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Robot Squeezes Suspected Nuclear Fuel Debris in Fukushima Reactor (theverge.com)
A robot outfitted with remotely controlled pinchers poked at debris that's suspected to contain molten nuclear fuel at the bottom of one of Fukushima's nuclear reactors, World Nuclear News reports. From a report: The poking and prodding is part of the ongoing cleanup effort at Japan's Fukushima Daiichi power plant, the site of a major nuclear accident in 2011. The dextrous robot was dangled into the Unit 2 reactor on February 13th, according to a news release from the plant's operator, Tokyo Electric Power Company (TEPCO). Unit 2 is one of the reactors at the Fukushima Daiichi power plant that overheated after a massive earthquake and tsunami hit Japan in 2011, which caused the reactor core to melt. TEPCO suspects that radioactive fuel may have melted through the bottom of the reactor vessel to fall into the containment structure surrounding it. The company has to find the radioactive debris and figure out how to remove them, so TEPCO has been sending in a series of robots to scout out the reactors. It's a dangerous journey that some of the robots haven't survived.
Scary.
Poke-e-mon.
Table-ized A.I.
....for 1000, Alex.
Palaces, barricades, threats, meet promises
Mr. Whipple will get upset.
Of course you can induce criticality that way. You can hit a small chunk of uranium with a hammer and reach criticality, at least for a moment. U-235 can reach criticality with a mass as small as 780 g under the right circumstances. And the presence of water, potentially with some amount of uranium in solution, greatly raises the risk. Of course, it would only remain critical while compressed, and so such a small criticality event would likely be a risk only to the robots, because it would be small and self-contained.
Perhaps you meant that it cannot cause a nuclear explosion (which requires not just enough material and moderation to sustain a reaction, but also for it to increase exponentially and not burn itself out in a fraction of a second).
Check out my sci-fi/humor trilogy at PatriotsBooks.
ok, youre there, hows the environment? theres enough radiation down here to cook a chicken guys, can i come back up now? not just yet, see that radioactive material? give it a squeeze ....for real? is that safe? that sounds like its not safe.
sure yeah youre a robot just...give it a quick squeeze
ok, i squeezed it, what now??
wear it like a little hat. little robot hat. ....so but this is for science?
oh uh, yeah all the best robots do it for science
Good people go to bed earlier.
The dextrous robot was dangled into the Unit 2 reactor
Maybe if they didn't make their robots out of sugar they would last longer under the heat.
I am armed because I am free. I am free because I am armed.
Like we should have stopped building railroads after the first fatal accident and stopped building airplanes after the first crash killed someone and stopped the space program after the Apollo 1 fire and stopped production of all monoclonal antibodies after the first patient died from side effects?
We learn from each accident and improve. You are including accidents from the relative infancy of nuclear power. For example, at the time of the accident, Chernobyl was an ancient plant of ancient design with idiot operators.
Anthropogenic climate change is likely to be much more dangerous to humans than nuclear power is even if every kWh of energy used by humans were produced by modern nuclear power plants. As well, accidents arising from nuclear power plants have tiny scope compared to the worldwide impact of climate change. Generating power via nuclear fission is an excellent way to reduce greenhouse gas emissions.
Why is there an "insightful" mod and why isn't it "-1"? If I wanted insight, I wouldn't be reading
about 20 years ramping up from 0 to 2000 TWh/yr, plus 30 years at about 2200 TWh/yr = (20*2000/2) + (30*2200) = 86000
Cost of the above two cleanups divided by the amount of energy generated by nuclear power: $432 billion / 86000 billion kWh = $0.005 per kWh = 0.5 cents per kWh
I can live with paying an extra half cent per kWh to cover cleaning up after the occasional disaster every 25 years, in exchange for using a completely carbon-neutral power source which boasts the fewest deaths per amount of power generated. Why exactly are you opposed to it?
I should hope they're trying to clean this mess up.
Well, first they've got to find the mess, which has taken years and which will probably take many more years. It's all well and good to say "clean the site up", but if you just had at it you'd probably cause more harm than good.
For the moment the situation appears stable-ish, but since we don't really know what's going on it makes sense to find out rather than trusting our luck.
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What makes you think that the "cleanup cost" of the Chernobyl and Fukushima disasters is yet known in its entirety?
Also, there are not only costs for disaster clean-ups, but currently completely unknown costs for the safe storage of the nuclear waste produced. The Asse II mine alone, which was attempted to be used for nuclear waste storage during 11 years, has cost ~9 billion Euro as of today, with no end of additional costs in sight. And that was just one small site.
I'm not a nuclear apologist by any means, but it's an empty argument to say Fukushima means nuclear is impossible. Nobody would build a plant remotely like this one, or situate a modern plant anywhere like there.
I'm a huge proponent of upgrade the electric grid. This would enable renewable sources to power distant cities, but it could *coincidentally* give more flexibility in locating nuclear plants, should we decide to build more of them. And if we do we need to build what we've learned about organizations running nuclear plants (we can't rely on them doing the right thing) into the design.
I don't believe we should have a all-eggs-in-one basket approach to our energy needs. A diverse portfolio of energy sources means we can build them where the marginal risk/environmental cost is minimal.
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... idiot operators.
Have we solved this problem yet?
dna.js
I'm not a nuclear apologist by any means, but it's an empty argument to say Fukushima means nuclear is impossible. Nobody would build a plant remotely like this one, or situate a modern plant anywhere like there.
Consider that there is approximately 80 of these types of reactors still in operation and that their service life is 40 years which has been extended to increase the return on investment.
The next thing to consider is that it is possible to make a reactor design that isn't an improvement over older designs. Currently the best one is EPR which...
And if we do we need to build what we've learned about organizations running nuclear plants (we can't rely on them doing the right thing) into the design.
incorporates some of the improvements the NRC commissioned the Nuclear industry to uncover. They came up with 30 improvements to Nuclear reactor design. The most significant improvement was to build them underground. What was discovered is that this makes Nuclear power more costly to build, which scares off investors. So it's not impossible to make nuclear safe, it's very expensive.
I'm a huge proponent of upgrade the electric grid. This would enable renewable sources to power distant cities, but it could *coincidentally* give more flexibility in locating nuclear plants, should we decide to build more of them.
The criteria for locating nuclear facilities is specific process based on its requirements. It is a difficult process so it is surrounded by law to exclude the general population from interfering with it. It's much easier to extend the grid to somewhere it is appropriate to build a nuclear facility.
I don't believe we should have a all-eggs-in-one basket approach to our energy needs. A diverse portfolio of energy sources means we can build them where the marginal risk/environmental cost is minimal.
Indeed. We should immediately begin a program to increase the amount of solar, wind and geothermal energy that we are producing while we can draw energy from these legacy supply methods.
My ism, it's full of beliefs.
I can live with paying an extra half cent per kWh to cover cleaning up after the occasional disaster every 25 years, in exchange for using a completely carbon-neutral power source which boasts the fewest deaths per amount of power generated. Why exactly are you opposed to it?
The first is that information related to this subject is heavily censored. The information you have provided is from organizations who are restricted in what they are allowed to publish.
Money isn't the main consideration. The impact of a single disaster is. Fukushima was four disasters at once and considering the amount of spent fuel rods stored on the site had the potential to be an extinction level event. It still does as the removal process has stalled with 566 rods remaining in a precarious position in the heavily damaged Unit 3 spent fuel pool. Tepco itself acknowledges this as the most potent risk for a much more serious disaster than the original.
At this point though it is worthwhile to point out that Tepco has removed approximately 1000 spent fuel rods - which is an enormous effort that should be commended, with gratitude to the workers and engineers that continue to risk their lives to eliminate this risk.
My ism, it's full of beliefs.
Nobody would build a plant remotely like this one, or situate a modern plant anywhere like there.
And was this the last unsafe plant in operation, or are there more plants at risk ? If there are more, what are the plans for shutting them down ?
Of course you can induce criticality that way. You can hit a small chunk of uranium with a hammer and reach criticality, at least for a moment. U-235 can reach criticality with a mass as small as 780 g under the right circumstances. And the presence of water, potentially with some amount of uranium in solution, greatly raises the risk. Of course, it would only remain critical while compressed, and so such a small criticality event would likely be a risk only to the robots, because it would be small and self-contained.
Perhaps you meant that it cannot cause a nuclear explosion (which requires not just enough material and moderation to sustain a reaction, but also for it to increase exponentially and not burn itself out in a fraction of a second).
But since it was a 60's style LWR, there wouldn't be pure U-235 in the reactor. It would be LEU which is probably 4% U-235 and 96% U-238 or so as new fuel. Exactly what the isotopic distribution of this material is, I'm not exactly sure, but I'm 100% certain it doesn't contain more than a few percent of U-235. Since U-238 is a neutron poison, I seriously doubt that criticality could be induced accidentally. You probably couldn't induce criticality in this material without explosives (or lots of a moderator material) but I can't be sure of that. The hazard with this material is the fission products and all but the medium lived ones like Cs-137 and Sr-90 will have already burned out by now to stable elements. The long lived stuff like U-235 isn't very radioactive (but it is poisonous). The short lived stuff is now stable isotopes, mostly heavy metals. Its still a hazard to human life, but not in the dramatic fashion you imagine. Its more dangerous because of the amount of heavy metals which are poisonous to humans in high amounts and less dangerous because of nuclear issues at this point.
"Those that start by burning books, will end by burning men."
... idiot operators.
Have we solved this problem yet?
Somehow I don't think anyone will ever be that stupid again. Basically, they simulated a meltdown by shutting off all the safety and power systems to see if the momentum of the spinning turbines could keep the cooling system going. Well, they couldn't so then they turned up the reactor to full power to keep them going which caused the reactor to get too hot and then try tried backing off the reactor but it was already out of control. And since all the safety systems were already disabled and couldn't quickly be re-enabled, the reaction ran out of control and produced a huge steam explosion. Since it never happened before or since, I'm not sure its as big a problem as you think. Also, considering the deaths per TWh for all other power sources are the same or (often much) worse than nuclear, I'm not sure this is quite the showstopping problem you imagine it is.
"Those that start by burning books, will end by burning men."
You can't point at the cleanup costs, any more than you can point out how cheap it is for a dude to dig coal out of the ground and burn it or someone who just randomly put a wind turbine on his house and now claims to get free electricity.
The best method we have is levelised cost of energy. I don't know if LCOE for nuclear includes cleanup costs - I would guess not as it's rare that they need to deal with it, but as you note it might not be that much anyway.
The most interesting thing though is the LCOE of renewables continues to fall, while nuclear seems to be pretty steady in terms of cost.
Note: I'm not super opposed to nuclear. But I prefer the idea of small, more decentralised power generation + smart grid. Ultimately though most of what I read in LCOE terms seems to indicate that nuclear is just more expensive. (You can make the argument that nuclear is expensive because of regulatory pain, which is fair - but doesn't really help much. Expensive is expensive! )
You pay this in addition to other costs for nuclear which are already so high that nobody really invests in nuclear anymore. Also the deaths per TWh you refer to from a random source on the internet is not plausible as it obviously ignores excess deaths from radiation which is hard to estimate but also can't be ignored completely.
I can live with paying an extra half cent per kWh to cover cleaning up
Something you wouldn't need to do if our reactors weren't 40+ years old and if the greenies hadn't handcuffed development of safer nuclear technologies for the past 50 years.
but currently completely unknown costs for the safe storage of the nuclear waste produced
1. Hyperbole claiming something we've been doing for 40 years is unknown. X.
2. Pointing to a single case to make a general claim rather than a study of industry practice. X.
3. Ignoring that the issue is mostly of political nature and that many better options for waste exist. X
4. Not reading the original links posted and making a claim that something is unknown. X
BINGO! Hey everyone, I got NIMBY Nuclear Bullshit Bingo!
That's a vast under-estimate for the cost of the Fukushima clean up. Are you including all the compensation and knock-on costs like delayed tsunami damage repair and having to build new communities because the old ones have dissipated over the years?
Also, calculating the per kWh cost based on global production is ridiculous. Only Japanese people are paying that cost, and for them it's vastly higher.
Of course, this is a pretty horrific example of externalizing your costs. Even if you accept the monetary cost, you are not the one being forced out of your home, your community and your job, or getting cancer.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Fukushima was four disasters at once and considering the amount of spent fuel rods stored on the site had the potential to be an extinction level event.
This is by far the stupidest thing I have read so far in 2019. You have another 10 months to try and top it, but I doubt that's possible.
No. There are a number of plants *exactly like this one*, although few in such dangerous places.
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Sorry, all I read was "blah blah blah, I'm a dirty tramp".
That's an incredibly long way of saying "I have absolutely nothing to support my ridiculous assertion".
A report called Nuclear Power Plant Security and Vulnerabilities explored vulnerabilities at nuclear power plants.
From that the issue of spent fuel pool vulnerabilities warranted further study in the now declassified report Safety and Security of Commercial Spent Nuclear Fuel Storage: Public Report by the Committee on the Safety and Security of Commercial Spent Nuclear Fuel Storage within the National Research Council which details variation of the above scenario from a terrorist attack, as opposed to a disaster.
You can find information about plutonium oxidization Evaluation of source-term data for plutonium aerosolization which starts at around 500 centigrade.
Actions to reduce the possibility of these kinds of scenarios are simple and cost effective. Mainly by dry cask storing fuel that has cooled for 5 years and separating and dispersing spent fuel recently removed from the reactor throughout the pool. All very practical, affordable actions for reducing this risk.
Information about the fuel removal process and the damage to the Unit 3 spent fuel pool in Tepco's Fukushima spent fuel removal plan.
There is very little point arguing with people who look at Nuclear power from an idealistic viewpoint. For them Nuclear power is perfect and requires no improvements. This, according to the official report into the Fukushima accident is how it occurred.
Again I would like to express my gratitude to the workers and engineers attempting to get the Fukushima disaster under control.
My ism, it's full of beliefs.
I said "There is a reason that spent fuel rods are kept in a pool with a constant supply of cool water" that is the context. The fuel rods are MOX so we agree that they contain plutonium.
Sure, you could swim in a spent fuel pool, you just wouldn't open your eyes. However I wouldn't hang around if the water drained out or the spent fuel pool collapsed and smashed several thousands tones of concrete and fuel rods together.
Unless you happen to have the manifest for the fuel composition of Fukushima Unit 3 that you can share it's fair to say that you don't know what it is going into the reactor. No one has any idea what the composition of those fuel rods are when they are hot and coming out of the reactor. At issue is there is enough plutonium to start criticality and more than enough energy in the mass of remaining spent fuel for it to become critical within a supercritical radioactive fire outside of a nuclear reactor.
The key take-away for you here is the difference between inside and outside of the body and bio-accumulation in the food chain.
I think you're missing that Fukushima is in the presence of seawater because it's next to the ocean therfore Plutonium *Chloride* is produced which is highly soluble to metabolic processes. Your ignorance lies in that plutonium is an energetic alpha emitter which you refer to as weak because most living things are resistant to external alpha exposure. However it is an energetic alpha so when it is absorbed *into* the body that exposure is *internal* exposure and much more problematic because the layers of skin aren't wrapped around our internal organs.
Plutonium oxide is a potential inhalant and once it is breathed in it is very difficult to remove.
This is the difference between external radiation exposure and internal radiation exposure.
Except we are talking about reactor cores that weigh about 160 tonnes and we have 40 years worth of spent fuel stacked up. So yeah it's many hundreds of tonnes.
I note how emotional you appear and how divorced from reality this makes your rant.
In this sentence several thousand of TONNES with roughly a one kilo warhead would translate to "several thousands" of nuclear warheads when we know there were several hundreds of nuclear tests. That's several hundred kilograms, not several thousand tonnes. Quite a discrepancy in what
My ism, it's full of beliefs.