Date: Thu, 17 Mar 2011 16:32:00 Subject: Alternate view of the Japanese Nuclear Damage From: Bill Williams This is what John DeArmond had to say on the subject! I have a high regard for his opinions! Bill Yes, media coverage is particularly bad on this one. I happened to have spent a couple of years working in the bowels of Browns Ferry NP which are identical units to those in Japan. GE Mk I BWRs. To sum it up in a few sentences, this is essentially identical to TMI. A Loss of Coolant Accident followed by failed fuel and probably substantial fuel melt (there was at TMI). The huge hydrogen production is from the zircalloy fuel cladding actually burning in the steam environment, stripping the oxygen atom from water and releasing the hydrogen. Same thing happened at TMI and there was a hydrogen explosion, though since with a PWR, the entire reactor building is the containment, the explosion was contained within the reactor building. At TMI the core remained uncovered for about 24 hours, long enough for the fuel to reach its maximum temperature and equilibrate with its surroundings. The fuel that did melt simply flowed out of the core and quenched in the water that remained below the fuel. It did not melt through the reactor vessel. In fact it didn't even scar the inside surface of the vessel. This is what I see happening in Japan. There has been partial or complete fuel failure in both units. That is indicated both by the huge hydrogen production and by the trace of Cs-137 and I-131 detected on the outside. There is a very large inventory of both isotopes in an operating reactor. The plant design assumes that both are released as gases during an accident and plan accordingly. That didn't happen at TMI. Once things cooled off enough that we could enter the containment, what we found was that the Cs and I had reacted chemically to form cesium iodide, a solid material. Most of it stayed in the reactor. Some came out into the containment building and settled out on surfaces. A very tiny amount escaped during the initial containment venting at TMI. Again, the same thing is happening in Japan. The trace of Cs and I that has been detected on the outside, if chemically analyzed, will be found to be the compound cesium iodide. This compounding is why there is but a tiny bit of material released despite practically constant containment venting. I don't quite understand the pumping of sea water. That's kind of a last ditch decision because the salt in the seawater destroys the stainless steel in the plant. Normally there are a few million gallons of demineralized water on-site for emergency cooling. Maybe it got contaminated by the tsunami. Maybe the piping from the storage tank(s) got broken in the shake. I certainly can't second-guess the on-site people. I did see mention in one news report that they were using large diesel construction pumps to pump the water. That indicates to me that the plant is still completely blacked out. It's possible that this is the reason for using seawater - that none of the electric pumps in the plant are working. When all the dust has settled, I predict this to be identical to TMI. An unmitigated disaster for the utility. No significant off-site radiation exposure and no off-site contamination. In other words, a non-event as far as the public is concerned. The massive evacuation will prove to have been precipitous and unnecessary. John