Live data from Hacker News

Small nuclear reactors: tiny NuScale reactor gets safety approval

popularmechanics.com

41–50 of 554 posts

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

#41
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.

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

#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

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

#43
post #8
post #2

"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.

The passive safety is a big leap forward. Removing humans from that process makes it safer. "In the event of any runaway reactor event, NuScale says, the reactor quenches itself in its pool, making it “passively safe.”"

Any plausible scenarios where the pool leaks?

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

#44
post #37

Have they announced an estimate of how much a reactor/cost of energy production will be? That’s kind of the most important factor, isn’t it?

$0.24 per kwh is a rough estimate I've seen for NuScale. Typically initial costs for microreactors right now are around $0.25 to $0.30/kwh which is about the cost of energy created by diesel generators. Natural gas is much lower. However they hope that as we make a lot of them the cost will drop.

Wow. That’s substantially more expensive than I was expecting. It’s been years but we always assumed ~$0.08/KWh for on-site natural gas generated electricity on US based projects.

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

#45
post #36

Earlier quoted context omitted.

you forgot to mention that those 23 m high containment vessels are places in in a pool which of course have to be much bigger than that: "The reactor and containment vessel operate inside a water-filled pool that is built below grade." We'll see of this is in any way or form sustainable, especially since uranium is also a finite ressource.

>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....

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

#46
post #2

"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…

> What a bad faith post.

Yeah, when humans can be trusted, nuclear will be 100% safe. Any day now!

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

#47
Four links down: "The staff has determined that the plant design meets the applicable requirements for the design certification stage of licensing. ... The NRC staff’s issuance of this FSER does not constitute a commitment to issue the design certification"[1] The actual review document is not up yet; search for "ML20023A318".

It's not that this is smaller. It's comparable to Shippingport or Vallecitos. The argument is that it's safe enough against meltdowns not to need a full containment vessel, which makes it cheaper. The idea is to have a group of these sharing the same reactor pool. What they do if there's a leak into the cooling pool. Does that take down all the reactors?

Anyway, the plan is to build the first one at the Idaho Reactor Test Station, 830 square miles with reactors spread miles apart. If something bad happens there, it's not a major problem.

[1] https://www.nrc.gov/docs/ML2023/ML20231A804.pdf

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

#48
post #45

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... .

First section your Article: "As of 2017, identified uranium reserves recoverable at US$130/kg were 6.14 million tons (compared to 5.72 million tons in 2015). At the rate of consumption in 2017, these reserves are sufficient for slightly over 130 years of supply. The identified reserves as of 2017 recoverable at US$260/kg are 7.99 million tons (compared to 7.64 million tons in 2015).[9]"

Doesn't seem clearcut

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

#49

fyi, 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...

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

#50
post #15

Previous Discussion 2 days ago https://news.ycombinator.com/item?id=24345288

Yikes - that is a classic example of a post that accumulated lots of upvotes but stayed underwater the whole time: http://hnrankings.info/24345288/. This is a known problem and it's on our list to fix.

Since that story didn't get much attention (relative to the interest in it), we won't call the current thread a dupe.

Post reply on HN