Atomic parameters (, , , , and ), total and heating energies per decay (, ), specific heating rates (), and antineutrino luminosities () per unit mass of radionuclide Adapted from Dye [39].
U
U
Th
K
Natural isotopic fraction
0.9927
0.007204
1.000000
0.000117
Atomic mass
(g mol−1)
238.051
235.044
232.038
39.9640
Decay constant
( s−1)
4.916
31.210
1.563
17.200
Half life
(Gy)
4.468
0.7038
14.05
1.277
Decay energy
(pJ)
8.282
7.434
6.833
0.213
Energy for heating
(pJ)
7.648
7.108
6.475
0.110
Specific heat generation
(W kg−1)
95.13
568.47
26.28
's per chain
6
4
4
Specific luminosity
(kg−1 s−1)
74.6
319.9
16.2
231.2
Noninteger 's per chain value for K reflects branching into decay and electron capture. Heat generation from includes energy heat released in electron capture.