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

First contact made with melted nuclear fuel at Fukushima plant

asahi.com

Post reply on HN
Print view View original

81–90 of 222 posts

Re: First contact made with melted nuclear fuel at Fukushima plant

#81

Post by izend »

samstave wrote: post #59
JosephRedfern wrote: post #23

Forgive the macabre question, but if a human (or other living creatue) were to venture in to the plant and collect this fuel by hand, how long would they survive? I'm in no way suggesting that this is an option, of course -- just curious.

You should watch this documentary on Chernobyl: > According to Vyacheslav Grishin of the Chernobyl Union, the main organization of liquidators, "25,000 of the Russian liquidators are dead and 70,000 disabled, about the same in Ukraine, and 10,000 dead in Belarus and 25,000 disabled", which makes a total of 60,000 dead (10% of the 600,000 liquidators) https://en.m.wikipedia.org/wiki/Chernobyl_liquidators They had guys…

The accurate number of deaths appears to be very controversial.

Re: First contact made with melted nuclear fuel at Fukushima plant

#82

Post by srcmap »

ChuckMcM wrote: post #17

While I realize it was likely impractical to meltdown reactors just to develop the technology to clean them up, I find the process here pretty interesting. A lot of good engineering has gone into the effort, and the engineering challenges (and risks) of post runaway reactors has gotten a lot more data. The Chernobyl folks just entombed everything, which is a one approach, even though they can "walk up to"[1] the rema…

About the engineering challenges : I love to know the camera, sensors, electronic that let them take that picture in such high radioactive environment.

Re: First contact made with melted nuclear fuel at Fukushima plant

#83

Post by transistor-man »

ChuckMcM wrote: post #17

While I realize it was likely impractical to meltdown reactors just to develop the technology to clean them up, I find the process here pretty interesting. A lot of good engineering has gone into the effort, and the engineering challenges (and risks) of post runaway reactors has gotten a lot more data. The Chernobyl folks just entombed everything, which is a one approach, even though they can "walk up to"[1] the rema…

@ Melting down fuel to determine its properties, the US just restarted a facility that does exactly that! The TREAT reactor purposely melts fuel to determine its failure points and to study new cladding materials.

https://en.wikipedia.org/wiki/Transient_Reactor_Test_Facilit...

Re: First contact made with melted nuclear fuel at Fukushima plant

#84

Post by petschge »

lucb1e wrote: post #73
petschge wrote: post #62

Earlier quoted context omitted.

The logical argument is that we still do not have a good way to deal with the radioactive waste and that a lot can still go wrong in the next million years.

And another logical argument could be that this causes us to delay cutting emissions enough to prevent massive ecosystem changes resulting in humanity's death in the next few hundred years. It's just not that simple. We need to look at both sides, weigh the options, and find a solution which probably involves a mix where we compromise on having X m³ of earth dedicated for a long time to nuclear waste to save us in th…

The thing is that there is a rather pro-nuclear crowd on HN here that does not understand enough of the physics and the systems engineering of the large scale electrical grid that goes into making this trade-off in a rational way.

Re: First contact made with melted nuclear fuel at Fukushima plant

#85

Post by simmanian »

acidburnNSA wrote: post #49
simmanian wrote: post #16

Has there been a proper study done on how dangerous it is to live in areas around the plant, or how safe it is to eat produce grown from Fukushima and all the fish caught in the area? There's been so much rumor and fake news around this topic that I don't know what to think.

Absolutely yes. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) does reports every year or so on the status. Here's the 2017 one [1]. [1] http://www.unscear.org/docs/publications/2017/UNSCEAR_WP_201...

Thanks. I think page 20 has a lot of information I'd been looking for.

Re: First contact made with melted nuclear fuel at Fukushima plant

#86

Post by acidburnNSA »

simmanian wrote: post #85
acidburnNSA wrote: post #49

Earlier quoted context omitted.

Absolutely yes. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) does reports every year or so on the status. Here's the 2017 one [1]. [1] http://www.unscear.org/docs/publications/2017/UNSCEAR_WP_201...

Thanks. I think page 20 has a lot of information I'd been looking for.

Yes. And I recommend having https://xkcd.com/radiation/ handy as you read through those numbers. The units are consistent.

Re: First contact made with melted nuclear fuel at Fukushima plant

#87

Post by roywiggins »

meenzu wrote: post #64
roywiggins wrote: post #57

Earlier quoted context omitted.

Gamma radiation goes through everything. The only thing that stops it is mass and distance. You can only wear a certain amount of lead before you collapse. The amount of radiation is just too high.

Thanks for the answer, just curious would the lead sheet have holes thorough it if you put it up to that radiation? I'm picturing a sheet of paper with bullet holes through it. Or is there a better analogy of what is going on?

From the point of view of the radiation, there's a lot of empty space between lead atoms and a lot of it will just slip through and not interact with the lead at all. A fraction will slam into lead atoms, a fraction will slam into your atoms, a fraction will keep going.

Re: First contact made with melted nuclear fuel at Fukushima plant

#89

Post by rabidrat »

cgrand-net wrote: post #22
mimixco wrote: post #15

It took 10 years to even get a robot that could get close to the fuel... and people still ask if nuclear might not be as bad as coal! The truth is that accidents like this can never be cleaned up or salvaged. It's time to move away from nuclear, as other countries have already figured out. Fortunately for us in the US, the last nuclear plant under construction today will likely be cancelled, as the last two were. The…

> The truth is that accidents like this can never be cleaned up or salvaged. While global warming is easily solved. Coal or nuclear are both bad but differently. Which one is less bad depends on your risk model

If climate change truly is incompatible with global civilization, I would rather have some defunct coal plants laying around than spent nuclear fuel. Nuclear maybe would have helped us avoid the worst of climate change if we had adopted it at a broader scale sooner, but at this point I think we have to be planning for post-civilization scenarios.

Re: First contact made with melted nuclear fuel at Fukushima plant

#90

Post by pvaldes »

ChuckMcM wrote: post #79
pvaldes wrote: post #46

Earlier quoted context omitted.

> the "China Syndrome" speculation is pretty much completely debunked You would be dissapointed. Cou-cou! surprise! The ocean strikes back!. Unexpected source of Fukushima-derived radiocesium to the coastal ocean of Japan. 2017. Sanial, Buessler, Charette, and Nagao. PNAS. DOI:10.1073/pnas.1708659114 "Sanial, Buessler, Charette and Nagao, scientists from Massachusetts and Japan found a new source of Caesium-137 to th…

That is a great paper[1], thanks for the reference I've added it to my nuclear effects library. It doesn't involve the China Syndrome speculation though, what it does find is much much more interesting. The paper reports that beach sand is capable of 99% adsorption of Cs137. And then goes on to discuss how it gets de-adsorbed (up to 11%) when Cs137 free sea water is mixed with it. What this says to me is that you can…

> regardless of the salinity, sediment grain size, or mineralogy

Yes, I though also about it, but I will add something to the idea of a sand filter. This is not our average dead sand, is marine sand, cleaned and oxigenated constantly by the tides. If we discard an effect of grain size, and sand composition, the really interesting hot-stuff is IMHO probably in what remains, the bacterial biofilm coating the sand.

Post reply on HN