Re: Decay Storage Requirements - opinion

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

There are a number of 'guidances' and existing
rules, e.g., 49CFR's 2 nCi/g number, which have
the patina of being old and established but which,
if one looked too closely (or in some cases like
the 10 halflife rules looked at even cadually)
real question could be raised.  These continue
to exist because the regulatory system basically
is not now capable of establishing rational criteria
for issues that relate to release and exemption from
regulation. [my cynical alterego just poped up]

Lester.Slaback@NIST.gov


The 2 nCi/gm is straight out of the D.O.T. definition of when 
radioactive materials shall be considered hazardous and is a fine 
cut off point for transportation purposes.

The 10 half lives is one of those foolish consistency hobgoblins that 
keep cropping up in all sectors.  It kind of all depends on how much 
activity you start with.  As was pointed out sometimes it's too 
little and sometimes too much.  The survey requirement is a kind of 
double check and assumes the surveyor is using appropriate 
detector(s) and has an acceptible lower limit of detection.  And, of 
course, assuming that the "proper survey" is performed, there is no 
logical need to hold something for any additional number of half lives if the 
readings from it do not deviate from background.
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<>    Charles R. (Russ) Meyer                  <>
<> Email: cmeyer@tdh.state.tx.us           <> 
<>     Phone:(512)834-6688                       <>
<>        Fax:(512)834-6654                        <>
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