) site have been completed in what Utah Associated Municipal Power Systems (UAMPS) has described as a major milestone for the project to build a NuScale small modular reactor plant at the Idaho National Laboratory.
https://www.world-nuclear-news.org/Articles/Fieldwork-completed-in-milestone-for-UAMPS-SMR

As far as I know, UAMPS was teaming with Energy Northwest (WA) in developing a pilot plant using 6 modules of 77 MWe.

UAMPS expects to build six 77 MWe NuScale Power Modules - renamed VOYGR by NuScale late last year - at the Idaho National Laboratory site. The pressurised water reactor, with all the components for steam generation and heat exchange incorporated into a single unit, is the first SMR to receive NRC design approval.

Formal engagement of a plant operator is being negotiated, UAMPS said. Other work under way includes developing cost estimates, developing topic reports for submission to the NRC, continuing work on the standard plant design, and developing a supply chain pricing analysis. NuScale and Fluor are working on power module manufacturing trials and steam generator fabrication.

UAMPS is a political subdivision of the State of Utah that provides wholesale electric-energy, transmission, and other energy services to community-owned power systems throughout the Intermountain West region of the USA. Its members are located California, Idaho, Nevada, New Mexico and Wyoming as well as in Utah.

Last year, UAMPS was discussing a 12 unit, 600 MWe plant, or 50 MWe per module.
https://www.uamps.com/nu-scale-modular-reactor

https://www.neimagazine.com/news/newsuamps-downsizes-nuscale-smr-project-8937920

 

[gmax137]

It has been a while since I looked at the NuScale plant. Natural circulation drives the primary side flow through the "helical steam generators" which are located within the module containment shell. So each reactor has its own SGs. The steam exits the module and drives the main turbine/generator. External condenser and feed pumps return the feedwater to the module.

I did not see a description of the turbine/generator so I'm not sure if that is shared or if each module has its own.

Fuel Standard LWR fuel in 17 x 17 configuration, each assembly 2 meters (~ 6 ft.) in length; up to 24-month refueling cycle with fuel enriched at less than 5 percent

https://www.nuscalepower.com/technology/technology-overview

 

[BWV]

South Korea recommitting to nuclear

https://www.neimagazine.com/news/ne...-rapid-rebuilding-of-nuclear-industry-9849898

 

[Astronuc]

"NuScale Plant Design Overview", August 2012
https://www.nrc.gov/docs/ML1221/ML12216A392.pdf

Status Report on the NuScale Module Developed in the Modelica Framework
https://inldigitallibrary.inl.gov/sites/sti/sti/Sort_20117.pdf

The initial plant module was 160 MWt/50 MWe. The VOYGR system uses 250 MWt/77MWe modules.
https://www.nuscalepower.com/about-us/faq

https://www.power-eng.com/nuclear/report-claims-serious-problems-with-proposed-nuscale-smr/#gref

 

[etudiant]

"NuScale Plant Design Overview", August 2012
https://www.nrc.gov/docs/ML1221/ML12216A392.pdf

Status Report on the NuScale Module Developed in the Modelica Framework
https://inldigitallibrary.inl.gov/sites/sti/sti/Sort_20117.pdf

The initial plant module was 160 MWt/50 MWe. The VOYGR system uses 250 MWt/77MWe modules.
https://www.nuscalepower.com/about-us/faq

https://www.power-eng.com/nuclear/report-claims-serious-problems-with-proposed-nuscale-smr/#gref

Interesting that the power rating is up 50%, have to think that reduces the safety margin of the passive cooling setup.

 

[Astronuc]

The downside of nuclear energy (and the extractive industries) that folks don't like to discuss.
https://www.propublica.org/article/new-mexico-uranium-homestake-pollution

I remember a story from the 1970s about contamination where homes in Grand Junction, Colorado, were built with contaminated uranium mine tailings. I believe the tailing were added to the concrete or cinder blocks. The homes were well above normal background.

 

[artis]

The downside of nuclear energy (and the extractive industries) that folks don't like to discuss.
https://www.propublica.org/article/new-mexico-uranium-homestake-pollution

I remember a story from the 1970s about contamination where homes in Grand Junction, Colorado, were built with contaminated uranium mine tailings. I believe the tailing were added to the concrete or cinder blocks. The homes were well above normal background.

An interesting read.
I wonder why they don't put the waste simply back into the unused mine?
Apart from cost.

 

[Astronuc]

Bloomberg reports "World’s Biggest Nuclear-Fusion Project Faces Delays as Component Cracks"

• The $23 billion ITER project in France faces new delays

https://www.bloomberg.com/news/arti...at-fusion-power-shows-cracks-in-silver-lining

World Nuclear News reports "The International Thermonuclear Experimental Reactor (ITER) project has announced defects have been discovered in the thermal shields and vacuum vessel sectors and warned that the consequences on schedule and cost "will not be insignificant".
https://world-nuclear-news.org/Articles/Defects-found-in-two-key-components-of-ITER-tokama

The director general of ITER, Pietro Barabaschi, said: "If there is one good thing about this situation, it is that it is happening at a moment we can fix it. The know-how we are acquiring in dealing with ITER's first-of-a-kind components will serve others when they launch their own fusion ventures. It is in ITER's nature and mission, as a unique and ambitious research infrastructure, to go through a whole range of challenges and setbacks during construction. And it is therefore our task and duty to promptly inform the engaged scientific community so that they will take precautions when dealing with the same type of assemblies."

ITER is a major international project to build a tokamak fusion device in Cadarache, France, designed to prove the feasibility of fusion as a large-scale and carbon-free source of energy. The goal of ITER is to operate at 500 MW (for at least 400 seconds continuously) with 50 MW of plasma heating power input. It appears that an additional 300 MWe of electricity input may be required in operation. No electricity will be generated at ITER.

Thirty-five nations are collaborating to build ITER - the European Union is contributing almost half of the cost of its construction, while the other six members (China, India, Japan, South Korea, Russia and the USA) are contributing equally to the rest. Construction began in 2010 and the original 2018 first plasma target date was put back to 2025 by the ITER council in 2016.

That's an optimist spin.

he cause was found to be stress caused by the bending and welding of the cooling fluid pipes to the thermal shield panels "compounded by a slow chemical reaction due to the presence of chlorine residues in some small areas near the pipe welds".

This had caused "stress corrosion cracking", ITER said, "and over time, cracks up to 2.2 mm deep had developed in the pipes".

Now, that is a stunning revelation! What the heck are chloride residues doing on stainless steel?! Stress corrosion cracking!? This would appear to be negligence on the part of someone. The problem is supposed to have been resolved = for at least two decades, as the industry began learning about it ~4+ decades ago.

During an audit in the mid-1990s, I cited a shop over concerns of halide/chloride contamination of stainless steel components. Even nearly 30 years ago, we knew not to allow chloride contamination or residues on stainless steel! Twenty+ years later, it should be well-known!

 

[Vanadium 50]

I'd call ITER a dumpster fire, except that a dumpster fire actually produces energy.

 

[bhobba]

This is why at the current stage of the debate of transitioning to low-carbon power sources, or even if we should, engineers and engineering economists should have much more involvement. I find the lack of their current involvement somewhat disturbing. For example, a simple analysis of the current Australian government policies showed what they want to do would cost trillions - way beyond what we can afford, plus multiple wind farms the size of Tasmania in the Simpson desert. This is just early stages in the debate, but I don't think governments should be saying what they will be doing (e.g. relying mostly on wind and solar but dismissing nuclear) at this point. All that will happen is when the rubber hits the road, they will have eggs on their faces. We don't discuss politics here, but one would think such would not be good for their re-election prospects.

Thanks
Bill

 

[artis]

This is why at the current stage of the debate of transitioning to low-carbon power sources, or even if we should, engineers and engineering economists should have much more involvement. I find the lack of their current involvement somewhat disturbing. For example, a simple analysis of the current Australian government policies showed what they want to do would cost trillions - way beyond what we can afford, plus multiple wind farms the size of Tasmania in the Simpson desert. This is just early stages in the debate, but I don't think governments should be saying what they will be doing (e.g. relying mostly on wind and solar but dismissing nuclear) at this point. All that will happen is when the rubber hits the road, they will have eggs on their faces. We don't discuss politics here, but one would think such would not be good for their re-election prospects.

Thanks
Bill

But then again we are at a point where a teenager from Sweden can yell at grown ups at the UN and everybody just accepts that as normal.
These public stunts won't change a damn thing, we need to find a couple of engineers who could yell some sense into energy politics, maybe then we could balance our carbon emissions with carbon free sources so much so that we can buy ourselves time and have a rather decent living too.