RE: Am-242m Fission Fuel

["Franta, Jaroslav" <frantaj@aecl.ca>]

You wrote:

 Anyone know anything about Am242m???

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Comment (FWIW):

this idea was also discussed/referenced in a paper
published in Nuclear Science & Engineering (see Yigal Ronen,  and Melvin J.
Leibson, "Potential Applications of   242m Am as a Nuclear Fuel," Nuclear
Science and Engineering, Vol. 99, July 1988, pp. 278-284.)

As for production, I don`t think it would be any more difficult than
producing Pu-238 (for RTGs; its made from U-235). 
The 'only' problem is you need a fast reactor AND keep the neutron energy
roughly within a certain range in order to optimise the production yield and
minimise unwanted insitu burning (at low incident neutron energies typical
of moderated reactors like PWRs etc.). 
The production of Am242m is accompanied by the production of undesirable
Am242, the ground-state isomer. At thermal neutron energies (0.0253 eV), the
great majority of americium isotopes produced from Am241 is the undesirable
242 ground-state kind, with only about a 10% yield of Am242m. This ratio
changes at increased neutron energies. 

94 Pu 241 by beta decay => 95 Am 241 ( T½ = 432.2 yrs.)
95 Am 241 + neutron => 95 Am 242m (T½ = 152 yrs.) + 95 Am 242 (T½ = 16 hrs.)

In fast reactors the crossection for Am242m production is nearly the same as
that for Am242, so the yield will be close to half as well (some Am242f is
also produced - this has a 14ms T½ against spontaneous fission)

If you wish, I can send you graph combining the x-sections of the
above-mentioned isotopes, to illustrate the point... (please respond to me -
not the list ).

The FFTF would be a good production machine -- but its slated for permanent
shutdown, like BNL`s recent closure and similar antinuke  political
decisions of the outgoing US administration.
But IMO, application of Am242m in the "fissioning wires" concept may not be
the best choice (rel. to some less fanciful alternatives....)
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