LABORATORY METHODS APPLIED TO QUALITATIVE AND QUANTITATIVE ANALYSES OF SEIZED NUCLEAR MATERIALS AND RADIOACTIVE SOURCES

摘要

The National Radiation Hygiene Preparedness Service, operated by the National Research Institute for Radiobiology and Radiohygiene and the alpha and gamma spectrometric laboratories of the Institute, plays a central role in the detection and identification of illicit nuclear substances and radioactive sources found in Hungary. The first measurements of seized nuclear material were made in 1990-1991. Since then, a few dozen cases have been investigated. The calibration of the gamma spectrometer and results from characteristic cases are detailed. Investigated uranium samples can be divided into three main groups, according to the ratios of uranium isotopes of mass numbers 235 and 238: CANDU type pellets, boiling water reactor or pressurized water reactor type pellets, and samples of depleted uranium.