Program to Develop Analytical Techniques for Ultra Trace Amounts of Nuclear Materials in Environmental Samples

In order to establish environmental sample analysis techniques for the strengthened safeguards in Japan, the authors have commenced to develop analytical techniques for ultra trace amounts of nuclear materials in environmental samples. For bulk analysis, samples are to be chemically treated and then measured with regard to isotope ratios of U and/or Pu by inductively-coupled plasma mass spectrometry and thermal ionization mass spectrometry. In particle analysis, particles in swipe samples are to be checked by total reflection X-ray fluorescene spectrometry whether they include nuclear materials. Electron probe micro analysis will be applied to the determination of elemental composition and the observation of morphology of each particle. Isotope ratios of U and/or Pu in each particle will be measured by secondary ion mass spectrometry. In addition, screening techniques to determine how samples should be treated will be studied and QA/QC procedures will be established. For the purposes to develop the techniques and to perform sample analyses, the authors have designed a clean chemistry laboratory in cooperations with US DOE experts. The laboratory and the analytical techniques will be applied not only to safeguards but also to the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification and research activities on environmental science.