Re: NRC Licensing of Am-241 -Reply

[Keith Brown <KDB1@nrc.gov>]

>>>>>>>>>>>>>>>
David W. Lee wrote:

In general, the NRC is authorized to regulate only byproduct, source, and
special nuclear material.  Obviously, Am-241 is not byproduct or source
material, and it would appear as if Am-241 does fit or fall under the NRC's
definition of SNM (10 CFR 70.2); however, the rub is that Am-241 typically
is "produced" from the beta decay of Pu-241, which, itself, is
SNM.  

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Each of the following comments are my opinion, and my opinion only.  If I
am lucky, a couple may even be correct.

As another writer has already pointed, Am-241 is byproduct material.  I
want to add that several byproduct materials are not directly produced by
neutron capture.  The most common example of a byproduct material that
is produced as the result of the decay of material in a reactor is Tc-99m. 
Generally, one make Mo-99 in a reactor (either by fission or neutron
capture), and the moly beta decays to Tc-99m.  For Am-241, whether or
not Pu-241 is SNM, it is made by a reactor.

>>>>>>>>>>>>>>>>

Wesley M. Dunn wrote:

Note that other isotopes often fall into the same gap:  they can be
accelerator or reactor produced, so the NRC regulates it. 

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Not exactly.  The NRC regulates it if those particular atoms were made in a
reactor and doesn't if the atoms were made in an accelerator.  With some
frequency we deal with Cd-109 sources, and the question we always must
answer to determine if we need to license it (or to refer it to the state) is
how was the material in the source produced.

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Ron Kathren wrote:

I seem to recall in the dim dark past having seen noticies on smoke
detectors that indicated that they should be returned to the manufacturer.  

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True.  I think there may be some manufacturers who include a statement
like that even today.

It may be irrelevant , but in the not all that distant past smoke detectors
were generally licensed rather than exempt.  It was never a condition of the
general license that the detectors be returned to the manufacturer, but it
could have been a condition of the distributors that they include language
in the instructions suggesting their return.

>>>>>>>>>>>>>>>>

Finally, in the original question, Tad Blanchard wrote:

Can anyone tell me why Americium-241 is not listed in 10CFR30.71,
Schedule B?


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The real question is not why Am-241 is absent from the list, but why
Po-210 is present.  Note that no other alpha-emitting material is mentioned.
 Isotopes of neptunium, americium, and californium, are all absent. 
Furthermore, the "catch-all" at the end specifically excludes the alpha
emitting isotopes that have not been mentioned.



As a somewhat off-subject note: devices that can be distributed under an
exempt distribution (specific) license may contain more that an exempt
quantity of material.  If one produced a gauge that contained a curie of
cesium-137, and if it could be shown that there was essentially no external
radiation and that the containment could not be breached, etc. by
tampering or otherwise for about a thousand years (30 half lives to let the
curie decay), it might be approved for exempt distribution.  (Obviously, this
scenario is unrealistic.)  In other words, for manufacturers who go through
safety analysis of products, it the safety analysis rather than the quantity
that determines ability to distribute as exempt.

Again, all the above are my opinions.  They may be worthwhile, or you
may get what you paid for.

Keith Brown
kdb1@nrc.gov