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Fukushima Reactor: TEPCO robot aims to extract nuclear fuel

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Re: Fukushima Reactor: TEPCO robot aims to extract nuclear fuel

#101

Post by WalterBright »

ViewTrick1002 wrote: post #33
Scarblac wrote: post #26

Earlier quoted context omitted.

61.5% sounds like a lot, but how much electricity is needed to replace everything that fossil fuel is now used for? I think it needs to increase to 400% or so to do that.

We don't need to replace primary energy with electric energy in a 1:1 ratio. An ICE car is 20-30% efficient, an EV is 90% efficient. Generally we are looking at a grid expansion, but it is not massive. See this amazing chart on rejected vs. useful energy: https://flowcharts.llnl.gov/

> an EV is 90% efficient

An EV is 85-90% efficient with power coming out of the batteries. However, the charging efficiency of the batteries is at about 80%. So the overall efficiency is 80% of 90%, or 72%.

Re: Fukushima Reactor: TEPCO robot aims to extract nuclear fuel

#102

Post by WalterBright »

teamonkey wrote: post #58
Dalewyn wrote: post #38

Earlier quoted context omitted.

The Fukushima #1 meltdown was man-made, namely the absolute ineptitude of the Japanese government at the time. As disasterous as the 3/11 earthquake and tsunami were, those were not what ultimately caused the meltdown.

The government was no more or less inept than any other organisation - government or private - anywhere in the world. When faced with pressure to save money but still deliver, weighed up against a very low risk of catastrophe in their time, they did the mental math and cut corners, found ways around the safeguarding policies previously put in place and kicked infrastructure spending down the line. The big problem wit…

It wouldn't have cost hardly anything to have a pipe so the hydrogen could vent outside rather than inside, which resulted in a detonation.

Re: Fukushima Reactor: TEPCO robot aims to extract nuclear fuel

#103

Post by FastFT »

duskwuff wrote: post #89
rtpg wrote: post #86

Earlier quoted context omitted.

This information is definitely dated and I might be misremembering (but it was given to me right next to the clean room where ICs for satelites were being prepped), but for ICs from a certain manufacturer "rad-hardened" was basically "we take ICs from our normal production batch, and do even more tests on them". The idea being that failure is bimodal: most stuff fails very quickly, _or_ after a long time, but rarely…

You might be thinking of temperature ratings, which are indeed just based on more stringent testing. Radiation hardening is, well, harder . It typically means some combination of different semiconductor processes (often silicon-on-sapphire and/or larger feature sizes) and added internal redundancy (ECC memory, TMR, watchdogs, etc). All of these require that the rad-hard parts be manufactured separately from the comme…

Both cases occur in industry. The parts that only go through additional testing (radiation lot acceptance testing aka RLAT) are commonly sold as “radiation tolerant”. Parts that undergo hardening via design/manufacturing changes are often branded “radiation hardened”. In either case though, the available part portfolio is much smaller than commercial. Further increasing cost is that these parts are often geared for military/aerospace so have expanded temperature ranges, stricter qc, weird package types, etc.

Re: Fukushima Reactor: TEPCO robot aims to extract nuclear fuel

#104

Post by elzbardico »

OrigamiPastrami wrote: post #45
akerl_ wrote: post #34

Earlier quoted context omitted.

https://news.ycombinator.com/newsguidelines.html > Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes. > Comments should get more thoughtful and substantive, not less, as a topic gets more divisive.

I strongly wish we had more comments like the one you're responding to. I find most comments here to be obnoxiously polite and I wish more ignorant opinions were publicly demolished as they should be, rather than continue to spread misinformation because it's the polite thing to do. Not all opinions are created equal.

Well, I may be ignorant, but the reality of the my relatives energy bill in Germany and the UK tends to agree with my ignorance. Maybe you are just smart enough to regurgitate the propaganda, but not enough to think for yourself.

https://www.theguardian.com/business/2024/oct/01/the-man-in-...

Re: Fukushima Reactor: TEPCO robot aims to extract nuclear fuel

#105

Post by jamesknelson »

legulere wrote: post #67
JumpCrisscross wrote: post #29

Earlier quoted context omitted.

> 61.5% of Germany's electricity comes from renewable sources Now. For years they switched to coal. Even today, Germany falls to the siren songs of the gas lobby, who promise a €1.5tn investment into gas infrastructure will be happily written off for the sake of the planet.

Nuclear was replaced by renewables, not by coal: https://commons.wikimedia.org/wiki/File:Energiemix_Deutschla... https://commons.wikimedia.org/wiki/File:Electricity_generati... A point you certainly can argue about, is that coal should have been replaced by renewables before nuclear, but that discussion is over now. For gas use electricity production is just a minor use. Most gas is consumed by industry and for heati…

Nuclear wasn’t completely replaced. The graphs you link to show that Germany’s electricity generation have dropped to the level it was at in the year 2000, and that’s before the last of the nuclear plants were turned off.

As a result, Germany’s industrial production is falling. Which will be great for the environment if countries who previously imported goods produced by Germany’s clean nuclear power don’t just switch to goods produced by China and South East Asia’s far dirtier electricity.

Of course, China is steadily increasing its own nuclear energy production, so it’ll end up being clean eventually, and likely sooner than us given how efficient they are.

But it’s not like we’re reducing dependency on nuclear power. It’s more like we’re trading the risk of nuclear accident in our own backyards for something else. I tend to think that the something else is the risk that the eastern world’s factories stop accepting the western world’s increasingly worthless paper money, which they’ll be in a much stronger position to do once we’re no longer able to manufacture what we need due to environmental concerns.

Re: Fukushima Reactor: TEPCO robot aims to extract nuclear fuel

#106

Post by rtpg »

duskwuff wrote: post #89
rtpg wrote: post #86

Earlier quoted context omitted.

This information is definitely dated and I might be misremembering (but it was given to me right next to the clean room where ICs for satelites were being prepped), but for ICs from a certain manufacturer "rad-hardened" was basically "we take ICs from our normal production batch, and do even more tests on them". The idea being that failure is bimodal: most stuff fails very quickly, _or_ after a long time, but rarely…

You might be thinking of temperature ratings, which are indeed just based on more stringent testing. Radiation hardening is, well, harder . It typically means some combination of different semiconductor processes (often silicon-on-sapphire and/or larger feature sizes) and added internal redundancy (ECC memory, TMR, watchdogs, etc). All of these require that the rad-hard parts be manufactured separately from the comme…

it definitely wasn't temperature ratings, and it definitely was chips going into satellites. This was part of an internship at a place (I was in the "normal IC chip" testing zone, though).

I just might not be sure on the "space-rated" things being "radiation-hardened" or if it's more just "well they're gonna be more tested".

Re: Fukushima Reactor: TEPCO robot aims to extract nuclear fuel

#107

Post by kelnos »

Dalewyn wrote: post #96
jborean93 wrote: post #81

Earlier quoted context omitted.

How does that refute what the parent comment was saying? Sounds like you are agreeing that the problem is not the technology but the people and processes in place.

The problem is (or at least was) with the people in political chairs playing power games. No amount of better regulations or technology can prevent fucking morons going on power trips screwing everything up and then get away with it. The nuclear (TEPCO) people in the field were and are amazing, and it is a cardinal sin they got scapegoated for political purposes.

But that's kinda the point: name one government in the world where politicians don't play political games, sometimes in ways that put their citizens in danger. I'm sure you can't, because no such government exists.

"Everything would have been fine if it weren't for the politicians" is not a path forward. These sorts of disasters will continue to happen.

Re: Fukushima Reactor: TEPCO robot aims to extract nuclear fuel

#108

Post by Dalewyn »

kelnos wrote: post #107
Dalewyn wrote: post #96

Earlier quoted context omitted.

The problem is (or at least was) with the people in political chairs playing power games. No amount of better regulations or technology can prevent fucking morons going on power trips screwing everything up and then get away with it. The nuclear (TEPCO) people in the field were and are amazing, and it is a cardinal sin they got scapegoated for political purposes.

But that's kinda the point: name one government in the world where politicians don't play political games, sometimes in ways that put their citizens in danger. I'm sure you can't, because no such government exists. "Everything would have been fine if it weren't for the politicians" is not a path forward. These sorts of disasters will continue to happen.

I agree, but then that should not be falsely characterized as a failure of the nuclear industry and technology. The failure was humans, and a very specific subset at that.

Re: Fukushima Reactor: TEPCO robot aims to extract nuclear fuel

#109

Post by nl »

jamesknelson wrote: post #105
legulere wrote: post #67

Earlier quoted context omitted.

Nuclear was replaced by renewables, not by coal: https://commons.wikimedia.org/wiki/File:Energiemix_Deutschla... https://commons.wikimedia.org/wiki/File:Electricity_generati... A point you certainly can argue about, is that coal should have been replaced by renewables before nuclear, but that discussion is over now. For gas use electricity production is just a minor use. Most gas is consumed by industry and for heati…

Nuclear wasn’t completely replaced. The graphs you link to show that Germany’s electricity generation have dropped to the level it was at in the year 2000, and that’s before the last of the nuclear plants were turned off. As a result, Germany’s industrial production is falling. Which will be great for the environment if countries who previously imported goods produced by Germany’s clean nuclear power don’t just switc…

> As a result, Germany’s industrial production is falling

The causality here seems debatable.

Cheap Chinese goods which take market share from German goods aren't just cheap because of cheap energy.

Re: Fukushima Reactor: TEPCO robot aims to extract nuclear fuel

#110

Post by portaouflop »

foxyv wrote: post #66
baq wrote: post #2

> “With the goal of completing the decommissioning in 30 to 40 years [...]" Can't decide if it's a success of nuclear or a failure. Leaning towards success: - ~900 tons of super duper radioactive material is more or less safely sitting in steel enclosures - we're (as a global civilization) slowly but surely figuring out how to move the hazardous waste to a safer storage, and it may only (ahem) take a couple generatio…

To add to your point. Disposal of nuclear waste at sea was common up until 1993. There is still a couple hundred thousand tons of such waste sitting in the ocean right now. In addition, about 214 times as much radioactive material was generated by nuclear testing than the Chernobyl breach. Fukushima wouldn't even come close to the waste that has already been released prior to the 1994 ban on Oceanic dumping.

What is the point ? That we dumped so much crap into the ocean a little more won’t hurt?
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