[ RadSafe ] Question about 10 CFR 30-15

[BRISSON Nicolas]

Hi all,

I recently had to characterize an electron tube coming from the US, manufacturer unknown.
I only had one info : Cs-137 activity < 5 microCi.
I know it’s the exemption limit given by 10-CFR 30-15.

My question concerns the age of this regulation.
Has the limit always been the same and when has it first been implemented ?

Thanks for your help.

Nicolas Brisson
IRSN