Japan Earthquake: nuclear plants

AntonL

This may help
By what I can make of it, it is a theoretical simulation based on an assumed release and
nothing to do with actual release values.

I suppose you can email Dr G Wotawa directly and ask him.

AntonL

However, villages are protected by a 10 metre Tsunami wall, needless to say they were
breached and wiki Historic Tsunami list numerous Tsunamis 20 metres plus.


We are witnessing a designed "accident-in-waiting";
same can happen at San Onofre southern California and many more others .

|Fred

the presence of Corium outside the reactor is inconstant with the isotopes founded so far

AtomicWombat

Astronuc,

Are you aware of failure mechanisms involving an explosion in the wet well?

It has occurred to me that the reactor (85 atm design) is exceptionally robust compared to the primary containment (5 atm design). An explosion in the wet well could simply blast past the reactor without penetrating it, but blowing the concrete plug high into the sky.

PietKuip

I now read their Possible source of leaks at spent fuel pools at Spent Fuel Pools at Fukushima. And I am flabbergasted by how these things are designed: the gates are sealed with an inflatable thing that needs to be kept pressurized by electrical power. Without electricity, water will be running out. And this had happened in the US at the Hatch nuclear plant in Georgia in 1986. There someone had closed a valve. They cought it in time, but if water levels had fallen further, radiation levels would have made it difficult to fix the problem.

So maybe there is no structural damage or cracks in the concrete caused by the quake or the tsunami. The leaks in all these pools are a consequence of design, almost guaranteed to happen when electrical power is lost. That is very worrisome.

TCups

REACTOR UNIT 3 BUILDING ORIENTATION?

Starting with the diagram found here:
http://modernsurvivalblog.com/wp-con...tor-mark-I.jpg

1) If this general schematic is correct (and I realize it may not be), then the north-south axis of the core's center is located west of the central north-nouth axis of the building, but the east-west axis of the core is centered.

2) It appears that a tunnel structure at ground level is located where the well shaft for the fuel assembly lift with the crane takes place. A very similar tunnel exits the southwest corner of Bldg 3 and, this appears to coincide with where, on the west side of Bldg 3 the refueling trucks were parked.

3) It appears that the upper portion of the shaft (intact, or largely intact) and a portion of a pool, severely damaged, can be seen on the helicopter fly-over photos. The helicopter spends a long time looking at the southeast corner of the building.

4) The location of the overhead crane is not a constant reference as it can be moved north-south

5) From this information, I have concluded that the SFP in Unit three is nearest the southeast corner of Bldg 3, and that appears to me to be the epicenter of the blast, directed upward and to the south, toward Bldg 4.

(see attached annotated diagram, NorhtSouthOrientation.jpg)

Any errors in this logic?
OOPS! the original NorthSouth diagram was incorrectly annotated. I have corrected it. Sorry!

After the explosion, from the helicopter fly over, this is the view from the southeast corner. One can see part of a tunnel structure exiting the back (west side, southwest corner) of the building, a part of the well shaft, what appears to be a blown out SFP in the southeast corner and steam venting from where the head of the primary (dry) containment of the reactor core might be.

(see picture38)

Part of Building 4 is included. In closer detail, it is apparent that the top of the north face of Bldg 4 has been blasted inward (not melted as earlier posted). If you look closely at several of the views of the northeast corner of Bldg 4, you can even see that the concrete pillar at the northeast corner of Bldg 4 buckles inward, presumably also from the blast. Although it has been posted that the north side of Bldg 4 was intact after the blast (at least it lacked the large, square hole we later concentrated on), it appears to me that blast damage occurred to Bldg 4. In fact, shrapnel from Bldg 3 may have penetrated the exterior of Bldg 4, not been visible by satellite, and may have been responsible for the later fire and additional damage at Bldg 4. Note also that a portion of the roof of Bldg 4 is peeled back.

(see pictre 37)

Does anyone find any error with these observations?

More later as I have time today.

Attached Thumbnails

     

jensjakob

Place of SFP is confirmed by Japanese authorities and mentioned in CNN and BBC

artax

BUMP!!

Not a very good image I know, but the vid has been pulled from you tube japan, and these fuel rods are s'posed to be a few cm thick and four metres long, and I assume very stiff as they're ceramic (?) or is that just the pills inside?
Anyway, would anyone else like to suggest what these are falling out the back (seaward or eastern side of unit 3

Attached Thumbnails

 

AntonL

TCups, SFP has been stated to be in SE corner of building, At fukushima reactor 1 is north of reactor 4, you have North South interchanged

(By the way you can image link and attachment) as I have done here by clicking on the thumb twice)
http://www.physicsforums.com/attachm...3&d=1300788049

jensjakob

AntonL, I think youre wrong. Servicetunnel goes towards the Northwest.

Reactor 1 is at the North?

And landside is on the West?

Then Servicetunnel goes to the Northwest?

TCups

Yes (darn it) and I didn't catch it immediately. I re-uploaded a correct annotation. I think the diagram matches the text now. SFP is at the SOUTHEAST corner of Bldg 3 as best I can tell.

I MUST be off to work. Will read all replies later.

AntonL

jensjakob, I do think the IAEA will have it correct check here top left hand corner of slide 1

TCups

Yes, apologies again. My typing fingers didn't keep up with my mind. Unit 3 is north of Unit 4. Unit 3's SFP is on the southeast corner of the building, more or less, but the buildings do not set on a true North-South-East-West axis as my diagram would seem to suggest. Obviously the ocean side is to the east. None the less, the "anatomy" of the building with respect to the location of the shaft, SFP, and core containment and therefore, the logic of the blast coming through the SFP, NOT the equipment pool holds up, which is the point I was, in my imperfect way, trying to make here.

jensjakob

The picture is rotated.

I google mapped it. Please review the orientation.

http://maps.google.dk/maps?f=q&sourc...67344567820820

dgdd

Quoting http://www.nytimes.com/2011/03/22/wo...22nuclear.html:

TCups

REGARDING THE DAMAGE AND MECHANISM OF DAMAGE TO UNIT 3

How unfortunate that my error on the N-S label (now corrected) or whether or not the buildings are in a true N-S-E-W orientation or somewhat askew misdirects the discussion. In general, the MAJOR POINT is that it is the corner nearest the SE of Building 3 where the SFP is located.

If one assumes that the long-distance video of the explosion was taken from high ground to the west, instead of out to sea, to the east, then the initial explosion was directed to the right, or generally to the south and toward Bldg 4, then it is the south wall of Bldg 3 that is blown out by the initial explosion and the north wall of Bldg 3 that is destroyed by the overhead crane.

If we agree on those points, then the pictures of the damage I see seem to make sense and reinforce the sequence of events I suggested and outlined earlier:

1) the hydrogen & oxygen from hydrolysis of hot steam in the presence of zirconium comes from the core of the reactor, and indicates at least some damage to the core.

2) the hydrogen accumulated in the primary (dry wall) containment and at relatively low pressure, could escape from the drywell cap.

3) the force of the earthquake alone could have sloshed out significant amounts of water from the SFP, irrespective of boiling, evaporation, or loss of circulation pumps

4) there is a transfer chute and a mechanical gate mechanism connecting the drywall containment to the SFP used to transfer fuel rods, underwater, from the core to the SFP.

5) the pneumatic seals on the gate are inflatable and would be compromised by a prolonged loss of power.

6) a lower water level in the SFP, and thus, loss of hydrostatic pressure behind the gate (outside of the primary, drywall containment) would further compromise the strength and integrity of the gate if a blast occurred from within the drywall containment

7) If the force of a blast exiting the primary containment were directed sideways, through that gate and the transfer chute, then the reinforced floor and walls of the SFP would function as an acoustic lens, directing much of the force of the blast (and perhaps a large, expanding volume of steam from the vaporized water which remained in the lower portion of the SFP) upward.

8) there may or may not have been a secondary explosion of hydrogen leaked into the upper portion of Bldg 3. (A primary explosion of that sort, external to the containment in the upper portion of the building, probably occurred in Bldg 1).

9) the blast blew portions of the south wall of Bldg 3 into Bldg 4's north wall. "Shrapnel" from the Bldg 3 blast may have initially damaged Bldg 4 leading to the fire(s) that occurred in Bldg 4 thereafter. (questionable, not confirmed by satellite photos. See Anton's later post, #820)

10) Blast damage from Bldg 3 can also be clearly seen involving the roof of the steam turbine buildings to the east and to at least one of the additional buildings to the west. A large portion of the crane fell, damaging the adjoining building structure below, to the north.

11) It is not possible to tell with certainty if the drywell containment plug atop Reactor 3 has been blown skyward. Perhaps not, the evidence being lack of conclusive damage to the roof girder structure directly over the apparent location of the plug, but instead, primarily over the SFP.

12) If there are fuel rods in the photos of the damage and debris atop Bldg 3's east side, then it appears more likely to me that they came from the SFP of 3, not the reactor core. Certainly any remaining water in the SFP would act to transfer the force of the blast (shock wave) more efficiently into the submerged portion of the pool and the rods therein, and the floor of the pool would reflect that shock wave, water, steam, and maybe spent fuel rod assemblies skyward.

13) Steam appeared to be venting, in a jet, into the region of the damaged SFP of Unit 3 after the blast (the helicopter flies through this cloud of steam). The pressure in the primary containment of Unit 3 has dropped. Radioactivity levels especially around unit 3 have risen. Black smoke was later seen rising from the same region.

14) It is very likely that the primary drywall containment of Unit 3 and not unlikely that the Unit 3 reactor vessel or pipes or valves connected to the RV have been damaged, initially venting steam, then, perhaps something else burning within the RV.

15) from the available photos, such as they are, I cannot confirm that there are fuel rod assemblies or water remaining in the SFP of unit 3.





Comments or corrections?

jensjakob

TCups - quite plausible I would say.