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Komura, Keitaro*; Kaneda, Heitaro*; Tanaka, Tomoki*; Kojima, Satoru*; Inoue, Tsutomu*; Nishio, Tomohiro
Geomorphology, 365, p.107214_1 - 107214_22, 2020/09
Times Cited Count：4 Percentile：27.58(Geography, Physical)On the basis of pit excavations and sediment cores at an off-fault deep-seated gravitational slope deformation (DGSD) site and a trench excavation across the active Neodani fault at a nearby site, we examined the records of DGSD and surface-rupturing paleoearthquakes of the Neodani fault. We found the four most recent DGSD events and the four most recent surface-rupturing earthquakes, respectively and conclude that the ages of events are overlapped each other. We infer that static crustal strain from repeated seismogenic faulting plays an important role in the occurrence of DGSD events, at least in the immediate vicinity of active faults, although coseismic severe shaking would have at least some effect on them. Our case study suggests that off-fault DGSDs can be used to reconstruct or refine the paleoseismic history of a nearby active fault.
-ray pipe monitoring for comprehensive safeguards process monitoring of reprocessing facilitiesRodriguez, D.; Tanigawa, Masafumi; Mukai, Yasunobu; Isomae, Hidemi; Nakamura, Hironobu; Rossi, F.; Koizumi, Mitsuo; Seya, Michio
Proceedings of INMM 58th Annual Meeting (Internet), 9 Pages, 2017/07
Safegaurding nuclear material at reprocessing facilities utilizes sampling to verify the quantity and process monitoring to maintain continuity-of-knowledge to reduce re-verification. Solution Monitoring and Measurement Systems that determine the solution density and volume are installed at solution tanks, though this only provides indirect verification. To offset this safeguards limitation we propose measuring rays from solutions passing through the pipes and at the tanks to provide improved continuous monitoring and direct verification. This can provide both real-time flow measurements and Pu isotopic composition quantification through passive nondestructive assay. This concept was tested by recent experimental studies performed at the Japan Atomic Energy Agency's Plutonium Conversion Development Facility of flowing Pu-nitrate rays. This presentation will describe the concept details and analysis of using ray pipe monitoring as a capability for real-time safeguards verification.
Mukai, Yasunobu; Ogawa, Tsuyoshi; Nakamura, Hironobu; Kurita, Tsutomu; Sekine, Megumi; Rodriguez, D.; Takamine, Jun; Koizumi, Mitsuo; Seya, Michio
Proceedings of INMM 57th Annual Meeting (Internet), 7 Pages, 2016/07
The development of Delayed Gamma-ray Spectroscopy (DGS) for analyzing the composition ratio of fissile nuclides (
Pu, 
Pu, 
U) focused on the Delayed Gamma-ray having energy over 3 MeV has been performed for the development of active neutron non-destructive assay techniques. In PCDF, measurement tests of Delayed Gamma-ray using Pu solution and MOX powder samples to prove the DGS technique is planned to be performed in following 4 stages. (1) Measurements for Delayed Gamma-ray originated from spontaneous fission nuclide (Passive), (2) Measurements for the Delayed Gamma-ray with fast neutron (Active), (3) DGSI (DGS combined with self-interrogation) measurements (Passive), (4) Measurements for the Delayed Gamma-ray with thermal neutron (Active) In this paper, the plan of measurement tests for nuclear material samples with use of DGS is presented.
rays for fissionable material measurement in NDARodriguez, D.; Takamine, Jun; Koizumi, Mitsuo; Seya, Michio
Proceedings of 37th ESARDA Annual Meeting (Internet), p.831 - 836, 2015/08
A non-destructive analysis system using a pulsed neutron source is under design by researchers of the JAEA, and JRC-ITU (Ispra) and JRC-IRMM. The system will utilize a combination of neutron resonance transmission analysis and differential die-away and both prompt and Delayed Gamma-ray (DG) Spectroscopy (DGS) techniques. This system will be applied toward safeguards applications by effectively determining Nuclear Material (NM) compositions within MOX fuel samples and NM samples with high neutron or -ray emissions (including the melted fuel). Additionally, this system can be applied toward nuclear security by detecting the high-energy DGs that can more efficiently pass through shielding materials. This presentation will describe the initial status of the DG portion of this system and how it will be used in conjunction with the other techniques to provide both high accuracy and high precision of the composition of the NM of interest.
