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A robot will soon try to remove melted nuclear fuel from Fukushima reactor
- fbdab103 2y agoGiven the damage is already done, why not leave it in place? Encase it in concrete and come back in a decade or two when the worst products have decayed?
- loeg 2y ago> an extremely important step to steadily carry out future decommissioning work > Better understanding the melted fuel debris from inside the reactors is key to their decommissioning It's not exactly clear to me how this benefits decommissioning either, but that's all I got from the article.
- Retric 2y agoPeople can’t safely work near the fuel(high level nuclear waste) because it’s really radioactive. They can work where high level nuclear waste (fuel) used to be.
- lazide 2y agoAlso, if they don’t know exactly how thoroughly it melted or the precise level of damage, it’s pretty hard to fix it. It isn’t the type of problem amenable to just bulldozing it into a hole, unless you’re Russian anyway.
- dylan604 2y agoFix it? Do you mean the design? Because there's not fixing this one. It seems to me the fix would be to not have your backup generators below the water line.
- Dalewyn 2y agoNo, the fix is to not have fucking politicians in charge of practical matters. Yes, I'm serious. TEPCO wanted to dump sea water into the reactors as a last resort so they wouldn't melt down, but the Japanese government at the time didn't allow it because the reactors would be rendered unusable. Of course, the reactors melted down and became unusable anyway. Fukushima #1 was a human failure and the only solution to that is a human solution. Any engineering solution will be foiled by a bigger human failure, as the saying goes.
- dylan604 2y agoI mean sure, but if the backup generators weren't submerged from failure to plan for flooding, then the politicians wouldn't be in that situation. That's an engineering solution that isn't like earth shattering. Maybe it was a human bean counter that said it would cost too much (ha!) to do that for the generators. This isn't the same situation of planning to use school buses as an evacuation plan not realizing their parking lot is likely to be flooded. This is a nuclear reactor and there's meant to be some really smart people involved.
- Dalewyn 2y ago>if the backup generators weren't submerged from failure to plan for flooding We need to be fair here: Plans for potential flooding were made, the issue was nobody expected a tsunami that fucking tall and reasonably so. Guidelines and such have been updated since so it (hopefully) won't happen again, but you can't fault engineers of the past for working with the data they had and coming to the conclusions they did.
- serf 2y ago>the issue was nobody expected a tsunami that fucking tall and reasonably so. that's less reasonable when you consider Japan's history with tsunami. The events in 1933,1896, and 1993 produced tsunamis with larger wave heights than the Tohoku event.
- 2y ago
- loeg 2y agoYeah but why have people there at all? Upthread commenter is asking about just filling it with concrete and leaving it alone.
- Retric 2y agoThey need to freeze the ground to avoid water flowing into and out of the area. Covering in concrete alone wouldn’t safely contain it, they would need to add concrete beneath the fuel, which while physically possible would be unbelievably expensive and not actually last that long. Eventually tossing future generations an even more expensive problem. https://www.tepco.co.jp/en/decommision/planaction/landwardwall/index-e.html#:~:text=It%20is%20actually%20a%20frozen,its%20mixing%20with%20contaminated%20water https://www.tepco.co.jp/en/decommision/planaction/landwardwa....
- loeg 2y agoThanks.
- robertlagrant 2y agoThe article mentions a 30-40 year cleanup target; perhaps they're using these samples to analyse how best to proceed?
- Retric 2y agoIt’s contained, not stable. They are doing a bunch of things like freezing the ground to avoid water intrusion which have high ongoing costs. Remove high level waste to a more stable environment is the first step in reducing those ongoing costs.
- surfingdino 2y agoIt may not be that simple. Scientists want to know what's going on down there. As Chernobyl shows us, we don't really know when it's over https://www.extremetech.com/extreme/322755-chernobyl-is-heating-up-again-and-scientists-arent-sure-why https://www.extremetech.com/extreme/322755-chernobyl-is-heat...
- joe_the_user 2y agoI think a problem that all the previous robots faced was the way that radiation interferes with the operation of any and all electronic devices.
- HeatrayEnjoyer 2y agoIs there a barrier to powering it with mechanical energy instead of electronic? Gas combustion and hydraulics instead of batteries, CPUs, and servomotors.
- pathartl 2y agoI wonder if there's an issue with exhaust and radiation, like not wanting irradiated gas to escape into the atmosphere more than it already is.
- patmorgan23 2y agoAnd control it how?
- andrewflnr 2y agoFiber optic endoscope for the view, and manual mechanical controls. A big fat umbilical does reduce the mobility options a bit, granted, but it sounds/looks like they're already resigned to something along those lines with their '“telesco-style” extendable pipe robot'.
- HPsquared 2y agoIf they don't care about going slow, they could reduce the wire count massively using a relay multiplexer. One input/output at a time.
- HeatrayEnjoyer 2y agoCamera broadcast and remote control vehicles existed before the invention of the microchip. You don't need a computer.
- ESTheComposer 2y agoReminds me of this story by Isaac Asimov https://en.wikipedia.org/wiki/Runaround_(story) https://en.wikipedia.org/wiki/Runaround_(story)
- ErkanSensei 2y agoReminds me of this story by Isaac Asimov https://en.wikipedia.org/wiki/Runaround_(story) https://en.wikipedia.org/wiki/Runaround_(story)
- andrewflnr 2y agoThis account has just one comment, which is a duplicate of another one in this thread.
- worldsayshi 2y agoWhy would anyone create an account 4 years ago just to use it on a copy of someone else's comment...?
- andrewflnr 2y agoMaybe they deleted their old comments? Maybe some weird bot? I'm mostly frustrated that I flagged it and someone vouched the comment despite it being an obvious dupe from a sketchy account.
- CatWChainsaw 2y agoHN only allows comment deletion for about an hour after you comment, right?
- worldsayshi 2y agoYup the comment is still there as the only one of the account...
- defrost 2y agoPeople do actually generate and not use HN accounts and then later sell them on or give them some life (repeating other comments in days old threads is common) so they can later be used to "chime in entusiastically" when a product is launched. Watch that account and see if it endorse | votes up a submission next week.
- netcraft 2y ago> TEPCO plans to remove less than 3 grams (0.1 ounce) of debris in the test at the Fukushima plant. ... > About 880 tons of highly radioactive melted nuclear fuel remain inside the three damaged reactors talk about starting small
- babypuncher 2y ago880 tons of nuclear fuel sounds like a typo. Radioactive debris, sure, but not melted fuel.
- joha4270 2y agoIt sounds a little high, but not massively so. I couldn't find fuel weight in a BWR-3, but a RBMK reactor (Chernobyl) contains between 150 and 200 tons of Uranium. Now, a RBMK runs natural uranium, so you're going to be using more fuel for the same power, but it suggests the number isn't totally whack. I would not be surprised by it being a typo, but depending on what you include in "melted fuel" (fuel assembly, reactor parts, etc), 880 tons isn't outrageously high either.
- egorfine 2y agoWell, ~75 tons of fuel per three units fully loaded plus a few times that for the spent nuclear fuel pools. Also bear in mind that fuel being melted with concrete and metal becomes one, so you can add a hefty multiplier to the above figure. So it seems like 800 tons is in the ballpark of the fuel assemblies plus molten metal structures of the lower part of the reactors vessels.
- johnea 2y ago[flagged]
- odyssey7 2y ago> Critics say the 30- to 40-year cleanup target set by the government and TEPCO for Fukushima Daiichi is overly optimistic. Wow. By the time they finish the cleanup, we could be running profitable fusion power plants, have humans living on mars, discovered new physics…
- jvanderbot 2y agoCould. More likely we'll be debating the usefulness of yet another fusion plant over some hydrothermal project vs some tidal energy project vs UBI expansions and on and on.
- odyssey7 2y agoIndeed, yes, nothing is certain... The other part, which is about certain, is that we'll have been dealing with the fallout of this particular meltdown for 30 to 40 years, or more.
- belorn 2y agoThe third part that is also about certain is that we'll be dealing with climate change, since we are not stopping burning fossil fuels. Instead we are building new fresh power plants fueled by fossil fuels with planned operational life times far into the future.
- odyssey7 2y agoI guess in listing other milestones, I might have alluded to an ongoing debate? Whether to build new fission reactors or to wait for new fusion tech? My intention was only to indicate the scale of the harm in this particular instance. However, it’s still tempting for me to respond to this fission-prevents-global-warming claim with my own appraisal. You’re right, it is certain that we’ll still be using fossil fuels. I’ve given up worrying about fossil fuels and global warming. It’s something I can’t do anything about, and I think it will be fine: the people who make the macro decisions decided decades ago that we didn't really need to / weren’t going to risk economic growth by suddenly reducing fossil fuel use as much as the scientists said would be needed. It was really a masterwork: the same political groups eager to go to war in the Middle East and hungry for tax breaks were kept more than eager to keep buying gas, effectively sending their money to the Middle East about once or more a week in many cases. There are some nuances that undermine the reasoning expressed in my last sentence, but I’m sure that those particular nuances weren’t the justification, as much of the public has indicated that they support bombing even Agrabah. [0] Why didn’t we do enough? Well, lately it has turned out that geo-engineering was taboo only to indicate as an option, not to actually do when the time came. [1] It looks like the plan all along has been geo-engineering, while keeping the public on-edge about that to justify projects like fission plants. Fission research has long been an avenue to develop knowledge essential for nuclear weapons R&D. In the context of international relations and international nuclear treaties, the cover story of saving the planet makes even more sense as an essential. The Secretary of Energy was in Congress just the other day discussing compensation for victims of Manhattan Project radiation [2], a topic which has nothing to do with nuclear energy, unless nuclear energy is sometimes a codeword for nuclear weapons. Fission isn’t really important to stop global warming if we’re just going to implement geo-engineering. [0] https://www.snopes.com/news/2015/12/18/agrabah-aladdin-republican-poll/ https://www.snopes.com/news/2015/12/18/agrabah-aladdin-repub... [1] https://www.usatoday.com/story/news/weather/2024/05/24/can-geoengineering-help-solve-climate-change-the-excerpt/73843579007/ https://www.usatoday.com/story/news/weather/2024/05/24/can-g... [2] https://m.youtube.com/live/Xwx5pLoDXIg?t=66m50s https://m.youtube.com/live/Xwx5pLoDXIg?t=66m50s
- nijuashi 2y agoCrane game player: “my time has come”
- rassimmoc 2y agofigures.... robots and AI keep stealing our jobs and politicians not doing anything about it
- ramon156 2y agoWhen I was growing up I was dreaming of exploring in the radiation, thanks Biden.
- rassimmoc 2y agothats how real men did it in chernobyl
- SixDouble5321 2y agoTwo days too late to comment this. Think about how many people could be employed. It would be a lot too because they could only work for 45 seconds each.
- osigurdson 2y agoI'm pro-nuke, until I read stories like this and then I become anti-nuke. Eventually these thoughts fade and I become pro-nuke again. - Humanity
- preisschild 2y agoBut why would you become anti-nuclear energy because of this? The cleanup is obviously professionally handled and it doesn't appear to be an issue for nature and nearby population.
- osigurdson 2y agoProperty values dropped by more than 30% [1]. I doubt people are happy that they have a blown up nuke near their house. https://scholarbank.nus.edu.sg/handle/10635/223658 https://scholarbank.nus.edu.sg/handle/10635/223658
- avery17 2y agoWont someone think of the property values!!
- osigurdson 2y agoYeah, who cares about that (unless it is your house).
- sesuximo 2y agoThe trusty one dimensional model of things. This is why I always train my neural nets with one parameter (sign bit only).
- osigurdson 2y agoThat is the ultimate output - net positive or net negative. Nice work.
- comfrey11 2y agoWill learn from attempt to
- pvaldes 2y agoTechnically impressive, but unfortunately feels basically like a PR stunt. The title suggests that the melted material will be removed soon but is not realistic. At this moment should say "will try to remove 3 grams from the >800 tons of melted fuel. At this pace, the place will be safe by natural means much before the robot will end the work. Apart of this, I wonder... is this stuff still usable? There is something that could be done with this grams of melted dust that would worth the risk of spreading it around? ... Second: why to design a robot for that, or move electronics close to this area so they can fry in seconds?. The idea that must be some sort of robot (because some sort of idealized human rescuer figure is what the public expects) is not very smart. What they need is maybe (IMAO) a sort of "anteater-tongue machine" that just will try each crevice until finding the correct path. A sort of strictly mechanical machine moved from a safe distance with a real human brain taking the decisions much faster. If you need to move a tube there are a lot of solid mechanical joints in the market tested since decades for every possible need. All needed is an axis able to rotate, a motor placed very far away, and a removable set of arms that would pick and vacuum the stuff and would double as "fuel rods" or something later when will be unavoidably contaminated. Just cut the tube in appropriate lengths and put the contaminated rod to sleep in the pool with the other stuff. If electronics are an obstacle, just remove it entirely and use a stochastical movement instead a directed one. Radioactive dust in the path could be grabbed with some type of greasy or sticky material before to be collected by a moving ring. No need to design a complicated claw here. There are several metallic types of grease available that could jail the dust and maybe even, dunno, provide benefits to block the dust radiation somehow into a matrix of metallic particles. If you need to see the path, use echolocation or maybe run a camera forward for one second to retreat it fast to safety. The "tongue" could be used as a rail for the camera. Alternatively, they could made the path safer first deploying a lead jacket made with tubes or plates where the robot can move. If the room is radioactive, line it in lead lames. That would also remove coins and crevices and would made the route much safer for people and machines and easier to navigate until the final part.
- aloisklink 2y agoI was at Fukushima Daiichi on Monday, and they explained that they only want to take a few grams of the melted material to test the composition of the melted fuel/debris, e.g. what elements are in it. Even just planning to remove all of the melted fuel is a long way away. I can't remember if they were talking about Unit 1 or Unit 2, but from what I understood is that due the collapsed rubble above/around the reactor, they only have a very narrow opening, which means they've struggled to use larger robots. And I believe the robot operating centre is a bit of a distance away from the reactors too (probably so that the robot operators don't need to wear protective equipment). > What they need is a sort of "anteater-tongue machine" that just will try each crevice until finding the correct path. I think the problem is that once you get through all the debris, there's a big cavern. Hence why they're using some sort of crane robot on a rope (it reminds me a bit of a [claw machine game][1]). [1]: https://en.wikipedia.org/wiki/Claw_machine https://en.wikipedia.org/wiki/Claw_machine