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JAEA Reports

Research and development of transparent materials for radiation shield using nanoparticles (Contract research); FY2018 Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development

Collaborative Laboratories for Advanced Decommissioning Science; Kyushu University*

JAEA-Review 2019-039, 104 Pages, 2020/03

JAEA-Review-2019-039.pdf:5.57MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2018, this report summarizes the research results of the "Research and Development of Transparent Materials for Radiation Shield using Nanoparticles". The present study aims to reduce radiation exposure of workers in debris retrieval/analysis and reduce deterioration of optical and electronic systems in remote cameras. For these purposes, we develop transparent radiation shield by making the shield materials into nanoparticles, and dispersing/solidifying them in epoxy resin. By making B$$_{4}$$C and W into nanoparticles, we will also develop a radiation shield that shields both neutrons and gamma-rays, and also suppresses secondary gamma-rays produced from neutrons.

Journal Articles

Development of transportation container for the neutron startup source of High Temperature engineering Test Reactor (HTTR)

Shimazaki, Yosuke; Ono, Masato; Tochio, Daisuke; Takada, Shoji; Sawahata, Hiroaki; Kawamoto, Taiki; Hamamoto, Shimpei; Shinohara, Masanori

Proceedings of International Topical Meeting on Research Reactor Fuel Management and Meeting of the International Group on Reactor Research (RRFM/IGORR 2016) (Internet), p.1034 - 1042, 2016/03

In High Temperature Engineering Test Reactor (HTTR), three neutron holders containing $$^{252}$$Cf with 3.7 GBq for each are loaded in the graphite blocks and inserted into the reactor core as a neutron startup source which is changed at the interval of approximately ten years. These neutron holders containing the neutron sources are transported from the dealer's hot cell to HTTR using the transportation container. The holders loading to the graphite block are carried out in the fuel handling machine maintenance pit of HTTR. There were two technical issues for the safety handling work of the neutron holder. The one is the radiation exposure caused by significant movement of the container due to an earthquake, because the conventional transportation container was so large ($$phi$$1240 mm, h1855 mm) that it can not be fixed on the top floor of maintenance pit by bolts. The other is the falling of the neutron holder caused by the difficult remote handling work, because the neutron holder capsule was also so long ($$phi$$155 mm, h1285 mm) that it can not be pulled into the adequate working space in the maintenance pit. Therefore, a new and low cost transportation container, which can solve the issues, was developed. To avoid the neutron and $$gamma$$ ray exposure, smaller transportation container ($$phi$$820mm, h1150 mm) which can be fixed on the top floor of maintenance pit by bolts was developed. In addition, to avoid the falling of the neutron holder, smaller neutron holder capsule ($$phi$$75 mm, h135 mm) with simple handling mechanism which can be treated easily by manipulator was also developed. As the result of development, the neutron holder handling work was safely accomplished. Moreover, a cost reduction for manufacturing was also achieved by simplifying the mechanism of neutron holder capsule and downsizing.

Journal Articles

Neutronics assessment of advanced shield materials using metal hydride and borohydride for fusion reactors

Hayashi, Takao; Tobita, Kenji; Nishio, Satoshi; Ikeda, Kazuki*; Nakamori, Yuko*; Orimo, Shinichi*; DEMO Plant Design Team

Fusion Engineering and Design, 81(8-14), p.1285 - 1290, 2006/02

 Times Cited Count:20 Percentile:81.23(Nuclear Science & Technology)

Neutron transport calculations were carried out to evaluate the capability of metal hydrides and borohydrides as an advanced shielding material. Some hydrides indicated considerably higher hydrogen content than polyethylene and solid hydrogen. The hydrogen-rich hydrides show superior neutron shielding capability to the conventional materials. From the temperature dependence of dissociation pressure, ZrH$$_{2}$$ and TiH$$_{2}$$ can be used without releasing hydrogen at the temperature of less than 640 $$^{circ}$$C at 1 atm. ZrH$$_{2}$$ and Mg(BH$$_{4}$$)$$_{2}$$ can reduce the thickness of the shield by 30% and 20% compared to a combination of steel and water, respectively. Mixing some hydrides with F82H produces considerable effects in $$gamma$$-ray shielding. The neutron and $$gamma$$-ray shielding capabilities decrease in order of ZrH$$_{2}$$ $$>$$ Mg(BH$$_{4}$$)$$_{2}$$ and F82H $$>$$ TiH$$_{2}$$ and F82H $$>$$ water and F82H.

Journal Articles

Comparison of synchrotron radiation calculations between analytical codes(STAC8,PHOTON) and Monte Carlo codes (FLUKA,EGS4)

Liu, J. C.*; Fasso, A.*; Prinz, A.*; Rokni, S.*; Asano, Yoshihiro

Radiation Protection Dosimetry, 116(1-4), p.658 - 661, 2005/12

 Times Cited Count:6 Percentile:42.45(Environmental Sciences)

no abstracts in English

Journal Articles

Shielding analysis at the upper section of the accelerator-driven system

Sasa, Toshinobu; Yang, J. A.*; Oigawa, Hiroyuki

Radiation Protection Dosimetry, 116(1-4), p.256 - 258, 2005/12

 Times Cited Count:0 Percentile:0.01(Environmental Sciences)

The proton beam duct of the accelerator-driven system (ADS) acts a streaming path for spallation neutrons and photons and causes the activation of the magnets and other devices above the subcritical core. We have performed a streaming analysis at the upper section of the lead-bismuth target/cooled ADS (800MWth). MCNPX was used to calculate the radiation dose from streamed neutrons and photons through the beam duct. For the secondary photon production calculation, cross sections for several actinides were substituted for plutonium because of the lack of gamma production cross section. From the results of this analysis, the neutron dose from the beam duct is about 20 orders higher than that of the bulk shield. The magnets and shield plug were heavily irradiated by streaming neutrons according to the DCHAIN-SP analysis.

Journal Articles

Radiation safety design for the J-PARC project

Nakashima, Hiroshi; Nakane, Yoshihiro; Masukawa, Fumihiro; Matsuda, Norihiro; Oguri, Tomomi*; Nakano, Hideo*; Sasamoto, Nobuo*; Shibata, Tokushi*; Suzuki, Takenori*; Miura, Taichi*; et al.

Radiation Protection Dosimetry, 115(1-4), p.564 - 568, 2005/12

 Times Cited Count:7 Percentile:47.08(Environmental Sciences)

The High Intensity Proton Accelerator Project, named as J-PARC, is in progress, aiming at studies on the latest basic science and the advancing nuclear technology. In the project, the high-energy proton accelerator complex of the world highest intensity is under construction. In order to establish a reasonable shielding design, both simplified and detailed design methods were used in the shielding design of J-PARC. This paper reviews the present status of the radiation safety design study for J-PARC.

JAEA Reports

TIARA annual report 2003

Advanced Radiation Technology Center

JAERI-Review 2004-025, 374 Pages, 2004/11

JAERI-Review-2004-025-p0001-p0116.pdf:20.67MB
JAERI-Review-2004-025-p0117-p0247.pdf:21.34MB
JAERI-Review-2004-025-p0248-p0374.pdf:23.39MB

This annual report describes research and development activities which have been performed with the JAERI TIARA (Takasaki Ion Accelerators for Advanced Radiation Application) facilities from April 1, 2003 to March 31, 2004. Summary reports of 115 papers and brief descriptions on the status of TIARA in the period are contained. A list of publications, the type of research collaborations and organization of TIARA are also given as appendices.

Journal Articles

Measurement of radiation skyshine with D-T neutron source

Yoshida, Shigeo*; Nishitani, Takeo; Ochiai, Kentaro; Kaneko, Junichi*; Hori, Junichi; Sato, Satoshi; Yamauchi, Michinori*; Tanaka, Ryohei*; Nakao, Makoto*; Wada, Masayuki*; et al.

Fusion Engineering and Design, 69(1-4), p.637 - 641, 2003/09

 Times Cited Count:7 Percentile:47.54(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Comparison of synchrotron radiation calculation between EGS4, FLUKA, PHOTON and STAC8

Asano, Yoshihiro; Liu, J. C.*

KEK Proceedings 2002-18, p.48 - 54, 2003/01

The light energy was not higher than soft X-rays so that the radiation safety for synchrotron radiation passed for unworthy issues of attention. With constructing and operating the third generation facilities such as SPring-8, however, high energy synchrotron radiation of extremely high intense is available, and high accuracy should be required in the shielding and safety design for the beam of synchrotron radiation. Furthermore, the middle size facilities such as CLS (Canadian Light Source) are now under construction and the optimum design of shielding is desired to construct the beamline with safety and compact. It is necessary for the purpose to verify the detailed evaluation technique. Therefore, taking the SPEAR3 bending magnet and BL11-3 wiggler beamlines in the examples, the characteristics of the codes were investigated in comparison with synchrotron radiation shielding design code PHOTON, STAC8 and Monte Carlo simulation code EGS4, FLUKA

JAEA Reports

Dose equivalent rate and radiation monitoring results during power distribution measurements of HTTR

Takada, Eiji*; Fujimoto, Nozomu; Nojiri, Naoki; Umeta, Masayuki; Kokusen, Shigeru; Ashikagaya, Yoshinobu

JAERI-Data/Code 2002-009, 83 Pages, 2002/05

JAERI-Data-Code-2002-009.pdf:3.51MB

Dose equivalent rate around the fuel handling machine, the control rod handling machine, stand pipe compartment, maintenance pit were measured during gamma ray measurements from HTTR fuel, which was called as “power distribution measurements". The power distribution measurement was the first time to handle the fuel blocks irradiated in the core. Dose equivalent rate measurement aiming the check of shielding performance of components, the check of unexpected streaming path. The radiation monitoring during operation was carried out. As the results, there was no problem on shielding. The measured data at operation condition were also obtained. The data will be useful to expect operation circumstance in the future.

JAEA Reports

Evaluation of dose equivalent rate for IASCC water control unit

Tobita, Masahiro*; Itabashi, Yukio

JAERI-Tech 2002-042, 40 Pages, 2002/03

JAERI-Tech-2002-042.pdf:2.09MB

In relation to aging of light water reactors (LWRs), Irradiation Assisted Stress Corrosion Cracking (IASCC) has been regarded as a significant and urgent issue for reliability of in-core components of LWRs. It is essential for IASCC studies to irradiate test materials under well-controlled of Boiling Water Reactor (BWR) conditions simulating the in-core environment. Therefore, the study for the design of the new water control unit to supply high temperature water into saturated temperature capsules in the Japan Materials Testing Reactor (JMTR) has been carried out. This report summarizes the results of estimation using ORIGEN-2 and QAD-CGGP2 codes of dose equivalent rate on outer surface of the concrete wall of installation room and dose equivalent rate around the ion-exchangers where the highest dose equivalent rate is expected in the unit after the reactor shutdown.

JAEA Reports

Evaluation of dose attenuation factor of armored car against radiation accidents

Sato, Tatsuhiko; Fujii, Katsutoshi; Murayama, Takashi; Sakamoto, Yukio; Yamaguchi, Yasuhiro; Sato, Yukio*; Soma, Nobuyuki*; Fujisaki, Noboru*; Hara, Satoshi*; Aikawa, Yukio*; et al.

JAERI-Tech 2002-028, 20 Pages, 2002/03

JAERI-Tech-2002-028.pdf:5.01MB

Tokyo Fire Department developed an armored car against radiation accidents. Dose attenuation factors of the radiation shields had been determined by a simple estimation, and a more precise evaluation was required. By request from Tokyo Fire Department, a precise evaluation of the dose attenuation factor was carried out. The evaluation was done by a Monte Carlo radiation transport simulation code MCNP4B. Benchmark experiments using neutron and gamma ray sources were also performed for ensuring the evaluation method. As a result, it was found out that doses of neutron and gamma ray were attenuated to approximately 10% and 25% by the thickest shield, respectively. These values were close to the ones which had already obtained by the simple estimation.

Journal Articles

Shielding design study for the JAERI/KEK spallation neutron source

Maekawa, Fujio; Teshigawara, Makoto; Konno, Chikara; Ikeda, Yujiro; Watanabe, Noboru

JAERI-Conf 2001-002, p.907 - 916, 2001/03

no abstracts in English

JAEA Reports

Proceedings of the Symposium on the Joint Research Project between JAERI and Universities; Status and Perspective of the Advanced Radiation Technology Project, January 27, 1999, National Education Center, Tokyo, Japan

Committee for the Joint Research Project on the Advanced Radiation Technology; Committee for the Collaborative Research on the Advanced Radiation Technology

JAERI-Conf 2000-008, 113 Pages, 2000/06

JAERI-Conf-2000-008.pdf:11.5MB

no abstracts in English

Journal Articles

Neutron streaming evaluation for the DREAM fusion power reactor

Seki, Yasushi; Mori, Seiji*; Nishio, Satoshi; Ueda, Shuzo; Kurihara, Ryoichi

Journal of Nuclear Science and Technology, 37(Suppl.1), p.268 - 275, 2000/03

no abstracts in English

Journal Articles

Characteristics of shielding design calculation for the SPring-8 synchrotron radiation beamlines

Asano, Yoshihiro; Sasamoto, Nobuo

Radiation Protection Dosimetry, 82(3), p.167 - 174, 1999/00

 Times Cited Count:8 Percentile:55.01(Environmental Sciences)

no abstracts in English

JAEA Reports

Journal Articles

Shielding design calculation of SPring-8 beamlines using STAC8

Asano, Yoshihiro

Journal of Synchrotron Radiation, 5, p.615 - 617, 1998/00

 Times Cited Count:6 Percentile:49.88(Instruments & Instrumentation)

no abstracts in English

JAEA Reports

49 (Records 1-20 displayed on this page)