Re: RADSAFE digest 1240

[enielsen@webspun.com (Erik C. Nielsen)]

Previously Submitted
>Date: Fri, 24 Jan 1997 14:05:07 -0500
>From: MARK WINSLOW <WINSLOW.MARK@EPAMAIL.EPA.GOV>
>Subject: Tritium and plastic
>
>I remember a while back I asked a question
>regarding tritium permeating through protective
>clothing.  I have another question regarding
>tritium.  Can tritium permeate through plastic
>sample containers?  And if you were going to
>sample for tritium would you use glass or plastic
>sample jars?
>
>Mark P. Winslow
>US EPA - Region II
>
>ps.  This is concerning the "leak" at BNL.
>
It does't go "through" as much as "diffuse".

Translocation (H3 for H in the hydrocarbon plastic) is counteracted by the
higher level of evaporation of the lower mass water differentially diffusing
thru plastic easier than glass.

Your agency specifies in the tritium method for drinking water that sample
be stored in glass for less than 6 months without a chemical preservative.
For practical purposes < 6 months it just doesn't matter.

In a "leak" situation it is very different...If the levels are high the
diffusion coefficient through plastic can be significant.  After all
plastics are hydrocarbons..so substitute tritium for H.

As an analytical effort for a customer, we burned the plastic container
containing a tritiated organic solvent...the tritium concentration in the
plastic was near equilibrium to that of the material contained.

Tritium moves very easily,

Erik C. Nielsen
Heritage Laboratories
enielsen@webspun.com
enielsen@webspun.com

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