Greetings RadsafersMy question is this:
Is there a definitive legal threshold activity per mass value defining
the limit below which material can be considered non-active (either
generically or individually)? i.e. have I missed something?(This question relates mainly to the UK legislation but information
with regard to other country's laws will be useful and appreciated.
Perhaps the IAEA has some guidance on threshold values?)
If you're unlucky you may get reply's basically stating - what does it matter, radioactivity is positively good for you at levels far above the Harwell figures. (and who knows, it may very well be! - my own comment)
However the 100Bq/g in the Code of Practice is also the legal interpretation of radioactive substance in the IRR85 (Reg 2.). But I guess you know it's not that simple. The Radioactive Material (Road Transport) Act 1991 defines a radioactive substance as having an activity concentration of more than 70Bq/g (I think too this is the IAEA definition). Two different values, two perfectly valid UK Statutory Instruments. You're right about the RSA93, the interpretation is that just about everything under the sun is radioactive.
The key I think here is who's definition is it, HSE, the DoT, or DoE. The legal definition changes depending upon what you intend to do with your radioactivity: work with it - transport it - or keep it. There you go, the good old British legal system.
Have you noticed also the confusion over further aspects of the definition of Radioactive Material?
The DoE decided long ago that radioactive substances are either radioactive materials, or radioactive wastes, and that a radioactive material cannot be a radioactive waste, and vice versa. The DoT however define radioactive material as any radioactive substance (above the 70Bq/g level) regardless of it being a waste or not. (What's going on here then, what they trying to pull?)
Now you've kicked off what's the trickier question. (do ants go to discos?)
Cheers
Andy Hancock
Charing Cross Hospital, London
a.hancock@cxwms.ac.uk
http://www.cxwms.ac.uk/~rakv300/Rad_Prot_Home.html
(like the Millenium Dome - under construction)