(Fwd) (Fwd) Re: Working life of sealed industrial sources

["Charles Meyer" <CMEYER@brc1.tdh.state.tx.us>]

------- Forwarded Message Follows -------
From:          "Robert Free" <TDHBRC1/RFREE>
Organization:  Texas Department of Health
To:            cmeyer
Date:          Fri, 11 Oct 1996 11:07:39 -0600 (CST)
Subject:       (Fwd) Re: Working life of sealed industrial sources

Russ, would you forward this to radsafe for me?

------- Forwarded Message Follows -------
From:          Self <TDHBRC1/RFREE>
To:            Multiple recipients of list 
<radsafe@romulus.ehs.uiuc.edu
Subject:       Re: Working life of sealed industrial sources
Date:          Tue, 8 Oct 1996 08:46:24 -0600 (CST)

It is true that the chemicals involved in the original discovery of 
contamination were traced to Ashland Chemical in Dallas and that the 
source was Po-210 from static eliminators manufactured by 3M.  
However, I think everyone shared in the responsibility for the event.  
The design was reviewed by both the NRC and, obviously,3M.  The 
devices were used in almost if not every state. Most state regulatory 
agencies knew the static eliminators were present in use in their 
states.  Literature issued to users cautioned against using the devices in caustic 
environments.  However, it appeared some sales reps were unaware or 
ignored  these caution statements..

Many of these devices were used in photographic labs as well as chemical 
plants. That is not to say the design was good, only that the 
magnitude of the problem might have been reduced had the devices been 
used in more apppropriate environments.

I saw a remark from one respondent indicating NRC overreacted to the 
event.  Actually, the NRC in this case recommended a less agressive 
approach on the part of regional offices and agreement states 
suggesting they wait for users to make contact after receiving 
notification from 3M.  They didn't ask regulatory agencies to run out 
and perform surveys of every facility on 3M's list, but rather to let 3M's consultants take 
necessary actions.

Our information on the design of the sources was that the microspheres 
were  ceramic matrices which were heated and immersed in Po-210 solution(?).  
The heating process opened fissures in the microspheres which closed 
when they cooled and bound the Po-210 in place. I don't recall the 
activities per microsphere, but they were then "lodged" in an epoxy 
which was placed into  static eliminator device so that the 
microspheres were on the inside surface.  Air was forced over this 
surface to accomplish the users' desired result.

 
Robert Free
Bureau of Radiation Control
Texas Dept. of Health
<><><><><><><><><><><><><><><><><>            
<>    Charles R. (Russ) Meyer                  <>
<> Email: cmeyer@tdh.state.tx.us           <> 
<>     Phone:(512)834-6688                       <>
<>        Fax:(512)834-6654                        <>
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