jensjakob said:
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?
