ACTINIDES

Are there any uses for trans-Uranium elements?

Principal Actinide Isotopes Available in Macroscopic Quantities

Isotope	Half-Life	Source	Quantities
232Th	1.39 x 1010 y	Natural (100% abundance)	k. tonnes
231Pa	3.28 x 105 y	Natural (0.34 ppm in uranium ores)	grams
235U	7.13 x 105 y	Natural (0.7204% abundance)	k. tonnes
238U	4.5 x 109 y	Natural (99.2739% abundance)	k. tonnes
237Np	2.2 x 106 y		multi kg
238Pu	86.4 y		kg
239Pu	24,360 y		k. tonnes
241Am	433 y		kg
243Am	7650 y		kg
243Cm	18.12 y		kg
249Bk	325 days		mg
252Cf	2.57 y		mg

Other long-lived isotopes are known, but generally only obtained in traces

Plutonium:

²³⁹Pu

• produced from ²³⁸U by neutron capture in all nuclear reactors
• acts as nuclear fuel in fast-breeder reactors
• processed for nuclear weapon applications

²³⁸Pu

• produced by
• used as a compact energy source due to the heat from a -decay

  N.B. a-emission is harmless, unless the emitter is ingested

  deep-sea diving suits are heated by ca. 750g of ²³⁸Pu

  combined with PbTe thermoelectric Þ totally reliable electricity

  used in Apollo space missions / Human heart pacemakers

Americium:

²⁴¹Am is used as the a-emission source in smoke alarms