Page 340 - Advanced Mine Ventilation

Measurement and Monitoring of Mine Gases 317

Table 19.2 Uranium Disintegration Process

Common Name
or Symbol Isotope Type of Radiation Half-Life
9
Uranium 238 Uranium Alpha 4.49 10 year
92
234 Thorium Beta 24.1 days
UX 1
90
234 Protactinium Beta 1.17 min
UX 2
91
5
Uranium-234 234 Uranium Alpha 2.48 10 year
92
4
Ionium 230 Thorium Alpha 8 10 year
90
Radium 226 Radium Alpha 1622 year
88
Radon 222 Radon Alpha 3.825 days
86
Radium A 218 Polonium Alpha 3.05 min
84
Radium B 214 Lead Beta, gamma 26.8 min
82
Radium C 214 Bismuth Beta, gamma 19.7 min
83
Radium C 0 214 Polonium Alpha 2.73 10 6 min
84
Radium D 210 Lead Beta, gamma 22 year
82
Radium E 210 Bismuth Beta 5.02 days
83
Radium F 210 Polonium Alpha 138.3 days
84
Radium G 206 Lead – Stable
82

in the series is being generated at the same rate which it is decaying. The time required
for the radon daughters through radium C to reach equilibrium from a given quantity
0
of radon is approximately 3 h. In approximately 40 min, the alpha energy reaches
approximately 50% of maximum.