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Re: SI unit of WL (was: Bq soon)



Were the annual limits expressed in SI units? Were they round numbers, or was it just 4 (or 4.7) WLM converted to the SI unit with 3 or 4 significant figures?
 
There is no incentive in Canada for anyone to change procedures to calculate J/m3, when the annual limit is in WLM. Of course you are correct and it would not be difficult to change the calculation once J/m3 has some meaning wrt limits.
 
----- Original Message -----
Sent: Tuesday, April 08, 2003 5:58 PM
Subject: RE: SI unit of WL (was: Bq soon)

When I worked in a uranium mine we always calculated J/m3 (or should i say micro J/m3). It is a simple matter to include the conversion factor for WL to J/m3 into the calculation. Basically the calculation involves counts, detector efficiency and a "factor". This "factor" is a single number that takes into account sample, decay and counting times, volume collected among other times like the number that converts WL to J/m3. I guess the calculation used by the technicians should have been updated.
 
-----Original Message-----
From: Kai Kaletsch [mailto:eic@shaw.ca]
Sent: Wednesday, 9 April 2003 4:38 AM
To: William V Lipton; mark.hogue@SRS.GOV
Cc: radsafe@list.vanderbilt.edu
Subject: SI unit of WL (was: Bq soon)

I believe the HPS once endorsed J/m3 for WL and Jh/m3 for WLM. Of course, h is not an SI unit (even though its use is still permitted) and the correct unit should be Js/m3. People get paid by the hour, not by the second, so Js/m3 is not very convenient.
 
A while ago, it looked like Canada was going to adopt SI units and we once wrote an entire EIS in J/m3 and Jh/m3. It is easy to do theoretical calculations in those units. The problem is that the technicians on the ground don't have any means of measuring J/m3. They collect radon progeny on a filter and then count the activity in a portable counter. The formulas that they use for converting the counts to airborne activity either have never been converted to produce J/m3, or the converted formulas have not been widely distributed and the regulatory agencies have not given their stamp of approval on the formulas.
 
The technicians would therefore have to calculate the airborne radiation in WL and then convert it to SI units. This defeats the purpose of adopting SI units, which is to make things simpler.
 
The SI units for radon progeny never caught on and we ended up converting the predictions back to WLM. [And yes, there were some conversion mistakes, but of course these happened after I quit the company :).]
 
My guess is that WL will be one of the last things to get converted to SI, but they will get converted.
 
Kai
 
----- Original Message -----
Sent: Tuesday, April 08, 2003 8:17 AM
Subject: Re: Bq soon

This is the best posting I've seen on this subject.  I remember the top down, "Do it my way or else..." campaign in the 1970's.  My facility had a full time, "metrification coordinator."   I was reprimanded for not supporting metrification with sufficient enthusiasm.  That, more than anything, is what turned me against SI units.

Regarding "Working Levels." - If there was ever a unit that needed to be SI'd, this is it.  On the other hand, I think that most persons, other than those who earn a living from Rn testing and remediation, agree that this is a solution looking for a problem, EPA scare ads notwithstanding.

The opinions expressed are strictly mine.
It's not about dose, it's about trust.
Curies forever.

Bill Lipton
liptonw@dteenergy.com

mark.hogue@SRS.GOV wrote:


I think Bjorn gave us the best flavor of what it takes to get used to a system.

The reason it's taking so long for the US to go metric is because the big push in the '70's (when I was in grade school) was such a flop. Instead of trying to give everyone a feel for the 'new' units, we were told, hey, look, an inch is 2.54 centimeters and a gallon is 3.7854 liters! No problem! Here's a table for you to memorize. Naturally, that made no sense to anyone. Plus, manufacturers objected to the real cost: retooling factories for metric sizes on nuts and bolts, etc.

Now, I have to think we've come a long way. Most people who use wrenches have already bought a metric set and maybe wish they wouldn't have to keep the english set too.

By the way, for radon measurements, is there anything metric that captures the real meaning of a working level?

Mark G. Hogue, CHP
mark.hogue@srs.gov
"But we surely overrate the usefulness of what we like to call "stimulation" and underrate the need for time, peace of mind, mature reflection." -  Susan Haack

"DISCLAIMER: The opinions expressed are mine and do not necessarily represent Westinghouse Savannah River Co. or the United States Department of Energy."
 
 
 



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