Plutonium
Decay heat and fission properties
Plutonium isotopes undergo radioactive decay, which produces decay heat. Different isotopes produce different amounts of heat per mass.

Plutonium

Section Title: Decay heat and fission properties
Table Section Text: Plutonium isotopes undergo radioactive decay, which produces decay heat. Different isotopes produce different amounts of heat per mass.

Isotope	Decay mode	Half-life (years)	Decay heat (W/kg)	Spontaneous fission neutrons (1/(g·s))	Comment

238Pu	alpha to 234U	87.74	560	2600	Very high decay heat. Even in small amounts can cause significant self-heating. Used on its own in radioisotope thermoelectric generators.

239Pu	alpha to 235U	24100	1.9	0.022	The principal fissile isotope in use.

240Pu	alpha to 236U, spontaneous fission	6560	6.8	910	The principal impurity in samples of the 239Pu isotope. The plutonium grade is usually listed as percentage of 240Pu.

241Pu	beta-minus, to 241Am	14.4	4.2	0.049	Decays to americium-241; its buildup presents a radiation hazard in older samples.

242Pu	alpha to 238U	376000	0.1	1700

Sentence(s)

The isotope plutonium-238 has a half-life of 87.74 years.

final_sentence: The isotope plutonium-238 has a half-life of 87.74 years.