Comment on nuclear

• kameecoding@lemmy.world ⁨1⁩ ⁨year⁩ ago

  Well there is a difference between marketing and physics

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  • Saleh@feddit.org ⁨1⁩ ⁨year⁩ ago

    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.

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    • kameecoding@lemmy.world ⁨1⁩ ⁨year⁩ ago

      Impossible?

      www.eria.org/…/8_Ch.2-Safety-Economics-SMR.pdf

      Page 7

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      • Saleh@feddit.org ⁨1⁩ ⁨year⁩ ago

        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.

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• LandedGentry@lemmy.zip ⁨1⁩ ⁨year⁩ ago

  [deleted]

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  • Saleh@feddit.org ⁨1⁩ ⁨year⁩ ago

    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.

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• KillingTimeItself@lemmy.dbzer0.com ⁨1⁩ ⁨year⁩ ago

  i mean, the titanic was also definitionally, not unsinkable, they just called it that.

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