Re: What is a contaminated soil ?

["Frank "Free Spirit" Borger" <frank@rover.bsd.uchicago.edu>]

> Date:          Fri, 17 Jan 97 14:48:26 -0600
> Reply-to:      radsafe@romulus.ehs.uiuc.edu
> From:          Randall_F_Brich@RL.gov
> To:            Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
> Subject:       Re: What is a contaminated soil ?

>      "Any area where radioactive material contamination exists in a matrix 
>      (eg. soil) at levels exceeding natural background and has not been 
>      release for unrestricted use in accordance with DOE Order 5400.5, 
>      Radiation Protection of the Public and the environment."
>      
	Excuse a question from someone not totally expert in
	rule interpretation, but doesn't the above leave a gaping  hole
	in the determination of what "natural background" is?

	From a map obtained from Busby's web site, natural x-ray
	radiation 1-foot above the ground varies from about 2.5 to
	8.5 micro-R per hour,  and these numbers are themselves
	averages, subject to significant local variences.

	The second question of course is if local background is
	4.0 micro-R/hour and  the reading for your "soil" is 4.1, 
	is this contaminated?

	And of course, can you ship that soil to a different state
	where background is higher, and does it suddenly become
	"uncontaminated" as a result?

	We recently had a mini-scare in Chicago concerning some soil
	with low-level Thorium contamination that had to be removed
	before they paved over it and made it a parking lot, (shades of
	the 60's song.) Surprisingly local reporters stayed away from
	the "scare" possibilities and generally came up  with a "no big
	deal" summation  of the story. As I remember, the level was
	such that it approximated background for some areas in the
	Rockies.

Frank R. Borger - Physicist - Center for Radiation Therapy
net: Frank@rover.uchicago.edu   ph: 312-791-8075 fa: 791-3697

How many physicists does it take to change a light bulb?
Only one. According to Heisenberg, all you have to do is
observe it, and you change it.