Re: [LAU] OT: metal, money, changes, bleg

On 04/04/2011 08:42 AM, Patrick Shirkey wrote: no. and to see how hard it actually is: there were news of a botched nuclear test in north korea a while ago, where international observers found evidence of an explosion (by satellite or seismic measurements) that was vastly less than what was anticipated. such a situation is called a "fizzle", and what happens is that you bring the two halves of sub-critical material together too slowly or in the wrong way, and the chain reaction then heats it up and tears the material apart again before the entire mass has started to react. when you pile up too much plutonium or uranium, criticality accidents can occur, but there is no possibility of an explosion even remotely comparable to a fission bomb. which is not necessarily a good thing: iiuc, a good clean atomic bomb test can be more "environmentally friendly" than a botched one, because a fizzle explosion distributes the material over a large area and could even lead to greater contamination than the fallout of a full explosion. all this information can be found all over the web, in wikipedia, and various physics textbooks. for instance, there's a very interesting anecdote where richard feynman claims he had to show the uranium processing guys at oak ridge labs how to avoid criticalities (during the manhattan project) - they had been kept in the dark about this problem because some nuthead top-brass figured they had no "need to know". turns out they were keeping large cauldrons of enriched material lined up against a dry wall, and guess what a second team was doing on the other side of this wall? yup. btw, there have been reports cropping up every now and then that re-criticality incidents have indeed happened in fukushima after the cold shutdown, either due to overcrowded spent fuel pools or the melting of one or more core. this was substantiated by traces of very short-lived decay products that should not have been detectable anymore if no more chain reactions had occured after the cold shutdown. this is of course reason to worry, because criticality would pose a great danger to the crew who has to mop up the mess, due to extremely high and uncalculable radiation peaks. but it also shows that criticality != fission explosion. i'm as pissed as you at the nuclear industry and current energy politics (and in fact, it looks like that at least in germany, the political climate will now finally allow us to retire nuclear energy for good and fully replace it with renewables). but spreading vague fear and misinformation is really not helpful at all. there is a very clear danger, but it's important to get the facts straight, otherwise it's too easy for proponents of nuclear energy to re-spin the current outcry into irrational fearmongering - which is going on alright, but the fact remains that fukushima is a huge environmental fuckup and the source of much human tragedy. and if you continue to go on record with perpetuum mobile schemes and other easily refutable statements, you will not only be wasting your and other people's time, but also ultimately discredit your vote and work against your own political ends. (meta-conspiracy theory anyone?)