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Preparation of calibrated reference sources containing "fresh" fission products

  • S. M. Jerome
Article

Summary

NPL was recently asked to provide reference sources containing &ggr;-ray emitting fission product radionuclides, with certification completed within 50 days of the irradiation. Furthermore, the reference sources were to contain fission products, but no fissile material. The samples in the first reference source were to contain a mixture of fission products with only the <Superscript>235</Superscript>U removed, leaving the fission products as &apos;undisturbed&apos; as possible. A number of radionuclides were reported in this sample and included: <Superscript>91</Superscript>Y, <Superscript>95</Superscript>Zr, <Superscript>95m</Superscript>Nb, <Superscript>95g</Superscript>Nb, <Superscript>99</Superscript>Mo, <Superscript>99m</Superscript>Tc, <Superscript>103</Superscript>Ru, <Superscript>106</Superscript>Ru, <Superscript>127</Superscript>Sb, <Superscript>129m</Superscript>Te, <Superscript>129g</Superscript>Te, <Superscript>131</Superscript>I,<Superscript>132</Superscript>Te, <Superscript>132</Superscript>I, <Superscript>137</Superscript>Cs, <Superscript>140</Superscript>Ba, <Superscript>140</Superscript>La, <Superscript>141</Superscript>Ce, <Superscript>144</Superscript>Ce, and<Superscript>147</Superscript>Nd. Of these nuclides, NPL provided certified values for <Superscript>91</Superscript>Y, <Superscript>95</Superscript>Zr, <Superscript>95m</Superscript>Nb, <Superscript>95g</Superscript>Nb, <Superscript>99</Superscript>Mo, <Superscript>99m</Superscript>Tc, <Superscript>103</Superscript>Ru, <Superscript>106</Superscript>Ru, <Superscript>132</Superscript>Te, <Superscript>132</Superscript>I, <Superscript>137</Superscript>Cs, <Superscript>140</Superscript>Ba, <Superscript>140</Superscript>La, <Superscript>141</Superscript>Ce, <Superscript>144</Superscript>Ce, and <Superscript>147</Superscript>Nd. The second reference source focused on a smaller subset of radionulides: <Superscript>95</Superscript>Zr, <Superscript>99</Superscript>Mo, <Superscript>103</Superscript>Ru, <Superscript>106</Superscript>Ru, <Superscript>140</Superscript>Ba, and <Superscript>155</Superscript>Eu, although <Superscript>95g</Superscript>Nb, <Superscript>99m</Superscript>Tc, <Superscript>132</Superscript>I and <Superscript>140</Superscript>La were present as daughter radionuclides and <Superscript>91</Superscript>Y, <Superscript>127</Superscript>Sb, <Superscript>129m</Superscript>Te, <Superscript>129g</Superscript>Te, <Superscript>131</Superscript>I, <Superscript>132</Superscript>Te, <Superscript>137</Superscript>Cs, <Superscript>152</Superscript>Eu and <Superscript>154</Superscript>Eu were present as impurities. This paper describes the preparation of these sources, based on a combination of cation- and anion-exchange chromatography with selective precipitation. The separation techniques were used to (1) produce the &apos;fresh&apos; fission product mixture from irradiated <Superscript>235</Superscript>U, and (2) isolate the specific set of radionuclides in the second exercise from mixtures containing irradiated <Superscript>235</Superscript>U and fission products. To enable accurate assay of parent-daughter systems, integrated ingrowth and decay equations were derived from original Bateman equations and tested by observing the <Superscript>140</Superscript>Ba-<Superscript>140</Superscript>La system over time.

Keywords

Radionuclide Fission Product Reference Source National Physical Laboratory Fissile Material 

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Copyright information

© Springer-Verlag/Akadémiai Kiadó 2005

Authors and Affiliations

  • S. M. Jerome
    • 1
  1. 1.Quality of Life Division, National Physical Laboratory

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