Some questions on Pu

["Nimmo,Elsa (NCS1)" <ENIMMO@EMS1.Measurex.com>]

Radsafers:

Below are some Pu questions from friend -- a reading member of the
public.  While I can respond to some of these questions, I'm no expert
on Pu & could also benefit from hearing from those who are!

The person who wrote the questions understands that external radiation
exposure isn't the same thing as radioactive contamination.

I don't (at this time) know the author/date/source of the referenced
article on Pu in space.

Anyone care to recommend articles or other references that do a good job
of addressing these sorts of questions or to respond to my friend's
questions directly?


BTW -- Thanks to all who responded to my earlier query on NEI.  I will
be contacting a few of you directly & also NEI!

Elsa Nimmo


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If Pu is not  an external radiation hazard, does that mean that it does
not burn your skin and that it is not absorbed by your skin?  And what
are
critical mass quantities (in layman's terms)?  Does that mean a
specific number or concentration?

So, I assume that when someone describes plutonium as a "radioactive
material so toxic that less than a millionth of a gram can give a person
cancer" they are referring to ingestion?

If ingestion includes inhalation, are the concerns raised
by an article I read about plutonium in space valid?  The article
stated that a 1997 mission to Saturn will have 72.3 pounds of
plutonium, to be launched atop a Titan IV rocket, which has been
plagued by explosions on launch.  So, if the 1997 rocket explodes on
launch, and if the container holding the plutonium breaks, will there
be plutonium in the air for people to breath?

About the 8.3 pounds of plutonium on the Apollo lunar excursion
module (LEM): the LEM was to have been left on the moon, but instead
came back down.  NASA aimed it a a spot off New Zealand, and, according
to NASA (per this article), the plutonium container survived re-entry
and was "deposited intact in the Tonga Trench in the South Pacific where
it is effectively isolated from man's
environment".  Potential consequences?
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