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Journal Articles

Development of $$alpha$$-ray visualization survey meter in high gamma and neutron background environment

Tsubota, Yoichi; Kobayashi, Kenji; Ishii, Tatsuya; Hirato, Misaki; Shioya, Satoshi; Nakagawa, Takahiro

Radiation Protection Dosimetry, 200(16-18), p.1676 - 1680, 2024/11

 Times Cited Count:0 Percentile:0.00(Environmental Sciences)

In the decommissioning of the Fukushima Daiichi Nuclear Power Station (FDNPS, 1F), workers are removing structures from inside the buildings, monitoring radioactive contamination, and decontaminating inside the buildings. For the measurement of contamination of suit surfaces of workers, we have developed a hand-held survey meter that can measure and visualize surface radioactive contamination of $$alpha$$-nuclides in a high $$beta$$/ $$gamma$$-ray background environment. In order to selectively measure $$alpha$$-nuclides, we designed and built a prototype hand-held survey meter for $$alpha$$-rays, which consists of a thin-film ZnS:Ag scintillator, a multi-anode photomultiplier tube (MA-PMT), individual amplification and counting circuits for each channel of the MA-PMT. Based on the result of $$alpha$$-ray counting, the developed device is capable of counting the $$alpha$$-radiation beyond 2.1$$times$$10$$^{7}$$ cpm. In the $$gamma$$-ray response test, there was no $$gamma$$-ray response even when the detector was in close proximity to a high intensity source; The dose rate was estimated to be more than 1 Sv/h. In the future, we plan to reduce the weight and size of the device, as well as improve the usability of the device through actual testing in contaminated environments.

JAEA Reports

Countermeasure against Beyond Design Basis Accident of HTTR by using fire engine

Shimazaki, Yosuke; Jidaisho, Tatsuya; Ishii, Toshiaki; Inoi, Hiroyuki; Iigaki, Kazuhiko

JAEA-Technology 2024-005, 23 Pages, 2024/06

JAEA-Technology-2024-005.pdf:5.53MB

HTTR has newly assumed Beyond Design Basis Accident (BDBA) as part of conformity assessment with the new regulatory standards and has established measures to prevent the spread of BDBA. Among these measures, to prevent the spread of BDBA caused by cooling water leaks from spent fuel storage pool, the Oarai Research Institute's fire engine was selected as an equipment to prevent the spread of BDBA, and required performances such as pumping water performance were determined. After all required performances were confirmed by inspections, the fire engine passed the operator's pre-use inspection and contributed to the restart of the HTTR operations.

Journal Articles

Structural and compositional characteristics of Fukushima release particulate material from Units 1 and 3 elucidates release mechanisms, accident chronology and future decommissioning strategy

Martin, P. G.*; Jones, C. P.*; Bartlett, S.*; Ignatyev, K.*; Megson-Smith, D.*; Satou, Yukihiko; Cipiccia, S.*; Batey, D. J.*; Rau, C.*; Sueki, Keisuke*; et al.

Scientific Reports (Internet), 10, p.22056_1 - 22056_17, 2020/12

 Times Cited Count:4 Percentile:19.25(Multidisciplinary Sciences)

Journal Articles

Compositional and structural analysis of Fukushima-derived particulates using high-resolution X-ray imaging and synchrotron characterisation techniques

Martin, P. G.*; Jones, C. P.*; Cipiccia, S.*; Batey, D. J.*; Hallam, K. R.*; Satou, Yukihiko; Griffiths, I.*; Rau, C.*; Richards, D. A.*; Sueki, Keisuke*; et al.

Scientific Reports (Internet), 10(1), p.1636_1 - 1636_11, 2020/01

 Times Cited Count:9 Percentile:29.89(Multidisciplinary Sciences)

JAEA Reports

Hydraulic tests using borehole PB-V01 in the Horonobe Underground Research Project

Samata, Yoichi; Iwata, Tatsuya*; Ishii, Eiichi

JAEA-Data/Code 2019-008, 19 Pages, 2019/09

JAEA-Data-Code-2019-008.pdf:2.82MB
JAEA-Data-Code-2019-008-appendix(CD-ROM).zip:1.38MB

In Horonobe Underground Research Laboratory Project, hydraulic tests for the excavation damaged zone have been performed in order to characterize the hydrological properties of the zone. In PB-V01 borehole, pore pressure observation started in October 2008, but the pore pressure is currently reduced by about 3 MPa compared to that time. In this report, in order to evaluate the influence that this pore pressure drop has on the permeability of the rock, the results of the in-situ permeability test using the long-term hydraulic pressure monitoring device installed in the same hole are summarized.

Journal Articles

Effect of water for the oxygen adsorption on surface of PtCo catalysts

Cui, Y.-T.*; Harada, Yoshihisa*; Niwa, Hideharu*; Oshima, Masaharu*; Hatanaka, Tatsuya*; Nakamura, Naoki*; Ando, Masaki*; Yoshida, Toshihiko*; Ishii, Kenji*; Matsumura, Daiju

NanotechJapan Bulletin (Internet), 11(4), 6 Pages, 2018/08

no abstracts in English

Journal Articles

Wetting induced oxidation of Pt-based nano catalysts revealed by ${{it in situ}}$ high energy resolution X-ray absorption spectroscopy

Cui, Y.-T.*; Harada, Yoshihisa*; Niwa, Hideharu*; Hatanaka, Tatsuya*; Nakamura, Naoki*; Ando, Masaki*; Yoshida, Toshihiko*; Ishii, Kenji*; Matsumura, Daiju; Oji, Hiroshi*; et al.

Scientific Reports (Internet), 7(1), p.1482_1 - 1482_8, 2017/05

 Times Cited Count:21 Percentile:46.97(Multidisciplinary Sciences)

Journal Articles

Electronic structure of Pt and Pt-Co nanoparticles with O$$_{2}$$ and O$$_{2}$$/H$$_{2}$$O adsorption revealed by in situ XAFS and hard X-ray photoelectron spectroscopy

Cui, Y.*; Harada, Yoshihisa*; Hatanaka, Tatsuya*; Nakamura, Naoki*; Ando, Masaki*; Yoshida, Toshihiko*; Ikenaga, Eiji*; Ishii, Kenji*; Matsumura, Daiju; Li, R.*; et al.

ECS Transactions, 72(8), p.131 - 136, 2016/10

 Times Cited Count:1 Percentile:44.59(Electrochemistry)

Journal Articles

Adsorption behaviors of platinum group metals in simulated high level liquid waste using macroporous (MOTDGA-TOA)/SiO$$_{2}$$-P silica-based absorbent

Ito, Tatsuya; Kim, S.-Y.*; Xu, Y.*; Hitomi, Keitaro*; Ishii, Keizo*; Nagaishi, Ryuji; Kimura, Takaumi

Separation Science and Technology, 48(17), p.2616 - 2625, 2013/10

As fundamental research for separation of platinum group metals (PGMs) from high level liquid waste (HLLW) by macroporous silica-based adsorbent, (MOTDGA-TOA)/SiO$$_{2}$$-P adsorbent was prepared by impregnation of N,N'-dimethyl-N,N'-di-noctyl-thiodiglycolamide (MOTDGA) and Tri-n-octylamine (TOA) into silica/polymer composite support (SiO$$_{2}$$-P). The adsorption behavior of Ru(III), Rh(III), and Pd(II) in simulated HLLW onto the adsorbent were investigated by the batch method to obtain their corresponding equilibrium and kinetic data. The adsorbent showed strong adsorption for Pd(II) and the adsorption reached equilibrium within 2 hr. In addition, the use of both MOTDGA and TOA improved adsorption of Ru(III) and Rh(III) better than individual use of them. The adsorptions of Ru(III), Rh(III), and Pd(II) followed the Langmuir adsorption model, and were found to be controlled by the chemisorption mechanism.

Journal Articles

Replacement of the criticality accident alarm system in the Tokai Reprocessing Plant

Sanada, Yukihisa; Ishii, Masato*; Hasegawa, Ichiro; Kanazawa, Nobuyuki; Chikazawa, Tatsuya*; Momose, Takumaro

NEA/CSNI/R(2010)4 (Internet), p.351 - 370, 2010/11

A criticality accident alarm system (CAAS) was installed in the 1980s as part of criticality safety management at the Tokai Reprocessing Plant (TRP) to reduce the chance of workers being exposed to radiation in the rare case of a criticality accident. From a compliance point of view processing at TRP cannot take place without the criticality monitoring provided by the CAAS. This paper gives an overview of the process of the CAAS being replaced as part of aging management.

Journal Articles

Production of no-carrier-added $$^{64}$$Cu and applications to molecular imaging by PET and PETIS as a biomedical tracer

Watanabe, Shigeki; Iida, Yasuhiko*; Suzui, Nobuo; Katabuchi, Tatsuya*; Ishii, Satomi; Kawachi, Naoki; Hanaoka, Hirofumi*; Watanabe, Satoshi; Matsuhashi, Shimpei; Endo, Keigo*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 280(1), p.199 - 205, 2009/04

 Times Cited Count:25 Percentile:81.54(Chemistry, Analytical)

Journal Articles

Progress of the ITER central solenoid model coil programme

Tsuji, Hiroshi; Okuno, Kiyoshi*; Thome, R.*; Salpietro, E.*; Egorov, S. A.*; Martovetsky, N.*; Ricci, M.*; Zanino, R.*; Zahn, G.*; Martinez, A.*; et al.

Nuclear Fusion, 41(5), p.645 - 651, 2001/05

 Times Cited Count:58 Percentile:82.58(Physics, Fluids & Plasmas)

no abstracts in English

Oral presentation

Detection and measurement of abnormal posture under stressful conditions in nematode $textit{C. elegans}$

Ide, Kazunori*; Ishikawa, Tomoya*; Arai, Shingo*; Morioka, Tatsuya*; Kaneda, Hiroki*; Suzuki, Michiyo; Sakashita, Tetsuya; Ishii, Naoaki*; Yanase, Sumino*

no journal, , 

Oral presentation

Current status of R&D on minor actinide separation process with CHON Extractants in JAEA

Matsumura, Tatsuro; Ban, Yasutoshi; Suzuki, Hideya; Tsubata, Yasuhiro; Hotoku, Shinobu; Tsutsui, Nao; Suzuki, Asuka; Toigawa, Tomohiro; Kurosawa, Tatsuya*; Shibata, Mitsunobu*; et al.

no journal, , 

To continue the utilization of the nuclear fission energy, the management of the high-level radioactive waste is one of the most important issues to be solved. Partitioning and Transmutation technology is expected to be effective to mitigate the burden of the HLW disposal by reducing the radiological toxicity and heat generation. JAEA has been conducting R&D on the MA separation process to remove of MA from HLW and supply the recovered MA to the transmutation system such as ADS. The MA separation process contains three steps. For An(III)+RE recovery process, we developed TDdDGA which has very high performance to recover of MA from high level waste. HONTA and ADAAM were developed for An(III)/RE separation process and Am/Cm separation process respectively. All extractants satisfy CHON principle to minimization of the secondary waste from the process. The separation performances of the flowsheets were evaluated by continuous extraction tests using simulated and genuine high level liquid waste.

Oral presentation

Separation and recovery of platinum group metals from high-level radioactive liquid waste, 7; Comparing investigation of (Crea-TOA)/SiO$$_{2}$$-P and (MOTDGA-TOA)/SiO$$_{2}$$-P

Ito, Tatsuya; Kim, S.-Y.*; Xu, Y.*; Hitomi, Keitaro*; Ishii, Keizo*; Nagaishi, Ryuji; Kimura, Takaumi

no journal, , 

no abstracts in English

Oral presentation

Elucidation for production scenario of insoluble Cs particles from Unit 1 using multifaceted analysis

Satou, Yukihiko; Kobata, Masaaki; Okane, Tetsuo; Sueki, Keisuke*; Matsuo, Kazuki*; Ishii, Tatsuya*; Martin, P.*; Scott, T.*

no journal, , 

no abstracts in English

Oral presentation

Research and development of the "SELECT process" for Actinide separation

Matsumura, Tatsuro; Ban, Yasutoshi; Hotoku, Shinobu; Suzuki, Hideya; Tsubata, Yasuhiro; Tsutsui, Nao; Morita, Keisuke; Toigawa, Tomohiro; Shibata, Mitsunobu*; Kurosawa, Tatsuya*; et al.

no journal, , 

no abstracts in English

Oral presentation

Study on separation of platinum group metals from high level liquid waste using macroporous (MOTDGA-TOA)/SiO$$_{2}$$-P silica-based absorbent

Ito, Tatsuya; Kim, S.-Y.*; Xu, Y.*; Hitomi, Keitaro*; Ishii, Keizo*; Nagaishi, Ryuji; Kimura, Takaumi

no journal, , 

To research recovering of platinum group metals (PGMs) from high level liquid waste (HLLW) by macroporous silica-based adsorbent, the adsorbent of (MOTDGA-TOA)/SiO$$_{2}$$-P was developed by impregnating two extractants of N,N'-dimethyl-N,N'-di-n-octyl-thiodiglycolamide (MOTDGA) and tri-n-octylamine (TOA) into a silica/polymer composite support (SiO$$_{2}$$-P). The adsorbent showed good adsorption property for Pd(II). In addition, the combined use of MOTDGA and TOA improved adsorption of Ru(III) and Rh(III) better than the individual use of them. The usability of adsorbent in radiation fields was further confirmed by irradiation experiments. The adsorbent remained to have adsorption capability for PGMs at least adsorbed dose of 100 kGy, correspomding with one adsorbed by the adsorbent in their adsorption, and showed good retention capability for adsorbed Pd(II) even at the adsorbed dose of 800 kGy.

Oral presentation

Separation and recovery of platinum group metals from high-level radioactive liquid waste, 5; Radiation effects on retention of PGMs in silica-supported adsorbent

Ito, Tatsuya; Kim, S.-Y.*; Xu, Y.*; Hitomi, Keitaro*; Ishii, Keizo*; Nagaishi, Ryuji; Kimura, Takaumi

no journal, , 

no abstracts in English

Oral presentation

Uncategorized radioactive particles isolated from southwest region from the Fukushima Dai-ichi Nuclear Power Station

Satou, Yukihiko; Sueki, Keisuke*; Ishii, Tatsuya*; Igarashi, Junya*; Martin, P.*; Jones, C.*; Scott, T.*

no journal, , 

In Fukushima accident, insoluble radioactive Cs particles found at the northwestern region from the Fukushima Dai-ichi Nuclear Power Station (1FNPS). Presence of Cs particle in other surrounding area from 1FNPS is unclear yet. In the present study, the presence of other particle emission events and the presence of new types of radioactive particles were investigated by expanding the search object to soil samples collected outside the 1FNPS northwest region where insoluble Cs particles were reported. Four radioactive particles found from the samples. The particles look like pebbles and diameter is 0.4 to 2 mm, and the size feature is Type B. Isotopic ratio of Cs is very similar to type A of 1.0. EDS results confirmed the presence of iron and aluminum in addition to silicon. Further, in the CT image, there was an absorption point near the surface indicating that the element is heavier than iron. Although these features are clearly different from the insoluble Cs particles that have been reported in the past, in this implementation item it is not possible to find the location where Cs is adsorbed, and further direct emission from uranium or in the reactor.

43 (Records 1-20 displayed on this page)