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). And yes, the valves are designed to deal with tremendous pressures, until they fail of course. >> I do not claim to know everything about the operation of the GE reactors in >> trouble in Japan right now. I did learn the basics as a teenager some 50 >> years ago, conversing with my father as well as listening in on many >> conversations over dinners with several of the big names in the Atomic >> Energy business. R.G. McAllister was a Nuclear Health Physicist sent to >> represent the the U.S.A. Insurance Pool at several ISO conventions held at >> the Hague in the 1950's and 60's where the many safety measures in the use >> of these radioactive materials, from dentists and hospital use up to weapons >> production, were discussed and agreed upon. The reason for these month long >> meetings was that no insurance company, nor any country's insurance >> industry, could afford to cover a catastrophic event such as the one we are >> currently witness to in Japan. The risk had to be covered on a global scale. > > just don't get me started on weapons. this is bad enough as it is. > >> Don't be surprised if some of the large insurance companies in the world >> start selling off assets such as downtown buildings and other properties in >> the next year or three. > > sounds probable indeed. Russia did not see fit to buy insurance for their reactors, in hindsight a poor vision of the possible problems. But it' not just science and weaponry that need underwriting protection, it's the rider on every other insured within reach of a nuclear incident. Joseph McAllister pentax...@mac.com “ It is still true, as was first said many years ago, that people are the only sophisticated computing devices that can be made at low cost by unskilled workers!” — Martin G. Wolf, PhD -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.