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JAEA Reports

Comprehensive evaluation system for environmental remediation of Fukushima; Toward integration of three components as a whole system

Saito, Hiroshi; Nozawa, Takashi; Takemiya, Hiroshi; Seki, Akiyuki; Matsubara, Takeshi; Saito, Kimiaki; Kitamura, Akihiro

JAEA-Review 2017-040, 34 Pages, 2018/03

JAEA-Review-2017-040.pdf:9.52MB

The accidents at Fukushima Daiichi Nuclear Power Station on March 11th 2011, released significant amount of radionuclide to the environment. It has migrated to the human habitation and raised concerns of possible effect on human health, and for that a lot of researches have been performed. JAEA created and opened "Database for Radioactive Substance Monitoring Data" for usage of obtained data. For accurate modelling and future forecast using numerical code and the data, "Supporting Environment for Processing Simulation Codes" has been operated. In addition, research results have been opened as Q&A style "Knowledge Base for Environmental Remediation" in JAEA's website. The "Comprehensive Evaluation System" composed of these components, should act more interrelated and integrated as one system. Besides, information dissemination is not enough to the outside. The report summarizes the current status, remaining issues and expected improvement of each component and the system.

Journal Articles

Improvement of a metabolic model for iodine and consideration of a equivalent dose to the thyroid reduction factor for application to the OSCAAR code

Kimura, Masanori; Hato, Shinji*; Matsubara, Takeshi*; Kanno, Mitsuhiro*; Munakata, Masahiro

Proceedings of Asian Symposium on Risk Assessment and Management 2017 (ASRAM 2017) (USB Flash Drive), 9 Pages, 2017/11

The authors developed a new metabolic model for iodine by combining the respiratory tract model (Publ.66), the gastrointestinal tract model (Publ.30) of the ICRP and the metabolic model for iodine (Johnson's model) in order to evaluate the behavior of radioiodine and stable iodine in the body more realistically. The developed metabolic model indicated that a reduction factor (RF) depends on dosage of stable iodine, timing of the administration of stable iodine, different iodine isotopes ($$^{131}$$I - $$^{135}$$I), and age groups. Therefore, the RF was calculated by changing these parameters and then a database of the RF was constructed for the application to the OSCAAR code.

Journal Articles

Change in the electrical performance of GaAs solar cells with InGaAs quantum dot layers by electron irradiation

Oshima, Takeshi; Sato, Shinichiro; Imaizumi, Mitsuru*; Nakamura, Tetsuya*; Sugaya, Takeyoshi*; Matsubara, Koji*; Niki, Shigeru*

Solar Energy Materials and Solar Cells, 108, p.263 - 268, 2013/01

 Times Cited Count:12 Percentile:51.84(Energy & Fuels)

GaAs solar cells which have a PiN structure with 50 self-organized In$$_{0.4}$$Ga$$_{0.6}$$As Quantum Dot (QD) layers were irradiated with 1 MeV electrons up to 1$$times$$10$$^{16}$$ /cm$$^{2}$$. After irradiation at 1$$times$$10$$^{16}$$/cm$$^{2}$$, the remaining factor of I$$_{rm SC}$$, V$$_{rm OC}$$ and P$$_{rm MAX}$$ for the InGaAs 50 QD solar cell becomes 80, 90 and 55% of the initial values, respectively. On the other hand, those values for non QD GaAs solar cells decrease to 95, 80 and 63% of the initial values, respectively. Since the i-layer for the 50 QD solar cells (1.1 $$mu$$m) is thicker than the non QD solar cells (660 nm), the larger degradation of I$$_{rm SC}$$ for the 50 QD solar cells than the non QD ones can be interpreted in terms that the carrier recombination in the i-layer for the 50 QD solar cells is larger than that for the non QD solar cells. For V$$_{rm OC}$$, the 50 QD solar cells showes better radiation resistance than the non QD solar cells. Furthermore, the annealing behavior of the electrical characteristics for the 50 QD and the non QD solar cells was investigated at RT under AM 0 immediately after the irradiation. As a result, the recovery of the electrical characteristics for both solar cells was observed, and the GaAs solar cells shows relatively larger recovery compared to the 50 QD solar cells. Although the mechanism of this recovery has not yet been clarified, the origin of this recovery is thought not to come from the existence of QDs because the GaAs solar cell without QD layers also shows the recovery.

JAEA Reports

Development of ESRAD program for estimation of spatial radioactivity distribution based on Kriging; User's manual

Ishigami, Tsutomu; Mukai, Masayuki; Sukegawa, Takenori; Matsubara, Takeshi*

JAEA-Data/Code 2012-023, 83 Pages, 2012/11

JAEA-Data-Code-2012-023.pdf:5.51MB

Verification for site release is one of procedures to confirm termination of decommissioning of nuclear installations. The verification procedure would need to confirm that the radioactive concentration at the site is lower than the criterion value by measurement. Then to efficiently perform the measurement and verification it is one of important issues how to efficiently estimate and evaluate overall spatial radioactivity distribution using a sampling method. For the efficient estimation and evaluation we have applied a Kriging technique which in the geostatistics, and have developed a computer program ESRAD (Estimation of Spatial RadioActivity Distribution). The ESRAD program is designed to support sample selection, calculate a variogram, and estimate a radioactivity distribution for the area concerned. This report describes the Kriging technique, structure and functions of ESRAD, input file format, output examples, execution procedure of ERSAR, and sample run with ESRAD.

Journal Articles

Validation of an accident consequence assessment code using field data

Matsubara, Takeshi*; Homma, Toshimitsu

Proceedings of International Conference on Environmental Radioactivity (Internet), 5 Pages, 2010/00

no abstracts in English

Journal Articles

Study on the intervention and return criteria for relocation using PSA method

Takahara, Shogo; Kimura, Masanori; Matsubara, Takeshi*; Homma, Toshimitsu

Journal of Nuclear Science and Technology, 45(Suppl.5), p.714 - 717, 2008/06

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

It is recognized that good preparedness and arrangement in advance of an emergency can improve the emergency response to a nuclear and radiological emergency. In the preparedness, comprehensive threat assessment is very important to provide technical guidance for developing the protective actions. Probabilistic safety assessment method is useful for assessing accident consequences comprehensively and quantitatively. In this study, an accident consequence assessment code OSCAAR, which was developed at the Japan Atomic Energy Agency, is used to provide the information for the guideline of intervention and return criteria for relocation on the long-term emergency situation.

Journal Articles

Technical considerations for emergency preparedness with a probabilistic accident consequence assessment model

Homma, Toshimitsu; Kimura, Masanori; Matsubara, Takeshi*; Ishikawa, Jun

Proceedings of 9th International Probabilistic Safety Assessment and Management Conference (PSAM-9) (CD-ROM), 6 Pages, 2008/00

Journal Articles

An Application of accident consequence assessment models to off-site emergency planning

Kimura, Masanori; Matsubara, Takeshi; Ishikawa, Jun; Homma, Toshimitsu

Proceedings of International Symposium on Environmental Modeling and Radioecology, p.348 - 351, 2007/03

no abstracts in English

Journal Articles

Testing of an accident consequence assessment model using field data

Homma, Toshimitsu; Matsubara, Takeshi; Tomita, Kenichi*

Proceedings of International Symposium on Environmental Modeling and Radioecology, p.196 - 203, 2007/03

This paper presents the results obtained from the application of OSCAAR to the Iput dose reconstruction scenario of BIOMASS and also to the Chernobyl $$^{131}$$I fallout scenario of EMRAS, both organized by International Atomic Energy Agency. The Iput Scenario deals with $$^{137}$$Cs contamination of the catchment basin and agricultural area in the Bryansk Region of Russia, which was heavily contaminated after the Chernobyl accident. This exercise was used to test the chronic exposure pathway models in OSCAAR with actual measurements and to identify the most important sources of uncertainty with respect to each part of the assessment. The OSCAAR chronic exposure pathway models almost successfully reconstructed the whole 10-year time course of $$^{137}$$Cs activity concentrations in most requested types of agricultural products and natural foodstuffs. The Plavsk scenario provides an good opportunity to test not only the food chain transfer model of $$^{131}$$I but also the method of assessing $$^{131}$$I thyroid burden. OSCAAR showed in general good capabilities for assessing the important $$^{131}$$I exposure pathways, but also limitations using constant isotopic ratio $$^{131}$$I /$$^{137}$$Cs provided by the scenario to estimate $$^{131}$$I deposition for whole Plavsk district.

Journal Articles

Gated multiple-sampling and tracking proportional chamber; New detector system for nuclear astrophysical study with radioactive nuclear beams

Hashimoto, Takashi; Ishiyama, Hironobu*; Ishikawa, Tomoko*; Kawamura, Takashi*; Nakai, Koji*; Watanabe, Yutaka*; Miyatake, Hiroari; Tanaka, Masahiko*; Fuchi, Yoshihide*; Yoshikawa, Nobuharu*; et al.

Nuclear Instruments and Methods in Physics Research A, 556(1), p.339 - 349, 2006/01

 Times Cited Count:31 Percentile:89.78(Instruments & Instrumentation)

A new type of three dimensional tracking and proportional gas counter has been developed. Adopting a gating-grid system, performance of the detector becomes stable under the injection rate of charged particles less than 4$$times$$10$$^4$$ pps. It is a useful detection system for astrophysical experiments using radioactive nuclear beams, since the efficiency is so high as 100 %.

Journal Articles

A Code for predicting the migration of ground additional MOGRA

Amano, Hikaru; *; Uchida, Shigeo*; Tsuzuki, Katsunori; Matsuoka, Shungo*; Ikeda, Hiroshi*; Matsubara, Takeshi*; Kurosawa, Naohiro*

KURRI-KR-80, p.48 - 49, 2001/12

no abstracts in English

Oral presentation

Oral presentation

Study on stable iodine administration using a PSA methodology

Homma, Toshimitsu; Kimura, Masanori; Matsubara, Takeshi; Ishikawa, Jun

no journal, , 

no abstracts in English

Oral presentation

Calculations using a Level 3PSA code in support of deriving performance goals

Homma, Toshimitsu; Matsubara, Takeshi

no journal, , 

no abstracts in English

Oral presentation

Study on implementation of protective action in nuclear emergency

Kimura, Masanori; Takahara, Shogo; Homma, Toshimitsu; Matsubara, Takeshi*

no journal, , 

no abstracts in English

Oral presentation

Validation of dosimetric models and assessment of protective actions using Chernobyl $$^{131}$$I release data

Homma, Toshimitsu; Matsubara, Takeshi*; Kimura, Masanori; Takahara, Shogo

no journal, , 

no abstracts in English

Oral presentation

Radiation degradation of the electrical performance of InGaAs quantum dot solar cells and its recovery at room temperature

Oshima, Takeshi; Sato, Shinichiro; Imaizumi, Mitsuru*; Nakamura, Tetsuya*; Sugaya, Takeyoshi*; Matsubara, Koji*; Niki, Shigeru*

no journal, , 

Oral presentation

Fabrication of the ordered array of optical centers in diamond by low energy ion implantation

Komatsubara, Akira*; Teraji, Tokuyuki*; Hori, Masahiro*; Kumagai, Kuninori*; Tamura, Shuto*; Oshima, Takeshi; Onoda, Shinobu; Yamamoto, Takashi; Muller, C.*; Naydenov, B.*; et al.

no journal, , 

no abstracts in English

Oral presentation

Fabrication of the ordered array of optical centers in diamond by low energy ion implantation, 2

Tamura, Shuto*; Komatsubara, Akira*; Teraji, Tokuyuki*; Onoda, Shinobu; Oshima, Takeshi; Christoph, M.*; Naydenov, B.*; McGuinness, L.*; Jelezko, F.*; Shinada, Takahiro*; et al.

no journal, , 

no abstracts in English

Oral presentation

Fabrication of silicon-vacancy center array in diamond by low-energy single-ion implantation

Tamura, Shuto*; Komatsubara, Akira*; Teraji, Tokuyuki*; Onoda, Shinobu; McGuinness, L.*; Jelezko, F.*; Rogers, L.*; Oshima, Takeshi; Isoya, Junichi*; Shinada, Takahiro*; et al.

no journal, , 

no abstracts in English

31 (Records 1-20 displayed on this page)