Radioactive graphite bricks

Craig Deller <craig [at] deller__com> writes

>I had written a post earlier (Instance: 12:76, Friday, March 26,
>1999) looking for people who had worked on radioactive materials of
>an historic nature and received one response off-list (thank you),
>so I assuming that this is not done very often if at all. One
>question that has come up is whether or not the radioactivity
>associated with these very historically important materials should
>be considered part of the objects fabric.  Should it be removed?

I noticed your note but only read as far as bricks and decided that
it did not concern me however the question of preservation of
radioactive fabric certainly does. It is an excellent question and
one that needs public debate and discussion on the DistList!

I my field of specialty, horology, many clocks and watches have
hands and dials that are still "active". This is especially true of
objects that were prepared for the 2nd world war. Ship board and
aircraft time pieces were almost always prepared in a way that would
allow them to "glow in the dark". The amount of radiation intensity
varied from country to country. One of the highest reading levels I
have made was from a Japanese Ships Chronometer. The question is:
should one preserve these with their decayed radioactive level or to
remove it.

I believe that (aside from difficulties with the Atomic Energy
Commission and the Nuclear Regulatory Commission) if there is the
potential for human contact with the objects or components of the
objects, then it is incumbent that the radioactive material be
removed for public safety. For example, if the object is to be put
on display to the general public and is placed at an appropriate
distance behind leaded glass such that their exposure levels are
well within the NRC acceptable levels, then there is no need for
removal of the radio active substance or material . However, if the
object is to be touched or handled by a member of the general public
such as a private citizen winding and setting their clock or watch,
then the radioactive substance or material must be removed
(regardless of its emission rate) and a substitute for that
substance provided to insure visual integrity. Of course,
documentation would be required.

Another question arises from this and that is how does one remove
radioactive material safely? And, where does one dispose of it
properly? And could we get into serious "hot water" for working on
radioactive materials? In my case, it has been suggested that in
order to remove radioactive paint from horological objects that I
work behind lead bricks and leaded glass with a HEPA vacuum at the
point of work such that the particulate will be drawn into the
vacuum. Thus, after removal, I could remove the bag from the vacuum
and dispose of it in the local landfill as the amount of
radioactivity is minimal. Of course, I haven't figured out what to
do with the vacuum hose....  At this point, I have done nothing
because I am not confident in the removal process nor the disposal
process. Any ideas?

Jim Moss
James Moss Clockmakers, Inc.
Horological Conservators
Littleton, MA 01460
978-952-0070

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                  Conservation DistList Instance 12:82
                 Distributed: Thursday, April 22, 1999
                       Message Id: cdl-12-82-002
                                  ***