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First contact made with melted nuclear fuel at Fukushima plant

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

#61

Post by petschge »

roywiggins wrote: post #57
mehrdadn wrote: post #50

Are there not any suits that protect against the radiation to let them go in and do some things by hand? If there are but it's still not a good idea -- why?

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.

Gamma radiation not so much simply makes it through everything, but it does indeed take a lot of shielding to attenuate to save level if there is enough radiation to begin with.

The fact that it interacts with stuff is actually what makes it dangerous. If it went through every thing it would not interact with the worker either and would not pose a thread to them.

Btw. there is a type of radiation that is practically like that: neutrinos. Impossible to shield against, but also completely harmless if you are not standing right next to a super nova.

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

#62

Post by petschge »

lucb1e wrote: post #31
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…

> ... and people still ask if nuclear might not be as bad as coal! That's playing on feelings rather than making a rational argument. Regardless of whether I am for or against widely deploying nuclear energy, this is not the way to talk about it and create informed opinions. The media are already doing their best to play on feelings on this topic, we don't need to replicate that here.

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.

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

#63

Post by agumonkey »

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.

This was heavily documented after Chernobyl. If you're not affraid of heavy and even gruesome recollection from people and relatives there at the time you can find documentaries on youtube

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

#64

Post by meenzu »

roywiggins wrote: post #57
mehrdadn wrote: post #50

Are there not any suits that protect against the radiation to let them go in and do some things by hand? If there are but it's still not a good idea -- why?

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?

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

#65

Post by pixl97 »

jade12 wrote: post #47
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…

Lest anyone forget, the Centralia (coal) mine fire has been burning since at least 1962 and no one knows how to stop it. The Fukushima Daiichi incident really doesn't seem that bad to me, comparatively speaking. https://en.wikipedia.org/wiki/Centralia_mine_fire

Granted that coal fires can occur due to other causes than mining (such as simply exposing a coal seam to air during construction). That said, mining greatly increases the number of incidents that occur.

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

#66

Post by folkrav »

tonyedgecombe wrote: post #27
acidburnNSA wrote: post #21

Earlier quoted context omitted.

If you look objectively at the numbers, you'll see that nuclear is one of the safest forms of energy production we know. Even considering conservative estimates from Fukushima and Chernobyl, nuclear power has net saved over 2 million lives simply by displacing air-pollution related deaths that would have occurred had the nukes not been built. Coal kills on the order of hundreds of thousands of people per year. Fukush…

We shouldn’t be burning coal either.

What we have right now are three options : fossil fuels, renewable sources like wind/solar/hydro, or nuclear.

Fossil fuels kill millions a year related to pollution, and does make whole areas unlivable. About 16% of all fracking oil in the US gets spilled in nature every year[1], on top of crap like Flint. Coal is responsible for 80% of energy-generated related air pollution, worldwide[2]. They are not a good solution.

Natural sources are simply extremely limited in terms of access. Few countries can realistically really rely on these as a main source of electricity.

The, there's nuclear. We have fission, which is, while relatively safe (5 major impactful accidents since the rise of nuclear power, 3 of those being the three Fukishima plants), pretty damaging _when_ shit happens. However, are the damages realistically worse than fossil fuels? I'm not exactly qualified to figure this out myself but just looking at the numbers really doesn't make fission look that bad. Finally, there's nuclear fusion, which is a lot safer, while we've been making decent progress in the recent years, doesn't look like it's gonna run our cities any time soon.

So no, we shouldn't be burning coal, obviously, but if nothing's perfect, the logical option is the next best thing.

[1] https://www.bbc.com/news/science-environment-39032748 [2] https://www.ucsusa.org/clean-energy/decrease-coal-use

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

#67

Post by petschge »

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?

It would not have holes in it. The main reason why the gamma radiation makes it through is because it never interacted with any of the lead. And even if a (unlucky) gamma photon interacts inside the lead sheet it would not do much damage there. The only thing that really do damage to the material is neutron radiation and even there the damage is on the microscopic level (atoms getting knocked out of place) than anything macroscopic.

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

#68

Post by ChuckMcM »

petschge wrote: post #45
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…

Boron actually mostly acts as a neutron poison, i.e. it absorbs neutrons. That way further (stimulated) decay of other nucleii that were hit by a neutron is eliminated and the chain reaction stops, reducing the production of thermal energy. A moderator on the other hand inelastically scatters neutrons, converting some of the kinetic energy of the neutrons to heat and leaving a slower neutron. Moderators are used in r…

Correction noted! Thanks!

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

#69

Post by wolco »

komali2 wrote: post #60
ctoth wrote: post #55

I suspect I am not the only person who saw "First contact made" at the top of HN and for one brief, shining moment lived in a far more interesting Universe.

This has happened to me here and there on various aggregators over the years, and every time I get the goosebumps, and ride it out without fully reading the headline all the way, letting myself imagine, think "yeah, this is probably how I'd find out about it!" To me it would feel like discovering magic, or the existence of latent psychic abilities in humans. A reality shattering event.

[flagged]

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

#70

Post by [deleted] »

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?

[deleted]
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