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Suwaki, Takuro*; Zaima, Naoki; Nakashima, Shinichi; Nakatsuka, Yoshiaki; Fujiki, Naoki*; Kureta, Masatoshi; Ozu, Akira
no journal, ,
Japan Atomic Energy(JAEA) configurated the non-destructive assay (NDA) systems, which applied to the bulk state nuclear inventory and actual uranium bearing waste drums generated from Ningyo-Toge uranium plants. The methodology of newly active neutron assay systems (JAWAS-N) is based on the fast neutron direct interrogation (FNDI) method developed by NSEC. The systems are composed of neutron generator and He-3 proportional counters with concrete structures functioned as reflector or shielding. FNDI method is defined as followings. Neutron generator produces pulses of 14 MeV neutrons that are directed into drum to induce U-235 fissions in matrix. Secondary fission neutrons generated from U-235 with fast or epithermal neutron energy will be detected by He-3 proportional counters with the diffusion decay time on the order of hundreds micro-second. Neutron detectors which are designed to detect only fast and epithermal neutrons, will be extracted fission neutrons by mathematical analysis methods and be determined U-235 mass. The Systems will be contributed to the field of material accountancy in Ningyo-Toge uranium plants. The systems' verifications through the mockup tests and trials for actual waste drams measurement will be reported.
Nakatsuka, Yoshiaki; Zaima, Naoki; Nakashima, Shinichi; Fujiki, Naoki*; Suwaki, Takuro*; Kureta, Masatoshi; Ozu, Akira; Komeda, Masao
no journal, ,
The historical procedures and target of active neutron measurements devices will be reported beside requirements of SG/MA tools. Also introduced the principles of FNDI methods and its applicability.
Fujiki, Naoki*; Nakatsuka, Yoshiaki; Zaima, Naoki; Nakashima, Shinichi; Suwaki, Takuro*; Kureta, Masatoshi; Ozu, Akira; Komeda, Masao
no journal, ,
The performances of methodological characteristics, operation stability and radiation control of active neutron measurements devices will be reported.
Suwaki, Takuro*; Zaima, Naoki; Nakatsuka, Yoshiaki; Fujiki, Naoki*; Nakashima, Shinichi; Kureta, Masatoshi; Ozu, Akira; Komeda, Masao
no journal, ,
The mockup tests used standard uranium source and simulated matrices have been successfully performed. The well performances of this device are introduced.
Zaima, Naoki; Nakatsuka, Yoshiaki; Nakashima, Shinichi; Fujiki, Naoki*; Suwaki, Takuro*; Kureta, Masatoshi; Ozu, Akira; Komeda, Masao
no journal, ,
The trials for measuring actual waste drums have been performed, and validated good applicability active neutron measurements device on site.