Development of active neutron NDA techniques for nuclear non-proliferation and nuclear security, 3; DGS measurements

Takahashi, Tone; Koizumi, Mitsuo ; Rodriguez, D. ; Rossi, F.  ; Takamine, Jun ; Seya, Michio; Paradela, C.*; Heyse, J.*; Schillebeeckx, P.*; Pedersen, B.*; Mondelaers, W.*

Delayed Gamma-ray Spectroscopy (DGS) has been developed as one of the non-destructive assay using active neutron for nuclear non-proliferation and nuclear security in the collaboration research between Japan Atomic Energy Agency and Joint Research Center of European Commission. The differences of fission-product (FP) yield distributions are depending on the fissile nuclide (e.g. U, Pu, and Pu). Therefore, ratios of fissile materials can be deduced by analyzing spectra of delayed gamma-rays which are emitted from radioactive decays of unstable FPs produced by irradiating neutrons and causing induced fission. We are developing an analytical method focusing on high energy delayed gamma-rays above 3 MeV from FPs with relatively short half-life (seconds to several minutes). The demonstration plan of DGS will be presented.