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| Titel |
Plutonium age dating reloaded |
| VerfasserIn |
Monika Sturm, Stephan Richter, Yetunde Aregbe, Roger Wellum, Klaus Mayer, Thomas Prohaska |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250092477
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| Publikation (Nr.) |
 EGU/EGU2014-6827.pdf |
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| Zusammenfassung |
| Although the age determination of plutonium is and has been a pillar of nuclear forensic
investigations for many years, additional research in the field of plutonium age
dating is still needed and leads to new insights as the present work shows: Plutonium
is commonly dated with the help of the 241Pu/241Am chronometer using gamma
spectrometry; in fewer cases the 240Pu/236U chronometer has been used. The age
dating results of the 239Pu/235U chronometer and the 238Pu/234U chronometer are
scarcely applied in addition to the 240Pu/236U chronometer, although their results
can be obtained simultaneously from the same mass spectrometric experiments as
the age dating result of latter. The reliability of the result can be tested when the
results of different chronometers are compared. The 242Pu/238U chronometer is
normally not evaluated at all due to its sensitivity to contamination with natural
uranium. This apparent ‘weakness’ that renders the age dating results of the 242Pu/238U
chronometer almost useless for nuclear forensic investigations, however turns out to be an
advantage looked at from another perspective: the 242Pu/238U chronometer can be
utilized as an indicator for uranium contamination of plutonium samples and even
help to identify the nature of this contamination. To illustrate this the age dating
results of all four Pu/U clocks mentioned above are discussed for one plutonium
sample (NBS 946) that shows no signs of uranium contamination and for three
additional plutonium samples. In case the 242Pu/238U chronometer results in an
older ‘age’ than the other Pu/U chronometers, contamination with either a small
amount of enriched or with natural or depleted uranium is for example possible. If
the age dating result of the 239Pu/235U chronometer is also influenced the nature
of the contamination can be identified; enriched uranium is in this latter case a
likely cause for the missmatch of the age dating results of the Pu/U chronometers. |
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