If you want a reaction that you can take energy away from the reaction, the reaction needs to create more energy than it needs to maintain itself. If you fail to take that energy away, the reaction will accelerate and your output will grow even further.
It is basic physics.
The only alternative would be to have an open system that runs on so little fuel that you need to feed it continuously. This has an entirely different level of problems, as now it will be impossible to contain the radiation to the reaction chamber and the containers of the spent fuel. Also with that you would need an entirely different design of how the radioactive material is held in place and how the reactions are controlled. The current way of adjusting how much you block with control rods probably won’t work.
It is just impossible to have an exponential system like the nuclear reactions used in a reactor without active control measures. And active measures can fail.
A reactivity accident is a situation in which such a control device that
absorbs neutrons malfunctions or is accidentally removed for some reason, causing a sharp
increase in the nuclear reaction, leading to an output surge and sometimes a runaway reaction.
Some SMRs, however, are not confined to the existing light water reactor (LWR) concept of ‘no
fuel supply during operation’, but have the concept that fuel supply during operation is possible.
Since such reactors are not overloaded with fuel, there is no possibility of a reactivity accident
even if there is a failure in the control devices.
Page 4. Describing exactly what i said.
n Japan, where even at 30% power with zero coolant flow, the
reactor shuts DON automatically without the insertion of control rods, and heat can be removed
without mechanical means by radiation and natural convection to the water-cooled cooling
panels outside the reactor. Figure 2.2 shows the results of the zero-coolant test.
The US metal-fuelled fast reactor, the Experimental Breeder Reactor-II (EBR-II, 19 megawatts
electrical (MWe)), shows similar results to the above when the coolant flow is set to zero […] Aurora (4 MWth) by Oklo, which applied for a Combined
Construction and Operating License (COL) in 2020, has the same characteristics as the EBR-II.
Page 6, which refers to the graphic on page 7. So this only applies if the reactor was at around 30% or less of the design power output.
Meanwhile, the largest equipment in an NPP is the containment vessel. Containment vessels are
generally much larger than reactor vessels. With a diameter of more than 10 m and a height of
more than 30 m, they cannot be transported by ordinary means, such as by trucks on public
roads. Although a containment vessel is important equipment for preventing the release of
radioactive materials in the event of an accident, it is possible to have a design concept without
a containment vessel if the NPP has other equipment that has equivalent functions or safety
characteristics. The presence or absence of a containment vessel is another guideline for
determining whether modularisation can be achieved.
Page 10.
Yeah great idea. This is Titanic all over again. We don’t need a last resort because we have been so smart, that all preliminary features are deemed infaillable. A story as old as humans building complex technology.
For starters we are talking about concepts, not actually built and tested Reactors. If you have any connection to scientific research, technology development or engineering, you should know that between hypothesis, laboratory testing, prototype development, technology upscaling, establishment of production lines and finally long term operation routines there is a lot that will not be like expected, has to be revised, adjusted, scrapped, redesigned…
The history of nuclear energy is riddled with cases of hubris leading to disasters. It is evident that so far humans were unable and unwilling to give safety the proper considerations.
But from a practical point of view anyone with some industry experience would find the idea insane, that Small and Modular systems, so high throughput of small batches would increase safety. It is much more complicated to provide Quality and Safety checks in such an environment. Especially as these would be done by multiple for profit companies, the necessary oversight would be more difficult to provide for the regulation authorities, so in the medium run we will get Boeing like situations. Just that cost cutting and mingling will lead to reactors contaminating large swaths of areas on top of potentially killing hundreds of people.
So now you explain, why we should totally listen to the claims made by for profit cost cutting companies, that are solely based on concepts, without any actual field testing.
Because that was exactly the Titanic situation. People believed it to be unsinkable and decided to cut on costs for emergency measures. Reality proved them wrong on the first and last voyage.
For starters we are talking about concepts, not actually built and tested reactors
Oh so you’re saying you’re completely full of shit because you’re talking about the theoretical consequences of theoretical devices that don’t even exist yet?
Yes we can make reasonable predictions about things that don’t exist yet but you are acting like it is a forgone conclusion. Unless you are actually involved in the field your opinion is, at best, as good as anyone else’s . I would say that to you or to any of the myriad of Tech Bros who are all fired up about small reactors like a cryptobros are about their next meme coin. You’re either an evangelist or expecting Armageddon these days. People don’t just wait and see or have less exciting takes. It’s “this is the greatest thing since fire” or “it’s going to kill everyone.”
Counter example to your quality and safety arguments: cars and car engines. Larger, higher output engines in larger machines require higher quality checks and safety regulations. A car engine isn’t generally going to rip your arm off or produce an explosion that can level a building. Plenty of larger machines/engines can and will.
Can’t have a runaways reaction like the Titanic was unsinkable.
Well there is a difference between marketing and physics
If you want a reaction that you can take energy away from the reaction, the reaction needs to create more energy than it needs to maintain itself. If you fail to take that energy away, the reaction will accelerate and your output will grow even further.
It is basic physics.
The only alternative would be to have an open system that runs on so little fuel that you need to feed it continuously. This has an entirely different level of problems, as now it will be impossible to contain the radiation to the reaction chamber and the containers of the spent fuel. Also with that you would need an entirely different design of how the radioactive material is held in place and how the reactions are controlled. The current way of adjusting how much you block with control rods probably won’t work.
It is just impossible to have an exponential system like the nuclear reactions used in a reactor without active control measures. And active measures can fail.
Impossible?
https://www.eria.org/uploads/media/Research-Project-Report/2021-07-Small-Modular-Reactor-/8_Ch.2-Safety-Economics-SMR.pdf
Page 7
Page 4. Describing exactly what i said.
Page 6, which refers to the graphic on page 7. So this only applies if the reactor was at around 30% or less of the design power output.
Page 10.
Yeah great idea. This is Titanic all over again. We don’t need a last resort because we have been so smart, that all preliminary features are deemed infaillable. A story as old as humans building complex technology.
Flippant “it sounds true-isms” are not useful for discussion and can even spread misinformation.
So please: explain your comment or stop repeating it
For starters we are talking about concepts, not actually built and tested Reactors. If you have any connection to scientific research, technology development or engineering, you should know that between hypothesis, laboratory testing, prototype development, technology upscaling, establishment of production lines and finally long term operation routines there is a lot that will not be like expected, has to be revised, adjusted, scrapped, redesigned…
The history of nuclear energy is riddled with cases of hubris leading to disasters. It is evident that so far humans were unable and unwilling to give safety the proper considerations.
But from a practical point of view anyone with some industry experience would find the idea insane, that Small and Modular systems, so high throughput of small batches would increase safety. It is much more complicated to provide Quality and Safety checks in such an environment. Especially as these would be done by multiple for profit companies, the necessary oversight would be more difficult to provide for the regulation authorities, so in the medium run we will get Boeing like situations. Just that cost cutting and mingling will lead to reactors contaminating large swaths of areas on top of potentially killing hundreds of people.
So now you explain, why we should totally listen to the claims made by for profit cost cutting companies, that are solely based on concepts, without any actual field testing.
Because that was exactly the Titanic situation. People believed it to be unsinkable and decided to cut on costs for emergency measures. Reality proved them wrong on the first and last voyage.
Oh so you’re saying you’re completely full of shit because you’re talking about the theoretical consequences of theoretical devices that don’t even exist yet?
Yes we can make reasonable predictions about things that don’t exist yet but you are acting like it is a forgone conclusion. Unless you are actually involved in the field your opinion is, at best, as good as anyone else’s . I would say that to you or to any of the myriad of Tech Bros who are all fired up about small reactors like a cryptobros are about their next meme coin. You’re either an evangelist or expecting Armageddon these days. People don’t just wait and see or have less exciting takes. It’s “this is the greatest thing since fire” or “it’s going to kill everyone.”
Counter example to your quality and safety arguments: cars and car engines. Larger, higher output engines in larger machines require higher quality checks and safety regulations. A car engine isn’t generally going to rip your arm off or produce an explosion that can level a building. Plenty of larger machines/engines can and will.