Re: Working life of sealed industrial sources

["Robert Free" <rfree@brc1.tdh.state.tx.us>]

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. 
Literature issued to users cautioned against using the devices in caustic 
environments.  However, it appeared some sales reps were unaware of this.
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.

I saw a remark from one respondent indicationg 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, but rather to let 3M's consultants take 
necessary actions.


Robert Free 
Bureau of Radiation Control
Texas Dept. of Health 

Our information on the design was that the microspheres were a ceramic 
matrix which were heated and immersed in aPo-210 solution(?).  The 
heating process opened fissures in the microspheres and when cooled, 
locked the Po-210 in place.


in a soliution containing