RE: Removable Contamination Surveys

I agree somewhat with Dr. Marcus' statement....but beware because at least one U.S. reg does reference a standard smear area (namely transportation regs). She is correct that it says nowhere in 10 CFR Part 20 what surface area must be covered in a smear sample...in fact I don't even think it says you MUST perform a "smear survey"....you just got to perform appropriate surveys to define the extent and nature of contamination in work areas. Your licensing document is where the "standard" is developed. I believe the 100 cm^2 area is arbitrary but has become "canonized" as common practice. However, as you are probably aware, there are specific regulatory requirements when it comes to shipping/transportation--specifically 49 CFR Part 173.443 states:

(1) Wiping an area of 300 square cm of the surface concerned with an absorbent material, using moderate pressure, and measuring the activity on the wiping material. Sufficient measurements must be taken in the most appropriate locations to yield a representative assessment of the non-fixed contamination levels. The amount of radioactivity measured on any single wiping material, when averaged over the surface wiped, may not exceed the limits set forth in table 11 at any time during
transport; or
(2) Using other methods of assessment of equal or greater efficiency, in which case the efficiency of the method used must be taken into account and the non-fixed contamination on the external surfaces of the package may not exceed ten times the limits set forth in table 11....

Many licensees have adopted RegGuide values and methodology into there radiation safety programs (by referencing them in their licenses)---so they are "stuck" unless they get an amendment. You do have some basis in 49 CFR for going to a larger value (e.g., 300 cm^2)...but to get this change you would likely have to enter the netherworld where politics and science meet (you know--get a license amendment from your regulator). What you will most likely find is that the burden of justification will be on you to deviate from your existing practice--the irony is that there is no real "scientific" justifcation for the common practice (100 cm^2).

Dear Peter:

Rest assured that NRC has absolutely no scientifically valid reasoning supporting any contamination standard. There is nothing in the regulations about a contamination standard. There are only radiation limits to members of the general public, workers, and the environment. The NRC contamination requirements are arbitrary and capricious licensing conditions with no regulatory requirement backing them up. They are a superb example of regulatory abuse. This particular example of regulatory abuse has been pointed out to the NRC over and over again for about a dozen years by the medical community, who presented credible models and internal and external dosimetry, all to no avail. There is a huge lack of scientific competence and honesty at NRC, which is evident to all who try to deal with it.

In the latest regulatory mess concerning the new Part 35, NRC actually dropped the contamination level for some radionuclides to 20 dpm/100 cm squared! After the medical community made its case once more and demanded science, NRC merely stated that "20 dpm seemed low", and raised it to 200 again, ignoring any demands for valid scientific analysis once more. It is reprehensible indeed that the entire food chain of NRC management failures could sign off on this arrogant junk and still keep their positions.

Obviously, if you are going to base permissible contamination levels on the Part 20 radiation standards, there would have to be a different value for every radionuclide, every situation, and different values for various radiochemical forms of each radionuclide.

The real answer is not to try to set a contamination limit at all. The radiation standards themselves say it all, and every medical licensee should have the ability to estimate contamination limits that would impose an appreciable percentage of the maximum radiation limits in Part 20. If NRC insists on ignoring licensee competence in basic radiation protection physics in its greed to amass as much license fee money as possible to support its runaway bureaucracy, then it is only NRC's fault if licensees do not understand how much contamination, and with which radiochemical, is significant. It is clear that NRC, with its present staff and management and Commissioners who do not or can not understand the relevant math and physics, will never understand how to intelligently handle the contamination issue.

Instead we have a dysfunctional system that exists to produce paper for untalented inspectors to inspect, giving an opportunity for large numbers of pointless "violations" and "notifications", all of which create completely unnecessary pseudoregulatory "work" with which NRC bureaucrats justify their existence.

Peter, you should never look for scientific reasoning in NRC requirements. Look instead at how many jobs of otherwise unemployable people rely on keeping those intellectually challenged requirements alive and well.

Ciao, Carol

Carol S. Marcus, Ph.D., M.D.
<csmarcus@ucla.edu>