Reply #277: prompt critical

[divvy]

Supporters of nuclear power (like me) lIke to say (not me) that a nuclear power plant can't explode like a nuclear bomb. That is technically true, but a prompt critical can take the reactor to extreme over power in milliseconds. That is what blew Chernobyl apart. That is what blew the SL-1 reactor apart in the US... remember xxxx asking if I had seen a film on it. xxxxxxx

http://www.google.com/images?q=SL-1+reactor&oe=UTF-8&hl=en&client=safari&um=1&ie=UTF-8&source=univ&sa=X&ei=cDOZTavPHsGM0QG0uITxCw&ved=0CDgQsAQ&biw=980&bih=1208 xxxxxxx

As you can see from the SL-1 (really tiny experimental reactor) pictures, it can be explosive. There is a picture of it exploding. That is virtually the same thing that the Russians did with their sub reactor. There is a possibility, though as far as I know it has never happened, that fuel that partially or completely melts, either in the RX or fuel pool, could loose its geometry in such a way that fuel could develop a localized critical and even a prompt critical... resulting in an explosion that would spread really nasty radioactive material over a wide area. That is the worst case if the Japanese have to abandon the site and let the RX's and fuel pools go to he//. Melting down and contaminating the groundwater is another bad outcome. I am not sure it is worse, though. A large explosion at the site would be very very bad. I don't see a recovery path from that tragedy. Today, they discovered 2 missing TEPCO employees dead in the basement of one of the plant's turbine buildings. I did not hear the cause of death... fallen heroes.