On NHK now: Tepco finds damaged zirconium fuel rod elements in No.3 basement water

[flamingdem]

On NHK now: addmission by TEPCO that fuel rods are damaged in reactor 3 - and probably in 1 and 2 as well. Zirconium cladding elements have been found in basement water in reactor 3. Spokesman admitting that this is why large amounts of radiation are leaking into the enviroment, and making attempts to control the situtation 'very challenging'.

[The_Casual_Observer]

1. Did someone actually go in there & find those fragments?

Brave/crazy souls.

[flamingdem]

2. The workers went into the pool and got radiation burns today

they are in the hospital.

Bless them.

[hlthe2b]

3. Bless them, is right...

Heavens... Such sacrifice that can never be repaid.

[flamingdem]

4. NYT - Japan Raises Possibility of Breach in Reactor Vessel

I'd say they made a critical confirmation, and this was important to getting more international help for the crisis.

-------snip
The development, described at a news conference by Hidehiko Nishiyama, deputy director-general of the Japan Nuclear and Industrial Safety Agency, raises the possibility that radiation from the mox fuel in the reactor — a combination of uranium and plutonium — could be released.

One sign that a breach may have occurred in the reactor vessel, Mr. Nishiyama said, took place on Thursday when three workers who were trying to connect an electrical cable to a pump in a turbine building next to the reactor were injured when they stepped into water that was found to be significantly more radioactive than normal in a reactor. The No. 3 unit, the only one of the six reactors at the site that uses the mox fuel, was damaged by a hydrogen explosion on March 14. Workers have been seeking to keep it cool by spraying it with seawater along with a more recent effort to restart the reactor’s cooling system.

[hlthe2b]

5. So what can be done?

[flamingdem]

6. US forces are going to aid them with the water problem

that was breaking news a bit ago, but it's a very bad scene, and there are no models for how to handle this, especially the issue of the fuel mixture MOX. So many unknowns.

[buddysmellgood]

7. Holy shit.

[suffragette]

8. Sounding very much like what Alvarez was bringing up on 3/11

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=439x619287#620599

[democrank]

9. My heart goes out to the people of Japan

[GliderGuider]

10. Does anyone have any idea what the road-map is from here to a sarcophagus?

How the hell will they get the reactors secure enough to entomb them? They can't do it when they're in this condition, it seems to me. Will it be enough to just spray water on them for a few months? will they need to open the reactor buildings more to expose the reactors and cover them with boron?

Any thoughts?

(Normal Stuff)---> (Whoopsie!)---> (Panicky Stuff!)---> (More panicky Stuff!!)---> (Really Panicky Stuff!!!)---> (((...Here a miracle occurs...)))---> (Sarcophagus)---> (Self-congratulatory backslapping)---> (Normal stuff...)
                                                                                                                                    ^
                                                                                                            You are here------------+

[jpak]

11. Major breach - very bad

I would suspect not the only one

:(

[FBaggins]

12. So now you don't think that any of the fuel in the pools overheated?

The only possibility in your mind is the worst one you can think of?

[GliderGuider]

13. He didn't say that. Please don't put words in peoples' mouths.

The worst case scenario looks like all the reactor containments being breached, all the spent fuel pools boiling dry, and all their cooling systems and all backup and jury-rigged cooling systems failing, and the site becoming too radioactive for anyone to work at for longer than 5 minutes. We're not even close to that. However, just because it's bad doesn't mean we're forbidden to contemplate it - so long as we don't mistake our contemplation for sober prediction.

What is the path from here to a sarcophagus, any ideas?

[FBaggins]

14. He seems pretty sure that it came from the reactor core through a major breach.

Doesn't he?

If we believe that fuel in those pools has overheated (at least at SOME point), then it isn't a big leap to assume that lots of cladding was damaged. They've pumped thousands of tons of water into those pools. Some of it may have boiled off, but the bulk of it has just flowed back out again (either through leaks or overflowing). Wouldn't that water contain zirconium? Wouldn't that water then flow all through the lower levels of the plant (possibly including the basement of the generator building)?

I think that we can be almost certain that this is happening. Why do we need to postulate a far less likely scenario? Particularly when nothing else seems to point to it?

What is the path from here to a sarcophagus, any ideas?

I don't think that a sarcophagus is an option at this point. They can't leave the spent fuel in the pools and just cover them up.

There are two dangers here. Direct radiation from a stationary source, and the release of radioactive material that itself releases radiation wherever it goes. A sarcophagus really only protects against the first danger. In Chernobyl, it limits the second by keeping dust form getting kicked up, but wouldn't do much if there were an active fire in there.

If you have a stationary source (say, a core that's gotten our of containment and is sitting in the basement radiating)... you can put a shield around it once you get comfortable that it isn't going to do anything else. In Fukushima you wouldn't know that. the pools would catch fire and release radioactive elements.

[GliderGuider]

15. Interesting. So what are the options for dealing with both issues?

It sounds as though both the live and spent fuel is going to have to be physically removed at some point and transported to a secure storage site. That sounds like a very nasty piece of work, and getting the situation stable enough to do that could take a very long time.

It looks more and more like the big problems are still ahead.

[FBaggins]

16. If I knew... I'd be selling them my services.

It looks like a nasty business from here.

My working assumption is that the spent fuel pools have a leak part way up the side of the pool. There is no immediate danger because they can keep them cool enough and covered... but that doesn't let you work up there, because there isn't enough water to shield the workers from direct radiation. At some point they'll have to use a crane to pick away at the debris and see what the situation is (how badly damaged the fuel is, etc). Eventually they have to remove the fuel and move it to a safer environment. Maintaining safety in that evolution looks hard to me.

THEN you get to the cores. You can't just leave them there for years as their activity levels decline because I don't think that you can get comfortable that your cooling ability is reliable long-term even if you get it working again. You can't GET to the cores until the pools are cleared and now you're got a problem of how to get at the core. Normally you flood the entire basin above the reactor and then open the containment. Who knows if that's even possible in this case? If the fuel pools aren't able to be filled completely, how can we be comfortable that the entire upper portion of the reactor will hold a water-tight seal?

At this point they should be getting close to limiting any large releases of radioactive material into the surrounding area, but the plant itself is going to be a very challenging place to work for quite some time.

[GliderGuider]

18. Thanks, that's pretty much what I thought the situation was.

In science the phrase "a hard problem" tends to mean "impossible" in street-speak. I hope "nasty" doesn't turn into "hard" here.

[kristopher]

24. This is what I mean about you not only being incorrect...

but incorrect with a certitude that cannot be justified in any degree by your demonstrated ability to read the available evidence.

You have literally been wrong more than 90% of the time yet you persist with"I think that we can be almost certain that this is happening. Why do we need to postulate a far less likely scenario? Particularly when nothing else seems to point to it?"

The briefing said twice that the probability that the zirconium came for the pool was extremely low. They posit a breach out of the reactor via the pipes since the pressure is being maintained, although they do not say what is required to maintain it.

[FBaggins]

17. After finding a better source... it probably did come from a reactor.

But the fact that they found zirconium doesn't tell us this.

It's the reported radiation level that implies this.

If, as I speculated earlier, the broken torus on #2 means that it's just centing away through that breach, then my guess is that this is where it came from (and it's quite possibly all over the place under those buildings).

[CRH]

19. Can you clarify what you mean, ...

If, as I speculated earlier, the broken torus on #2 means that it's just centing away through that breach, then my guess is that this is where it came from (and it's quite possibly all over the place under those buildings).

The radioactive water containing zirconium was found in the basement of reactor building 3. Are you suggesting the source of this radioactive water was really from the landfill beneath the reactor buildings that has become saturated from the suspected breach in the torus of reactor #2? If this was the case, then what forces the water up into the basement of reactor #3, and through what means? Common drain pipes, venting tunnels, increased pressure from high tide, osmosis through the concrete floor?

I'm trying to imagine what you are saying, can you expand on your thought?

[AtheistCrusader]

20. The 'Torus' is the suppression pool.

It's where steam is managed from the reactor core, around the base of the containment. It is part of the containment. (I don't believe it can be isolated but I may be wrong) But it isn't the 'catch pan' for the core if it melts through primary containment.

This likely just makes it a bitch and a half to work on the reactor, that's all. They need to get in there, and this inhibits that. So far, venting of gaseous material from the core to release pressure is the threat to the surrounding countryside (and whatever may have happened to the storage pools when the buildings exploded from hydrogen buildup.)

[CRH]

22. Are you saying, ...

that this suppression pool is common to and used by multiple reactors in multiple reactor buildings? This suppression pool is therefore located below the basements of several reactors buildings, and a leak in one torus can deposit water into a different building?

[AtheistCrusader]

25. Each (mark 1) reactor has a separate suppression pool.

Whether or not there are common drainage systems below the suppression pool, I do not know. That goes outside knowledge of the Mark 1 containment design, and into the specific plans of *this* particular power plant.

It wouldn't take much of a cross-connect between the drainage systems of these buildings for that to happen. For us, observing from afar, we would likely need access to actual plans from this plant, or a designer that worked on them to help us understand. Problem is, you can bet they've tapped and brought in every design expert that worked on this plant, so they are busy, and not talking to us.

[CRH]

26. OK, I think I've got it now, ...

because from the schematic I have seen it didn't seem possible. So if the above post by Baggins is correct or within reason, it must be something within the individual plant design that would permit the possibility. And the common union of different suppression pools, or the transfer of affluent from one pool into a different building, would be a huge flaw in design, allowing problems in the containment of one reactor to effect the integrity of the environment in another reactor building.

Thanks for your input.

[FBaggins]

28. It has to have spread - regardless of which reactor it came from.

IIRC the exposure happened in the basement of the generator building, not the reactor. So regardless of which core (or pool) the zirconium came from, it had to travel some distance either way.

My guess is that it came from #2. #3 has reportedly held pressure so I'm not sure where that much radiation would come from otherwise (steam doesn't account for it as it wouldn't be released where it could end up under the buildings).

I also have other reasons to believe that #2's broken torus may be leaking out large volumes of cooling water. Others have debated the point with decent positions, but that's where I stand right now.

[AtheistCrusader]

30. They reported the day of the hydrogen explosion

that the suppression pool on #2 was suspect. (This stood out in my mind, because it indicated the first possible containment breach)

It could even be as tangential as the torus is leaking radioactive steam, carrying zirconium particles, and that is condensing somewhere down the line in some tunnel along the way to the generator building, and then running onto the floor in the generator building.

There's an awful lot of ways it could be getting around. There's also that material on the cladding of the fuel rods in the storage pools, so those could be the source, one way or another, as well.


But I also suspect Reactor 2 as the most likely source.

[FBaggins]

31. I agree. Your "tangential" is actually my current working hypothesis.

Note that the temperature in that unit is much lower than the others (basically at the boiling point of water at normal pressure). They reported an inconsistent or odd pressure reading in that unit, but I take it to be pretty low (or the water couldn't get so cool).

I just don't know enough about the design of whatever gate controlls the flow into the torus OR whether that too was damaged at the time.

There's also that material on the cladding of the fuel rods in the storage pools, so those could be the source, one way or another, as well.


That was my first guess as well... until I saw the reported radiation levels. They were awfully high to be overflow from the spent fuel pools. But I could be wrong.

[kristopher]

33. They think it is from #3 and possibly other sources. 3 & 4 looked to be connected

in their simplified visual aid.

[FBaggins]

36. Well #4 is pretty much out.

There wouldn't be enough iodine in that pool and there's nothing in the core.

Three makes sense from a location standpoint, but doesn't seem to fit otherwise...

...unless maybe the torus leaks but isn't otherwise broken. All of those core elements would have been vented through that ring to supress pressure and the water in there would have become heavily irradiated.

But we know that #2 is in pretty bad shape so it's still where I would lean.

Of course you're correct that it could be a combination.

[kristopher]

38. Not me, them.

[FBaggins]

39. That's fine. There was no argument in there.

As long as you're not giving us "Oh NO! Now they're ALL dead! Tokyo was better off with Godzilla and the liquidators at Chernobyl were safer!"... I'm fine. :)

[ReturnoftheDjedi]

21. and in the groundwater underneath and in the ocean, too

they've been pumping water through there for days and days since the hydrogen explosion that likely caused the containment breach.

[FBaggins]

27. Probably so. Yep. n/t

[Yo_Mama]

29. They might think so

The very high, but different contamination levels found in the basement of 1 make it unclear.

They are saying that they are finding very contaminated water in the basements of 1, 2 & 3.

It's a different mix. Here's water sampled in the basement at 1:
http://www.nisa.meti.go.jp/english/files/en20110325-6.pdf

Here's TEPCO's release about the water in basement 3:
http://www.tepco.co.jp/en/press/corp-com/release/11032503-e.html

It's possible that the all the water that has been dumped has just resulted in a very contaminated and very waterlogged site with stuff bleeding everywhere.

[FBaggins]

32. Thanks, Based on that source I'm pretty sure it's a reactor core and not a pool

Way too much Iodine 131 to be from spent fuel. It's a fission product with a pretty short half life. There wouldn't be any to speak of in spent fuel.

[AtheistCrusader]

34. Reactor 4 had fresh and old fuel sitting in the storage pool.

Reactor 3 and 4 buildings have some plumbing connections, so I suppose I wouldn't rule out #4's storage pool based on that.

[FBaggins]

37. It would have to be awfully "fresh".

Radioiodine has only an 8-day half life... and it isn't just from when the fuel leaves the reactor, it's from when it was shut down. If all of the fuel was already out of the core, that was some time ago.

[Yo_Mama]

35. Except there is the wild card from the active rods on top of 4

My hunch is that you are right. My hunch is worth nothing, though.

They've been trying to raise water levels in Reactor 2's core; maybe it leaked out from there. But you can make an argument that it's from multiple sources because of the different results.

I bet the people there don't know much for certain.

[kristopher]

23. That is what the daily briefing said. From the core, not the pool.