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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

#31

Post by ghaff »

jjoonathan wrote: post #23
civilian wrote: post #18

What is the article talking about when they say "radiation-hardened materials"? What kind of materials might that be?

"Neutron embrittlement" is a term to chase down. Generally people talk about the effects on metal, but I'm sure neutrons affect ceramics, too.

One of the issues with metal is that it starts out as a ductile material and neutrons can embrittle it by introducing voids and dislocations. (i.e. basically moving the atoms around from their ordered crystal state) I'm sure some of the same mechanisms apply to ceramics but they're fairly brittle to start with so designs/applications using ceramics need to account for the fact that they're brittle from Day One.

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

#32

Post by faceplanted »

Neil44 wrote: post #30
IshKebab wrote: post #12

Earlier quoted context omitted.

Clay would hold that wouldn't it?

Depends, most types of ceramic are molten by 1300-1400 centigrade

These catchers exist, they use a ceramic-concrete mixture with a massive melting temperature.

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

#33

Post by faceplanted »

thesmallestcat wrote: post #13
Barrin92 wrote: post #11

Earlier quoted context omitted.

maybe they thought they could find a genuine pokemon?

It's exactly the sort of place where you'd find the baddest pokemon in the game.

Definitely the kind of place you should find Ditto.

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

#34

Post by Rapzid »

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.

Sounds like life :| Those cigarettes you smoked in your early twenties? Those beers you smashed working in IT? 63 will be interesting..

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

#35

Post by jdubs »

Rapzid wrote: post #34
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.

Sounds like life :| Those cigarettes you smoked in your early twenties? Those beers you smashed working in IT? 63 will be interesting..

elaborate plz

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

#36

Post by bamboozled »

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.

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.

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

#37

Post by ChuckMcM »

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.

I have seen reactor designs with a borosilicate sand pile under the reactor. Presumably the molten core will turn the sand into borosilicate glass which not only freezes at a high temperature but is also a radiation shield.

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

#39

Post by sschueller »

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.

Wasn't something like that poured under Chernobyl after the accident which prevented the radioactive slurry from entering deep into the ground?

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

#40

Post by eritain »

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 Shelter Object with the long-delayed New Safe Confinement, which includes cranes and other robotics intended to dismantle and decontaminate both the Shelter and the ruins of the reactor.

It's certainly true that the Soviets, and after them Belarus and Ukraine, did/do use the "just leave it alone" strategy for part of their Chernobyl response. But it's by no means the whole story.

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