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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

#61

Post by jjoonathan »

bamboozled wrote: post #36
jjoonathan wrote: post #20

Earlier quoted context omitted.

> Kind of surprising at this point Fukushima was built when the nuclear power industry was 13 years old. Now it's 63 years old. You are seeing the folly of youth, with consequences delayed 60 years, not a design that would be typical of new construction.

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 correctly. The industry quickly learned how to build reactors that could handle neglect and abuse, but by then the reactors under the ground were out of their control, and were essentially ticking time-bombs. Everyone in the industry knew it. The IAEA had been complaining about ancient, unsafe reactor designs in the ring of fire for decades when Fukushima happened. So it goes.

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

#62

Post by beached_whale »

jjoonathan wrote: post #20
rtkwe wrote: post #8

Kind of surprising at this point that there’s not an area directly below the bottom of the reactor with a giant ceramic catch basin (or something similarly heat resistant) to catch these failures and cleared of pipes etc so when this happens cleanup workers know the location of the materials.

> Kind of surprising at this point Fukushima was built when the nuclear power industry was 13 years old. Now it's 63 years old. You are seeing the folly of youth, with consequences delayed 60 years, not a design that would be typical of new construction.

Also, from what I understand, they ignored the reports that recommended to put the backup generators on higher ground and to make the sea wall higher. Fukashima is the worst case for that design I think.

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

#63

Post by jjoonathan »

eeZah7Ux wrote: post #57
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. https://en.wikipedia.org/wiki/Nuclear_and_radiation_accident... Not only scientists but the whole humanity is acting like "naive teenagers" here.

I'd go even further: the bigger the aggregation of people, the younger they act. The UN is basically kindergarten with fancy clothes and longer words.

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

#64

Post by thaumaturgy »

baron816 wrote: post #44
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...

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 China. Then, multiply that rate by the world's population, and you have, let's say 450,000 coal-related deaths per year worldwide. This is a really squishy number, but we only need approximations here.

You were concerned about how many people would die every hundred years from nuclear disasters, so let's see if we can work today's 450,000 per year estimated deaths backwards for the last hundred years.

The world population was somewhere in the neighborhood of 1.8 billion people in 1917. Assuming linear growth (I know, I know) and a strong r-value correlation for population vs. coal-related deaths (arguable, but again, Fermi estimate), we have to sum .00006 * population from 1.8 billion -> 7.6 billion, and we end up with approximately 28 million people.

Which is to say, if we could gather up all the deaths, worldwide, from coal, over the last hundred years, and convert it into a single disaster, it would kill the entire city of Shanghai, and New York for the apple on top.

That would have to be one hell of a nuclear disaster.

Now, there are arguments to be made that the energy we've received from coal has also powered hospitals and technology which have saved or improved people's lives. There are also arguments to be made that the side-effects of coal (hospitalization, environmental disasters) cause the death toll to absolutely pale by comparison.

And again, I've rounded these numbers down at every stage of the calculation.

[1]: http://www.catf.us/resources/publications/files/The_Toll_fro... [pdf]; it includes its own numbers, at the 13,000 estimate, and the EPA's, at 14,000 to 36,000 range.

[2]: https://www.nextbigfuture.com/2011/03/deaths-per-twh-by-ener... (blog, but includes lots of supporting links; I'm open to alternative sources that give vastly different estimates).

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

#65

Post by kurthr »

tigershark wrote: post #56
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...

Go and live there if you think that it is really harmless. I would rather not honestly after it took them 6 years just to get the first image of the corium after endless attempts.

Well, just note that after Chernobyl, Western Europe did live there. The size of the smoke plume (1000s km), radioactive material released (6000kg), and wind/weather during the event affected almost every country including Spain, England, and Norway. Those 300M people arguably recieved higher doses than you would living in the evacuated Fukushima area.

https://youtu.be/MU4_bJT8W3Y

The point is that it remained contained... that's good. With prpoer monitor wells even the ground water need not be badly contaminated.

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

#67

Post by Alex3917 »

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…

> Every industry makes severe mistakes early on and eventually irons them out with time. Are you arguing that's not the case?

Given that they already knew this could happen when they built it, what could you plausibly claim has been learned?

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

#68

Post by serichsen »

tigershark wrote: post #56
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...

Go and live there if you think that it is really harmless. I would rather not honestly after it took them 6 years just to get the first image of the corium after endless attempts.

Given the choice, I would.

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

#69

Post by [deleted] »

kurthr wrote: post #26
hexane360 wrote: post #15

"At Chernobyl, the Soviets simply entombed the charred reactor in concrete after the deadly 1986 accident. But Japan has pledged to dismantle the Fukushima plant and decontaminate the surrounding countryside, which was home to about 160,000 people who were evacuated after accident." How much of this decision is simply about space? Russia is the largest country by area, with 21 people per square mile, while Japan is m…

Chernobyl is still in Ukrane (near the boarder with Belarus) and not Russia (yet). At the time it was part of the Soviet Union, but Ukraine has always been a bread basket of Central Europe. Fundamentally, Chernobyl is a much larger (order of magnitude) event with 6 tons of radioactive material burned and released. Frankly, for all the coverage Fukushima gets, it's amazing that you rarely hear about the associated tsu…

[deleted]

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

#70

Post by harlanlewis »

eritain wrote: post #40
hexane360 wrote: post #15

"At Chernobyl, the Soviets simply entombed the charred reactor in concrete after the deadly 1986 accident. But Japan has pledged to dismantle the Fukushima plant and decontaminate the surrounding countryside, which was home to about 160,000 people who were evacuated after accident." How much of this decision is simply about space? Russia is the largest country by area, with 21 people per square mile, while Japan is m…

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
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