magnetron from microwaves

[gustavus]

Inside the magnetron the tungsten cathode contains 2% thorium 232 which is radio active this is what sets off the radiation scanners at the scrap yards.



The image below is thoriated tig welding electrodes which are much larger than the microwave cathode. The welder who has to sharpen the tip has much more exposure to this radio active material than you will ever experience.

I would think any welding shop disposing on the electrode nibs in the scrap bin would also have a rejected load, finding that nib would be like looking for a needle in a hay stack.

how come the scanners never go off when I take microwaves to the scrapyards then???

Obviously the scrap yard scanners are not sensitive enough to pick up on low level radiation, yards that do not know where the radio active piece of metal is located choose to error on the side of caution banning the acceptance of microwave appliances. While other yards better educated will accept them once the capacitor has been removed on the other hand some do not care if the appliance is intact.

A hand held Geiger counter or x-ray film strip such as those worn by technicians who work with radiation daily may be more sensitive to low level sources of radio activity.

Now you know the culprit is located inside the ,magnetron.

You saw it first here on the scrap forum.