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| DOE-STD-1128-98
Guide of Good Practices for Occupational Radiological Protection in Plutonium Facilities
Table 2.2. Uses and Availabilities of Plutonium Isotopes
Isotope
Uses
Availability
236
Pu, 237Pu
Both available in microcurie quantities.(a)
Popular environmental and biological chemical
tracers.
238
Pu
Small thermal and electric-power generators.
Available in various isotopic enrichments,
ranging from 78% to 99+%.(a)
239
Available enrichments range from 97% to
Pu
Nuclear weapons and as a fast reactor fuel. Also,
99.99+%.(a)
frequently used in chemical research where
production-grade material of mixed isotopic content
is suitable.
240
Pu
Principally in flux monitors for fast reactors.
Available enrichments range from 93% to
99+%.(a)
241
The parent from which high-assay 241Am can be
Samples available in enrichments of 93%.(a)
Pu
isolated for industrial purposes.
242
Pu
For study of the physical properties of plutonium;
Samples available in enrichments ranging
also as a mass spectroscopy tracer and standard.
from 95% to 99.9+%; enrichments of
production-grade material range from 85% to
95%.(a)
244
Pu
Currently, the only isotope available as a National
Can be obtained from DOE's New Brunswick
Institute of Standards and Technology (NIST)
Laboratory.
(b)
Standard Reference Material (SRM).
(a)
Available in small quantities from the Oak Ridge National Laboratory (ORNL): ORNL Isotopes Sales Office, Oak Ridge
National Laboratory, P.O. Box X, Oak Ridge, Tennessee 37830.
A second NIST/SRM (a 1:1 mixture of 239Pu and 242Pu) is being prepared, and a third (239Pu) is planned for the future.
(b)
2.1.2 Laser Isotope Separation Process
Several new technologies are being considered to provide more highly purified plutonium
isotopes for various purposes. One of these processes, laser isotope separation (LIS), has the
potential to purify 239Pu from almost any source of plutonium. The LIS process produces a
product enriched in 239Pu and a byproduct that contains the remaining plutonium isotopes. It
is conceivable that the byproduct stream could be further purified to produce a specific
plutonium isotope, such as 238Pu used for isotopic heat sources.
The LIS process has many benefits. It can significantly reduce external radiation exposure
problems from the byproduct stream are discussed later in this section.) The International
Commission on Radiological Protection (ICRP) and the National Council on Radiation
Protection and Measurements (NCRP) have recommended increasing quality factors to a
value of 20 for fast neutrons (ICRP, 1985; NCRP, 1987a). Thus, it may be desirable to
reduce neutron exposures. Neutrons arise primarily from even-numbered plutonium
2-4
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