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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

#51

Post by slt2021 »

Krasnol wrote: post #17
slt2021 wrote: post #8

Earlier quoted context omitted.

japan has limited land, no oil&gas resources, so the nuclear is the perfect source of electricity for them, plus they have the expertise.

Japan has 34 000km (21 126 miles) of coastline. They import about 90% of its energy requirements. This includes nuclear fuel. So this is far away from "perfect" if you can get wind and sun without having to import it.

nuclear fuel: nuclear rods can last about 3-7 years, lets say 5 on avg. 150 rods per 1 GW reactor. so its like one or two rail cars of fuel - extremely compact footprint.

how calculate yourself how much fossil fuel you need to power 1 GW power plant for half a decade, and how much CO2 emissions will you generate?

How many rail cars of coal Germany will need to generate 1 GW 24/7/365 for 5 years reliably ?

it is just unfair comparison, nuclear is several orders magnitude better in all aspects compared to fossil fuel and renewable - just due to physics of the process. Nuclear is capturing strong and weak forces, while combustion is capturing electromagnetic force with piss poor thermal efficiency and losses abound.

The only reason countries fumble nuclear energy is because they dont invest enough into new designs and constructions and still employ old design plants.

If there was as much investment into new nuclear plants as it was in renewable tech - we would have solved many of our energy needs long long time ago.

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

#52

Post by chasil »

polotics wrote: post #36
fsh wrote: post #10

Earlier quoted context omitted.

The explosion of Chernobyl released a few thousand PBq of activity. Coal contains a few tens to a few hundreds of Bq/kg. You would have to burn something like 50 times the world coal reserves (and make sure not to use any exhaust filters) in order to match the radiation release of Chernobyl.

Chernobyl with its totally mad graphite design is not representative of safe designs like Fukushima, or French plants, or even Chinese plants...

Are there safer plants still, that focus on eliminating the daughter nuclei?

I understood that one benefit of molten salt reactors is that the fission products were easier to process or burn.

Edit: "MSRs enable cheaper closed nuclear fuel cycles, because they can operate with slow neutrons. Closed fuel cycles can reduce environmental impacts: chemical separation turns long-lived actinides into reactor fuel. Discharged wastes are mostly fission products with shorter half-lives. This can reduce the needed containment to 300 years versus the tens of thousands of years needed by light-water reactor spent fuel."

https://en.wikipedia.org/wiki/Molten-salt_reactor

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

#53

Post by autoexecbat »

bamboozled wrote: post #50
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…

If you were a Japanese tax payer, would it be a success ? The total cleanup costs were estimated to be between 50.5 and 71 trillion yen ($470 to $660 billion). For the cleanup, only 184.3 billion yen was reserved in the September supplementary budget of prefecture Fukushima, and some funds in the central government's third supplementary budget of 2011.

They don't have to pay for it all this year

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

#54

Post by bamboozled »

autoexecbat wrote: post #53
bamboozled wrote: post #50

Earlier quoted context omitted.

If you were a Japanese tax payer, would it be a success ? The total cleanup costs were estimated to be between 50.5 and 71 trillion yen ($470 to $660 billion). For the cleanup, only 184.3 billion yen was reserved in the September supplementary budget of prefecture Fukushima, and some funds in the central government's third supplementary budget of 2011.

They don't have to pay for it all this year

Very naive comment. It’s still a lot of money.

Are you aware about the current economic and demographic situation in Japan ?

It’s not good here. That money could’ve went to a lot more useful things. Also remember this was a man made disaster. The plant was not upgraded (as recommended) to meet new safety guidelines, because, as if a mega tsunami would actually happen, right ? Then right after the event the operator was downplaying the extent of meltdown for too long. The PM had to step in and get a proper response team organised.

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

#55

Post by wkat4242 »

bell-cot wrote: post #27
Kon5ole wrote: post #21

Earlier quoted context omitted.

Once you decide to run nuclear power in a country you have centuries of unavoidable costs no matter what the next government, or next ten generations of citizens decide to do. This is a unique cost consideration for nuclear power, which IMO is rarely considered by the proponents.

> ...centuries of unavoidable costs no matter what... OR, you put the nasty and long-lived radwaste into (say) lead barrels, and bury those below some nice, deep, easily-monitored ocean trench. Absolutely nobody's going to accidentally dig those up. And if the effort needed to intentionally do so would be greater than the effort to brew their own fresh radwaste, then nobody will bother trying that, either.

Barrels don't last when filled with nuclear material. The radiation embrittles the materials over time, they wouldn't last 100 years. And then all that crap will be released into the ocean and swerve all over the world.

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

#56

Post by pvaldes »

bell-cot wrote: post #27
Kon5ole wrote: post #21

Earlier quoted context omitted.

Once you decide to run nuclear power in a country you have centuries of unavoidable costs no matter what the next government, or next ten generations of citizens decide to do. This is a unique cost consideration for nuclear power, which IMO is rarely considered by the proponents.

> ...centuries of unavoidable costs no matter what... OR, you put the nasty and long-lived radwaste into (say) lead barrels, and bury those below some nice, deep, easily-monitored ocean trench. Absolutely nobody's going to accidentally dig those up. And if the effort needed to intentionally do so would be greater than the effort to brew their own fresh radwaste, then nobody will bother trying that, either.

People keep proposing that nonsense from 70's but can be cured studying some really basic biology and oceanography. In 2024 is at a level similar than saying that smoking is good for your children. Is not even funny as a joke.

> Absolutely nobody's going to accidentally dig those up

Read about the concept of vertical migration

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

#57

Post by fsh »

polotics wrote: post #36
fsh wrote: post #10

Earlier quoted context omitted.

The explosion of Chernobyl released a few thousand PBq of activity. Coal contains a few tens to a few hundreds of Bq/kg. You would have to burn something like 50 times the world coal reserves (and make sure not to use any exhaust filters) in order to match the radiation release of Chernobyl.

Chernobyl with its totally mad graphite design is not representative of safe designs like Fukushima, or French plants, or even Chinese plants...

Fukushima also released more radiation than all the coal that has ever been burned (a few hundred PBq, ignoring the thousands of PBq of Xe-133). The amount of radiation created by a nuclear power reactor is on an entirely different scale than any natural source of radiation.

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

#58

Post by teamonkey »

Dalewyn wrote: post #38
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…

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 with nuclear is not technological, it’s guaranteeing that whoever is responsible for it will be competent, capable and solvent for hundreds of years.

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

#59

Post by credit_guy »

Kon5ole wrote: post #3

Are the costs of this 13 years and counting expense tab added to the cost of electricity generated by nuclear power plants in any way? Seems to me like it should, so that generations-long decisions are not made from overly optimistic numbers.

At least in the US such costs are factored in. First of all, after Fukushima, the Nuclear Regulatory Commission (NRC) performed a huge "Lessons learned" exercise, and asked all the power plants to do various upgrades. Here are some links [1], [2]. The ask was not "pretty please, can you do this if it's not much of a trouble for you", it was "you have to do this by this date if you want to continue to operate".

Second, it's the nuclear insurance. The scheme is codified in the Price-Anderson Act [3]. Basically, all the nuclear power plants need to purchase insurance for $0.5 BN per reactor. If anything happens, and the cleanup costs exceed this number, then the rest of the industry has to chime in, and the total is up to $16 BN per reactor. So, if 3 reactors were to have a core meltdown, the industry would have to pay close to $50 BN. The total estimate of the Fukushima cleanup stands currently at about twice that, so one can say that $50 BN is too little, but it certainly is not nothing.

Edit: the efficacy of the Price-Anderson Act was tested at the Three-Mile Island. Virtually no taxpayer money was used in the cleanup [4]. Of course, there were other costs incurred, such as in collecting data, doing investigations, upgrading regulations and enforcing them, but that's how Government should work.

[1] https://www.nrc.gov/docs/ML2132/ML21322A288.pdf

[2] https://www.nrc.gov/reactors/operating/ops-experience/fukush...

[3] https://crsreports.congress.gov/product/pdf/IF/IF10821

[4] https://www.gao.gov/products/117345

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

#60

Post by wkat4242 »

polotics wrote: post #36
fsh wrote: post #10

Earlier quoted context omitted.

The explosion of Chernobyl released a few thousand PBq of activity. Coal contains a few tens to a few hundreds of Bq/kg. You would have to burn something like 50 times the world coal reserves (and make sure not to use any exhaust filters) in order to match the radiation release of Chernobyl.

Chernobyl with its totally mad graphite design is not representative of safe designs like Fukushima, or French plants, or even Chinese plants...

Yet we've had Chernobyl, Fukushima, Three Mile Island, Sellafield and many others (military ones too). Unforeseen accidents happen. Wars too, which tend to destroy safety equipment.

Artillery was fired around Zaporizhzhia when the reactors were still online, Ukraine is currently invading Russia near Kursk where two of the mad-graphite RBMK reactors are still operational today. I hope they try to avoid those when blowing stuff up. Because they don't have containment vessels.

And then see how difficult it is to clean up an accident like Fukushima where the containment mostly held. It feels like playing with fire.

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