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Six Years After Fukushima, Robots Finally Find Reactors’ Melted Uranium Fuel

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Re: Six Years After Fukushima, Robots Finally Find Reactors’ Melted Uranium Fuel

#91

Post by cocoablazing »

jjoonathan wrote: post #61
bamboozled wrote: post #36

Earlier quoted context omitted.

Nuclear scientist's weren't like "naive" teenagers though. Sure the design could've been better; However by your logic they had 50 years to take extra safety pre-cautions and improve the structure. In-fact, it still absolutely amazes me it was even running at the time of the disaster and built on a coast in a country notorious for Tsunamis.

> Nuclear scientist's weren't like "naive" teenagers though. Every industry makes severe mistakes early on and eventually irons them out with time. Are you arguing that's not the case? > However by your logic they had 50 years to take extra safety pre-cautions and improve the structure. Economically retrofitting an old reactor with safety mechanisms is a much more challenging task than designing new reactors correctl…

Moving several EDGs and support system a couple kilometers is a small task in comparison to the design, qualification, construction, and training associated with a new power reactor design.

There’s nothing very complicated about the EDG buses that supply safety-system components.

Re: Six Years After Fukushima, Robots Finally Find Reactors’ Melted Uranium Fuel

#92

Post by retromario »

harlanlewis wrote: post #70
eritain wrote: post #40

Earlier quoted context omitted.

This badly understates the Chernobyl response. They did remove the heavily contaminated surface soil from the immediate vicinity and clean up the rest of the site so they could continue to operate the remaining reactors. They built the Shelter Object ("sarcophagus"), instead of just pouring concrete all over the site, so that they could continue to monitor and inspect. And earlier this year, they at last covered the…

The scale of the New Safe Confinement is stunning. Here’s a 2min video of it being moved into place: https://www.youtube.com/watch?v=n7aMcKinrWY

Thank you for sharing this. I had read about it when they were still building it and marvelled at the scale and ambition of the project. That structure is so large it apparently has its own weather system inside.

Re: Six Years After Fukushima, Robots Finally Find Reactors’ Melted Uranium Fuel

#93

Post by archgoon »

SomeStupidPoint wrote: post #89
archgoon wrote: post #79

Earlier quoted context omitted.

Would you prefer for them to be referred to them as "Cosmic Rays" :) ? To be honest, "Space Particles" sounds less silly and more descriptive. It also emphasizes that they're not generating the muons themselves, but collecting them from space. EDIT: Though I guess, now that I think of it, it's a bit unfair to refer to muons as 'exotic'. People will typically encounter thousands of them in a day [1]. [1] http://cosmic…

Aren't muons terrestrial particles created by cosmic ray impacts on the atmosphere, though?

Well, yes; but calling them "exotic-in-the-sense-we-don't-talk-about-them-very-much-even-though-they-pass-by-all-the-time-that-got-created-when-an-actual-space-particle-that-wasn't-that-exotic-like-a-proton-or-helium-atom-hit-the-atmosphere particles called muons" doesn't quite roll off the tongue. :)

They ultimately (and not in the we're all space dust sense, more like 2.2 microseconds ago sense) are caused by interactions with particles from outer space, so calling them space particles, isn't that bad. :) But yeah; it's does elide that aspect of them.

Re: Six Years After Fukushima, Robots Finally Find Reactors’ Melted Uranium Fuel

#94

Post by smallnamespace »

lovemenot wrote: post #75
adekok wrote: post #46

Earlier quoted context omitted.

And that's with incompetence and neglect. http://chernobylgallery.com/chernobyl-disaster/cause/ Personnel had an insufficiently detailed understanding of technical procedures involved with the nuclear reactor, and knowingly ignored regulations to speed test completion And a Japanese reactor that didn't melt down: https://thebulletin.org/onagawa-japanese-nuclear-power-plant... Before beginning construction, Tohoku Ele…

>> And that's with incompetence and neglect. Yes, and rightly so. Engineers must design around human fallibility. They don't get to blame human error and claim the whole system is otherwise perfectly safe. Either the system is safe under conditions of human fallibility, or it is unsafe. >> There's just no good reason for either Chernobyl or Fukushima Of course there is reason. Humans are part of the system and a rela…

How do engineers design around the propensity of politicians to kick the can down the road?

Re: Six Years After Fukushima, Robots Finally Find Reactors’ Melted Uranium Fuel

#95

Post by nl »

thaumaturgy wrote: post #85
nl wrote: post #83

Earlier quoted context omitted.

There are very few people who are anti-nuclear power who are pro-coal. Even ignoring renewables, gas solves many of the worst problems with coal.

Sure, but even natural gas and rooftop solar have higher rates of death per year than nuclear. (In my second link above.) In a world in which we must choose the lesser of evils for energy, nuclear is among the least evils, yet faces the greatest overall public resistance to new installations.

I dunno - even that source itself says that the death rates from solar would fall using better construction methods. It also notes (in the case of wind) that increased take up is associated with lower death rates ("Wind power proponent and author Paul Gipe estimated in Wind Energy Comes of Age that the mortality rate for wind power from 1980–1994 was 0.4 deaths per terawatt-hour. Paul Gipe’s estimate as of end 2000 was 0.15 deaths per TWh, a decline attributed to greater total cumulative generation.")

I'd also note that the very low rates of death from nuclear power do not appear to include construction deaths, which are the only source of death measured from wind and solar.

Re: Six Years After Fukushima, Robots Finally Find Reactors’ Melted Uranium Fuel

#96

Post by nv-vn »

nl wrote: post #83
thaumaturgy wrote: post #64

Earlier quoted context omitted.

Ok, let's do a Fermi-like estimation. Estimates on the number of deaths related to coal generation vary from around 13,00 to 30,000 per year in the US [1] and 500,000 per year in China [2]. The current world population is 7.6 billion, of which the US and China account for approximately 1.8 billion people. Let's round the coal-related death rate way down for easy math: 10,000 per year in the US and 100,000 per year in…

There are very few people who are anti-nuclear power who are pro-coal. Even ignoring renewables, gas solves many of the worst problems with coal.

Being anti-nuclear is pretty much accepting the status quo though. Modern nuclear power is much, much more sustainable than coal, scales very well, and is very safe. If you believe in a quick solution for energy issues then you shouldn't halt all nuclear development and leave fossil fuels for the next couple decades.

Re: Six Years After Fukushima, Robots Finally Find Reactors’ Melted Uranium Fuel

#97

Post by QAPereo »

smallnamespace wrote: post #94
lovemenot wrote: post #75

Earlier quoted context omitted.

>> And that's with incompetence and neglect. Yes, and rightly so. Engineers must design around human fallibility. They don't get to blame human error and claim the whole system is otherwise perfectly safe. Either the system is safe under conditions of human fallibility, or it is unsafe. >> There's just no good reason for either Chernobyl or Fukushima Of course there is reason. Humans are part of the system and a rela…

How do engineers design around the propensity of politicians to kick the can down the road?

Dual major in theology?

Re: Six Years After Fukushima, Robots Finally Find Reactors’ Melted Uranium Fuel

#98

Post by nl »

thaumaturgy wrote: post #64
baron816 wrote: post #44

Earlier quoted context omitted.

I’m not worried about how many people nuclear power kills every year. I’m worried about how many people it kills every hundred years. A major nuclear disaster, however unlikely, has the potential to kill millions of people and leave a big portion of the Earth uninhabitable for centuries. Just because we haven’t seen one on that scale yet, doesn’t mean we never will.

Ok, let's do a Fermi-like estimation. Estimates on the number of deaths related to coal generation vary from around 13,00 to 30,000 per year in the US [1] and 500,000 per year in China [2]. The current world population is 7.6 billion, of which the US and China account for approximately 1.8 billion people. Let's round the coal-related death rate way down for easy math: 10,000 per year in the US and 100,000 per year in…

Is that 0.04 deaths/TWh sourced anywhere?

I've seen it before, but trying to trace it down is... troubling.

There's this report[1], where they only count accidents where more than 5 people were killed. This coincidentally manages to avoid counting all accidents in nuclear plants, where in the US alone there were 8 deaths[2]. I assume other energy sources would see a jump too, but that doesn't give me great confidence. The number from that report is different anwyay.

[3] http://wps.prenhall.com/wps/media/objects/2513/2574258/pdfs/... references some authors which appear to have this 0.04 number, but I can't find the source.

[1] https://www.oecd-nea.org/ndd/reports/2010/nea6861-comparing-...

[2] https://en.wikipedia.org/wiki/Nuclear_reactor_accidents_in_t...

[3] http://wps.prenhall.com/wps/media/objects/2513/2574258/pdfs/...

Re: Six Years After Fukushima, Robots Finally Find Reactors’ Melted Uranium Fuel

#99

Post by nl »

nv-vn wrote: post #96
nl wrote: post #83

Earlier quoted context omitted.

There are very few people who are anti-nuclear power who are pro-coal. Even ignoring renewables, gas solves many of the worst problems with coal.

Being anti-nuclear is pretty much accepting the status quo though. Modern nuclear power is much, much more sustainable than coal, scales very well, and is very safe. If you believe in a quick solution for energy issues then you shouldn't halt all nuclear development and leave fossil fuels for the next couple decades.

Being anti-nuclear is pretty much accepting the status quo though.

Elon Musk would disagree.

If you believe in a quick solution for energy issues then you shouldn't halt all nuclear development and leave fossil fuels for the next couple decades.

Nuclear plants take 30 years at least to get through planning and building. Gas fired plants or pump solar can be deployed within a year, Wind + Solar in even less time.

Re: Six Years After Fukushima, Robots Finally Find Reactors’ Melted Uranium Fuel

#100

Post by Aron »

wiz21c wrote: post #38

https://en.wikipedia.org/wiki/Fukushima_Daiichi_nuclear_disa... reminds us that nuclear kills much less than regular earthquakes, car accidents, or air pollution due to the burning of fossil fuels...

Gah -- reminds me of the press at the time talking about detectable radiation on the West Coast of the US. Yeah -- you know what else is detectable radiation? Stars from light-years away. I was shocked to see Germany respond so strongly to Fukushima. I think fortunately for the world solar and wind have become so cheap we can give up on making the world more rational about nuclear power.
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