Gundersen: 200 brand new fuel bundles in Fukushima Unit 4 pool are most at risk to start nuclear chain reaction — If too close together during removal, there will be a criticality — “They have to be very, very cautious” (AUDIO)

Published: September 27th, 2013 at 6:25 pm ET
By

35 comments


Title: Bridging the News Gap
Source: Fairewinds Energy Education
Date: Sept. 26, 2013

At 22:30 in

Arnie Gundersen, Fairewinds’ Chief Engineer: The Unit 4 fuel pool has 200 bundles of brand new fuel. Brand new fuel, while cold as a cucumber, runs the risk of starting a nuclear chain reaction. The nuclear fuel in the new portion of the pool is more likely to undergo what we call an inadvertent criticality, a nuclear chain reaction that nobody wants.

I build fuel racks, and I know that the gap between the fuel is really, really critical. If the fuel gets too close together you will get a chain reaction. That’s not something you want to happen in the fuel pool. As they’re pulling this fuel out, they have to be very, very cautious that they don’t get the fuel too close together.

Full interview available here

See also: [intlink id=”nuclear-engineer-damage-new-fuel-assemblies-be-bad-many-reasons-new-fuel-highly-reactive-easier-critical-spent-fuel-video” type=”post”]{{empty}}[/intlink]

Published: September 27th, 2013 at 6:25 pm ET
By

35 comments

Related Posts

  1. Gundersen: They’ve admitted that all the boron has disintegrated in between spent fuel at Fukushima — It can cause a nuclear chain reaction if rods get too close together in pool (AUDIO) September 17, 2013
  2. Nuclear Engineer: New cover on Unit 4 can trap hydrogen gas during criticality in fuel pool — Blast would be close to a nuclear explosion, from a practical standpoint (AUDIO) November 22, 2013
  3. Gundersen: Fuel already “very close to going critical” at Unit 4 — Must be extraordinarily careful about starting chain reaction (VIDEO) November 15, 2013
  4. Now revealed there’s 80 damaged spent fuel assemblies leaking radioactive materials in Fukushima storage pools — Kyodo: Removal attempt at Unit 4 starts later today — Japan nuclear official ‘nervous’, as one slip could result in monumental chain reaction (AUDIO) November 17, 2013
  5. NHK: Fuel removal at Unit 4 underway — BBC: Concern casks not watertight, rods would contact air — WSJ: Exposure to air can cause sustained nuclear reaction — AFP: Tokyo evacuations if uncontrolled nuclear conflagration? AP: Rods contain plutonium, experts concerned quake to hit during process November 18, 2013

35 comments to Gundersen: 200 brand new fuel bundles in Fukushima Unit 4 pool are most at risk to start nuclear chain reaction — If too close together during removal, there will be a criticality — “They have to be very, very cautious” (AUDIO)

  • dka

    Is it possible to just remove the pellets one by one?
    Starting from the top one, making a small opening on the side of the bundle, and work down the bundle step by step, without ever moving the bundle.

    • Sickputer

      I doubt the tubes are in any shape for such finesse. 63 twelve-foot rods per assembly loaded with uranium pellets and maybe some with plutonium powder (Tepco denies it).

      Many smoke plumes from Unit 4 SFP in 2011 to 2013. Just how burned up is that fuel? They will find out the hard way.

    • corium pudding corium pudding

      @dka I doubt that level of intricacy would work. The cladding would work against you, plus it would take forever and that kind of timescale is simply not available. But +1 for creative thinking. We need a lot more of that if we are to avoid Fukushima Armageddon.

      • CodeShutdown CodeShutdown

        gel the water to some degree, then use suction. A little high tech monitoring and feedback would allow control of rates. Bent clad could be cut. But Im sure hundreds of engineers at DOE are working on a method, how could it be otherwise?

    • DeSwiss DeSwiss

      Each fuel rod assembly weighs about 300 kilograms (660 pounds) and is 4.5 meters (15 feet) long. There are 1,331 of the spent fuel assemblies and a further 202 unused assemblies are also stored in the pool.

      The fuel assemblies have to be first pulled from the racks they are stored in, then inserted into a heavy steel chamber. This operation takes place under water before the chamber, which shields the radiation pulsating from the rods, can be removed from the pool and lowered to ground level.

      Tepco confirmed the Reactor No. 4 fuel pool contains debris during an investigation into the chamber earlier this month. Removing the rods from the pool is a delicate task normally assisted by computers, according to Toshio Kimura, a former Tepco technician, who worked at Fukushima Daiichi for 11 years.

      "Previously it was a computer-controlled process that memorized the exact locations of the rods down to the millimeter and now they don't have that. It has to be done manually so there is a high risk that they will drop and break one of the fuel rods," Kimura said.

      "The problem with a fuel pool criticality is that you can't stop it. There are no control rods to control it," Gundersen said. "The spent fuel pool cooling system is designed only to remove decay heat, not heat from an ongoing nuclear reaction." The rods are also vulnerable to fire should they be exposed to air, Gundersen said.

      http://news.yahoo

      • CodeShutdown CodeShutdown

        Corrosion and irradiation can make the zircaloy brittle.
        Expansion of gases between fuel pellets and cladding can cause deformity and bursting of the cladding during a loss of coolant accident.

        The fission gases accumulate in the void that forms in the center of a fuel pellet as burnup increases. As the void forms, the once-cylindrical pellet degrades into pieces. These pieces can degrade to powder. So you might find some intact rods or assemblies, individual pellets, powder or melted fuel aggregates.

        The common failure process of fuel in the water-cooled reactors is a transition to film boiling and subsequent ignition of zirconium cladding in the steam. Seems like Arnie said you cant put this fire out, which sort of confuses the issue on the fate in question.

        As an aftermath of the Fukushima Daiichi nuclear powerplant disaster, a new method of covering active nuclear fuel pellets with ceramic silicon carbide is being developed at MIT

  • Heart of the Rose Heart of the Rose

    After Gundersen complimenting Enenews..
    I don't like to come in and disagree.

    I also have watched the smoke plumes..having posted vids dozens of times.

    There are not 200 bundles waiting in a perfect state of suspense.
    Nor am I going to involve myself..in that same state.

    • farawayfan farawayfan

      Respectful of you not to disagree, hotr, but we all know sfp4 is not recoverable. Just biding time, really….

      • Heart of the Rose Heart of the Rose

        Ummm..respectful..I wouldn't go that far..
        I'm simply getting used to playing 'second fiddle' to the'experts'.

  • Depends entirely on the condition of those bundles. Are their boron 'blades' disintegrated like those in most/all of the spent fuel bundles? Are they structurally intact (won't fall apart while lifting)? What kind of shape is the cladding in (were these bundles part of the early fires)? Have there been any criticalities in their corner of the SFP over the past two and a half years? Are they contributing at all to continued iodine/xenon releases?

    If they're in pristine condition they ought to be the easiest assemblies of all to remove, are far less radioactive than any of the spent assemblies. How likely it is they're in pristine condition is not something we know or are likely to be told.

    • Heart of the Rose Heart of the Rose

      Let me clarify..the condition is a given…
      I do not believe that cooling has been maintained.. in order for the bundles in question to remain in the condition being discussed here.

      • Was mostly being tongue-in-cheek, Heart. If the new assemblies were in pristine condition, they could be pulled out into the air and set aside, crated up and shipped off to some other plant somewhere as new fuel. Un-irradiated fuel rods have no problem with cladding fires, you don't even have to suit up or wear gloves when around them.

        I'm beginning to suspect there's not much in the pool they'll be able to safely remove. If anything. There's bound to be lots of broken rods and failed fuel in there, the odds on criticality quite high. But they can't just leave it up there either. If it weren't nuclear fuel it would be a job for a big-ass steam shovel. As it is, they'll need much better luck than they've had so far at Daiichi.

  • Judging by the transcripts NoNukes reposted its doubtfull coolant was maintained. The story is that hydrogen sourced from #3 through common vent or some thing but could more easily be criticality explosion from new fuel right? Or at least hyrogen produced from dry out of #4 spent fuel pool. Something bad blew the roof off and my money is on fuel pool drying out. Who knows how much fuel they will get out of there. Can someone explain why fuel removal is better then strengthening existing pool? Surely you could install twenty foot walls and upgrade cooling system. Only moving them into common spent fuel pool which already contains 6000 or more fuel assemblies and is only 50 yards away. How earthquake proof is that facility?

  • mld333

    FUKU is the first nightmare ive ever encountered awake…..in my entire lifetime….VERY SAD

    • vicky13 vicky13

      Hi mid333

      is a never ending fricking nightmare

      1st one I have too, at least when I sleep now the nightmare ends for a short time,,,

  • Dr. Anne Lee Tomlinson Maziar anne

    There have been fires, and at least one explosion was reported (by China, as I remember). The fires and explosion could only have happened in the SFP, because the reactor had been emptied. I seem to remember from my class that 1/3 of the fuel is taken out at a time. So were there 2/3 left in the reactor?

    Here is a photo. I don't see how the fuel is in condition to be removed:

    http://www.flickr.com/photos/simplyinfo/7071500201/

    • Dr. Anne Lee Tomlinson Maziar anne

      For 118 pages of archived photos of Fukushima Daiichi, see:
      http://www.flickr.com/photos/simplyinfo/

    • Go Flying

      Anne, I think the entire fuel load was emptied in order that the stainless steel should that surrounds the reactor core could be cut away and stored /in the equipment pool which is opposite the SPF.

      The shroud parts in the equipment pool are also very 'hot' in the order of greater than 10SV/hr.

    • NoNukes NoNukes

      I have read that the explosion at reactor 4 was really creepy.

      I have not seen it, no one I know has seen it.

      Think of all of those satellites with all those images, in addition to news stations, as well as Tepco's hundreds of cameras.

      There has been an orchestrated campaign to suppress these images of the explosion at reactor 4. A global conspiracy that I would not have thought possible, given all of the various parties involved.

      With this state of facts, I believe there was plenty of fuel left in the reactor, it is now corium barreling through the earth and ocean.

  • parwie

    Abe “assured”, the situation was under control. Why didn't anybody stand up and tell the truth? (That there are radioactive dust and water being released into the air and ocean day by day.) Because “Japan” spend a lot of money in order to “win”. They didn't win, they just got what they paid for. Money that should have been spent in order to at least try seriously to get the situation under control. Or to pay for what they (government et al.) have done and are still doing to their own nation and even the world.
    Now that Tokyo is aloud to host the games a lot of people think that the situation really is under control..
    But that liar outdid himself, when he said that Tokyo has never been and will never be affected- radioactive food and drink being sold all over Japan (and almost all over the world, Tokyo's tap water being contaminated, hot spots everywhere (in Tokyo too) and don't forget Busbys filter test, that showed how much radiation made its way even to Tokyo (Uranium etc.!).
    So why can't he be sued for his obvious lies? Because Japan has got too much money (of course not for compensating its crimes).
    BTW: Why are they planning to restart their NPPs? In order to stockpile Plutonium. Every NPP in the world exists in order to deliver weapon grade Plutonium to its government. And think about this: Which nation of the world wants to own atomic bombs more than the only one that has been hit by one (two!) during war? I really would like to know where every country…

  • Sol Man

    I hope that the leaders in any other country (Iran) is following this closely and any nuclear ambitions that they had/have are replaced with an Apollo Project with an emphasis on alternative means of producing electricity. We really don't want Pu around for anything in the world. It is good for death and disease leading to it. We need a better vision of the future for everybody's children.

  • We have a 1 in 100 chance of making it through nuclear Armageddon into the 'Golden Age'.

    Why only 1 in 100?

    Nuclear power, nuclear weapons, combined with sociopathic 1% leaders. It only takes one to push ONE button and it all goes from there.

    That is why EVERY PERSON is so important.

    We need to abolish and get rid of all nuclear plants and weapons, so that when a sociopath, or accident happens, it is not possible to start all out nuclear war, or melt down 400 nuclear power plants in a Carrington Event.

    This FUKU event is a warning, a prelude, a preview of what will happen on a global scale times 4,000 if we do not get rid of it all.

    If we can do this, we can and will enter the Golden Age, and much will happen that cannot be talked about here.

    Keep fighting… never give up!

    Every person matters!

    • ftlt

      Way to optimistic there, DGH

      Nuclear will be an add on on to other global triggers..

      The 4 Horseman are all saddled up and are casually setting about their given tasks… No need to rush… They've got a big job in front of themselves…

      In fact, the White and Red Horsemen have already arrived and are quite busy already…

      Old Blackie is not far behind now…

      Always the last to arrive is the Pale Horseman…

      """"When the Lamb opened the fourth seal, I heard the voice of the fourth living creature say, "Come and see!" I looked and there before me was a pale horse! Its rider was named Death, and Hell was following close behind him. """""

  • pure water

    One video illustrating the condition of the plant in May 2011:
    http://www.youtube.com/watch?v=BJwCFBoOlMM&NR=1&feature=endscreen
    See and judge for yourself.

  • newsblackoutUSA newsblackoutUSA

    This video spells out exactly what is going on and was posted yesterday:
    http://www.youtube.com/watch?v=CNAgU_ID4Rc
    This is outright genocide being perpetrated on the world.

  • obewanspeaks obewanspeaks

    One thing for sure is that they will always protect the money streams bore by the laymen..

  • obewanspeaks obewanspeaks

    .. 🙂

  • it seems there is some speculation thst the Unit4 SF has already achieved freedom to the atmosphere and that would mean we're dancing with the killers as we leave this world.
    ..
    i'm depending on arnie's study that this quamire of hell yet awaits intervention…
    can't they leave the horror where it sits and mitigate futugure scenarios…
    if it exist in fact….

  • Wotcha Wotcha

    I've just come across this interesting article titled 'Readying for Fukushima fuel Move':
    http://www.world-nuclear-news.org/RS_Readying_for_Fukushima_fuel_move_2609131.html
    Here is a snippet from the article:
    Within the new structure built over the badly damaged reactor building of unit 4, Tepco has been installing equipment that will allow the transfer of used nuclear fuel for long-term storage elsewhere. Underwater inspections in the pond have shown most of the fuel to be undamaged, but the pond contains a lot of dust and debris which will complicate operations.

    Naah, I don't believe most of the fuel is undamaged – just look back at those historical blackened pictures of that Reactor4! It's had several fires. I was also surprised by that photo of the fuel removal setup in that link. I wonder how World Nuclear News got hold of that picture?