Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 57

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Development of the multi-cubic $$gamma$$-ray spectrometer and its performance under intense $$^{137}$$Cs and $$^{60}$$Co radiation fields

Kaburagi, Masaaki; Shimazoe, Kenji*; Kato, Masahiro*; Kurosawa, Tadahiro*; Kamada, Kei*; Kim, K. J.*; Yoshino, Masao*; Shoji, Yasuhiro*; Yoshikawa, Akira*; Takahashi, Hiroyuki*

Nuclear Instruments and Methods in Physics Research A, 1010, p.165544_1 - 165544_9, 2021/09

 Times Cited Count:0 Percentile:0.03(Instruments & Instrumentation)

The number of nuclear facilities being decommissioned has been increasing worldwide, in particular following the accident of the Tokyo Electric Power Company Holdings' Fukushima Daiichi Nuclear Power Station in 2011. In these nuclear facilities, proper management of radioactive materials is required. Then, A $$gamma$$-ray spectrometer with four segmentations using small volume CeBr$$_{3}$$ scintillators with a dimension of $$5 times 5 times 5$$ $$rm{mm}^3$$ was developed. The four scintillators were coupled to a multi-anode photomultiplier tube specific to intense radiation fields. We performed the $$gamma$$-ray exposure study under $$^{137}$$Cs and $$^{60}$$Co radiation fields. Under the $$^{137}$$Cs radiation field, the relative energy resolution at 1375 mSv/h was the relative energy resolution at 1375 mSv/h was 9.2$$pm$$0.05%, 8.0$$pm$$0.08%, 8.0$$pm$$0.03%, and 9.0$$pm$$0.04% for the four channels, respectively.

Journal Articles

Gamma-ray spectroscopy with a CeBr$$_3$$ scintillator under intense $$gamma$$-ray fields for nuclear decommissioning

Kaburagi, Masaaki; Shimazoe, Kenji*; Kato, Masahiro*; Kurosawa, Tadahiro*; Kamada, Kei*; Kim, K. J.*; Yoshino, Masao*; Shoji, Yasuhiro*; Yoshikawa, Akira*; Takahashi, Hiroyuki*; et al.

Nuclear Instruments and Methods in Physics Research A, 988, p.164900_1 - 164900_8, 2021/02

 Times Cited Count:1 Percentile:81.22(Instruments & Instrumentation)

An increasing number of nuclear facilities have been decommissioned worldwide following the 2011 accident of the TEPCO' Fukushima Daiichi Nuclear Power Station. During the decommissioning, radioactive materials have to be retrieved under proper management. In this study, a small cubic CeBr$$_3$$ spectrometer with dimensions of 5 mm $$times$$ 5 mm $$times$$ 5 mm was manufactured to perform $$gamma$$-ray spectroscopy under intense $$gamma$$-ray fields. Furthermore, thanks to a fast digital process unit and a customized photomultiplier, the device could perform $$gamma$$-ray spectroscopy at dose rates of over 1 Sv/h. The energy resolution (FWHM) at 662 keV ranged from 4.4% at 22 mSv/h to 5.2% at 1407 mSv/h for a $$^{137}$$Cs radiation field. Correspondingly, at 1333 keV, it ranged from 3.1% at 26 mSv/h to 4.2% at 2221 mSv/h for a $$^{60}$$Co radiation field, which suggested to realize $$gamma$$-ray assessment of $$^{134}$$Cs, $$^{137}$$Cs, $$^{60}$$Co, and $$^{154}$$Eu at dose rates of over 1 Sv/h.

Journal Articles

Development of ${it spatiotemporal}$ measurement and analysis techniques in X-ray photoelectron spectroscopy; From NAP-HARPES to 4D-XPS

Toyoda, Satoshi*; Yamamoto, Tomoki*; Yoshimura, Masashi*; Sumida, Hirosuke*; Mineoi, Susumu*; Machida, Masatake*; Yoshigoe, Akitaka; Suzuki, Satoru*; Yokoyama, Kazushi*; Ohashi, Yuji*; et al.

Vacuum and Surface Science, 64(2), p.86 - 91, 2021/02

We have developed ${it spatiotemporal}$ measurement and analysis techniques in X-ray photoelectron spectroscopy. To begin with, time-division depth profiles of gate stacked film interfaces have been achieved by NAP-HARPES (Near Ambient Pressure Hard X-ray Angle-Resolved Photo Emission Spectroscopy) data. We then have promoted our methods to quickly perform peak fittings and depth profiling from time-division ARPES data, which enables us to realize 4D-XPS analysis. It is found that the traditional maximum entropy method (MEM) combined with Jackknife averaging of sparse modeling in NAP-HARPES data is effective to perform dynamic measurement of depth profiles with high precision.

Journal Articles

Field test around Fukushima Daiichi Nuclear Power Plant site using improved Ce:Gd$$_{3}$$(Al,Ga)$$_{5}$$O$$_{12}$$ scintillator Compton camera mounted on an unmanned helicopter

Shikaze, Yoshiaki; Nishizawa, Yukiyasu; Sanada, Yukihisa; Torii, Tatsuo; Jiang, J.*; Shimazoe, Kenji*; Takahashi, Hiroyuki*; Yoshino, Masao*; Ito, Shigeki*; Endo, Takanori*; et al.

Journal of Nuclear Science and Technology, 53(12), p.1907 - 1918, 2016/12

 Times Cited Count:24 Percentile:96.18(Nuclear Science & Technology)

The Compton camera was improved for use with the unmanned helicopter. Increase of the scintillator array from 4$$times$$4 to 8$$times$$8 and expanse of the distance between the two layers contributed to the improvements of detection efficiency and angular resolution, respectively. Measurements were performed over the riverbed of the Ukedo river of Namie town in Fukushima Prefecture. By programming of flight path and speed, the areas of 65 m $$times$$ 60 m and 65 m $$times$$ 180 m were measured during about 20 and 30 minutes, respectively. By the analysis the air dose rate maps at 1 m height were obtained precisely with the angular resolution corresponding to the position resolution of about 10 m from 10 m height. Hovering flights were executed over the hot spot areas for 10-20 minutes at 5-20 m height. By using the reconstruction software the $$gamma$$-ray images including the hot spots were obtained with the angular resolution same as that evaluated in the laboratory (about 10$$^{circ}$$).

JAEA Reports

Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage, 3; Progress report on NUMO-JAEA collaborative research in FY2013 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Kitamura, Akira; Yoshikawa, Hideki; Oda, Chie; Ishidera, Takamitsu; et al.

JAEA-Research 2014-030, 457 Pages, 2015/03

JAEA-Research-2014-030.pdf:199.23MB

JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and post-closure performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, based on some examples of developing method of hydro-geological structure model, acquired knowledge are arranged using the tree diagram, and model uncertainty and its influence on the evaluation items were discussed. With regard to (2) study on scenario development, the developed approach for "defining conditions" has been reevaluated and improved from practical viewpoints. In addition, the uncertainty evaluation for the effect of use of cementitious material, as well as glass dissolution model, was conducted with analytical evaluation. With regard to (3) study on setting radionuclide migration parameters, based on survey of precedent procedures, multiple-approach for distribution coefficient of rocks was established, and the adequacy of the approach was confirmed though its application to sedimentary rock and granitic rock. Besides, an approach for solubility setting was developed including the procedure of selection of solubility limiting solid phase. The adequacy of the approach was confirmed though its application to key radionuclides.

JAEA Reports

Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage, 2; Progress report on NUMO-JAEA collaborative research in FY2012 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Hayano, Akira; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.

JAEA-Research 2013-037, 455 Pages, 2013/12

JAEA-Research-2013-037.pdf:42.0MB

Following FY2011, JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, the tree diagram of methodology of groundwater travel time has been extended for crystalline rock, in addition, tree diagram for sedimentary rock newly has been organized. With regard to (2) study on scenario development, the existing approach has been improved in terms of a practical task, and applied and tested for near field focusing on the buffer. In addition, the uncertainty of some important processes and its impact on safety functions are discussed though analysis. With regard to (3) study on setting radionuclide migration parameters, the approaches for parameter setting have been developed for sorption for rocks and solubility, and applied and tested through parameter setting exercises for key radionuclides.

JAEA Reports

Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage; Progress report on NUMO-JAEA collaborative research in FY2011 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Hayano, Akira; Mitsui, Seiichiro; Taniguchi, Naoki; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.

JAEA-Research 2012-032, 298 Pages, 2012/09

JAEA-Research-2012-032.pdf:33.68MB

JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation phase. The topics and the conducted research are follows; (1) Study on selection of host rock: in terms of hydraulic properties, items for assessing rock property, and assessment methodology of groundwater travel time has been organized with interaction from site investigation. (2) Study on development of scenario: the existing approach has been embodied, in addition, the phenomenological understanding regarding dissolution of and nuclide release from vitrified waste, corrosion of the overpack, long-term performance of the buffer are summarized. (3) Study on setting nuclide migration parameters: the approach for parameter setting has been improved for sorption and diffusion coefficient of buffer/rock, and applied and tested for parameter setting of key radionuclides. (4) Study on ensuring quality of knowledge: framework for ensuring quality of knowledge has been studied and examined aimed at the likely disposal facility condition.

Journal Articles

Determination of trace amounts of plutonium in low-active liquid wastes from spent nuclear-fuel reprocessing plants by flow injection-based solid-phase extraction/electrochemical detection system

Taguchi, Shigeo; Yamamoto, Masahiko; Surugaya, Naoki; Kurosawa, Akira; Hiyama, Toshiaki; Tanaka, Tatsuhiko*

Journal of Radioanalytical and Nuclear Chemistry, 288(2), p.435 - 441, 2011/01

 Times Cited Count:6 Percentile:48.42(Chemistry, Analytical)

JAEA Reports

Precise and accurate determination of plutonium by controlled-potential coulometry and its uncertainty evaluation

Yamamoto, Masahiko; Ishibashi, Atsushi; Nagayama, Tetsuya; Surugaya, Naoki; Kurosawa, Akira; Hiyama, Toshiaki

JAEA-Technology 2010-040, 28 Pages, 2010/12

JAEA-Technology-2010-040.pdf:0.97MB

Precise analysis of plutonium is necessary for material control and safeguards in nuclear facility. Thus, controlled-potential coulometry, which yields absolute results and high precision, was applied for the determination of plutonium. The coulometry system and sample pretreatment procedures were optimized following ISO12183:2005. Plutonium sample prepared from NBL CRM-126 Pu metal was measured and agreed well with certified value. For spike preparation of isotope dilution mass spectrometry (IDMS), plutonium solution was prepared from MOX powder. Plutonium content was 15.5995 mgPu/g. The uncertainty was calculated by ISO/BIPM Guide to the Expression of Uncertainties in Measurements. The relative expanded uncertainty was 0.023% with confidence interval of 95%. The results were in good agreement with those obtained by IDMS. Thus the proposed coulometry method was successfully applied for the determination of plutonium at the highest level of precision and accuracy.

Journal Articles

Activities of Special Committee on "Quality Assurance of Accountancy Analysis for Safeguards"

Sumi, Mika; Surugaya, Naoki; Kurosawa, Akira; Suzuki, Toru; Kuno, Yusuke

Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-31-Kai Nenji Taikai Rombunshu (CD-ROM), 8 Pages, 2010/12

For the long-term stable operation of nuclear fuel cycle facilities, it is essential to satisfy the requirements of IAEA safeguards agreement. The requirements to maintain and improve the precision of DA are supposed to grow along with nuclear fuel cycle fully in progress and Pu handling amount increases. In order to maintain long-term stability of quality level of accountancy analysis for safeguards, a special committee on "Quality Assurance (QA) for Accountancy / Safeguards analysis" was established at Atomic Energy Society Japan supported by INNN-Japan. Experts for safeguards analysis, reference materials, statistics and QA were gathered and drafted the committee standard document for isotope dilution mass spectrometry, the major accountancy analysis technique for Pu and U, supported Pu standard preparation at JAEA and summarized the items needed for QA of DA.

Journal Articles

Determination of trace amounts of uranium by stripping voltammetry using a boron-doped diamond electrode

Taguchi, Shigeo; Surugaya, Naoki; Kurosawa, Akira; Hiyama, Toshiaki; Tanaka, Tatsuhiko*

Bunseki Kagaku, 59(11), p.1035 - 1041, 2010/11

 Times Cited Count:0 Percentile:0.01(Chemistry, Analytical)

no abstracts in English

Journal Articles

Extraction chromatographic separation of trivalent minor actinides using ${it i}$Hex-BTP/SiO$$_{2}$$-P resin

Surugaya, Naoki; Sano, Yuichi; Yamamoto, Masahiko; Kurosawa, Akira; Hiyama, Toshiaki

Nuclear Energy and the Environment; ACS Symposium Series 1046, p.131 - 139, 2010/10

Journal Articles

Verification of LSD spikes prepared in Japan from a MOX source material

Sumi, Mika; Abe, Katsuo; Kageyama, Tomio; Nakazawa, Hiroaki; Kurosawa, Akira; Yamamoto, Masahiko; Mason, P.*; Neuhoff, J.*; Doubek, N.*; Balsley, S.*; et al.

Proceedings of INMM 51st Annual Meeting (CD-ROM), 9 Pages, 2010/07

Large Size Dried (LSD) spikes are currently used in many facilities in Japan (and around the world) for U and Pu accountancy analysis by Isotope Dilution Mass Spectrometry (IDMS). Because of the large quantity of plutonium standard materials are needed to support Japanese facilities for nuclear fuel cycle and expected difficulties in the long term supply and transport of Pu reference materials, JAEA decided to evaluate the possibility of using MOX stored at Plutonium Fuel Development Center (PFDC) as a source of Pu standard material for LSD spike preparation. At PFDC, Pu nitrate solution was prepared from MOX and two types of the LSD spikes were prepared. The samples of each spike were distributed for verification measurements to international and domestic laboratories. Details of the Pu make-up value evaluation, the LSD spike preparation and the evaluation of the verification results will be presented.

Journal Articles

C-axis critical current of a PrFeAsO$$_{0.7}$$ single crystal

Kashiwaya, Hiromi*; Shirai, Kazumi*; Matsumoto, Tetsuro*; Shibata, Hajime*; Kambara, Hiroshi*; Ishikado, Motoyuki; Eisaki, Hiroshi*; Iyo, Akira*; Shamoto, Shinichi; Kurosawa, Itaru*; et al.

Applied Physics Letters, 96(20), p.202504_1 - 202504_3, 2010/05

 Times Cited Count:27 Percentile:73.57(Physics, Applied)

The ${it c}$-axis transport properties of a high-pressure synthesized PrFeAsO$$_{0.7}$$ single crystal are studied using s-shaped junctions. Resistivity anisotropy of about 120 detected at 50 K shows the presence of strong anisotropy in the electronic states. The obtained critical current density for the ${it c}$-axis of 2.9 $$times$$ 10$$^{5}$$ A/cm$$^{2}$$ is two orders of magnitude larger than that in Bi$$_{2}$$Sr$$_{1.6}$$La$$_{0.4}$$CuO$$_{6+delta}$$. The appearance of a hysteresis in the current-voltage curve below ${it T}$ $$_{c}$$ is the manifestation of the intrinsic Josephson effect similar to that in cuprate superconductors. The suppression of the critical current-normal resistance (${it I}$ $$_{c}$$ ${it R}$ $$_{n}$$) product is explained by an inspecular transport in ${it s}$ $$_{pm}$$ -wave pair potential.

Journal Articles

Rapid determination of trace uranium in liquid wastes from spent nuclear-fuel reprocessing plants using on-line solid-phase extraction / electrochemical detection

Taguchi, Shigeo; Surugaya, Naoki; Kurosawa, Akira; Hiyama, Toshiaki; Tanaka, Tatsuhiko*

Bunseki Kagaku, 58(10), p.901 - 907, 2009/10

 Times Cited Count:0 Percentile:0.01(Chemistry, Analytical)

An on-line analysis system using a solid-phase extraction column coupled to electrochemical detection has been developed for rapid determination of small amounts of uranium in liquid wastes of spent nuclear-fuel reprocessing plants. A sample solution with a concentration of 3 M HNO$$_{3}$$ was loaded onto the column: packed with U/TEVA$$^{textregistered}$$ resin. The interference elements were rinsed by passing 3 M HNO$$_{3}$$ through the column. The adsorbed uranium was eluted with 0.1 M HNO$$_{3}$$. The eluate was directly introduced into a flow-electrolysis cell. The result of five repeated analyses for a standard solution containing 2.5 $$mu$$g (0.1 mL at 25 $$mu$$g mL$$^{-1}$$) of uranium was found to be 2.5 $$pm$$ 0.025 $$mu$$g (mean $$pm$$ 1 $$sigma$$). The detection limit calculated from 3 times the standard deviation of background current was 56 ng. The analysis time required for one sample was within 5 min. The recoveries of uranium in actual nuclear waste reprocessing solutions were 92% $$sim$$ 112%.

JAEA Reports

Study on evaluation method of potential impact of natural phenomena on a HLW disposal system

Kawamura, Makoto; Oi, Takao; Niizato, Tadafumi; Yasue, Kenichi; Tokiwa, Tetsuya; Niwa, Masakazu; Shimada, Koji; Kurosawa, Hideki; Asamori, Koichi; Kawachi, Susumu; et al.

JAEA-Research 2008-018, 47 Pages, 2008/03

JAEA-Research-2008-018.pdf:24.18MB

In this report, we sophisticated the framework as a part of the total system performance assessment for two purposes: the first one is quantification of relationship of characteristic of natural phenomena between geological environmental conditions (THMCG), and the other one is quantification of relationship of THMCG condition between parameters of performance assessment. On the other hand, we applied the sophisticated framework to all natural phenomena. As a result, to apply the sophisticated framework, we could show that information integration could carry out efficiently. Moreover, we have checked that the framework was applicable to all phenomena. Furthermore, we could show that suitable scenarios might be chosen by information integration.

JAEA Reports

Development and management of the knowledge base for the geological disposal technology; Annual report 2006

Umeda, Koji; Oi, Takao; Osawa, Hideaki; Oyama, Takuya; Oda, Chie; Kamei, Gento; Kuji, Masayoshi*; Kurosawa, Hideki; Kobayashi, Yasushi; Sasaki, Yasuo; et al.

JAEA-Review 2007-050, 82 Pages, 2007/12

JAEA-Review-2007-050.pdf:28.56MB

This report shows the annual report which shows the summarized results and topic outline of each project on geological disposal technology in the fiscal year of 2006.

Journal Articles

Reevaluation of secondary neutron spectra from thick targets upon heavy-ion bombardment

Satoh, Daiki; Kurosawa, Tadahiro*; Sato, Tatsuhiko; Endo, Akira; Takada, Masashi*; Iwase, Hiroshi*; Nakamura, Takashi; Niita, Koji*

Nuclear Instruments and Methods in Physics Research A, 583(2-3), p.507 - 515, 2007/12

 Times Cited Count:22 Percentile:82.92(Instruments & Instrumentation)

Previously-published data of secondary neutron spectra from thick targets of C, Al, Cu and Pb bombarded with heavy ions from He to Xe are revised by using a new set of neutron-detection efficiency values for a liquid organic scintillator calculated with SCINFUL-QMD. Additional data have been measured for bombardment of C target by 400-MeV/nucleon C ions and 800 MeV/nucleon Si-ions. The set of spectra are compared with the calculation results using a Monte-Carlo heavy-ion transport code, PHITS. It was found that PHITS is able to reproduce the secondary neutron spectra in a wide neutron-energy regime.

Journal Articles

Improvement of analytical activities in the Tokai reprocessing plant, Japan, by measuring destructive and non-destructive assays

Surugaya, Naoki; Taguchi, Shigeo; Kurosawa, Akira; Watahiki, Masaru

STI/PUB/1298 (CD-ROM), p.673 - 679, 2007/08

We have been analyzing nuclear materials at the Tokai pilot reprocessing plant, Japan, since 1977. To obtain reliable measurements for nuclear material such as uranium and plutonium, we have developed various kinds of measurement techniques and implemented effective ones for accountability and verification analyses in a nuclear material accountancy system. One of our role as a pilot plant has been successfully accomplished with the effort put into various analytical activities. Now, it is time to transfer the experience gained with our technology to the next large-scale commercial plant in Rokkasho. This paper presents our analytical methods and their results obtained using analytical techniques we have applied over recent years.

JAEA Reports

Construction, management and operation on advanced volume reduction facilities

Higuchi, Hidekazu; Osugi, Takeshi; Nakashio, Nobuyuki; Momma, Toshiyuki; Tohei, Toshio; Ishikawa, Joji; Iseda, Hirokatsu; Mitsuda, Motoyuki; Ishihara, Keisuke; Sudo, Tomoyuki; et al.

JAEA-Technology 2007-038, 189 Pages, 2007/07

JAEA-Technology-2007-038-01.pdf:15.13MB
JAEA-Technology-2007-038-02.pdf:38.95MB
JAEA-Technology-2007-038-03.pdf:48.42MB
JAEA-Technology-2007-038-04.pdf:20.53MB
JAEA-Technology-2007-038-05.pdf:10.44MB

The Advanced Volume Reduction Facilities (AVRF) is constructed to manufacture the waste packages of radioactive waste for disposal in the Nuclear Science Research Institute of the Japan Atomic Energy Agency. The AVRF is constituted from two facilities. The one is the Waste Size Reduction and Storage Facility (WSRSF) which is for reducing waste size, sorting into each material and storing the waste package. The other is the Waste Volume Reduction Facility (WVRF) which is for manufacturing the waste package by volume reducing treatment and stabilizing treatment. WVRF has an induction melting furnace, a plasma melting furnace, an incinerator, and a super compactor for treatment. In this report, we summarized about the basic concept of constructing AVRF, the constitution of facilities, the specifications of machineries and the state of trial operation until March of 2006.

57 (Records 1-20 displayed on this page)