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Baron, P.*; Cornet, S. M.*; Collins, E. D.*; DeAngelis, G.*; Del Cul, G.*; Fedorov, Y.*; Glatz, J. P.*; Ignatiev, V.*; Inoue, Tadashi*; Khaperskaya, A.*; et al.
Progress in Nuclear Energy, 117, p.103091_1 - 103091_24, 2019/11
Times Cited Count：73 Percentile：94.03(Nuclear Science & Technology)The results of an international review of separation processes for spent nuclear fuel (SNF) recycling in future closed fuel cycles with the evaluation of Technology Readiness Level are reported. This study was made by the Expert Group on Fuel Recycling Chemistry (EGFRC) organised by the Nuclear Energy Agency (NEA) of the Organisation for Economic Co-operation and Development (OECD). A unique feature of this study was that processes were classified according to a hierarchy of separations aimed at different elements within spent fuel (uranium; uranium-plutonium co-recovery; minor actinides; high heat generating radionuclides) and also the Head-end processes, used to prepare the SNF for chemical separation, were included. Separation processes covered both wet (hydrometallurgical) and dry (pyro-chemical) processes.
Sanada, Yukihisa; Orita, Tadashi; Torii, Tatsuo
Applied Radiation and Isotopes, 118, p.308 - 316, 2016/12
Times Cited Count：28 Percentile：93.3(Chemistry, Inorganic & Nuclear)An unmanned helicopter monitoring system (UHMS) was developed to survey the environmental effect of radioactive cesium scattered as a result of the Fukushima Daiichi Nuclear Power Station accident. The UHMS was mainly used to monitor the area surrounding the Fukushima Daiichi Nuclear Power Station six times from 2012 to 2015. Quantitative changes in the radioactivity distribution trend were revealed from the results of these monitorings runs.
Sanada, Yukihisa; Urabe, Yoshimi; Orita, Tadashi; Takamura, Yoshihide; Torii, Tatsuo
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 5 Pages, 2015/05
There are approximately 3,700 irrigation ponds in the Fukushima prefecture. Contamination by radiocesium at the bottom of these ponds has been a concern since the accident at the TEPCO's Fukushima Daiichi Nuclear Power Station (FDNPS). Among them, there are some reservoirs which contain radioactive materials in the bottom sediment. Three years have passed since the accident of the Fukushima Daiichi Nuclear Power Station. In relation to the restoration of agriculture in the disaster-stricken area, there are concerns over the migration of radioactive cesium in the environment. We developed 20 meter-length a plastic scintillation fiber (PSF) for measurement in water. We have conducted tests at dozens of irrigation ponds in Fukushima pref. using PSF to confirm the performance of the devices and to standardize measurement techniques and analytical procedures.
Minato, Kazuo; Morita, Yasuji; Tsujimoto, Kazufumi; Koyama, Shinichi; Kurata, Masaki*; Inoue, Tadashi*; Ikeda, Kazumi*
Proceedings of 11th OECD/NEA Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation (Internet), p.341 - 349, 2012/00
In order to provide a quantitative assessment for the maturity of the partitioning and transmutation technology relative to its full-scale deployment, a technology readiness level (TRL) process was used. The definitions of TRL used in this study were based on those used in the Global Nuclear Energy Partnership (GNEP). The TRL was evaluated and the technology pathway was discussed for the systems of FBR and ADS for the minor actinides (MA) transmutation, MA partitioning processes, and MA-bearing fuels. Through the evaluation, it was recognized that hard requirements to be satisfied were present at TRL 5 for each technology development. The introduction of lab-scale tests with actual spent fuel for MA partitioning process and with actual separated materials for MA-bearing fuels fabrication and irradiation before the engineering scale tests may be effective and efficient solution.
Mineo, Hideaki; Suzuki, Tadashi; Morita, Yasuji
Proceedings of 2nd International Symposium on Supercritical Fluid Technology for Energy and Environment Applications (Super Green 2003), p.334 - 338, 2003/00
Behavior of spent nuclear fuel in subcritical water was investigated to look at the feasibility of fission-products (FPs) separation without organic solvent. The study employed unirradiated UO
particles simulating spent fuel burned up to 45,000MWdt
, which includes FP elements in oxide form: Sr, Zr, Mo, Ru, Rh, Pd, Ag, Ba, La, Ce, Pr, Nd and Sm. Also, alloy particles consisted of Mo, Ru, Rh and Pd were prepared to simulate the metallic phase of FP. 12.728 g of the fuel and 52 mg of the alloy were placed in a 10 ml pressure vessel, where subcritical water was fed. The temperature was 523, 573, 623 and 663K, while the pressure was kept at 29MPa. Dissolved fraction decreased with elevating temperature. It was found that more than 5% of Ba, Mo and Pr were respectively dissolved. The dissolved fraction of Sr and Rh were about 1%, and about 0.3% for Zr. La, Ce, Nd and Sm, indicated almost the same result as U, which was about 0.1%. It was suggested that the subcritical water could separate portion of FP. Further study would be carried out with smaller-sized fuel.
Kasagi, Jirota*; Kinoshita, Tadashi*; Yorita, Tetsuhiko*; Yamazaki, Hirohito*; Harada, Hideo; Shigetome, Yoshialki
PNC TY8601 97-001, 12 Pages, 1997/03
no abstracts in English
Oshima, Takeshi; Morita, Yosuke; Nashiyama, Isamu; Kawasaki, Osamu*; Hisamatsu, Tadashi*; Matsuda, Sumio*; Nakao, Tetsuya*; Wako, Yoshihito*
JAERI-Conf 97-003, p.256 - 260, 1997/03
no abstracts in English
Torii, Tatsuo; Sanada, Yukihisa; Yamada, Tsutomu; Orita, Tadashi; Muraoka, Koji*; Sato, Masayuki*; Watanabe, Akira*; Kume, Kyo*; Hasegawa, Takashi*; Sugita, Takeshi*
no journal, ,
Energetic radiation caused by thunderstorm activity is observed at various places, such as the ground, high mountain areas, and artificial satellites. In order to investigate the radiation source and its energy distribution, we measured energetic radiation by a sounding balloon, an airplane, and the ground observation. On the measurement inside the thundercloud, we conducted a sounding observation using a radiosonde mounted two GM tubes (for 
-rays, and for 
/-rays), in addition to meteorological instruments. The balloon passed through a region of strong echoes in a thundercloud shown by radar image, at which time an increase in counting rate of the GM tube about 2 orders of magnitude occurred at the altitude from 5 km to 7.5 km. Furthermore, the counting rate of 2 GM tubes indicated the tendency different depending on movement of a balloon. This result suggests that the ratio for the -rays (energetic photons) of the beta-rays (energetic electrons) varies according to the place in the thundercloud. Then, we measured the variation of the energetic radiation from the top of the thundercloud using an airplane. At this time, we used two NaI detectors different in the size. We performed the radiation measurement by flying around the thunderclouds at 12 - 14 km in height by the observation in the summer. Moreover, in the winter season, we flew 5 - 6 km in height and measured the radiation around the thunderclouds. Furthermore, we carried out a ground observation of the energetic rays during winter thunderstorm at a coastal area facing the Sea of Japan. Two types of the energetic radiation have been observed at this time. We report the outline of these measurements and analysis in the session of the JpGU meeting.
Usui, Yoshiya*; Ueshima, Makoto*; Hase, Hideaki*; Ichihara, Hiroshi*; Aizawa, Koki*; Koyama, Takao*; Sakanaka, Shinya*; Ogawa, Tsutomu*; Yamaya, Yusuke*; Nishitani, Tadashi*; et al.
no journal, ,
In the back-arc area of the southern Tohoku region, there are several quaternary volcanos and active faults that have the potential to cause M7-class inland earthquakes. In the vicinity of some of the volcanoes, deep low-frequency earthquakes occur, implying the transfer of melt or aqueous fluid. So as to reveal the magma supply system around the area, it is important to reveal the distribution of the subsurface fluid. Also, understanding the fluid distribution helps elucidate the earthquake generation process. To delineate the subsurface electrical resistivity structure, the authors estimated the resistivity structure in the area by performing magnetotelluric surveys and generating the 3-D resistivity structure model with high resolution. In this study, the authors show the resultant electrical resistivity structure and discuss the subsurface fluid distribution as well as its relationship with the volcanic and seismic activities around the study area.
