A silicon drift detector. (Credit: University of Jyväskylä)
A promising new safeguards tool for plutonium analysis has been developed by the Radiation and Nuclear Safety Authority of Finland (STUK) and the Joint Research Center (JRC), the EU in-house scientific service.
It is a novel technique for measuring the isotopic composition of radioactive samples involving a silicon drift detector for conversion electrons. It is regarded as a complementary tool to alpha particle spectrometry, which is commonly used for nuclear inspection in safeguards laboratories.
STUK and the JRC have demonstrated that conversion electron spectrometry is well suited for measuring relative amounts of plutonium isotopes, in particular to distinguish the fissile plutonium-239 from non-fissile plutonium isotopes, such as plutonium-240. This is essential information for the identification of weapon-grade plutonium in the context of non-proliferation of nuclear weapons.
This technique could provide input into the action plan of the International Atomic Energy Agency (IAEA), which is currently evaluating promising emerging technologies and instrumentation from the perspective of future specific safeguards inspectorate needs.
Vigilance against the diversion of plutonium is of growing concern in a context of increasing stocks of excess fissile material from dismantled weapons, as well as plans to use this material in power reactors.
K. Peräjärvi, J. Turunen, S. Ihantola, V. Kämäräinen, S. Pommé, R. Pöllänen, T. Siiskonen, H. Sipilä, H. Toivonen (2014). Feasibility of conversion electron spectrometry using a Peltier-cooled silicon drift detector Journal of Radioanalytical and Nuclear Chemistry , 1 (299), 229-234 DOI: 10.1007/s10967-013-2788-0
