It was just announced on MSNBC that electrical power was just restored to the complex. Hopefully this will allow some pumps to work, some controls, and the metering systems to be brought online. A much better overview should be available within 24 hours (Saturday, Japan Time).
I would think that quite a bit of the electrical circuitry in some of those units would have been damaged beyond use from the explosions. We shall see. Units 2, 5, & 6 will be in good shape. That leaves only 1, 3, & 4 to be dealt with ASAP. Best of luck over there. Thinking of you all the time. On Mar 17, 2011, at 10:05 , John Sessoms wrote: > From: Joseph McAllister > >> On Mar 16, 2011, at 17:00 , eckinator wrote: >> >>>> I would kind of think that all this pumping of water onto fuel >>>> rods glowing at somewhere between 800 and 2500 ?C would cause >>>> instant evaporation and the corresponding shock waves of pressure >>>> rises; AFAIK water expands 1700fold from liquid to vapor/gaseous >>>> after all. wouldn't that cause enormous stress and ultimately >>>> fatigue of the containment vessel? and are the pressure relief >>>> valves designed to withstand this abuse for an extended period? >> >> That is the challenge, once the fuel rods are uncovered. They get so >> hot that trying to cover them again with anything that could help >> reduce or stop the loss of coolant creates more steam which becomes >> volatile in contact with the hydrogen being released by the degrading >> fuel rods because it presents free oxygen to an increased amount of >> hydrogen. Like H3 0. >> >> So the helicopters that are currently (as I write this on Thursday >> morning Japan time) dumping water on the hot (burning at times) spent >> fuel rods would have to dump a lot in a short period of time to >> prevent it being boiled off instantly. They should be, and may be, >> dropping a slurry of water and sodium hydroxide (I think hydroxide, >> maybe not). >> > > > The containments are already breached. > > But the place where the helicopters are dumping water is a storage pool for > spent fuel rods, not inside the reactor. I think they've managed to get some > cooling water into the reactors. > > I'm wondering how the water got out of the storage pool. The ones I'm > familiar with are massive reinforced concrete structures with walls many feet > thick set below ground level. > > The ones I worked on back in the late 70s had walls & floors 10 feet thick, > all poured in one continuous pour. They had multiple layers of #18 rebar on > both the inside and outside faces with thousands of tie rods linking the two > faces. The earthquake might bounce it around a lot and it should stay intact. > > An earthquake strong enough to breach structure like that wouldn't leave > anything else standing, and I can see that there are towers and buildings > still standing at the site. > > To get water out of the storage pool you had to suck it out uphill. There's > supposed to be enough water in the pool to cover the spent fuel rod bundles > and keep them cool even if they temporarily lose the ability to add water to > the pool. > > If the pool is breached in some way that it has drained, they can't dump > enough water from helicopters to bring the reactions under control. They're > going to have to get multiple water pipe into that building to get control of > the situation. > > Chernobyl was a dry pile design and the helicopters there were dumping sand > and cement on to the exposed core. The sand and cement didn't flow away like > water will. Over time it built up in layers to contain the reaction so that > they could get a more permanent cap in place. Joseph McAllister Lots of gear, not much time http://gallery.me.com/jomac -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
