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Re: AW: Alternatives to lead blankets



Water shields are available, and represent a good alternative to Pb.  One problem

is that, if installed vertically, they tend to sag.  This can sometimes be

ameliorated by pressurizing them with compressed air.



One caution, especially at a nuclear power plant:  We were removing some water

shields in our restricted area and planned to drain them to a floor drain.  In

accordance with plant procedures, we had the water tested before draining, and

found high TOC (total organic carbon), which prevented us from draining to a

floor drain, since this goes to the plant radwaste system.  It seems that the

shields come with talc inside, to prevent sticking.  It may be helpful to flush

them out before bringing the shields into a restricted area.



The opinions expressed are strictly mine.

It's not about dose, it's about trust.

Curies forever.



Bill Lipton

liptonw@dteenergy.com



John Andrews wrote:



> Franz Schoenhofer wrote:

>

> > -----Ursprüngliche Nachricht-----

> >Von:   owner-radsafe@list.vanderbilt.edu

> >[mailto:owner-radsafe@list.vanderbilt.edu]  Im Auftrag von Dave Biela

> >Gesendet:      Mittwoch, 05. Februar 2003 20:41

> >An:    radsafe@list.vanderbilt.edu

> >Cc:    Tom Kocialski

> >Betreff:       Alternatives to lead blankets

> >

> >I have been asked to gather data on non-hazardous alternatives to lead

> >blankets for gamma shielding.  Any input will be appreciated.

> >

> >

> >-------------------------------------------------------------------

> >

> >Dave,

> > I have some problems with your request. Your posting would imply, that lead

> >blankets are hazardous. ?????? Very basic radiation protection knowledge

> >would show you, that the shielding efficiency depends on the Z of the

> >shielding material. Better than lead would of course be uranium, depleted

> >uranium available at very low cost. According to the last few years news on

> >gulf war syndrome etc. this seems to be a "very dangerous and hazardous

> >material". (Sometimes I am cynical...) Maybe you want to use bismuth?

> >

> >Yes, lead blankets are hazardous if they fall on the feet from great

> >heights.

> >

> >Could you please inform us on your profession and what is the reason to ask

> >such a question on RADSAFE?

> >

> >Franz

> >

> >

> Let me add another caution with lead blankets:  When removing them, do

> not the laborors pile them up in one place on the grating as happened to

> me one time.  We did not have the accident we could have if the grating

> had given away.  The caution applies to all sheilding removal.  Water is

> often an easy shield to place and remove.  I once borrowed a number of

> barrels, lined them up and filled them with water, finished my task that

> was threatened to be shut down because of the radiation in the adjacent

> area, then drained them into the floor drain and returned them as new.

>  I have also used barrels filled with sand to do temporary shielding.

>  This was especially useful in an area used for storing hot drums

> because we had all the barrel handling equipment available.

>

> John Andrews

> Knoxville, Tennessee

>

> John Andrews

>

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