PLUTONIUM
150
4. CHEMICAL AND PHYSICAL INFORMATION
Table 4-3. Radiological Properties of Plutonium Isotopes
Isotope
CAS Registry
No.
Half-life
Decay mode(s)/
Energy (MeV)
Decay
product(s)
Specific activity
(Ci/g)
236
Pu
15411-92-4
2.87 years
1.5x10
9
years
α/5.867 MeV
SF/1.9x10
-7
MeV
232
U
540
237
Pu
15411-93-5
45.7 days
EC/0.220(99.9%)
α/ 5.747 (0.003%)
233
U
12,100
a
238
Pu
13981-16-3
87.7 years
4.75x10
10
years
α/5.593
SF/ 1.8x10
-7
234
U
17
239
Pu
15117-48-3
b
19257-39-7
c
2.410x10
4
years
8x10
15
years
α/5.244
SF/3x10
-10
235
U
0.063
240
Pu
14119-33-6
6.56x10
3
years
1.14x10
11
years
α/5.255
SF/5.7x10
-6
236
U
0.23
241
Pu
14119-32-5
14.3 years
<6x10
16
years
β
-
/0.0208 (99+%)
α/5.139 (0.002%)
SF/>2.4x10
-14
241
Am
237
U
100
242
Pu
13982-10-0
3.75x10
5
years
6.77x10
10
years
α/4.983
SF/5.5x10
-4
238
U
0.0040
243
Pu
15706-37-3
4.956 hours
β
-
/0.582
243
Am
2.6x10
6c
244
Pu
14119-34-7
8.00x10
7
years
6.6x10
10
years
α/4.665 (99.9%)
SF/0.12
240
U
1.8x10
-5
a
Calculated
values
b
Another CAS Registry number listed for
239
Pu is 97918-67-7
c
CAS Registry Number for
239
Pu
4+
ion
α
= alpha particle emission;
β
-
= negative beta emission; SF = spontaneous fission
Sources: Baum et al. 2002; ChemIDplus 2009; Clark et al. 2006; DOE 2005a; Lide 2008
Figure 4-1.
238
Pu Decay Series
238
Pu
Pu
87.7 years
Np
234
U
U
2.46x10
5
years
Pa
230
Th
Th
7.54x10
4
years
Ac
226
Ra
Ra
1599 years
Fr
222
Rn
Rn
3.8325 days
218
At
At
1.5 sec
214
218
Po
Po
210
Po
Po
164
3.10
minutes
138.38 days
µseconds
214
Bi
210
Bi
Bi
19.9 minutes
5.01 days
214
Pb
210
Pb
206
Pb
Pb
27 minutes
22.3 years
Stable
210
Tl
206
Tl
Tl
1.3 minutes
4.20 minutes
alpha (
α
) decay
beta (
β
-
) decay
Sources: Baum et al. 2002; Lide 2005
PLUTONIUM
151
4. CHEMICAL AND PHYSICAL INFORMATION
PLUTONIUM
153
5. PRODUCTION, IMPORT/EXPORT, USE, AND DISPOSAL
5.1 PRODUCTION
No information is available in the TRI database on facilities that manufacture or process plutonium
because this chemical is not required to be reported under Section 313 of the Emergency Planning and
Community Right-to-Know Act (Title III of the Superfund Amendments and Reauthorization Act of
1986) (EPA 1998).
Plutonium was the first human-made element to be synthesized in weighable amounts.
238
Pu was
discovered in 1940 by Seaborg and co-workers; it was synthesized by the bombardment of uranium with
deutrons (
2
H). Isotopes with mass numbers 228–247 have been identified; all are radioactive (Clark et al.
2006). Trace amounts of plutonium are found
worldwide, mostly due to fall-out from atmospheric
nuclear testing, which ended in 1980 and released several isotopes of plutonium, including
238
Pu,
239
Pu,
240
Pu, and
241
Pu (Clark et al. 2006; DOE 2005a; Eisenbud and Gesell 1997). Plutonium is not considered
a naturally occurring element; however,
trace amounts of
239
Pu are found in naturally occurring uranium
ores, but the amounts are in such small amounts that extraction is not practical (Clark et al. 2006; EPA
2006b; Lide 2008). Small amounts of
244
Pu exist in nature from remnants of primordial stellar
nucleosynthesis (Clark et al. 2006). Small amounts of plutonium were produced in natural reactors, such
as the Oklo
natural reactor in Gabon, which existed about 2 billion years ago (DOE 2005a). The most
common form of plutonium found in the environment is
239
Pu, followed by
240
Pu (DOE 1999a).
Large quantities of plutonium were first produced during the 1940’s as part of the Manhattan Project in
order to produce the atomic bomb. Production continued throughout the years of the Cold War (DOE
2005a). The United States built and operated 14 plutonium-production
reactors at the Hanford and
Savannah River Sites starting in 1944 and ending in 1988 with the shutdown of the last reactor. A total of
approximately 100 metric tons of plutonium was produced during this time (DOE 1996b). Currently,
238,239, 240,241,242
Pu are commercially available from Oak Ridge National Laboratory for laboratory research
(DOE 2007a).
Plutonium is a byproduct of nuclear energy generation. Most plutonium isotopes are produced in
uranium-fueled reactors through neutron capture by
238
U (Clark et al. 2006; Koch 2005).
Approximately
1,855 metric tons of plutonium were estimated to exist worldwide at the end of 2003. Most of the
plutonium (1,370 metric tons) was found in irradiated fuel from nuclear power plants. A plutonium