Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Oklo, the Earth's Two-billion-year-old only Known Natural Nuclear Reactor (2018)

iaea.org

Post reply on HN
Print view View original

41–50 of 124 posts

Re: Oklo, the Earth's Two-billion-year-old only Known Natural Nuclear Reactor (2018)

#41

Post by teuobk »

foobarian wrote: post #29

> All natural uranium today contains 0.720% of U-235. If you were to extract it from the Earth’s crust, or from rocks from the moon or in meteorites, that’s what you would find. But that bit of rock from Oklo contained only 0.717%. Heh. The garbage web software developer me would have just called it good enough Would be really interesting to know what the error bars on those figures look like

Per NIST[1], the value is 0.7204% +/- 0.0006%, with the uncertainty representing one standard deviation.

[1] https://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl...

Re: Oklo, the Earth's Two-billion-year-old only Known Natural Nuclear Reactor (2018)

#42

Post by Loughla »

Manuel_D wrote: post #39
joe_the_user wrote: post #38

Earlier quoted context omitted.

I don't disagree that nuclear waste can be disposed of safely under good conditions[1]. But I think a fallacy to claim that natural phenomena should inherently be considered "environmentally safe" in human terms. There are coal seam fires that have been going on for centuries and the pollution of these is just as bad as the pollution generated by human created coal mine fires (and that's truly awful, a significant so…

What are the conditions under which nuclear waste buried a mile deep in bedrock will post a risk to society?

Burying it in a cheaper place that happens to flood occasionally?

Re: Oklo, the Earth's Two-billion-year-old only Known Natural Nuclear Reactor (2018)

#43

Post by ksenzee »

lazide wrote: post #27
the_arun wrote: post #7

Earlier quoted context omitted.

I wonder why Claude’s answers aren’t equal or better than Wikipedia - assuming Wikipedia is one of the training datasets. Is the temperature causing it to be probabilistic & other sources are carrying more weight?

You can think of a LLM as a type of lossy compression of knowledge. With that in mind, is it really surprising that you don’t get the ‘right’ answer out? Any more than if you compress an image with JPEG, a given pixel isn’t the ‘right’ color anymore either? They’re both close (kinda) at least, which is the point. If you wanted the exact right answer, don’t use lossy compression - it’ll be expensive in other ways thou…

What a great metaphor. I’m adopting that immediately, thank you.

Re: Oklo, the Earth's Two-billion-year-old only Known Natural Nuclear Reactor (2018)

#44

Post by brians »

Manuel_D wrote: post #39
joe_the_user wrote: post #38

Earlier quoted context omitted.

I don't disagree that nuclear waste can be disposed of safely under good conditions[1]. But I think a fallacy to claim that natural phenomena should inherently be considered "environmentally safe" in human terms. There are coal seam fires that have been going on for centuries and the pollution of these is just as bad as the pollution generated by human created coal mine fires (and that's truly awful, a significant so…

What are the conditions under which nuclear waste buried a mile deep in bedrock will post a risk to society?

[flagged]

Re: Oklo, the Earth's Two-billion-year-old only Known Natural Nuclear Reactor (2018)

#45

Post by bobmcnamara »

Manuel_D wrote: post #39
joe_the_user wrote: post #38

Earlier quoted context omitted.

I don't disagree that nuclear waste can be disposed of safely under good conditions[1]. But I think a fallacy to claim that natural phenomena should inherently be considered "environmentally safe" in human terms. There are coal seam fires that have been going on for centuries and the pollution of these is just as bad as the pollution generated by human created coal mine fires (and that's truly awful, a significant so…

What are the conditions under which nuclear waste buried a mile deep in bedrock will post a risk to society?

1) the assumption that because something can be done safely it will be done safely

2) transportation to the site: https://static.ewg.org/files/nuclearwaste/plumes/national.pd...

3) exploding waste barrels due to corner cutting in kitty litter selection exposing surface workers and contaminating the work area - only 1/2 mile down but this type of accident is depth independent https://www.latimes.com/nation/la-na-new-mexico-nuclear-dump...

4) fires

5) lack of a safety culture

6) communicating to future peoples not to mine here

7) long term structural stability and management (ex: Morsleben radioactive waste repository and Schacht Asse II)

Re: Oklo, the Earth's Two-billion-year-old only Known Natural Nuclear Reactor (2018)

#46

Post by legitster »

Loughla wrote: post #42
Manuel_D wrote: post #39

Earlier quoted context omitted.

What are the conditions under which nuclear waste buried a mile deep in bedrock will post a risk to society?

Burying it in a cheaper place that happens to flood occasionally?

Insisting on only worst case scenarios is such a bad faith argument. OP specifically asked about deep repositories.

It would be like having a discussion about green energy and insisting that people should assume dams will fail or that blades are going to fly off of turbines.

Re: Oklo, the Earth's Two-billion-year-old only Known Natural Nuclear Reactor (2018)

#48

Post by glompers »

joe_the_user wrote: post #38
legitster wrote: post #25

Richard Rhodes brought this up in an interview. He made it a point for critics who say nuclear waste can't be safely disposed of through burial. Well, we have pretty good natural evidence that nuclear fission products can remain buried and undisturbed for a pretty long time!

I don't disagree that nuclear waste can be disposed of safely under good conditions[1]. But I think a fallacy to claim that natural phenomena should inherently be considered "environmentally safe" in human terms. There are coal seam fires that have been going on for centuries and the pollution of these is just as bad as the pollution generated by human created coal mine fires (and that's truly awful, a significant so…

> There are coal seam fires that have been going on for centuries and the pollution of these is just as bad as the pollution generated by human created coal mine fires (and that's truly awful, a significant source of carbon pollution).

Has CO2 fire suppression been unsuccessfully attempted in these seams? Since nobody is underground and we know how to inject CO2 into underground deposits at various pressures, it seems like it would be a good candidate. Plus, with rotary steerable drilling, we could come in laterally (from a safe location above ground) to as many depths of injection as necessary.

Re: Oklo, the Earth's Two-billion-year-old only Known Natural Nuclear Reactor (2018)

#49

Post by legitster »

joe_the_user wrote: post #38
legitster wrote: post #25

Richard Rhodes brought this up in an interview. He made it a point for critics who say nuclear waste can't be safely disposed of through burial. Well, we have pretty good natural evidence that nuclear fission products can remain buried and undisturbed for a pretty long time!

I don't disagree that nuclear waste can be disposed of safely under good conditions[1]. But I think a fallacy to claim that natural phenomena should inherently be considered "environmentally safe" in human terms. There are coal seam fires that have been going on for centuries and the pollution of these is just as bad as the pollution generated by human created coal mine fires (and that's truly awful, a significant so…

No one is saying that it's "inherently" safe but there are a lot of people who claim it is inherently unsafe which is clearly untrue.

Re: Oklo, the Earth's Two-billion-year-old only Known Natural Nuclear Reactor (2018)

#50

Post by a11r »

glompers wrote: post #48
joe_the_user wrote: post #38

Earlier quoted context omitted.

I don't disagree that nuclear waste can be disposed of safely under good conditions[1]. But I think a fallacy to claim that natural phenomena should inherently be considered "environmentally safe" in human terms. There are coal seam fires that have been going on for centuries and the pollution of these is just as bad as the pollution generated by human created coal mine fires (and that's truly awful, a significant so…

> There are coal seam fires that have been going on for centuries and the pollution of these is just as bad as the pollution generated by human created coal mine fires (and that's truly awful, a significant source of carbon pollution). Has CO2 fire suppression been unsuccessfully attempted in these seams? Since nobody is underground and we know how to inject CO2 into underground deposits at various pressures, it seem…

These are large coal seams with significant exposure to the atmosphere. See https://en.wikipedia.org/wiki/Jharia_coalfield for an example. That excavator in the picture is not trying to put out the fire, it is just mining coal that happens to be burning. Spray some water, put out the fire and ship it off to customers.
Post reply on HN