Slashdot is powered by your submissions, so send in your scoop

 


Forgot your password?
Close
typodupeerror
×
Japan

A Robot Begins Removal of Melted Fuel From the Fukushima Nuclear Plant. It Could Take a Century (apnews.com) 143

Posted by msmash from the moving-forward dept.
A robot entered a damaged reactor at Japan's Fukushima nuclear power plant on Tuesday, beginning a two-week mission to retrieve melted fuel debris for the first time since the 2011 disaster. The operation marks a crucial step in the decades-long process to decommission the plant and address the highly radioactive material inside three damaged reactors.

The robot, maneuvered remotely due to lethal radiation levels, will collect less than 3 grams of debris using tongs. This sample will provide vital data on the status of the reactor cores and inform future cleanup strategies. An estimated 880 tons of molten fuel remains in the three reactors, posing potential safety risks as the structures age. AP adds: Removal of the melted fuel was initially planned to start in late 2021 but has been delayed by technical issues, underscoring the difficulty of the process. The government says decommissioning is expected to take 30-40 years, while some experts say it could take as long as 100 years.

Others are pushing for an entombment of the plant, as at Chernobyl after its 1986 explosion, to reduce radiation levels and risks for plant workers. That won't work at the seaside Fukushima plant, says Lake Barrett, who led the cleanup after the 1979 disaster at the U.S. "You're in a high seismic area, you're in a high-water area, and there are a lot of unknowns in those (reactor) buildings,â he said. "I don't think you can just entomb it and wait."
This discussion has been archived. No new comments can be posted.

A Robot Begins Removal of Melted Fuel From the Fukushima Nuclear Plant. It Could Take a Century More

A Robot Begins Removal of Melted Fuel From the Fukushima Nuclear Plant. It Could Take a Century

Comments Filter:

  • Clean energy (Score:5, Insightful)

    by Tony Isaac ( 1301187 ) on Tuesday September 10, 2024 @12:01PM (#64777291) Homepage

    Nuclear energy is often touted as "clean." And it's true, it doesn't spew carbon into the air. But nuclear fission does produce waste that is very, very hard to dispose of. And there is a non-zero percentage of plants that melt down, and this poses an even bigger, more costly problem.

    To call something "clean" you can't just look at one facet (lack of atmospheric pollution). And you can't just focus on when everything goes well. Accidents do happen, and those accidents do produce serious contamination.

    One has to look at the big picture.

    • Re: Clean energy (Score:2, Insightful)

      by St.Creed ( 853824 )

      I'm giving you a virtual plus one, because the mods did you dirty. Minus one isn't meant to indicate "I disagree".

      • Re: (Score:3, Informative)

        by val383 ( 10300561 )
        The big picture is that atmospheric pollution causes 7 millions deaths every year while nuclear which is millions times more than for nuclear accidents.

        • False dichotomy. Nuclear and coal are not the only alternatives. Another option is renewables + storage.

          Nuclear is cleaner than coal, but much more expensive than renewables. Renewables are getting cheaper. Nuclear is not.

          Standardized designs such as the AP1000 and EPR were supposed to fix the problem but failed.

          Thorium MSRs might be a solution, but they're unproven. Building more PWRs is nuts.

          • OP is not talking about alternatives. This is not theory, these plants are up and polluting as we speak (or type). Coal plants are releasing tons of radioactive material into the atmosphere every day. Assuming you are average Slashdot age, this is the lowest level of radioactive pollution in your lifetime. I am no nuclear booster, and renewables are clearly the future of electricity, but it is by far the lesser of the evils we have available today.

            • I am no nuclear booster, and renewables are clearly the future of electricity, but it is by far the lesser of the evils we have available today.

              We should not, now, be closing any existing nuclear plants unless they have serious problems (graphite in some reactors is seriously deteriorated and beyond reasonable repair). The question, though, is what to do with money that people are willing to invest? If there's, say $100 billion to spend, where is it best spent?

              There's a clear answer to that. Very wide scale grids + pumped storage + batteries + renewables, especially solar and wind can give a vastly bigger bang for buck than Nuclear already today.

              • Re: (Score:2)

                by AmiMoJo ( 196126 )

                It's difficult to tell if nuclear plants are having serious problems. It's not like you can just open the reactor up and inspect it, so you end up trying to use ultrasound and the like to detect cracks and other flaws. As the reactors get older they need more frequent inspections, more downtime etc.

                They get to a point where they are not safe to economically operate, so you have to choose between shutting them down and taking the risk of a catastrophic failure. As we have seen "containment" buildings are not

                • They get to a point where they are not safe to economically operate, so you have to choose between shutting them down and taking the risk of a catastrophic failure.

                  Absolutely, at the point where keeping it safe costs more than replacing it with renewable energy and storage, that's definitely the point where money should already have been made available to put those renewable sources online. My problem is that I don't fully trust the nuclear engineers, with their long history of overoptimism and denial, to make that judgement, however I think we need to take a little risk right now in order get the maximum push towards decarbonization. We know for sure that running fos

            • Once nukes are up and running, there is rarely a good reason to shut them down. That's what Germany did, and it was stupid. Nearly all the costs are upfront, and once it's running, the core is radioactive, and shutting it down doesn't change that.

              The question is, what do we do in the future? Coal is out of the question. No new coal plants are being built in developed countries. So it's nuclear or renewables+storage, and the renewables can be deployed far faster and at a much lower cost.

    • What is the basis of the censor mod points and why do the trolls or their sock puppets even have mod points to bestow?

      On the story, I think it's quite a stretch to call it a robot, at least as it's being described by local television news stories. But you are right that the cleanup costs need to be considered, though not just limited to disasters like this one. Even the reactors that don't have disasters will be quite and expensive hard to decommission.

      So I'll go for the joke? How about a company selling "c

    • Re:Clean energy (Score:5, Interesting)

      by sjames ( 1099 ) on Tuesday September 10, 2024 @01:01PM (#64777439) Homepage Journal

      Political paralysis is a big part of the waste problem. Most of the "waste" is usable fuel that could be re-processed. The rest is pretty nasty, but unlike the big piles of fly-ash next to every coal plant, the waste will over the course of time become less and less harmful until it becomes just a big pile of scrap.

      BTW, the "waste" could easily be processed into a mixed actinide fuel rather than into mixed oxide (uranium and plutonium). The process is much simpler and is proliferation resistant. There are reactors that will run fine on mixed actinides.

      With the right reactor designs and reprocessing, we could probably go for 70 to 100 years just on the "spent" fuel that is currently being held on-site at reactor facilities. The end result would be a drastic reduction in the required storage time for the actual waste.

      Note that once the more radioactive parts of the waste are concentrated, it might be (physically) hot enough to provide useful backup power to the nuclear plant.

      • Re:Clean energy (Score:5, Informative)

        by MachineShedFred ( 621896 ) on Tuesday September 10, 2024 @01:16PM (#64777511) Journal

        Reprocessing is prohibitively expensive. Japan has spent $27.5B and 30 years building a reprocessing facility that hasn't reprocessed a single gram of spent fuel yet.

        Reprocessing uses the exact same tech as weapons-grade material processing, so there is very little political will to expand usage of Plutonium / Uranium extraction (PUREX). And limiting reprocessing to only "trusted" countries that won't divert materiel to weapons programs means shipping highly radioactive spent fuel to countries that have the capability. That means lots of hazardous shit being moved around, and across borders.

        The UK shuttered it's MOX fuel assembly plant at Sellafield because orders dried up after Fukushima. "MOX" being mixed-oxide fuel - a combination of Uranium Oxide and Plutonium Oxide from fuel reprocessing.

        Until reprocessing can be made proliferation-safe and far less expensive, it's not economical or else we'd see a lot more of it.

        • Reprocessing is prohibitively expensive. Japan has spent $27.5B and 30 years building a reprocessing facility that hasn't reprocessed a single gram of spent fuel yet.

          It also raises France's nuclear energy costs (relevant since they are the poster children for reprocessing) by a factor of two to four depending on how you do the math and how honest you are about what decommissioning will eventually cost.

        • Re: (Score:2)

          by sjames ( 1099 )

          Reprocessing to MOX is expensive and also seen as a proliferation risk (the security measures add to the expense as well). One reason is that the actinide series is hard to separate out. Reprocessing to mixed actinide fuel is much less expensive because it can skip that step. It's also a much smaller proliferation risk since the actinides would poison a bomb.

          That does require the right reactor design to handle it. CANDU is an existing reactor that can be tuned to mixed actinide fuel.

      • Politics may seem trivial, but you can't just dismiss politics as "nothing." It's a reality that has to be dealt with.

        The political opposition from global warming deniers, has been a major bottleneck in dealing with the issue. As wrong as the deniers might be, they still wield political power. Too many environmentalists simply dismiss these people as kooks, and then become frustrated when their plans are stymied.

        Every good leader, and every successful movement, has to take politics into account.

        • Re: (Score:2)

          by sjames ( 1099 )

          Yes, the politcs is real and the resultant footguns have to be dealt with but it's unfair to assign the willful fail to nuclear. Imagine if some crap politician managed to pass a law that the ground under a solar panel installation must be sprayed monthly with waste oil, is it then fair to say solar power is a cancer risk?

      • Waste can't easily be reprocessed, or it would have been already done.

        • Re: (Score:2)

          by sjames ( 1099 )

          As AC indicates, it is done today. I pointed out that it can be done more cheaply with less risk to produce fuel usable in an existing reactor design.

          It's going to take more than Nuh-Uh to refute that.

          • Source, please.

            • Re: (Score:2)

              by sjames ( 1099 )

              Too many to list. Just google "mixed actinide fuel" and "mixed actinide fuel CANDU" and start reading. You may need to read up on the PUREX [wikipedia.org] process to have some background knowledge so you can see how much simpler it is if you leave the actinides in.

              For the proliferation resistance, you just need to know that the minor actinides are radioactive and so if they are in a bomb, they will cause premature criticality as the pit is crushed and so it will fizzle.

              Note, This paper [iaea.org] is good.

              Also google "TRUMOX"

      • Re: (Score:2)

        by AmiMoJo ( 196126 )

        The problem is that this is all new, unproven technology, in a field that has a history of massive cost overruns and failed ideas. Sure, there have been some prototypes and small scale non-commercial operations, but given how expensive nuclear is already, adding "you must develop new commercial scale reprocessing and new reactors to use that fuel", it's going to become even less viable.

        At this point it seems like a better investment to throw some money at fusion.

        • Re: (Score:2)

          by sjames ( 1099 )

          The fuel can be loaded into an existing operating CANDU reactor. Since the reprocessing plants already exist, the process can be modified mostly by skipping a few expensive steps.

    • Re: (Score:2)

      by gweihir ( 88907 )

      And it's true, it doesn't spew carbon into the air.

      Actually, not even that is true. Mining and refining the fuel creates plenty of CO2 and so does building the reactor, tearing it down, storing the spent fuel, transportation, etc.

      Here are some actually realistic estimates: https://www.dw.com/en/fact-che... [dw.com]
      TLDR: CO2 from nuclear is better than coal and natural gas, but much worse than all other electricity sources.

    • Look at where the radioactive waste i stored : the quantities are really small. Compare to the quantity of lightly radioactive coal ash and other pollutant ? Keep in mind coal burning *kills* people with the pollutant https://www.nih.gov/news-event... [nih.gov] example : "About 140 coal power plants were each associated with more than 1,000 excess deaths during the study period. Ten plants, all located east of the Mississippi River, were associated with more than 5,000 deaths.". Look up even in EU with coal plants wi

      • Nobody is defending coal here. We all know that's a dirty fuel. But it's reasonable to compare it to wind or solar power.

        Nuclear waste is typically stored on premises. https://www.nei.org/news/2019/... [nei.org]. Given that there are 440 nuclear power plants around the world, that's quite a few places where nuclear waste is stored, many in populated areas.

    • Nothing is clean when you look at the big picture. There are always inputs and outputs that are unclean somewhere in the process.

      There is only relative cleanliness compared to other energy producing systems. Some are better than others.

      • You are correct, and wind and solar are cleaner than nuclear, in the big picture.

        • Not if you look at emissions. [wikipedia.org]https://en.wikipedia.org/wiki/... [wikipedia.org] The IPCC rates nuclear median at 12. Others have nuclear at 5.1.

          • I stand corrected about solar, but wind is still cleaner (for the atmosphere). Nuclear waste, however, is still a big problem that neither wind nor solar struggle with. I know, that's not air pollution, and this is the point. It's not sufficient to look at just one kind of pollution. Nuclear power can contaminate water supplies, for example.

            • Wind is intermittent. So in order to provide 24/365 coverage wind needs some kind of backup. That is usually(almost always) fossil fuels.

              And again used fuel is a non problem. The fact that you can't find an example of used fuel killing a single human being is evidence of that. Maybe stop getting your science from a cartoon.

              • Google is a thing, here are some links related to the dangers of spent nuclear fuel.
                https://www.huffpost.com/entry... [huffpost.com]
                https://www.bbc.com/future/art... [bbc.com]
                https://www.cancer.gov/about-c... [cancer.gov]

                Wind and solar complement each other, as the graphs on this page show: https://www.ercot.com/ [ercot.com] In Texas, these two sources now account for about 25% of total electricity production. No, you wouldn't want *only* solar or *only* wind, but they are important sources of clean power.

                • Not one of those provided an example of someone dying from used fuel. Chernobyl was a meltdown, explosion and fire. Fukushima was a meltdown that killed zero people. They also mentioned iodine 131 with a half life of 8 days. Guess what? Iodine 131 ceases to exist in ~6 months.

                  And you are using Texas as example. Texas!? They are one of the dirtiest states in the nation.

                  No, you wouldn't want *only* solar or *only* wind, but they are important sources of clean power.

                  Which is why almost every pronuclear person(include me) supports wind and solar. But thanks for admitting that they can't power t

                  • Meltdowns also happen. To gauge the safety of a power source, you have to take into account all types of sources of pollution and harm, due to both normal operations and due to disasters. The disasters aren't going away, ever.

                    Yes, Texas, which is far and away the nation's leader in energy, including clean energy.
                    It has 3x more wind energy than any other state https://www.weforum.org/agenda... [weforum.org]
                    And it is also the #1 stat in utility-scale solar power: https://electrek.co/2024/09/09... [electrek.co]

                    • The disasters aren't going away, ever.

                      Why would you think that? Meltdown proof reactors are possible. We proved it with the Experimental Breeder Reactor 2. We tried to intentionally cause a meltdown twice and failed. The very physics of the rector make it impossible to meltdown. Watch this documentary about it- https://www.youtube.com/watch?v=Sp1Xja6HlIU [youtube.com].

                      And Texas is dirty. ERCOT is at 389 g CO2 per kWh which is terrible. That's slightly better than Germany but way off from France which is at 53.

                      And if you account for every possibilit

            • There's like an 8% difference there between wind and nuclear. And wind only works in some places. And it only works some times. And the amount of real estate it takes up is enormous compared to nuclear, so it's terrible from a land use perspective.

              • Nuclear also can be built only in some places. And wind can be a very reliable source of power, in places like west Texas, where there are vast wind farms. We are not running out of land for wind farms. (Agricultural) farmers don't mind wind turbines, they bring them income, and they just farm around them. In a given farmer's field, the turbine takes only a tiny plot of land. The land use difference, while significant, doesn't actually cause an issue.

                So an 8% difference doesn't seem large, but it's not just

    • It's hard to dispose of, but we have a way to do it completely safely. It's called WIPP. Put the waste in geologically stable salt caves below the water table. Salt because even if there is unexpected geological activity it just seals in the waste. It's not cheap, but waste in such a facility will remain there until the death of the sun.

      • Cost is a very important factor in the viability of any disposal technique. If it isn't cost-effective, it's not a useful mechanism.

        • Cost is a very important factor in the viability of any disposal technique. If it isn't cost-effective, it's not a useful mechanism.

          Cask storage is very effective and very cheap.

  • This is what engineers are for... (Score:3)

    by ctilsie242 ( 4841247 ) on Tuesday September 10, 2024 @12:16PM (#64777333)

    Japan arguably has some of the brightest engineers on the planet. The fact they got a robot to be able to scoop some up and not have the robot get fricasseed by all the gamma rays and neutrons bouncing around speaks volumes. Once a place is found for the fuel, it is only a matter of getting a radhard conveyance system in place to do this on a large level, then making a breeder reactor so the radioactive fuel can be used for something useful.

    Japan does a lot of miracles, and this is their first foray into something nobody has ever encountered before. I wouldn't be surprised to hear about all the fuel being moved to a safe location in a few years.

    • A lot of radiation hardened tech comes from satellite development because up there it is a constant bombardment of solar and cosmic radiation with no atmosphere to protect you.

    • On the other hand, let's not get too excited about the robot until it's got some significant run time on it. The effects of radiation being cumulative, we may only have to wait for a result. I wish them the best of course, they've got quite a mess to clean up, but it is also some fairly unexplored territory so we shouldn't be surprised if they have trouble.

  • misleading title once again (Score:4, Insightful)

    by La Gris ( 531858 ) <<lea.gris> <at> <noiraude.net>> on Tuesday September 10, 2024 @12:17PM (#64777337) Homepage

    A more appropriate title would have been:
    "A Robot Begins collecting samples of Melted Fuel From the Fukushima Nuclear Plant."

    But whatever. The person who wrote the misleading title perfectly knows it is misleading.

    Never take nuisance for ignorance.

    • Re: (Score:2)

      by AmiMoJo ( 196126 )

      NHK recently put a documentary on YouTube about the situation at Fukushima.

      The original plan was to have it all cleaned up but 2050. They are already years behind their schedule though. The original plan was to try to remove the melted remains of the reactors and fuel with robots, through pipes. It proved unworkable though, because they couldn't get enough access to the waste, and because breaking the waste up was releasing it into the atmosphere. You can't just cut up tonnes of high level nuclear waste, be

  • Chernobyl, isn’t an example. (Score:5, Interesting)

    by geekmux ( 1040042 ) on Tuesday September 10, 2024 @12:29PM (#64777359)

    Anyone even considering a “solution” like Chernobyl, isn’t familiar with how even that effort ultimately suffered from failures within a decade, and required manufacturing the New Safe Confinement around reactor #4. With all of it still sitting inside an exclusion zone 30km/18 miles around.

    And that, represents a problem one-fourth the size of Fukushima in regards to waste.

    • Re: (Score:2)

      by AmiMoJo ( 196126 )

      They couldn't build a new confinement vessel anyway at Fukushima. For a start they are still pumping water in to cool what is left of the reactors, without which there could be further fission or meltdown.

      Fukushima, like many nuclear plants, is located on the coast so that it can take advantage of seawater for cooling. That makes it difficult to build anything around it on one side. It also means that there is the potential for further earthquakes and tsunami.

      Finally, the government and TEPCO agreed to clea

      • Finally, the government and TEPCO agreed to clean the site up by 2050. Even if they miss that deadline, former residents and the Japanese public are not like to accept them abandoning those efforts in favour of confinement.

        If cleanup “efforts” are postponed that long, then there may not be an island nation worth saving. No, I’m not being cruel. Adult diapers have outsold infant diapers in Japan for over a decade now. It’s already a dying nation. Who will want to live there when “efforts” are measured with a politicians ruler instead of a realistic one?

        • Japan is going to become a multi-ethnic state through higher immigration. That plus their significant investments into automation in elder care will probably preserve them from the worst of their demographics.

          Japan is becoming pretty attractive for foreigners. They just gotta figure out how to culturally integrate immigrants like the U.S.

          I think they'll be around for a long while. Maybe changed fundamentally in some way, but still Japan.

  • Curious detail (Score:3)

    by necro81 ( 917438 ) on Tuesday September 10, 2024 @12:33PM (#64777371) Journal
    FTFA:

    The mission takes [about two weeks] because the robot must make extremely precise maneuvers to avoid hitting obstacles or getting stuck in passageways. That has happened to earlier robots.
    TEPCO is also limiting daily operations to two hours to minimize the radiation risk for [the robot operators] in the reactor building. Eight six-member teams will take turns, with each group allowed to stay maximum of about 15 minutes.

    This seems a curious detail. My assumption is that the robot is remotely operated, probably using some kind of tether / umbilical carrying power and comms. If that is the case, why do the operators need to be inside the reactor building at all? Surely you can make a robust communications channel (e.g., a fiber link) that let's them work from the other side of the Fukushima site, where radiation levels are low enough to permit continuous operation.

    There must be some added context - logistical info - that isn't in the reporting.

    • Re: (Score:2)

      by eth1 ( 94901 )

      Surely you can make a robust communications channel (e.g., a fiber link) that let's them work from the other side of the Fukushima site, where radiation levels are low enough to permit continuous operation.

      I'm not an expert, but I'm pretty sure that this kind of radiation would also affect optical sensors (cameras and fiber transceivers), so radio or copper might actually be better.

    • Re: (Score:3)

      by AmiMoJo ( 196126 )

      The robot isn't a rover, it's more like a very long multi-segment arm.

      Pipes have had to be installed to allow it to get into the reactor buildings through the debris. It was a very slow process and workers had to get pretty close. More pipes are needed.

      The robot is inserted into the pipes, which requires workers to handle it. They can't leave the robots in there permanently because the radiation will destroy them, and because they need maintenance periodically.

      Keep in mind also that quite a large area was c

  • A robot entered a damaged reactor at Japan's Fukushima nuclear power plant on Tuesday, beginning a two-week mission to retrieve melted fuel debris for the first time since the 2011 disaster. The operation marks a crucial step in the decades-long process to decommission the plant and address the highly radioactive material inside three damaged reactors.

    Cool. Basically the plot of Tom Swift and his Giant Robot!

  • Nuclear Powerplant Cleanup Could Keep Engineers Employed for Next Century, Create Hundreds of Jobs in Local Area.

  • Why move the stuff somewhere else? Just leave it in place and build a concrete sarcophagus around it all.

  • The vitrification project at Hanford to isolate low level waste is billions of dollars over budget and decades behind schedule. The project started in 2001 and the initial timeline stated it would be running by 2007. It is now processing it's first run in 2024. The contract for the vitrification plant alone is over $12 billion and the projected full cleanup cost is $45 billion. Given the history of the project the current cost and time estimates are a bad joke.

    And there is no current solution to deal with

Slashdot Top Deals

You know you've landed gear-up when it takes full power to taxi.

Close