Fissile

[Bates Estabrooks <besta@tis.eh.doe.gov>]

This may help clarify terms.

Rex Borders' book Health Physics and Nuclear Science Terms offers
several definitions, a few of which are:

Fissile (HPJ 60-1991):   A nuclide, capable of undergoing fission by
interaction with slow or thermal neutrons.

Fissile Material (49CFR173-1989):   Any material consisting of or
containing one or more fissile radionuclides.  Fissile radionuclides are
plutonium-238, plutonium-239, plutonium-241, uranium-233, and
uranium-235.  Neither natural or depleted uranium are fissile material. 
Fissile materials are classified according to the controls needed to
provide nuclear criticality safety during transportation.

Fissile Nuclide (ANSI/ANS-8.15-1981):    A nuclide capable of undergoing
fission by interaction with slow neutrons provided the effective thermal
neutron production cross section exceeds the effective thermal neutron
absorption cross section.

Hope this helps.
-- 
Bates Estabrooks
Westinghouse Elec. Corp
WIPP
P.O. Box 2078
Carlsbad, NM 88220

besta@tis.eh.doe.gov
505-234-8470
fax:505-885-4562


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