Construction of a car-borne survey system for measurement of dose rates in air; KURAMA-II, and its application

Tsuda, Shuichi; Yoshida, Tadayoshi; Nakahara, Yukio; Sato, Tetsuro; Seki, Akiyuki; Matsuda, Norihiro; Ando, Masaki; Takemiya, Hiroshi; Tanigaki, Minoru*; Takamiya, Koichi*; et al.

JAEA-Technology 2013-037, 54 Pages, 2013/10

JAEA-Technology-2013-037.pdf:4.94MB

JAEA has been performing dose rate mapping in air using a car-borne survey system KURAMA-II. The KURAMA system is a GPS-aided mobile radiation monitoring system that has been newly developed by Kyoto University Research Reactor Institute in response to the nuclear disaster. The KURAMA system is composed of an energy-compensated scintillation survey meter for measuring dose rate, electric device for controlling both the dose rates and the position data from a GPS module, a computer server for processing and analyzing data from KURAMA, and client PCs for providing for end users. The KURAMA-II has been improved in small-packaging, durability, and automated data transmission. In consequence, dose rate mapping in wide area has become possible in shorter period of time. This report describes the construction of KURAMA-II, its application and a suggestion of how to manage a large number of KURAMA-II.

Neutron powder diffraction and difference maximum entropy method analysis of protium- and deuterium-dissolved BaSnInO

Nagasaki, Takanori*; Shiotani, Shinya*; Igawa, Naoki; Yoshino, Masahito*; Iwasaki, Kota*; Fukazawa, Hiroshi; Utsumi, Wataru

Journal of Solid State Chemistry, 182(10), p.2632 - 2639, 2009/10

https://doi.org/10.1016/j.jssc.2009.06.024

We propose a new method, a difference maximum entropy method (MEM) analysis of the neutron diffraction data, for revealing the detailed structure around hydrogen atoms in proton-conducting oxides. This MEM analysis uses the differences between the structure factors of protium- and deuterium-dissolved crystals. Simulations demonstrate that it not only provides the distribution of hydrogen atoms alone, but also improves the spatial resolution of MEM mapping around hydrogen atoms. Applied to actual diffraction data of protium- and deuterium-dissolved BaSnInO at 9 K, difference MEM analysis reveals that O-D bonds mostly tilt towards the second nearest oxygen atoms, and that the distributions of deuterium and oxygen atoms are probably insignificant in interstitial regions.

Waste handling activities in glovebox dismantling facility

Kitamura, Akihiro; Okada, Takashi; Kashiro, Kashio; Yoshino, Masanori*; Hirano, Hiroshi*

Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM), p.531 - 536, 2007/09

We present our waste handling activities in glovebox dismantling facility, installed in Plutonium Fuel Production Facility, Nuclear Fuel Cycle Engineering Laboratories, JAEA. In this facility, we treat only one size gloveboxes (3m3m1m), but for the future waste treatment, we segregate waste into material categories. We analyzed the data collected for the future decommissioning, waste treatment and waste disposal. We also present the improvements which are already made and will be made in the near future.

Study of plasma termination using high-Z noble gas puffing in the JT-60U tokamak

Bakhtiari, M.; Tamai, Hiroshi; Kawano, Yasunori; Kramer, G. J.*; Isayama, Akihiko; Nakano, Tomohide; Kamiya, Kensaku; Yoshino, Ryuji; Miura, Yukitoshi; Kusama, Yoshinori; et al.

Nuclear Fusion, 45(5), p.318 - 325, 2005/05

https://doi.org/10.1088/0029-5515/45/5/002

In the previous works we had shown that injecting a mixture of large amounts of hydrogen and small amounts of argon can terminate a tokamak discharge quickly with avoiding runaway electron generation. In this work we have done the same experiments but with different gases in addition to argon. In fact we compared the effect of the puffing of argon, krypton, and xenon gases with and without simultaneous hydrogen gas puffing on disruption mitigation. We observed that injecting all impurities in the form of an admixture in hydrogen lead to faster plasma shutdowns with less runaway electron generation. We also found that injecting krypton gas (with or without hydrogen) seems to be a good candidate for plasma shutdown purposes since it induces low heat flux to divertor plates and avoids runaway electron generation more effectively.

Fusion plasma performance and confinement studies on JT-60 and JT-60U

Kamada, Yutaka; Fujita, Takaaki; Ishida, Shinichi; Kikuchi, Mitsuru; Ide, Shunsuke; Takizuka, Tomonori; Shirai, Hiroshi; Koide, Yoshihiko; Fukuda, Takeshi; Hosogane, Nobuyuki; et al.

Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.185 - 254, 2002/09

https://doi.org/10.13182/FST02-A227

With the main aim of providing physics basis for ITER and the steady-state tokamak reactors, JT-60/JT-60U has been developing and optimizing the operational concepts, and extending the discharge regimes toward sustainment of high integrated performance in the reactor relevant parameter regime. In addition to achievement of the equivalent break-even condition (QDTeq up to 1.25) and a high fusion triple product = 1.5E21 m-3skeV, JT-60U has demonstrated the integrated performance of high confinement, high beta-N, full non-inductive current drive with a large fraction of bootstrap current in the reversed magnetic shear and in the high-beta-p ELMy H mode plasmas characterized by both internal and edge transport barriers. The key factors in optimizing these plasmas are profile and shape controls. As represented by discovery of various Internal Transport Barriers, JT-60/JT-60U has been emphasizing freedom and restriction of profiles in various confinement modes. JT-60U has demonstrated applicability of these high confinement modes to ITER and also clarified remaining issues.

Runaway current termination in JT-60U

Tamai, Hiroshi; Yoshino, Ryuji; Tokuda, Shinji; Kurita, Genichi; Neyatani, Yuzuru; Bakhtiari, M.; Khayratdinov, R. R.*; Lukash, V.*; Rosenbluth, M. N.*; JT-60 Team

Nuclear Fusion, 42(3), p.290 - 294, 2002/03

https://doi.org/10.1088/0029-5515/42/3/309

no abstracts in English

High time resolution ion temperature and rotation velocity measurements by charge exchange spectroscopy using three interference filters

J.S.Koog*; Sakasai, Akira; Koide, Yoshihiko; Shirai, Hiroshi; Kamada, Yutaka; Fukuda, Takeshi; Yoshino, Ryuji; JT-60 Team

Review of Scientific Instruments, 70(1), p.372 - 374, 1999/01

https://doi.org/10.1063/1.1149444

no abstracts in English

High performance reversed shear plasmas with a large radius transport barrier in JT-60U

Fujita, Takaaki; Hatae, Takaki; Oikawa, Toshihiro; Takeji, Satoru; Shirai, Hiroshi; Koide, Yoshihiko; Ishida, Shinichi; Ide, Shunsuke; Ishii, Yasutomo; Ozeki, Takahisa; et al.

Nuclear Fusion, 38(2), p.207 - 221, 1998/02

https://doi.org/10.1088/0029-5515/38/2/305

no abstracts in English

Enhanced confinement of high bootstrap current discharges in JT-60U

Ishida, Shinichi; Matsuoka, Mamoru; Kikuchi, Mitsuru; Tsuji, Shunji; Nishitani, Takeo; Koide, Yoshihiko; Ozeki, Takahisa; Fujita, Takaaki; Nakamura, Hiroo; Hosogane, Nobuyuki; et al.

Plasma Physics and Controlled Nuclear Fusion Research 1992, Vol.1, p.219 - 233, 1993/00

no abstracts in English

Plasma feedback control system design and the results of JT-60U

Matsukawa, Makoto; Ninomiya, Hiromasa; Horiike, Hiroshi; Hosogane, Nobuyuki; Yoshino, Ryuji

Fusion Technology, 21(3), p.1624 - 1629, 1992/05

no abstracts in English