Verification of alternative dew point hygrometer for CV-LRT in MONJU; Short- and long-term verification for capacitance-type dew point hygrometer (Translated document)

Ichikawa, Shoichi; Chiba, Yusuke; Ono, Fumiyasu; Hatori, Masakazu; Kobayashi, Takanori; Uekura, Ryoichi; Hashiri, Nobuo*; Inuzuka, Taisuke*; Kitano, Hiroshi*; Abe, Hisashi*

JAEA-Research 2017-001, 40 Pages, 2017/03

JAEA-Research-2017-001.pdf:5.19MB

In order to reduce the influence on a plant schedule of the MONJU by the maintenance of dew point hygrometers, The JAEA examined a capacitance type dew point hygrometer as an alternative dew point hygrometer for a lithium-chloride type dew point hygrometer which had been used at the CV-LRT in the MONJU. As a result of comparing a capacitance type dew point hygrometer with a lithium-chloride type dew point hygrometer at the CV-LRT (Atmosphere: nitrogen, Testing time: 24 hours), there weren't significant difference between a capacitance type dew point hygrometer and a lithium-chloride type dew point hygrometer. As a result of comparing a capacitance dew point hygrometer with a high-mirror-surface type dew point hygrometer for long term verification (Atmosphere: air, Testing time: 24 months), the JAEA confirmed that a capacitance type dew point hygrometer satisfied the instrument specification (2.04C) required by the JEAC4203-2008.

Proceedings of the International Conference on Physics of Reactors (PHYSOR 2014); September 28-October 3, 2014, Kyoto, Japan

Suyama, Kenya; Sugawara, Takanori; Tada, Kenichi; Chiba, Go*; Yamamoto, Akio*

JAEA-Conf 2014-003, 76 Pages, 2015/03

JAEA-Conf-2014-003.pdf:5.13MB
JAEA-Conf-2014-003-appendix(CD-ROM).zip:360.78MB

Japan Atomic Energy Agency organized an international conference PHYSOR 2014 on the reactor physics which is one of basic researches in the nuclear engineering, in cooperation with Research Reactor Institute of Kyoto University. PHYSOR is the world's largest scale international conference in the reactor physics field. It originates in the conference held in Marseille, France in 1990, which originally had been organized in the United States as a Physics of Reactors Topical Meeting of the reactor physics division of the American Nuclear Society every two years. More than 500 papers had been submitted and finally 472 papers were presented in the conference after the paper review process. This report contains the presented papers, which the PHYSOR organizing committee has decided to publish in an official JAEA report with the permission by authors, except for several selected papers to be published in the Journal of Nuclear Science and Technology of the Atomic Energy Society of Japan.

High-pressure neutron study on silica glass at J-PARC high-pressure neutron diffractometer PLANET

Hattori, Takanori; Yagafarov, O.*; Katayama, Yoshinori; Chiba, Ayano*; Sano, Asami; Inamura, Yasuhiro; Otomo, Toshiya*

no journal, , 

SiO glass is an amorphous solid consisting of SiO tetrahedra. Each tetrahedra are connected to each other, and forms the many-menbered ring. Thus, the glass has large void space and therefore marked densification is expected under pressure. Actually, the density increases by 20% on compression to 8 GPa, accompanying the change in the intermediate range order. The density goes back to the original one on room-temperature decompression, but the high-density state is maintained once the sample is heated under pressure by structural relaxation (permanent densification). So far, the mechanism has been investigated, but remains to be revealed. To reveal the mechanism, in situ high-pressure diffraction is indispensable. Such data were obtained up to 10 GPa at the high-pressure neutron diffactometer PLANET in the last year, therefore we developed the method to analyze the data this year. By developing the program, we succeeded in obtaining structure factor and confirmed its reliability by comparing with the previous results.

Verification of phase transition/relaxation of SiO glass at high-PT condition by in-situ neutron diffraction

Hattori, Takanori; Sano, Asami; Inamura, Yasuhiro; Yagafarov, O.*; Katayama, Yoshinori*; Chiba, Ayano*; Otomo, Toshiya*; Funakoshi, Kenichi*; Abe, Jun*; Machida, Shinichi*; et al.

no journal, , 

SiO glass consists of SiO tetrahedra which are mutually connected and forms the many-membered ring. Thus, the glass has large void in its structure, and therefore marked densification is expected under pressure. Actually, it is known that the density increases by 20% on compression to 8 GPa, accompanying the change in the intermediate range order. The density goes back to the original value by decompression, whereas the high-density state is retained at ambient condition once the structure is relaxed by being heated at high pressures. In this study, the mechanism of the densification at room-temperature and high-temperature has been investigated by in-situ high-pressure neutron diffraction at high-pressure neutron beamline PLANET in J-PARC. Then, we have constructed 3-dimensional atomic arrangements by Reverse Monte Carlo simulation, coupling with previously reported X-ray data. In this talk, the mechanism of densification at room-temperature and high-temperature and their differences will be discussed based on the obtained atomic arrangements.

Partition behavior of acetic C in sedimentary rock; Effect of microbial activities in the presence of nitrate

Chiba, Takanori*; Yokochi, Takuya*; Kozaki, Tamotsu*; Sato, Seichi*; Miyauchi, Yoshihiro*; Kozai, Naofumi; Onuki, Toshihiko

no journal, , 

Partitioning behavior of acetic C in sedimentary rock has been studied in anaerobic atomosphere condition. Addition of nitrate salt in the solution showed good correlation between increase of oncentration of C in air and decrease of concentration of nitate salts. These results suggest that respiration of nitrifying bacteria result in the transformation of C.

First HT HP liquid data using a high-pressure neutron diffractometer, PLANET, in J-PARC/MLF

Katayama, Yoshinori; Yagafarov, O.*; Hattori, Takanori; Chiba, Ayano*; Sano, Asami; Saito, Hiroyuki; Suzuya, Kentaro; Otomo, Toshiya*

no journal, , 

As the first high-pressure experiments on structurally disordered materials using a newly-built high-pressure neutron diffractometer, PLANET, installed in J-PARC/MLF, measurements of silica glass, a typical oxide glass, were caried out. We compressed a sample in a ZrO cube using a six-axis press and measured diffraction at pressures of 0.1 MPa, 2.3, 5.5, 7.5 and 9.9 GPa at room temperature. Vanadium sample and empty cell were also measured for the correction of the diffraction intensity. Clean diffraction patterns without diffraction lines from surrounding materials were obtained thanks to the radial collimator system. Measurements on heavy water at room temperature, 100C and 200C at 0.8 GPa were also carried out as the first high-pressure high-temperature liquid measurement using PLANET. Significant temperature dependence of diffraction pattern was observed.

X-ray and neutron structural study on water under high pressure and high temperature, 2

Katayama, Yoshinori; Hattori, Takanori; Yagafarov, O.*; Saito, Hiroyuki; Sano, Asami; Suzuya, Kentaro; Chiba, Ayano*; Otomo, Toshiya*

no journal, , 

Liquid water at ambient conditions has an ice-like, characteristic structure due to the hydrogen bonds between molecules. To study pressure and temperature dependence of the structure of water, we have carried out in-situ high-temperature high-pressure measurements on liquid water by in-situ synchrtorn X-ray diffraction experiments at the SPring-8 and molecular dynamics simulations. The results revealed transformation from the ice-like structure to a simple-liquid-like structure. To investigate change in hydrogen bonds, neutron is an important probe. We carried out neturon diffraction measurements on heavy water at 100C and 200C at 2 GPa using high-pressure diffractometer, PLANET, at J-PARC/MLF. Significant temperature dependence of width of first peak in diffraction pattern, which is similar to that observed in the previous neutron diffraction experiments at 0.8 GPa.

Verification of phase transition/relaxation of SiO glass at high-PT condition by in-situ X-ray and neutron diffraction

Hattori, Takanori; Sano, Asami; Inamura, Yasuhiro; Yagafarov, O.*; Katayama, Yoshinori*; Chiba, Ayano*; Otomo, Toshiya*

no journal, , 

SiO glass consists of SiO tetrahedra which are mutually connected and forms the many-membered ring. Thus, the glass has large void in its structure, and therefore marked densification is expected under pressure. Actually, it is known that the density increases by 20% on compression to 8 GPa, accompanying the change in the intermediate range order. The density goes back to the original value by decompression, whereas the high-density state is retained once the structure is relaxed by being heated at high pressures. In this study, the mechanism of the densification at room-temperature and high-temperature has been investigated by in-situ high-pressure neutron diffraction at high-pressure neutron beamline PLANET in J-PARC, coupling with previously reported X-ray data. We have constructed 3-dimensional atomic arrangements by Reverse Monte Carlo simulation. In this talk, the mechanism of densification at room-temperature and high-temperature and their differences will be discussed based on the obtained atomic arrangements.

High-pressure neutron experiments on SiO glass using J-PARC high-pressure neutron diffractometer PLANET

Hattori, Takanori; Yagafarov, O.*; Katayama, Yoshinori; Sano, Asami; Saito, Hiroyuki; Chiba, Ayano*; Inamura, Yasuhiro; Suzuya, Kentaro; Otomo, Toshiya*

no journal, , 

SiO glass consists of SiO tetrahedra. This glass is easily densified by applying pressure, due to its relatively sparse network ring formed by the linkage of tetrahedra. The density increase amounts to 20% by room temperature compression to 8 GPa. This increase is, however, released after decompression because of insufficient structural relaxation. On the other hand, the heating at high pressures promotes the structural relaxation, resulting in permanent densification of 20% at most. The mechanism of this densification has been investigated so far, but the microscopic origin is still to be revealed. So, we performed in-situ high-pressure neutron experiments at newly constructed high-pressure neutron beamline PLANET in J-PARC. We will discuss the origin of the reversibility in the densification.

High-pressure neutron experiments on silica glass up to 17 GPa at J-PARC

Hattori, Takanori; Yagafarov, O.*; Katayama, Yoshinori; Chiba, Ayano*; Sano, Asami; Inamura, Yasuhiro; Otomo, Toshiya*; Funakoshi, Kenichi*; Abe, Jun*; Machida, Shinichi*

no journal, , 

SiO glass consists of SiO tetrahedra which are mutually connected and forms the many-membered ring. Thus, the glass has large void in its structure, and therefore marked densification is expected under pressure. Actually, it is known that the density increases by 20% on compression to 8 GPa, accompanying the change in the intermediate range order. The density goes back to the original value by decompression, whereas the high-density state is recovered at ambient condition once the structure is relaxed by heating at high pressure. The mechanism has been investigated, but is still unknown. To reveal the mechanism, in situ high-pressure diffraction is indispensable. In this study, we collected data up to about 17 GPa by using 6-axis press below 10 GPa and Paris-Edinburgh press above 10 GPa. Thanks to incident slits and receiving collimator, no peaks from the materials surrounding sample were observed. In the talk, I will discuss differences between the densifications with and without structural relaxation.