How is nuclear compatible with variable renewable energy sources? It can’t ramp up or down quickly, so it’s not good for filling the gaps in the day when the sun is not shining. And solar is now so cheap during sunny days that the excess power is curtailed or at a negative price.
Small nuclear reactors: tiny NuScale reactor gets safety approval
181–190 of 554 posts
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#182Earlier quoted context omitted.
It's really hard to comprehend just how much heat a reactor can make from decay alone. Like... boiling a hot tub in only a minute.
And so a pool of water is not enough because it will boil away. A continuous flow must be present that can not be interrupted.
According one of their videos[1] by the time the water has boiled away the reactor will be cool enough that it can be air cooled.
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#183fyi, OSU college has a 1-megawatt research reactor. https://www.oregon.gov/energy/facilities-safety/facilities/P... https://www.corvallisadvocate.com/2012/got-nuke-state-of-the...
The University of Texas at Austin has a 1-megawatt nuclear reactor: https://nuclear.engr.utexas.edu/netl/triga-reactor BUT... it also has two 74-megawatt gas turbines that supply the campus with electricity and steam: https://utilities.utexas.edu/chp/about-carl-j-eckhardt-combi...
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Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#184Earlier quoted context omitted.
In this particular case, a power plant with these nuscale reactors would probably have survived a Fukushima type accident. One effect of being small is that the reactors are designed to be passively cooled after shutdown, using convection instead of pumped flow. So there is no need for emergency diesel generators to keep the coolant pumps running.
What's the radius around a reactor where a critical core can trigger fission in the next reactor over?
You'd have to place both cores within the same reactor pressure vessel, which isn't possible.
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#185Earlier quoted context omitted.
In this particular case, a power plant with these nuscale reactors would probably have survived a Fukushima type accident. One effect of being small is that the reactors are designed to be passively cooled after shutdown, using convection instead of pumped flow. So there is no need for emergency diesel generators to keep the coolant pumps running.
Sure, it's safer for reactors to tolerate flooding, if indeed these reactors actually do tolerate flooding. Definitely that would be a better design in flood/tsunami-prone areas. No design (from history, especially no reactor design) is perfect. A set of smaller reactors that were not co-located would be more tolerant of site-specific vulnerabilities in their design.
I think you're screwed either way.
The odds that a concentrated site has an event are much higher with colocation. But the changes of having an event at multiple locations are higher if they're spread out.
Some things that I believe would matter for colocation would be:
- chance of cascading failures
- economies of scale/safety in numbers (1 large team vs many small)
- plant-to-home efficiency (n fewer reactors due to smaller transmission losses)
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#186"Officially safe" is a hilarious term which tries to predict the possibility of an MCA or "Maximum Credible Accident." Of course, Three Mile Island, Chernobyl, and Fukushima were also "officially safe" when they were built.
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…
Bad faith post? Call me when the Nuclear Industries Indemnity Act (which socialises all costs over $12.6B in case of an accident) is repealed.
What happens if the passive cooling pool drains? Let me guess, “That will never happen!”
https://en.m.wikipedia.org/wiki/Price–Anderson_Nuclear_Indus...
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#187How is nuclear compatible with variable renewable energy sources? It can’t ramp up or down quickly, so it’s not good for filling the gaps in the day when the sun is not shining. And solar is now so cheap during sunny days that the excess power is curtailed or at a negative price.
San Francisco in the summer :D
I kid! AFAIK you most want this kind of immense baselines power for heavy industrial activities.
Also AFAIK, if these are simple/easy/small enough, you could co-locate the heavy consumption with the generation which'd cut power consumption (due to transmission) by something like 30% (on top of infrastructure maintenance savings). Kinda like Netflix putting boxes in local switches (if I have those terms correct).
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#188Earlier quoted context omitted.
You don't need to be an expert. Ask anyone who has owned an in-ground pool. Leaks are rare but do happen.
Nuclear power plants were designed with this in mind. It would take a substantially larger earthquake to damage a nuclear power plant and cause it to leak than a commercial pool. Such a comparison is in bad faith and disingenuous.
Cool it (pun intended) with the accusations of bad faith. Unless you have enough data to prove it, don't accuse it.
"Substantially larger" is not the same as "impossible". And, given substantially larger consequences if a reactor pool breaks (compared to a swimming pool breaking), I don't think the question is out of line.
We learned from Fukushima that natural disasters don't always follow the parameters that we expect them to.
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#189Earlier quoted context omitted.
Another option which is completely safe and permanent* is drilling a borehole few km down and dumping the waste there. It's not coming back no matter what. The research done into it shows that "only" 800 boreholes would be required to store literally all nuclear waste ever produced. https://en.wikipedia.org/wiki/Deep_borehole_disposal *to a point where it was actually brought up as a negative, because if we ever want…
There's one in Finland: https://en.m.wikipedia.org/wiki/Onkalo_spent_nuclear_fuel_re... They have thought thousands of years ahead and set up many different types of warning signs and symbols in case a future civilization discovers it.
No, they put zero warnings. Warnings only make it more likely that someone decides to start digging.
Re: Small nuclear reactors: tiny NuScale reactor gets safety approval
#190Earlier quoted context omitted.
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…
Nukes are slow from a cold start but they can throttle up and down with load. https://en.wikipedia.org/wiki/Load_following_power_plant#Nuc... Modern nuclear plants with light water reactors are designed to have maneuvering capabilities in the 30-100% range with 5%/minute slope.
What's the maneuvering ability of a coal plant? I looked at the article, but didn't see it.