 Quote by liamdavis
It seems that the explosions at each plant would leave distinct evidence as to its nature. A shattering (high velocity) explosion should leave some sharp ragged edges on the concrete structure. Where as propellant (low velocity) damage should show erosion.
Water turning to steam expands about 1728 times in volume. It starts out with no velocity and accelerates. The speed it obtains between its point of origin and the building walls would give it an energy impulse upon impact similar to an explosion. However, between being water and being steam at full expansion, it would behave much like a fluid. If a significant quantity of water flashed to steam and had only expanded to 2-400 times its volume at the time it initially pushed the wall panels out then it would leave the marks of a (debris laden) fluid eroding the remaining concrete structure.
Hi-res close-up pictures of the remaining vertical supports and the underside of horizontal structure should bring clarity to which event happened at which buildings. This would make the reconstruction of events more focused and productive.
liam
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@liamdavis:
Thank you very much for that information. Very much looking forward to your analysis and what you can tell us about the various events at each of the buildings!
It is hard to escape the conclusion that water flashing to steam occurred at Bldg 3 and that the source of the explosion in Bldg 4 had to ultimately be the spent and un-spent fuel in the SFP.
Quote by MiceAndMen
Thanks AntonL!
Oyster Creek Reactor Building General Arrangement (approx. 1 MB)
http://i.min.us/ikukv6.jpg
Oyster Creek Reactor Building Refueling Level (approx. 5 MB)
http://i.min.us/ikum3E.jpg
The second pic shows a lot of little details, such as the height of the 4 reactor cavity shield plug slabs being 7 feet (2.13 meters). Note that the differences between the Oyster Creek plant and the Fukushima reactors are quite possibly non-trivial. It would be really nice if TEPCO would release a set of drawings  but I don't think that's going to happen.
I'll find the URLs for the PDFs I have of the Oyster Creek drawings. There are 4 PDF files totalling about 23 MB. Hmmm... now that I think about it, there are no direct PDF download URLs, you'll have to navigate an NRC website to get to them. I'll post how to do that tomorrow.
I spent more than a few hours searching for reactor building blueprints on the NRC site, and the ones for Oyster Creek are the only ones I could find. Others haven't been scanned into PDF form yet, and still others are, I think, not publicly available at all. That's too bad because I believe the closest reactors in the US to the Fukushima Daiichi ones are the ones at Vermont Yankee and (now closed) Millstone I. |
@MiceAndMen:
Thank you also for the detailed drawings of the reactors. The last in particular gives some excellent details on the "likely" construction of the upper containment including the shield plugs (which as it turns out) are clad in carbon steel -- at least at the Oyster Creek facility.
As above, flashing of water to steam seems at least to me to be what occurred in part at Unit 3. It also seems likely that the initiating event was an explosion occurring in the primary containment. How to get from "A" to "B" is a question that I don't think has been answered fully.
As for Unit 4, the shattered upper mast of the FHM seems to indicate a violent event in the SFP with lots of energy transferred to the mast, but perhaps not so much damage to the remainder of the FHM. And additional plans detailing what might have been directly behind the blown out panels at the north and south face of Bldg 4 would be most interesting.
@all:
Coming at the explosion in the lower building, here's a hypothetical question for someone who knows reactors:
In the myriad of pipes, tanks and accessories hooked up to the RPV and primary containment and housed
outside of the RPV and primary containment, in the lower building (other than the torus suppression pool), are there any of them that might explode as a direct result from over-pressure, steam or hydrogen accumulation
inside the primary containment or RPV?
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