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Journal Articles

Mesospheric ionization during substorm growth phase

Murase, Kiyoka*; Kataoka, Ryuho*; Nishiyama, Takanori*; Nishimura, Koji*; Hashimoto, Taishi*; Tanaka, Yoshimasa*; Kadokura, Akira*; Tomikawa, Yoshihiro*; Tsutsumi, Masaki*; Ogawa, Yasunobu*; et al.

Journal of Space Weather and Space Climate (Internet), 12, p.18_1 - 18_16, 2022/06

 Times Cited Count:1 Percentile:22.72(Astronomy & Astrophysics)

We identified two energetic electron precipitation (EEP) events during the growth phase of moderate substorms and estimated the mesospheric ionization rate for an EEP event for which the most comprehensive dataset from ground-based and space-born instruments was available. The mesospheric ionization signature reached below 70 km altitude and continued for ~15 min until the substorm onset, as observed by the PANSY radar and imaging riometer at Syowa Station in the Antarctic region. We also used energetic electron flux observed by the Arase and POES 15 satellites as the input for the air-shower simulation code PHITS to quantitatively estimate the mesospheric ionization rate. Combining the cutting-edge observations and simulations, we shed new light on the space weather impact of the EEP events during geomagnetically quiet times, which is important to understand the possible link between the space environment and climate.

Journal Articles

Evaluation of change of LSD spikes by long-term storage

Shibano, Koya; Abe, Katsuo; Tsukasa, Kazuo*; Hosogane, Tatsuya; Kayano, Masashi; Sumi, Mika; Fujiwara, Hideki*; Yamaguchi, Kazuya*; Motoki, Chika*

Dai-41-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2020/11

Large-sized dried spikes, called LSD spike, are used as reference material for accountancy analysis for Plutonium and Uranium by Isotope Dilution Mass Spectrometry. LSD spikes preparation is performed each steps as followed (1) Preparing Plutonium and Uranium mix solution, (2) Aliquoting mix solution to vials, and (3) Drying. J-MOX have planned prepared in-house LSD spike and utilized it for accountancy analysis. If LSD spikes are stored for long term, dried material peel off from bottom of vial and it may affect analytical results. In this study, LSD spikes, which have composition suitable for accountancy analysis in J-MOX, had been stored for about 2 years, then long-term stability of LSD spikes had been evaluated.

Journal Articles

Transient ionization of the mesosphere during auroral breakup; Arase satellite and ground-based conjugate observations at Syowa Station

Kataoka, Ryuho*; Nishiyama, Takanori*; Tanaka, Yoshimasa*; Kadokura, Akira*; Uchida, Herbert Akihito*; Ebihara, Yusuke*; Ejiri, Mitsumu*; Tomikawa, Yoshihiro*; Tsutsumi, Masaki*; Sato, Kaoru*; et al.

Earth, Planets and Space (Internet), 71(1), p.9_1 - 9_10, 2019/12

 Times Cited Count:8 Percentile:40.25(Geosciences, Multidisciplinary)

Transient ionization of the mesosphere was detected at around 65 km altitude during the isolated auroral expansion occurred at 2221-2226 UT on June 30, 2017. A general-purpose Monte Carlo particle transport code PHITS suggested that significant ionization is possible in the middle atmosphere due to auroral X-rays from the auroral electrons of $$<$$10 keV.

Journal Articles

Development of Pu standard material preparation and characterization technique in Japan

Okazaki, Hiro; Shibano, Koya; Abe, Katsuo; Sumi, Mika; Kayano, Masashi; Kageyama, Tomio; Mason, P.*

Proceedings of INMM 57th Annual Meeting (Internet), 7 Pages, 2016/07

The reference materials used for accountancy analysis by IDMS, referred to as LSD spikes allows to obtain accurate measurement results for a variety of nuclear materials under potentially difficult handling or measurement conditions. Because of expected difficulties in a stably long term supply of plutonium reference materials, which are the main source of plutonium for LSD spikes preparation, the JAEA's PFDC decided to evaluate the possibility of using domestically available MOX powders as a plutonium source material for LSD spikes. Therefore, PFDC started to separate, purify and characterize plutonium in MOX powders for plutonium reference materials (MOX-Pu) preparation that are suitable for source of LSD spikes in cooperation with the US DOE's NBL. The detailed preparation procedure of the latest MOX-Pu standard material and results of intercomparison for verification are presented.

Journal Articles

Approaches to characterization of nuclear material for establishment of nuclear forensics

Okazaki, Hiro; Sumi, Mika; Sato, Mitsuhiro; Kayano, Masashi; Kageyama, Tomio; Martinez, P.*; Xu, N.*; Thomas, M.*; Porterfield, D.*; Colletti, L.*; et al.

Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-35-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2015/01

The quality control section of Plutonium Fuel Development Center (PFDC) in Japan Atomic Energy Agency has been analyzing isotopic compositions and content of plutonium and uranium as well as impurity and physics of nuclear materials in the process of MOX fuel fabrication for accountancy purpose as well as process control purposes. These analytical techniques are also effective for nuclear forensics to identify the source, history, and route of the material by determining a composition and chemical property of it. Therefore, PFDC cooperates with Los Alamos National Laboratory which has broad experience and established measurement skill for nuclear forensics, and evaluates the each method, procedure, and analytical data toward R&D of characterizing a nuclear fuel for forensics purposes. This paper describes the approaches to develop characterization techniques of nuclear fuel for nuclear forensic purpose at PFDC.

Journal Articles

Approaches to the ISO/IEC 17025 accreditation for Pu and U accountancy analysis

Okazaki, Hiro; Sumi, Mika; Abe, Katsuo; Sato, Mitsuhiro; Kageyama, Tomio

Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-34-Kai Nenji Taikai Rombunshu (Internet), 9 Pages, 2013/10

The quality control section of Plutonium Fuel Development Center (PFDC) has been analyzing isotopic compositions by Mass Spectrometry as well as content by Isotope Dilution Mass Spectrometry (IDMS) of plutonium and uranium in nuclear materials. Along with establishing and managing the quality assurance system, ensuring the reliability of the analysis data is important. PFDC has been establishing the quality management system with ISO 9001. We addressed technical improvement to improve further reliability of analysis quality, and accredited for ISO/IEC 17025 in March 2010. While ISO 9001 consists of management requirements for quality system of organizations, ISO/IEC 17025 consists of technical requirements for the competence of testing and calibration laboratories in addition to the management requirements. In this presentation, we report our approaches to have accreditation and operation status for isotopic compositions and content of plutonium and uranium in nuclear materials.

Journal Articles

Report of 53rd INMM Annual Meeting in 2012, 5; MC&A: Outline of nuclear forensic session

Sumi, Mika; Okazaki, Hiro

Kaku Busshitsu Kanri Senta Nyusu, 41(12), p.5 - 6, 2012/12

Outline of the presentations given at "Material Control and Accountability-Destructive analysis/Forensics" of 53rd INMM annual meeting held in July 2012 is reported. It includes presentation by NBL and ORNL on reference material characterization and preservation, two presentations by Plutonium Fuel Development Center of JAEA on ISO/IEC 17025 accreditation process and establishment of uncertainty evaluation method and others. Also, outline of annual meeting for intercomparison organized by NBL is also reported.

Journal Articles

ISO/IEC 17025 accreditation for accountancy analysis at PFDC

Okazaki, Hiro; Sumi, Mika; Abe, Katsuo; Kageyama, Tomio; Nakazawa, Hiroaki

Proceedings of INMM 53rd Annual Meeting (CD-ROM), 9 Pages, 2012/07

Accurate and precise measurement of Pu and U is critically important for safeguards and is the premise of safeguards inspection by IAEA at Nuclear Fuel handling facilities. Quality control section of Plutonium Fuel Development Center (PFDC-lab) has been analyzing the Pu and U isotopic compositions by MS as well as its content by IDMS of the MOX fuel pellet and its source materials for the accountancy purposes. To maintain and improve analysis quality and analysis reliability, PFDC-lab decided to have accreditation of ISO/IEC 17025 (International standard for the General requirements for the competence of testing and calibration laboratories). PFDC-lab established analysis quality management system, acquired the knowledge and information of uncertainty evaluation under cooperative study with US DOE's NBL, ensured our analysis traceability and validates our methods to meet technical requirements. In conclusion, we have accredited for ISO/IEC 17025 in March 1st, 2010.

Journal Articles

Quality control and uncertainty evaluation for accountancy analysis at PFDC-JAEA

Sumi, Mika; Okazaki, Hiro; Abe, Katsuo; Kageyama, Tomio; Nakazawa, Hiroaki

Proceedings of INMM 53rd Annual Meeting (CD-ROM), 9 Pages, 2012/07

PFDC has been developing various technologies for MOX fuel production, and Pu and U isotopic composition and content of these samples are analyzed at PFDC-lab. For the analysis of MOX fuel material including raw material powders, PFDC-lab is accredited as the testing laboratory of ISO/IEC 17025 scoped for (1) Pu and U isotopic composition measurement in the nuclear fuel materials by MS and (2) Pu and U content measurement in the nuclear fuel materials by IDMS. This accreditation was granted in March 2010. While preparing for accreditation, the PFDC-lab established the capability to estimate measurement uncertainty in accordance with the GUM Guide and developed calculation program combining GUM-Workbench and Excel. This paper presents details of our quality control system and measurement uncertainty evaluation systems.

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

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

Experience on preparation of LSD spikes for MOX samples

Sumi, Mika; Abe, Katsuo; Kageyama, Tomio; Nakazawa, Hiroaki; Katchi, Tomokazu*; Murakami, Yoshiki*; Hishi, Tomoyuki*; Ai, Hironobu*

Proceedings of INMM 50th Annual Meeting (CD-ROM), 9 Pages, 2009/07

Currently, many laboratories who measure Pu and U concentration by isotope dilution mass spectrometry (IDMS) use Large Size Dried (LSD) spikes, which contain both Pu and U in individual vials. Plutonium Fuel Development Center (PFDC) prepared LSD spikes for MOX samples and has been used while LSD spikes prepared at inspection laboratories and commercially supplied are mainly aimed to measure input solution for reprocessing. Difficulties of importing reference materials are increasing though the needs of Pu reference materials are increasing. Stable securing Pu reference material is essential for facility operation and it is considered to be important to acquire technique to prepare domestic Pu reference material. Pu were prepared from MOX powder at PFDC and used for LSD spike preparation. Practical tests were performed with JNFL. Experience of preparation and utilization of LSD spike for MOX, consideration of certification method for MOX-Pu will be explained also in this paper.

Journal Articles

Present status and future plans of the study for preparation of Pu reference materials

Sumi, Mika; Kageyama, Tomio; Suzuki, Toru

Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-27-Kai Nenji Taikai Rombunshu (CD-ROM), 7 Pages, 2006/00

All accountancy analysis at the PFDC of JAEA is performed by isotope dilution mass spectrometry with well-characterized standard materials. Though Pu reference materials has been supplied from foreign country, importing those Pu is gradually becoming more difficult and may be almost impossible to import them in future. Thus, in order to establish the capability and expertise for the preparation of Pu reference materials, JAEA has started collaborative work with NBL who has high skills for preparing and supplying nuclear reference materials for long periods. One of the targets of this collaboration is preparation of standard material for IDMS. MOX powder which has been stored in JAEA was dissolved and purified to obtain Pu solution. A small portion of the purified solution was transported to NBL for analysis. LSD spike will be prepared from this Pu solution and then validation analysis and performance test including stability test will be performed with NBL and JAEA.

Journal Articles

Present status; Collaboration between NBL and JAEA on preparation of Pu reference material

Sumi, Mika; Kageyama, Tomio; Suzuki, Toru; Manson, P.*; Neuhoff, J.*

Proceedings of INMM 47th Annual Meeting (CD-ROM), 7 Pages, 2006/00

All accountancy analyses at the Plutonium Fuel Development Center (PFDC) of JAEA are performed by isotope dilution mass spectrometry (IDMS) with well-characterized standard materials, which prepared at PFDC itself from Pu and U reference materials. Currently, Pu reference materials must be obtained from foreign suppliers because there are no facilities in Japan with the capability for preparation and supply of Pu reference materials, and, importing those Pu reference materials is gradually becoming more difficult. Therefore, JAEA has started collaborative work with NBL for the preparation of Pu reference materials and associated Large Size Dried (LSD) spike. MOX powder which has been stored in JAEA was dissolved and ion-exchange was performed to obtain purified Pu solution at JAEA. Several aliquots had taken from the solution, dried, and sent to NBL for analysis. Pu samples were shipped and have arrived to NBL. After certification analysis on NBL, the Pu nitrate solution will be mixed with a U nitrate solution which prepared from CRMs. The uncertainty of the purified Pu solution and prepared LSD spikes will be evaluated by GUM method. This paper presents the present status and future plans for the collaboration work.

Journal Articles

Study of the IDGS Technique for Mixed Plutonium-Uranium Oxide (MOX) Samples

Sumi, Mika; Masashige, Kobayashi,*; Onishi, Sumitaka; Suzuki, Toru; Li, T. K.*; Vo, D.*

Final Program P.657 #229, 657- Pages, 2004/00

The Isotope Dilution Gamma-ray Spectrometry (IDGS) technique has developed at LANL. Feasibility study to implement IDGS for measuring MOX samples at PFC has performed and its results will be presented.

Journal Articles

Topical Overview of the Session on Material Control and Accountability at 45th INMM

Surugaya, Naoki; Sumi, Mika

Kaku Busshitsu Kanri Senta Nyusu, 33(12), p.7 - 8, 2004/00

Topics of the presentations on measurement and analysis which presented in MC&A session at INMM are reported.

Journal Articles

None

Sumi, Mika

Kaku Busshitsu Kanri Senta Nyusu, 32(1), p.13 - 15, 2003/00

None

Journal Articles

Minute of Material Control & Accountability Session at 44th INMM Annual Meeting

Sumi, Mika; Sumi, Mika

Kaku Busshitsu Kanri Senta Nyusu, 132(11), p.15 - 17, 2003/00

no abstracts in English

Journal Articles

None

Sumi, Mika;

Kaku Busshitsu Kanri Senta Nyusu, 31(5), p.1 - 5, 2002/00

None

Journal Articles

Interlaboratory Comparison for the Analysis of Plutonium and Uranium

Sumi, Mika; Kobayashi, Hideo;

Proceedings of 43rd INMM Annual Meeting, P. 79, 2002/00

None

43 (Records 1-20 displayed on this page)