Sasaki, Shinji; Maeda, Koji; Furuya, Hirotaka*
Journal of Nuclear Science and Technology, 55(3), p.276 - 282, 2018/03
Reza Kenkyu, 45(7), p.413 - 417, 2017/07
Inside and surrounding area of reactor buildings of Fukushima Daiichi Nuclear Power Plants became high radiation condition because of radioactive materials release by the accidents caused by earthquake of Pacific coast on eastern and northern Japan. In the stage of emergency response to the accidents, more than 20 robots had been deployed, and some of them had equipped with laser technologies like as laser range finder. In the following decommissioning stage of the plans, operations under higher radiation condition will be required, so that varied laser technologies will be needed to fuse with robot technologies. Laser checker laser analysis would be expected besides laser range finder. However those technologies will be deployed under higher radiation condition, so radiation hardening and control stabilizing should be solved.
Sato, Masayuki*; Muraoka, Koji*; Hozumi, Koki*; Sanada, Yukihisa; Yamada, Tsutomu*; Torii, Tatsuo
Nihon Koku Uchu Gakkai Rombunshu (Internet), 65(2), p.54 - 63, 2017/02
This paper is concerned with the design problem of preview altitude controller for Unmanned Airplane for Radiation Monitoring System (UARMS) to improve its control performance. UARMS has been developed for radiation monitoring around Fukushima Daiichi Nuclear Power Plant which spread radiation contaminant due to the huge tsunamis caused by the Great East Japan Earthquake. The monitoring area contains flat as well as mountain areas. The basic flight controller has been confirmed to have satisfactory performance with respect to altitude holding; however, the control performance for variable altitude commands is not sufficient for practical use in mountain areas. We therefore design preview altitude controller with only proportional gains by considering the practicality and the strong requirement of safety for UARMS. Control performance of the designed preview controller was evaluated by flight tests conducted around Fukushima Sky Park.
Tokuyasu, Kayoko; Furuta, Sadaaki*; Kokubu, Yoko; Umeda, Koji
Nihon Hoshasen Anzen Kanri Gakkai-Shi, 15(1), p.80 - 87, 2016/07
An optically stimulated luminescence reader (Riso TL/OSL DA-20) was installed in Toki Research Institute of Isotope Geology and Geochronology (Toki-shi, Gifu Prefecture), Japan Atomic Energy Agency (JAEA) for dating the geological sample. An accumulated dose of the sample is obtained using the reader. Sealed beta source of strontium-90 is required to be mounted on the reader because repeated artificial irradiation is necessary for the accumulated dose estimation. However, there are not many introduction examples for the reader domestically, and the information as to radiation control of the reader is limited. We therefore report here the process of source loading on the reader and radiation control associated with the use of the source.
Miyamoto, Yukihiro; Sakamaki, Tsuyoshi*; Maekawa, Osamu*; Nakashima, Hiroshi
JAERI-Tech 2004-054, 72 Pages, 2004/08
A standard is provided for the radiation monitor based on LAN (Local Area Network) and PLC (Programmable Logic Controller) technology at the introduction to the Japan Proton Accelerator Research Complex (J-PARC). The monitor consists of radiation measurement equipments and the central monitoring panel. The formers are installed in the radiation field, and the latter is installed in the control room and composed of PLC, which are connected with LAN. Extension of the existing standard and the conformity to the international standard were thought as important in providing the standard. The standard is expected to improve the compatibility, maintenancability and productivity of the components.
Nishitani, Takeo; Vayakis, G.*; Yamauchi, Michinori*; Sugie, Tatsuo; Kondoh, Takashi; Shikama, Tatsuo*; Ishitsuka, Etsuo; Kawashima, Hisato
Journal of Nuclear Materials, 329-333(Part2), p.1461 - 1465, 2004/08
no abstracts in English
Kikuchi, Masamitsu; Taki, Mitsumasa; Kume, Etsuo; Kobayashi, Hideo*; Yamada, Toshio*; Yamaguchi, Takenori
JAERI-Data/Code 2004-006, 146 Pages, 2004/03
The nuclear facilities, which are required to control the released radioactive gases and liquid, exist in Tokai research establishment as much as 40. These radioactive controls are carried out complying with the statutes in each facility. The released radioactivity data of each facility must be reported to MEXT and Ibaraki Prefecture from Tokai Research Establishment. This system is developed to make the database gathering the radioactivity data of each facilities for unitary control as Tokai Research Establishment and contribute to make the reports to MEXT and Ibaraki Prefecture.
Miyamoto, Yukihiro; Ikeno, Koichi; Akiyama, Shigenori*; Harada, Yasunori
JAERI-Tech 2002-086, 43 Pages, 2002/11
Description is given for the characteristic radiation environment for the High Intensity Proton Accelerator Facility and the design concept of the radiation control system of it. The facility is a large scale accelerator complex consisting of high energy proton accelerators carrying the highest beam intensity in the world and the related experimental facilities and therefore provides various issues relevant to the radiation environment. The present report describes the specifications for the radiation control system for the facility, determined in consideration of these characteristics.
Hosogane, Nobuyuki; Ninomiya, Hiromasa; Matsukawa, Makoto; Ando, Toshiro; Neyatani, Yuzuru; Horiike, Hiroshi*; Sakurai, Shinji; Masaki, Kei; Yamamoto, Masahiro; Kodama, Kozo; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.368 - 385, 2002/09
This paper reviews developments of the JT-60U tokamak and coil power supplies and their operational experiences obtained to date. The JT-60U is a large tokamak upgraded from the original JT-60 to obtain high plasma current, large plasma volume and highly elongated divertor configurations. In the modification, all components inside the bore of toroidal magnetic field coils, a vacuum vessel, poloidal magnetic field coils (PF-coils), divertor etc., were renewed. Furthermore, boron carbide converted CFC tiles were used as divertor tiles to reduce erosion of carbon-base tiles. Later, a semi-closed divertor with pumps was installed in the replacement of the open divertor. Various technologies and ideas introduced to develop these components their operational experiences provide important data for designing future tokamaks. Also, major troubles that had influence on the JT-60U operations are described. As a maintenance issue for tokamaks using deuterium fueling gas, a method for reducing radiation exposure of in-vessel workers are introduced.
Takada, Eiji*; Fujimoto, Nozomu; Nojiri, Naoki; Umeta, Masayuki; Kokusen, Shigeru; Ashikagaya, Yoshinobu
JAERI-Data/Code 2002-009, 83 Pages, 2002/05
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.
Tobita, Masahiro*; Itabashi, Yukio
JAERI-Tech 2002-042, 40 Pages, 2002/03
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.
Mori, Yuichiro*; Ide, Hiroshi; Nabeya, Hideaki; Tsukada, Takashi
JAERI-Tech 2002-003, 32 Pages, 2002/02
In relation to the aging of Light Water Reactor (LWR), the Irradiation Assisted Stress Corrosion Cracking (IASCC) has been regarded as a significant and urgent issue for the reliability of in-core components of LWR, and the irradiation research on the IASCC is now under schedule. With the progress of the irradiation research on reactor materials, well-controlled environment conditions during irradiation testing are required. Especially for irradiation testing of IASCC studies, water chemistry control is essential in addition to the control of neutron fluence and irradiation temperature.According to these requirements, at the Japan Atomic Energy Research Institute (JAERI), an irradiation testing facility that simulates in-core environment of Boiling Water Reactor (BWR) has been designed to be installed in the Japan Materials Testing Reactor (JMTR). This facility is composed of the Saturated Temperature Capsules (SATCAP) that are installed into the JMTR's core to irradiate material specimens, the Water Control Unit that is able to supply high-temperature and high-pressure chemical controlled water to SATCAP, and other components.This report describes the design study of water chemistry control system of the Water Control Unit. The design work has been performed in the fiscal year 1999.
Kanno, Masaru; Kitajima, Toshio; Homma, Kenzo
KAERI/GP-195/2002, p.71 - 75, 2002/00
Recent irradiation studies aiming at clarifying the detailed mechanisms of irradiation damages to the reactor materials require to maintain the specimens at constant temperature regardless of the reactor power level,in order to avoid artificial effects of temperature transient due to reactor power change. In order to deal with this problem, JMTR has adopted feed-foward control to the gas pressure based on the reactor power signal, and developed new temperature control technique in combination with feedback control of heater power.
Komori, Yoshihiro; Matsui, Yoshinori; Itabashi, Yukio; Yamaura, Takayuki; Nagao, Yoshiharu
KAERI/GP-195/2002, p.59 - 69, 2002/00
JAERI has been developing irradiation technique and facilities for irradiation tests in the JMTR to improve irradiation capability keeping up with progress of nuclear fuels and materials research. This paper summarizes recent development on irradiation technique for the JMTR. Design study and installation of the IASCC (Irradiation Assisted Stress Corrosion Cracking) irradiation test facility was main and the most urgent task of the field in the last five years since two large projects for IASCC were planned in Japan to start irradiation tests in 2002. Almost four years were devoted to preliminary design study, detail design and installation of the facility, then IASCC irradiation test started in March, 2002. Instrumentation technique and capsules development for other research purposes also have been steadily progressing during the term, and new type of off-line temperature monitor, dual re-instrumentation device and the uniform irradiation capsule became available for the irradiation tests.
Nihon Robotto Gakkai-Shi, 19(6), p.710 - 713, 2001/09
no abstracts in English
Matsui, Yoshinori; Itabashi, Yukio; Shimizu, Michio; Tsuji, Hirokazu
Journal of Nuclear Materials, 283-287(Part.2), p.997 - 1000, 2000/12
no abstracts in English
Hoken Butsuri, 34(4), p.412 - 414, 1999/12
no abstracts in English
JAERI-Review 98-022, 265 Pages, 1998/11
no abstracts in English
*; Kunugi, Tomoaki
Nihon Kikai Gakkai Rombunshu, B, 64(617), p.65 - 70, 1998/01
no abstracts in English