[ RadSafe ] Silver from US reserves used in the Electromagnetic diffusion plant

[ksparth at vsnl.com]

Silver from the US reserves was used to fabricate the magnets for the electromagnetic diffusion plant.The chance of getting it contaminated with the radioisotopes of Uranium was minimum. No one refers to such a possiblity in the literature.

Contamination due to radioactive silver in nuclear power plants and its contribution to dose are well known. Please see the following extracts from th 15 Annual Workshop sponsored by Progress Energy at Washington from June 25-29, 2005

"A small percentage of Curies results in a large percentage of the Max. Individual/Max. Organ Invertebrate doses from liquids is shown to be due to one isotope, Ag-110m (activated silver). At Millstone Units, it has generally been understood that a major contributor to dose has been due to Ag-110m. This compares to the majority of Curies that come from Tritium. 

Further questioning led to the possible source of the silver. The Reactor Vessel O-Ring is a silver-coated component which leaves residue on both the RV flange and the head O-ring grooves. The method of silver residue removal is considered to be a likely source. In the early 1990’s the silver residue was manually removed by dry scrubbing of the RV flange and the head O-ring grooves. In order to reduce worker doses due to this activity, it was decided to perform the RV flange cleaning with the reactor cavity flooded, utilizing SCUBA divers. In the 2000 Unit 2 refueling outage, an underwater RV flange-cleaning machine was utilized. The 2 head O-ring grooves are still manually scrubbed. A video of the 2000 RV flange cleaning operation has been made and reviewed.

Consider these issues - 

 Does the silver residue from the RV flange cleaning result in the Ag-110m in the liquid effluents? 
 Can the silver residue be captured at the source, during the cleaning operation? 
 How much money should Millstone stations, and the Industry, spend to remove liquid curies (0.1 Curies) in this unregulated environment?  
 Or can a more cost-effective way of reducing Public Dose be achieved?  
 Why is Silver dose high? "

I am not sure that the contamination of silver  due to radioactive silver from nuclear power plants is so high that it gets into silver that is in general use and contaminates the silver emulsion in films!

K.s.Parthasarathy.
 


----- Original Message -----
From: Susan Gawarecki <loc at icx.net>
Date: Thursday, March 24, 2005 12:45 pm
Subject: Re: AW: [ RadSafe ] nuclear weapons impact thread

> The electromagnetic urnaium enrichment process at Oak Ridge used 
> all of 
> the US silver reserves during WWII for wiring.  After the war, the 
> silver was returned to government vaults.  It's not inconceivable 
> that 
> some was activated or otherwise contaminated with radionuclides.  
> The US 
> government ultimately sold its precious metal reserves.
> 
> Susan Gawarecki
> 
> Franz Schönhofer wrote:
> 
> >John, Susan, RADSAFErs,
> >
> >>From several sources and even projects I have been working with 
> I know
> >that film companies had severe problems with radioactivity of silver
> >used in film-emulsions. The problem arose, because in nuclear power
> >plants silver is used in the form of a seal to certain components 
> of the
> >NPP and becomes activated to Ag-110m and the long-lived Ag-110. Then
> >they are recycled.  
> >
> >  
> >
> 
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