Re: emergency responders -Reply

["J.J. Rozental" <rozental@unisys.com.br>]

----- Original Message -----
From: Grimm, Lawrence <LGrimm@ADMIN.UCLA.EDU>
To: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
Sent: Friday, January 21, 2000 5:59 PM
Subject: RE: emergency responders -Reply


> Re Moisture Density Gauges and Al Tesche's questions:
>
> All M-D gauges have A2 class sealed sources, therefore are tested to meet
> the DOT requirements for an A2 sealed source: drop test, fire, moisture,
> etc.  The shielding may melt in a fire, but the source should always
remain
> intact (extracting the source from the melted shield is a lot of fun - if
> you are a masochist).
==========
However in case of industrial fire > 1000 C, there is the possibility of
release, let's consider 1%. In such case, any guard from the installation's
vigilance attempting to put out the fire can breath the air for some
minutes, before leaving the room.
On the other hand it is necessary to take into account the Am-Be source. A
d/m gauge usually use the following sources: 10 millicuries (370 MBq) of
cesium-137 and 40 millicuries (1.48 GBq) of americium-241 in sealed sources.
Many of these Cs-137 sources is in form of cesium chloride, similar to one
that generated the Radiological Accident in Goiania.
There are also, I do not know if still in EEUU old gauges in operation as in
many developing countries, using 3 mCi (100 MBq) of Ra-Be sources.
It is important also to mention gauges for oil prosecution using sources up
to 2 Ci (74 GBq) of Cs-137 and up 20 Ci (740 GBq) of Am-241 source.
All these gauges are obliged to sources be tested for leakage and/or
contamination at intervals not to exceed 6 months. If leakage and
contamination have the possibility to occur, no doubt a source with such
possibility can release small amount of Cs-137 and Am-241 em case of fire.
Nevertheless there are not registered cases of industrial fires or explosion
affecting these gauges, there are more than hundreds of cases of incidents
and damage of such sources.

Jose Julio Rozental
rozental@unisys.com.br

Rio de Janeiro, Brazil


>
> The gauge itself is never used as the transport container.  All have an
> external case in which the gauge is carried.  The case is typically
designed
> to the exempt limited quantity specifications or the Type A container
> specification (presuming it is a newer model - some of the old M-D cases
> have wooden box construction that does not meet today's regulations.)
>
> Other than the neutron dose considerations, the recovery of a damaged M-D
> gauge should be a piece of cake and not a major media event.
>
> Larry Grimm
> UCLA Radiation Safety Division
> * On Campus: CHS A6-060 MS 957061
> * Off Campus: UCLA Radiation Safety Div, 2195 West Medical
> Building, Los Angeles, CA 90095-1764
> * lgrimm@admin.ucla.edu   Phone:310/206-0712   Fax 310/794-5825
> * If this email is not RSD business, the opinions are mine, not
> UCLA's.
>
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