h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

i heard that there was a case some 50 years ago that a 12 year old kid assembled an atomic bomb. he took the uranium from variouse electrical devicesm in which there used to be radioactive substances. now you can dis-assemble smoke detectors for radioactive material, although the quantity is extremely small (it will take about 10 thousent of them, i think. maybe much more).

Hmm, sounds a little like an urban rumour, 50 years ago would put the whole thing during the early stages of the cold war - there wasn't an awful lot of radioactive material floating around in public at the time - and to be honest, levels of education into nuclear physics just wouldn't have been up to it.

Actually there was a kid who took parts from smoke detectors and created an enriching reactor. He did not get anywhere near enough material to create a bomb, but he did manage to get highly radioactive uranium in small quantities (grams).

Probably another urban rumour...

Smoke detectors come in two types. one type uses photo-electric cells to detect the smoke whilst the other uses a radioactive source and detector... however, the second type uses Amerericium - a by product of Plutonium, and if you could turn that into Uranium you'd have to be an alchemist (and I've got several kilos of Lead I'd like turned into gold )

Am02 - as used in smoke detectors costs around 1500 dollars a gramme, and you'd need over 5000 smoke detectors to recover one gramme. The only way I can think of for a kid to get hold of over 5000 smoke detectors would be through an awful lot of burglaries


Then there's the sheer practicality of the matter... In a single smoke detector there is less than 0.0002 grammes of AmO2, (a grain of sand is three times heavier and much much larger), so imagine the equipment needed to deal with that sort of thing. Plus, getting rid of the remains of 5000 smoke detectors (each one 12 cm diameter by 2 cm deep... you're looking at a pile of plastic and metal weighing a couple of tonnes and even if you could crush the plastic down to powder, the resulting debris would still fill 5 or six 45 gallon oil drums (if you just broke them up and threw them in the dustbin you'd be looking at an awfully big pile of plastic...

I just don't think this sort of thing is physically probable.