Westinghouse AP300 Small Module Reactor
westinghousenuclear.com
westinghousenuclear.com
The AP1000 design was an evolution of an earlier design called the AP600. The AP600 conceptual design apparently didn't find any customers because the economics of it were unappealing compared to larger reactors. In a nutshell, if you're going to build a huge containment building etc etc etc, it doesn't cost (in theory) that much more to go even bigger and get more power out of it.
So why SMRs?
It turned out that because you were building so few AP1000s, and building them with different workforces each time, that there was very little learning going on.
Some bright spark seeing what's gone on in other industries had the bright idea that if you could build a nuclear reactor in a factory, and increase the number of units built and minimise the amount of work done on site, you'd start getting learning rates and economies of scale that easily outweigh the lower inherent efficiency of a smaller reactor.
At 300MW, this reactor seems to be too big to be "back of a few trucks" construction, and thus you still have the bespoke construction project issues, and sufficiently small that the construction costs of 4 of them are likely to be much higher than one AP1000 (the AP1000 actually puts out about 1100 MW).
At big jobs like these, especially outside a handful of major metro areas, there will never be enough local labor. Even for "unskilled" positions, you don't want too many unproven or inexperienced people as they're likely to cause trouble, such as hurting themselves or others, or not consistently showing up on time--schedules can be both grueling and erratic, and many people can't hack it.
The nomad tradespeople you mention exist, but they are rare, and most likely dwindling as they get old and die and no one replaces them (a problem all trades currently).
A smaller reaction vessel needs a smaller press which is easier to find.
This was actually attempted in the 1970s by Offshore Power Systems (joint venture between Westinghouse and Newport News). They bought and installed the world's largest gantry crane on Blount Island in Jacksonville Florida and got a license from the NRC to build the first 8 of them. Sadly no one bought and they shut it down. Crazy story. Super interesting from a rapid decarbonization perspective.
Those oil refineries you mention became prime targets for cogeneration. Instead of burning fuel to provide process heat (for distillation, for example), a refinery could instead add a combustion turbine topping cycle ahead of that and produce electric power at near 100% marginal efficiency. This reflects the large second law losses involved in burning a fuel to produce relatively low temperature process heat. Basically any industrial process that used low or moderate temperature process heat could become a source of electric power via cogeneration after PURPA was enacted.
The reason a combustion turbine can be so hot is that the heat is produced in the working fluid itself, by a chemical reaction. There is no need to conduct that heat from a solid material at higher temperature. All the solid parts that might be heated by the gas can be cooled by actively flowing a cooler fluid through them (air, steam).
Unless the waste heat put out by the NPP is too low temperature to be used for process heat? Or the real advantage is that the refineries ramped up their electricity generation (turning waste fractions into electricity), with the process heat becoming a secondary concern?
There is the question of why nuclear had not and has not penetrated the market for industrial heat. I suspect it has something to do with nuclear not scaling down well, not being suited to industrial applications that may require more flexibility, and concerns about nuclear requirements bleeding over into design and operation of otherwise non-nuclear industrial processes.
Where will process heat come from in the future? Possibly heat pumps. The thermal energy from these (or from resistive heaters, at high temperature) is much cheaper to store, per unit of energy, than electrical energy in batteries, so this would provide a large, cheap source of dispatchable demand to ease renewable integration.
There is no reason to assume that the downsides of various other techs are in any way more manageable. (And ironically some of the solutions proposed for the downsides of nuclear are also what you need for renewables, i.e. storage to maximize use of expensive infrastructure with low opex.)
It's exhausting to see this claim see the light so often, despite being debunked so frequently.
Nuclear doesn't require storage.
Some people claim that economies could be made with storage because then you wouldn't need to build production equivalent to 100% of your peak consumption.
The dishonest discourse happens when renewables proponent claim that this small potential optimization means nuclear needs storage just as much as renewables do. Actually, losing your power source is not equivalent to shaving a few %s of budget.
This idea also completely ignores the fact that power grids don't optimize for efficiency, but for stability. We want redundant production, and the ability to move as many cursors as possible on the grid, in order to balance for issues. The ability to ramp up a power plant isn't just useful to produce peak load, it also helps mitigating e.g. losing a power line or a power transformer.
https://www.lazard.com/research-insights/levelized-cost-of-e...
https://www.iaea.org/fr/newscenter/news/contribution-du-nucl...
The report you quote already cites load factor around 90% for new builds, a 50% load factor wouldn't double the costs. That being said, 90% load factor for a grid with a high share of nuclear is probably extremely optimistic.
The reason such high capacity factors can be reached in countries that have a low nuclear share is that nuclear has an extremely low marginal cost, and is always picked over plants that require fuel.
Running a pure nuclear grid will never get 90% capacity factor. That relies on only taking the base load and offloading the actual hard part to other generators. Exactly what nuclear proponents like to say will be impossible for renewables.
It's certainly not impossible, since that's what we do currently. The reason we would like to stop doing it in the future is co2 emissions, not a feasibility barrier.
Now my point was that we don't have experience of massive storage. And in the absence of storage, nuclear costs go up, while renewables output goes down. One is painful but manageable, we don't have a plan to handle the other.
Personally, I wish we spent a bit less subsidies on renewable production, and a bit more on grid-sized storage, so we can have an answer on costs. Without this, discussions on storage-enabled grids are conjectures at best.
Today electricity accounts for 20% of energy use, European estimates see that going up to 50% by 2050. A large chunk of that increase is heating.
Obviously other countries and climates will not see the same patterns here.
Also these details don't really matter: Storage is a viable solution to the problem that Renewables are not dispatch able. The only argument against storage could be economic: That the inefficiencies and cost of storage render nuclear cheaper after all.
Please note that my comment is not about the viability of storage for renewables.
Security of Supply is yet another issue.
Anyway, if you can use storage to lower you nuclear costs by 5% overall, would it not be used? If your comment is not about viability of large scale storage, then what is it about? Storage is dispatchable, and an economically optimal 100% renewables grid will have a peak capacity far above actual peak demand, meaning it's typically curtailed (or you run electrolysers which again can beade dispatchable and grid-forming as loads) which again means you have plenty of ability to react.
Resilience research tends to favor decentralized solutions as well. Look at how Puerto Rico is being rebuilt.
Hard to know which group of people you talk to. This kind of work happens at many different levels, for many different reasons. TSO investment decisions are not made by the same people than power production investment decisions. There is some coordination, but no centralized decision-making.
To the best of my knowledge of at least one major European TSO, investment decisions are not taken at european level. And while there is strong european coordination in grid management, it is still cooperation and not an unified decision process. Any europe-level investment advice would have to be evaluated and selected by the TSO to become effective. Also the further you go from the field, the more likely studies are to consider spherical cows. Still useful, but not the full picture.
> Anyway, if you can use storage to lower you nuclear costs by 5% overall, would it not be used?
Of course it would, and we do use reversible dams to optimize costs. My point is that:
1) that's a whole-production optimization, and the trigger for that optimization is increasingly renewables rather than optimizing for nuclear production stability
2) the difference between paying 5% more and having to cut consumers from the grid is massive. for any TSO trying to save money is a goal, but curtailing consumption is an absolute failure criterion, second only to damaging the grid itself.
> Resilience research tends to favor decentralized solutions as well.
I might be biased by my personal experience, but when it comes to a power grid, planning ahead of time is much more valuable than decentralization. There is a difference between avoiding concentration of material, something which can be handled with central oversignt, and decentralization, which creates a coordination cost and sometimes loss of information (which is the case when small renewable production is connected to the distribution network rather than the transport network).
How to make sure that everything that is needed in order to have sufficient production capacity in all scenarios is also built is not in the responsibility of TSOs. Of course when we consider how to develop flexibility and system service markets we are exactly talking about making sure that everything that is needed _is_ built. Not through centralized planning but by making sure we have a market where we pay for people to provide what is needed.
The big questions, like energy only vs capacity markets, are directly about making sure the necessary investments are made, no matter what technology options are backing them up. You don't need central planning, but you need ESM studies to guide your market designs and long term political decisions (i.e. do we need a hydrogen grid).
And the fact that right now we don't have a market (or other incentives/regulations) for virtual inertia is a real problem worrying TSOs (much more so than the hypothetical issue of under-supply in 10-20 years that you raise for which the basic organisational mechanisms are in place).
> 2) the difference between paying 5% more and having to cut consumers from the grid is massive. for any TSO trying to save money is a goal, but curtailing consumption is an absolute failure criterion, second only to damaging the grid itself.
Of course, but what is your point? That renewables require massive storage to ensure supply at all time? Yes. That's obvious.
But, as every study and common sense shows, it turns out massive storage is also helpful for a nuclear grid, especially once we get into electrifying the heat sector (an important point you have not acknowledged at all).
Finally security of supply studies also assume that conventional generators sometimes fail for unpredictable reasons. In Texas it wasn't the renewables, it was the gas system freezing over that almost fucked up the grid.
I still don't get what your initial complaint was about. The point I made was pretty explicitly: "Renewables require massive storage to solve the fact that they are not dispatchable. But actually so does nuclear for completely different, economic reasons." What was it that you object to in that statement? What are you "debunking"?
Finally: As to the idea that energy systems are optimized for reliability first, and that renewables threaten this somehow:
Germany had an average of 12 outage minutes in 2020 on 49% renewables.
US: 280 outage minutes on 23%.
Germany outage minutes have been trending down as well last I checked, with the general explanation I have heard being that the focus on renewables has forced people to coordinate better, and check their grids more thoroughly than they did before.
That you can't compare two requirements when the consequences for failing to meet them are so different. To make an iffy comparison, you don't need brakes on a skateboard just as much as you need brakes on a car, even if a skateboard would stop a bit faster with brakes.
Incidentally, a few remarks on some unrelated points that were brought up:
> Not through centralized planning but by making sure we have a market where we pay for people to provide what is needed.
And we're seeing how well it's going.
> How to make sure that everything that is needed in order to have sufficient production capacity in all scenarios is also built is not in the responsibility of TSOs.
No, but as coordinators of the grid, TSOs have a lot to say about the impact and viability of production choices. There's a reason why TSOs publish their own studies on this topic.
> much more so than the hypothetical issue of under-supply in 10-20 years that you raise for which the basic organisational mechanisms are in place
I don't remember raising that point. Long-term supply volume decisions are a political choice, on which TSOs have no unique insight.
> Finally: As to the idea that energy systems are optimized for reliability first, and that renewables threaten this somehow
You keep bringing renewables in the discussion, I really don't know why.
I never claimed that they played the same role either. Again, why is that an issue?
That said, the point of storage for nuclear is exactly also that you don't build out the peak load, so if large scale storage failure leading to undersupply is your worry (as you indicate elsewhere), then that is a concern for this scenario as well.
But again, why? Storage backed energy grids are already a reality: we were running Europe on stored Gas for much of the winter. We are not talking about hypothetical batteries but about storing methane/H2 and operating gas power plants in these scenarios. Nothing in this tech stack is unproven by now, it is primarily a question of economics.
You insinuate (without clarifying) that markets arent working, yet we have fantastically reliable grids in Europe. Finally, the degree to which economics trumps reliability can be seen very directly in the energy-only vs capacity market debate. Energy only puts the critical safety decisions in the hand of market actors. Negative and very high positive prices in the market are supposed to incentivise building a base load that will only run for a few weeks a year and feeding it with flexibly produced gas/storage. Capacity markets put the decision how much of this to build I. The hands of the planners and engineers instead. Much to the horror of most engineers and planners I know energy-only markets won the political debate a few years ago. It seems politicians really hate giving engineers money to spend on reliability directly.
This debate probably would work if we were at a bar or conference, but it's not really clear it makes sense here...
It's not a very large point, and I believe I fleshed it enough already.
> so if large scale storage failure leading to undersupply is your worry (as you indicate elsewhere)
I don't remember mentioning that. If we work under the hypothesis that we have large scale power supply available at reasonable cost, then yes, there is no reason not to use them. Currently, pumpable hydro is the closest we have, and it's more or less capped out here.
> But again, why? Storage backed energy grids are already a reality: we were running Europe on stored Gas for much of the winter.
This is the first time I hear someone mention gas as storage, in the context of a power grid. If you forget emissions, then, I guess, why not. But if you forget emissions, 90% of the public discourse on the european power grid stops making sense. To date, I have knowledge of no large-scale environmentally viable way to produce this fuel in a renewable way.
> You insinuate (without clarifying) that markets arent working, yet we have fantastically reliable grids in Europe.
The grid was already working well before the introduction of markets. Since then, in my neck of the woods we have seen a complete failure of investment in the production side. In other countries that already had a built grid like us, renewal was only possible with heavy public subsidies.
I would welcome an explanation on what you believe markets brought to an already working grid.
https://en.wikipedia.org/wiki/Power-to-gas
Methanation and methane storage is at the same level as Hydorgen storage in optimal models. This here has 500 citations:
https://arxiv.org/pdf/1801.05290.pdf
They also cite something I haven't personally read, but which goes back all the way to 2009, again with hundreds of citations:
M. Sterner, Bioenergy and renewable power methane in integrated 100% renewable energy systems, Ph.D. thesis, Kassel University (2009).
Of course as the roundtrip efficiency is better, its preferable to store Hydrogen directly if that is feasible (and this is why a pure electricity sector optimization model will never show methane).
But fundamentally the idea has been for a long time to run Gas power plants on carbon neural gases. This is an explicit point in the EU Taxonomy of labeling Gas investments as green. They can only do so if they retrofitted to running on carbon free gas from 2035 onwards. Siemens is selling their stuff as H2-ready for that exact reason [1].
Pumped hydro can not be meaningfully expanded, its only a small part of the overall solution.
[1] https://www.siemens-energy.com/global/en/news/magazine/2022/...
Both systems have their flaws: the first one is clearly detrimental to democratic oversight, and may sometimes cause authoritarian problems, where administrators don't see or overlook problems caused to individuals.
On the other hand, political-first systems tend to kill unviable or uncompetitive projects way too late, because implementer signal is attenuated.
A good example of this is the development of nuclear power in France and the UK in the 60's: both countries had a local reactor project which was politically favored. France, where engineers had a strong influence on politicians, killed it quickly and bought US licenses for its program. The UK on the other hand moved on with their local graphite-gas reactors, which proved much harder to implement, and hampered their program.
All of this to point out that power2gas is currently at a very early stage, and since this program is dominated by political will, it's extremely hard to know how well it will work, let alone have a good idea of the economic figures.
Maybe it will work. I hope so. But it's certainly not a done deal, and it's extremely unsettling to see our countries' energy safety be debated based on a few scientific papers or a planned demonstrator by people that won't have to actually implement it.
Solar wind is volatile and non-dispatchable, so you need something to balance it. Of course we can always say heck it and live with constant brownouts and highly variable energy cost, but that is a non-solution in my book. You can overprovision generation, you can build dispatchable storage solution or dispatchable alternative generation source. In the end you need this because of variability and non-dispatchability of solar wind. Nuclear does not have this property, ergo it does not need storage to prevent brownouts. Sure, some models suggest that storage could under certain circumstances maybe help shave off a few percent of the cost, but that is the extent nuclear needs storage.
And this brings us back to original issue of payback time. Solar wind has lower payback time, because the cost of variability is borne by the grid, i.e. classical example of privatizing the profits and socializing the losses.
https://www.nytimes.com/2022/11/15/business/nuclear-power-fr...
Every model I have seen does that. And for Europe at least that total cost of doing all that is below nuclear.
Not really. Both overprovisioning and dispatchable storage are hugely expensive, therefore dispatchable alternative generation is employed, which is gas. So in an attempt to move away from carbon-emitting generation these models make carbon-emitting generation integral part of the system.
What models based on renewables actually do is try to find a problem for a solution: throw away grid stability requirements out of the window altogether, introduce huge variabilities and hope that spending power inequality will mask brownouts, i.e. it is hoped that pricing changes and consumer reaction to those changes will be fast enough for load to disconnect voluntarily before parts of grid are forcibly disconnected.
I don't think they exist, or if they do they will not be the prominent highly cited ones. Yes, storage and methanation and electrolysis are expensive. These expenses are explicitly modeled in the energy system models. Modeling these expenses for a complete system that satisfies the security of supply constraints is the very essence of what these models do [1]. Criticism against them would be exactly that they don't assume some market/price dynamics but a perfect central planner.
Flexible loads are a fundamentally different thing than brownouts. Electricity consumers opt in to being flexible, and this is about sophisticated industrial consumers, not private consumers anyway. The market mechanism you describe would only be true for energy-only markets anyway, and no one is proposing energy only markets for primary and secondary control energy that balances out short term variability.
[1] E.g. Figure 7 in https://arxiv.org/pdf/1801.05290.pdf gives the cost breakdown for a 0-Carbon configuration of generation storage (and optionally transmission expansion) investment that can serve all loads for the entire year under different assumptions for other energy sectors participation in flexibility provision. While this modeling set up is a lower bound on the costs, a deeper analysis shows that this is actually pretty accurate especially when storage investment is reasonably high, as the overall storage cost is dominated by seasonal variability which is highly regular.
Instead we got this crap that is a floating barge of environmental ruin:
https://karpowership.com/en/global-presence
Notice how it's only been installed in 3rd world countries.
This article goes into detail of you have access: https://www.newyorker.com/magazine/1975/05/12/the-atlantic-g...
The usefulness of the ocean as a thermal sink though depends on water temperature which can vary a lot depending on where you are.
Not to mention all the sea life that isn’t going to respond well to high temp water spewing out..
Ideally, you're not dumping the hot water back into the harbor. At least from a naive theory perspective, you could put huge cooling towers on deck and cool the reactor 100% through evaporative cooling. Bonus: the huge steam/mist cloud out of the cooling tower could help delay global warming through marine cloud brightening [0]. Whether the deck of a floating reactor has enough space and stability to support cooling towers of the appropriate size is a question for the engineers.
That's how most reactors in first world countries with temperate climates work anyway. Because it really messes up the biosphere of your river/coast, if you just dump 3GWh of thermal power straight into the water.
This is also why most of those power plants have to shut down. It's not the physical lack of water, but instead input is already so hot that output would already be over the upper limit.
Nobody build enough cooling towers to cool with them "needlessly".
Which is also why global warming is disastrous to energy sector. Those older power plants just don't have enough cooling capacity for newer higher temperatures.
https://www.e-education.psu.edu/meteo3/sites/www.e-education...
That's usually not done with saltwater plants, because there are more issues with mineral deposit, i.e. salt.
The issue happens with river plants, more specifically those that release cooling water back to the river.
No. The difference between pumping water at 15°c or 30°c is negligible when you're cooling water at 325°c. You may have to pump a tiny bit more water, but that's a non-problem when you have an ocean.
https://en.wikipedia.org/wiki/Russian_floating_nuclear_power...
"An academic reactor or reactor plant almost always has the following basic characteristics:
1. It is simple.
2. It is small.
3. It is cheap.
4. It is light.
5. It can be built very quickly.
6. It is very flexible in purpose (“omnibus reactor”)
7. Very little development is required. It will use mostly “off-the-shelf” components.
8. The reactor is in the study phase. It is not being built now."
Some of the "small modular nuclear reactor designs are built on the assumption that they don't need a full scale containment vessel because nothing can go that wrong. That may not be a good assumption. There's a lot to be said for large amounts of steel and concrete around reactors.
Containment vessels could also be made smaller if steam filtering were used instead of planning to just contain and condense it. I don't know if any SMRs plan to do this.
[1] https://www.nrc.gov/docs/ML1535/ML15355A411.pdf
[2] https://spectrum.ieee.org/media-library/image.jpg?id=2557419...
I don't see a future for this. If somebody thought it was a feasible design for construction in Western countries, they could buy the half completed sites at Summer for a song.
I also think 300MW is too big. It's not really small enough to get the supposed benefits of small and modular.
The entire nuclear industry appears to be off its rocker when it comes to designs that are possible to construct for any reasonable amount of money. They bungled the AP1000 so badly that it bankrupted Westinghouse, and there's no reason to believe that they learned enough from the experience to do better next time. It's all terribly depressing, and completely soured me on the possibility of nuclear for the next 20-40 years. And in 20-40 years, look at how far storage, wind, and solar will have developed. It's unlikely that my nuclear will ever be a dominant energy source.
My hypothesis is that modern economies with high wages will simply not be able to build a nuclear reactor economically. It appears to require a certain amount of 20th century technological advancement, but not so much economic advancement that labor costs are too high.
France had a much better track record with nuclear in their first round of building. France can also build large construction projects without the massive cost overruns that the US has had. But they can't seem to get a next gen reactor built.
A piece about it: https://www.archyde.com/the-folz-report-draws-up-a-severe-as...
This study may also offer some hints: https://www.sciencedirect.com/science/article/pii/S030142151...
Smaller, simpler projects don't tend to have the same issues because contractors know they can be replaced easily if they fail.
> France can also build large construction projects without the massive cost overruns that the US has had
Not always, some easily go overboard, like with the Parisian Philharmonic, or the absolutely massive Grand Paris Express (~200km of new high capacity metro lines around Paris) which has seen the budget go up from an original estimate of 19 billion to 35 billion (euros). Completely normal considering the scale and complexity, but still.
> Since construction began in March 2017, the project has been subject to several delays, including some caused by the COVID-19 pandemic,[10] and this has resulted in significant budget overruns. As of May 2022, the project is two years late and the expected cost is £25–26 billion,[11] 50% more than the original budget from 2016. It is currently planned to be commissioned in June 2027 and has a projected lifetime of 60 years. In February 2023, EDF announced that costs would rise to £32.7bn and completion would be delayed by a further 15 months to September 2028.[2][12]
https://en.wikipedia.org/wiki/Hinkley_Point_C_nuclear_power_...
South Korea was able to eke our small decreases in cost (though some people have ended up in jail for falsifying record keeping). But otherwise, costs tend to rise. And I'm definitely not aware of a drop of 50% or so, to bring these excessive costs into the realm of competitiveness.
Which is 101 of big projects anyway. Hard to understand why french project wasn't deemed to risky to investors.
Lead is such a superior concept for reactor design and neutron economy, and mostly held back by the pace in material science.
https://news.ycombinator.com/item?id=35818261
>Not small, modular, or new. But certainly a decent reactor. They clearly want something to slot in against the GE BWRX-300. But they would probably be better served by going all-in on their eVinci reactor, which is small, modular, and new
>https://www.westinghousenuclear.com/energy-systems/evinci-mi...
The bulk of our power comes from coal fired plants but due to the low quality coal for cost reasons and thus high sulphur and lack of preventative maintenance it results in boiler tube leaks nearly every week.
Some of our plants are at the end of their lives and their replacements are no better off due to corruption and a malady of technically incompetent builders (looking at you Hitachi South Africa).
7000MW out of commission so we get daily power cuts for half the day.
Those like myself who have the ability just install home solar systems for some measure of sanity while most companies are using diesel standby generators for their infrastructure.
Walking into the office park and you can hear the chugg chugg and smell the fumes.
If only that had been continued.
[0] https://en.wikipedia.org/wiki/Pebble_bed_modular_reactor
It's cool that they call out 15 MWe / min "load following" capability. Ramping up and down in response to renewables will be an important function of any nuclear reactor installed today.
I know nothing of nuclear. What sets this rate? Is it some system level thermal gradient limitation? Or maybe the complexity of the safety around the movement?
As simple as it is, this really blew my mind. I never considered that all the plants need to work together, as a system, each with "inertia", but all without ringing/oscillations. Thanks, I'll need to dig into this deeper!
I can only assume that having grid batteries can really clean things up.
But it is kinda amazing to know that all of these generators run essentially in sync. If one slows down all of them slow done.
Realistically, it's not going to happen. PWRs are inherently stable, that's one of their big selling points. If anything goes wrong and the reactor becomes too hot, the water expands, moderates less the neutrons and they don't slow down enough to trigger fission events, so the rate of fission decreases. If for some reason the reactor stops producing enough heat, the water cools down and more fission starts happening. And there are other negative feedback processes in place too, for example Doppler broadening [1].
This is great for safety, but not so great for load following. If you want to load follow, it's probably going to be many times cheaper to just invest in a bunch of batteries.
[1] https://en.wikipedia.org/wiki/Doppler_broadening#Application...
The only really needed to do this at any thermal plant is to over size the steam turbines, install some piping, and build an insulated salt tank.
Of course Westinghouse hasn't built any plants with that feature since it doesn't make economic sense without variable energy pricing.
[1] "Status Report – Westinghouse Lead Fast Reactor," (Westinghouse Electric Company LLC, United States of America), https://aris.iaea.org/PDF/W-LFR_2020.pdf
The salt used for energy storage is normally a eutectic mixture of ~60% sodium nitrate and ~40% potassium nitrate (not NaCl) and has a melting temperature of ~260 °C. The secondary on a PWR has a maximum temperature of 275 °C. So within the liquid range of typical thermal storage salts, though I suspect finer tuning of the salt composition would be used to reduce the melting temperature to closer to the feed water temperature of ~220 °C.
A nuclear reactor uses fuel juuuust barely above critical mass so the reaction is slow. It's a very different thing. Producing the fuel is just basic centrifuge isotope separation, which has many non-fission applications.
Interesting. Everyone says that nuclear reactors are safe and material can't be used to build bomb, how are we ensuring that were always only tiny bit above CM... And this bit doesn't grow unexpectedly.
As laic, i see many failure modes, starting with simple accidents in handling of rods or bad storage
You need sufficient fissile material to provide the increased neutron flow generating heat which you can use to power generators, but you have to then extract that heat efficiently to prevent your nuclear core from literally melting.
Good old Eisenhower and Atoms for Peace, 1953.
This was more what I was trying to motion toward — if you sell a power reactor to the private market, aren't you basically guaranteeing that "locations of security hardening features" and so forth will be able to be scrutinized at leisure by foreign state actors who can then use that information to attack other power infrastructure made to the same template?
secrecy is a sliding scale, and delaying and thinning out access to this information makes it "more secure" but surely some cleaning person will tell their buddies over a pint.
https://www.nei.org/resources/fact-sheets/nuclear-plant-secu...
I worked on automated conversion of a large collection of documents for nuclear power stations some years back, and there was a lot of bureaucracy around who could access the documents, and how. I wasn’t supposed to take any files home, for example, which meant I couldn’t copy them onto a laptop. Management claimed that this was due to federal laws, but I didn’t ever investigate the legal basis.
Yes, I understand it isn't comparable (1.2MW). But portable doesn't require construction. Surely something in-between can be built?
"Extensive shielding was omitted in favor of a personnel exclusion zone of 500 feet (150 m) while in operation"
"THE FORGOTTEN HISTORY OF SMALL NUCLEAR REACTORS"
https://spectrum.ieee.org/the-forgotten-history-of-small-nuc...
France: https://twitter.com/Mangeon4/status/1632627857837924352
Florida: https://whatisnuclear.com/offshore-nuclear-plants.html
[1] https://www.nrc.gov/reactors/new-reactors/smr/licensing-acti...