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Small nuclear reactors: tiny NuScale reactor gets safety approval

popularmechanics.com

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Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#51

Post by petre »

welfare wrote: post #45
deeeeeplearning wrote: post #40

Earlier quoted context omitted.

>We'll see of this is in any way or form sustainable, especially since uranium is also a finite ressource. I believe at current consumption rates there is still several hundred years worth of uranium. Presumably Fusion will have been figured out by then or we've killed ourselves with a climate disaster or something worse.

Nope, at the current rate of consumption it will last 70-80 years: https://en.wikipedia.org/wiki/Peak_uranium#:~:text=According... .

I wouldn't worry too much about running out of nuclear fuel. There's also Pu used in MOX fuel, breeder reactors, nuclear fuel reprocessing.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#52

Post by jhallenworld »

Here is the NRC website about this reactor:

https://www.nrc.gov/reactors/new-reactors/smr/nuscale.html

Here is an interesting sub-report:

https://www.nrc.gov/docs/ML2022/ML20224A525.pdf

Information withheld for security reasons. One item concerns the "ultimate heat sink". What happens when the ultimate heat sink is lost?

Well a design assumption is that it is not lost:

https://www.nrc.gov/docs/ML2020/ML20205L410.pdf

"A key assumption of the PRA is the availability of the UHS to provide an adequate heat sink. To support passive heat removal with the DHRS or ECCS, the reactor modules are housed and partially submerged in the UHS such that most of the outer surface of the CNV directly contacts the UHS, which is a large pool of water in the reactor building (RXB). "

DHRC is decay heat. CNV is reactor containment vessel. So drain the pool and the reactor is in trouble.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#53

Post by tlb »

welfare wrote: post #45
deeeeeplearning wrote: post #40

Earlier quoted context omitted.

>We'll see of this is in any way or form sustainable, especially since uranium is also a finite ressource. I believe at current consumption rates there is still several hundred years worth of uranium. Presumably Fusion will have been figured out by then or we've killed ourselves with a climate disaster or something worse.

Nope, at the current rate of consumption it will last 70-80 years: https://en.wikipedia.org/wiki/Peak_uranium#:~:text=According... .

Almost all predictions of running out of ores have been wrong. They’re based on “proven reserves,” but mining companies don’t bother proving much beyond 50 years worth.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#54

Post by sudosysgen »

welfare wrote: post #45
deeeeeplearning wrote: post #40

Earlier quoted context omitted.

>We'll see of this is in any way or form sustainable, especially since uranium is also a finite ressource. I believe at current consumption rates there is still several hundred years worth of uranium. Presumably Fusion will have been figured out by then or we've killed ourselves with a climate disaster or something worse.

Nope, at the current rate of consumption it will last 70-80 years: https://en.wikipedia.org/wiki/Peak_uranium#:~:text=According... .

No, these are the reserve that are available at a given price. It is very sensitive to technology. Moreover, price of uranium is a small part of the cost of a powerplant, so there is not as much price sensitivity. We're still good for around ~200 years.

Also, fuel can be reprocessed, and we can use other things than Uranium

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#55

Post by read_if_gay_ »

isatty wrote: post #13
core-questions wrote: post #9

Earlier quoted context omitted.

What a bad faith post. > Three Mile Island Was handled reasonably well, resulted in safety improvements to procedures and designs for future reactors. From https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3... > The approximately 2 million people around TMI-2 during the accident are estimated to have received an average radiation dose of only about 1 millirem above the usual background dose. To put this int…

> Accident caused by Communists who did not care about what happened to Ukrainians There were many such RBMK reactors spread all over the Soviet world that had the same flaws . There are many problems with your summary so can I just recommend that you watch the HBO mini series "Chernobyl" instead? It's a great watch.

That mini series is indeed a great watch but it's also not exactly factual.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#56

Post by m463 »

adrianmonk wrote: post #39
EricE wrote: post #12

This is huge. Not only are micro reactors far more economical, it dramatically reduces the need to maintain a massive nationwide grid and provides flexibility to people in remote areas including greater autonomy. Efficiency should be greater without massive transmission line losses. Might start fewer fires in California too.

I'm not an expert, but I'm not convinced about it reducing the need to maintain a nationwide grid. Nuclear reactors take ages to ramp up and down. It's basically going to be generating the same amount of power 24x7, but demand is going to fluctuate. The more other areas you're connected to, the more opportunity there is to send that power to someone who can use it. Obviously there's a law of diminishing returns at so…

I can see that if these are distributed, the grid can be more of a mesh than spokes on a wheel.

solar can do the same sort of thing.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#57

Post by draugadrotten »

marshray wrote: post #42

I think it's disingenuous to argue the economics of nuclear without mentioning: "DOE reported that it faced an estimated $494 billion in future environmental cleanup costs — a liability that roughly tripled during the previous 20 years." https://www.gao.gov/assets/700/696956.pdf

How much is the future environmental cleanup costs of coal and oil?

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#58

Post by RhodesianHunter »

marshray wrote: post #42

I think it's disingenuous to argue the economics of nuclear without mentioning: "DOE reported that it faced an estimated $494 billion in future environmental cleanup costs — a liability that roughly tripled during the previous 20 years." https://www.gao.gov/assets/700/696956.pdf

This is IMO a positive for nuclear, not a negative. You're forced to confront the cleanup as opposed to fossil fuels, where you just blow your waste out into the atmosphere and make it the commons' problem.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#59

Post by xigency »

draugadrotten wrote: post #57
marshray wrote: post #42

I think it's disingenuous to argue the economics of nuclear without mentioning: "DOE reported that it faced an estimated $494 billion in future environmental cleanup costs — a liability that roughly tripled during the previous 20 years." https://www.gao.gov/assets/700/696956.pdf

How much is the future environmental cleanup costs of coal and oil?

If you consider the climate, about 100 times that.

Re: Small nuclear reactors: tiny NuScale reactor gets safety approval

#60

Post by petre »

adrianmonk wrote: post #41
nsxwolf wrote: post #24

Article gave absolutely no indication of its dimensions. How "tiny" is it exactly?

Maybe tiny refers to the power output. The article says it makes 50 megawatts. Compare that to a nuclear plant near me which has two reactors that each generate 1280 megawatts. So it would take about 25 of these to equal the power output of a traditional nuclear reactor.

Yes but it's inherently safer. Utility scale nuclear was scaled up from naval reactors which are smaller, use highly enriched uranium as opposed to LEU and are safer. Alvin Weinberg, the father of several LWR designs cautioned about the safety of utility scale reactors (17:51):

https://youtu.be/EviEN0ScOwg

The NuScale design also uses LEU and a plant is comprised of up to 12 of these modules sitting in water pools. You can view it as a battery pack where batteris are continously rotated as they are refuelled.

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