Difference between revisions of "Primordial Radionuclides"

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Some other primordial radionuclides are <sup>50</sup>V, <sup>87</sup>Rb, <sup>113</sup>Cd, <sup>115</sup>In, <sup>123</sup>Te, <sup>138</sup>La, <sup>142</sup>Ce, <sup>144</sup>Nd, <sup>147</sup>Sm, <sup>152</sup>Gd, <sup>174</sup>Hf, <sup>176</sup>Lu, <sup>187</sup>Re, <sup>190</sup>Pt, <sup>192</sup>Pt, <sup>209</sup>Bi.<br>  
 
Some other primordial radionuclides are <sup>50</sup>V, <sup>87</sup>Rb, <sup>113</sup>Cd, <sup>115</sup>In, <sup>123</sup>Te, <sup>138</sup>La, <sup>142</sup>Ce, <sup>144</sup>Nd, <sup>147</sup>Sm, <sup>152</sup>Gd, <sup>174</sup>Hf, <sup>176</sup>Lu, <sup>187</sup>Re, <sup>190</sup>Pt, <sup>192</sup>Pt, <sup>209</sup>Bi.<br>  
  
[[Category:Nuclear_Properties]] [[Category:Half_life]] [[Category:Natural_activity]]
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[[Category:Nuclear_Properties]] [[Category:Half_life]] [[Category:Natural_activity]] [[Category:Master]]

Latest revision as of 09:48, 9 July 2012

Written and developed by Prof. Tor Bjørnstad (IFE/UiO) 

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Primordial radionuclides are left-over from when the world and the universe were created. They are typically long-lived, with half-lives often on the order of hundreds of millions of years. Radionuclides that exist for more than 30 half-lives are not measurable. The progeny or decay products of the long-lived radionuclides are also under this heading. Here is some basic information on some common primordial radionuclides:

Primordial nuclides
Nuclide          
Symbol
Half-life             
Natural Activity
Uranium 235
235U
7.04 x 108 a
0.72% of all natural uranium
Uranium 238
238U
4.47 x 109 a
99.2745% of all natural uranium; 0.5 to 4.7 ppm total uranium in the common rock types
Thorium 232
232Th
1.41 x 1010 a
1.6 to 20 ppm in the common rock types with a crustal average of 10.7 ppm
Radium 226
226Ra
1.60 x 103 a
0.42 pCi/g (16 Bq/kg) in limestone and 1.3 pCi/g (48 Bq/kg) in igneous rock
Radon 222
222Rn
3.82 days
Noble Gas; annual average outdoor air concentrations range in the US from 0.016 pCi/L (0.6 Bq/m3) to 0.75 pCi/L (28 Bq/m3)
Potassium 40
40K
1.28 x 109 a
Soil - 1-30 pCi/g (0.037-1.1 Bq/g)


Some nuclides like 232Th have several members in its decay chain. You can roughly follow the chain starting with 232Th:

232Th[math]\rightarrow[/math]228Ra[math]\rightarrow[/math] 228Ac[math]\rightarrow[/math]228Th[math]\rightarrow[/math]224Ra[math]\rightarrow[/math]220Rn[math]\rightarrow[/math]216Po[math]\rightarrow[/math]212Pb[math]\rightarrow[/math]212Bi[math]\rightarrow[/math]212Po[math]\rightarrow[/math]208Pb(stable)

or starting with 238U:
238U[math]\rightarrow[/math]234Th[math]\rightarrow[/math]234mPa[math]\rightarrow[/math]234U[math]\rightarrow[/math]230Th[math]\rightarrow[/math]226Ra[math]\rightarrow[/math]222Rn[math]\rightarrow[/math]218Po[math]\rightarrow[/math]214Pb[math]\rightarrow[/math]214Bi[math]\rightarrow[/math]214Po[math]\rightarrow[/math]210Pb[math]\rightarrow[/math]210Bi[math]\rightarrow[/math]210Po[math]\rightarrow[/math]206Pb(stable)


Some other primordial radionuclides are 50V, 87Rb, 113Cd, 115In, 123Te, 138La, 142Ce, 144Nd, 147Sm, 152Gd, 174Hf, 176Lu, 187Re, 190Pt, 192Pt, 209Bi.