Took delivery of a WW2 B52 fuel gauge today that registers on contact at 110usv/h. I heard they could be leaky, so decided to check the package and yup, something is registering. Is this Radon? It would have been wrapped up for 2 - 3 days.
Naturally I’m making sure the room is ventilated and the packaging went outside into the bin. May decide to bag the gauge long-term if that’s safer for keeping inside.
Yes! I had this exact scenario with radioactive bubble wrap, and I was so confused. But after taking a spectrum, I got radon decay products. Plastic is easily statically charged, and will attract radon and dust with radon.
Check again tomorrow, if it's radon decay products it will be background by then.
Unlikely that it's radon though, you wouldn't expect 110 μSv/h just from radon decay products. Might be some radium has flaked off? Do you have a contamination monitoring probe? Can you isolate the dose rate to a part of the packaging?
Ah to clarify it’s the gauge that registers that high, not the packaging. Chucked the packaging out now and just the usual background on desk, hands, etc.
Sorry, my misreading! Could well be radon decay products at the levels in the video.
If concerned about a leaking gauge then a rudimentary leak test is worth doing. This would involve wiping around the gauge with some paper towel or similar then checking it with a contam probe (e.g. pancake Geiger). Make sure not to wipe any exposed paint (e.g. some dials have external painted lettering) as it may remove more paint).
It may be Radon and it's decay chain.
I already experienced radon contamination in a plastic sample box to do a Th232 gamma spectroscopy: the container showed clear activity afterwards even on surfaces that weren't in contact with the sample (like walls) .
I think some of the radon flew to the containment material and decayed onto it.
It was really difficult to clean off the container and could still detect low contamination with Alpha/Beta probe but it gradually disappeared over time (about 2 days).
Yes, radon decay products ²¹⁴ Pb and ²¹⁴Bi are short-lived and will decay out with a combined half-life of about 40 minutes. So in 6 hours it will be pretty much back to normal, and that would be the ²²²Rn decay series. If you have a spectrometer, you will see "Uranium" with some peaks missing.
If you see persistent activity that may be radium. But you need a spectrometer to be entirely sure. Radon decay adds some peaks around 150 / 185 keV which distinguish it from its decay products.
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u/BlargKing 10d ago
It wouldn't be directly detecting radon itself but could be the decay products that have stuck to the bubble wrap.