Conceptual design of multipurpose compact research reactor; Annual report FY2011

Watahiki, Shunsuke; Hanakawa, Hiroki; Imaizumi, Tomomi; Nagata, Hiroshi; Ide, Hiroshi; Komukai, Bunsaku; Kimura, Nobuaki; Miyauchi, Masaru; Ito, Masayasu; Nishikata, Kaori; et al.

JAEA-Technology 2013-021, 43 Pages, 2013/07

JAEA-Technology-2013-021.pdf:5.12MB

The number of research reactors in the world is decreasing because of their aging. On the other hand, the necessity of research reactor, which is used for human resources development, progress of the science and technology, industrial use and safety research is increasing for the countries which are planning to introduce the nuclear power plants. From above background, the Neutron Irradiation and Testing Reactor Center began to discuss a basic concept of Multipurpose Compact Research Reactor (MCRR) for education and training, etc., on 2010 to 2012. This activity is also expected to contribute to design tool improvement and human resource development in the center. In 2011, design study of reactor core, irradiation facilities with high versatility and practicality, and hot laboratory equipment for the production of Mo-99 was carried out. As the result of design study of reactor core, subcriticality and operation time of the reactor in consideration of an irradiation capsule, and about the transient response of the reactor to the reactivity disturbance during automatic control operation, it was possible to do automatic operation of MCRR, was confirmed. As the result of design study of irradiation facilities, it was confirmed that the implementation of an efficient mass production radioisotope Mo-99 can be expected. As the result of design study with hot laboratory facilities, Mo-99 production, RI export devised considered cell and facilities for exporting the specimens quickly was designed.

Magnetic and superconducting properties of LaIrSi and CeIrSi with the non-centrosymmetric crystal structure

Okuda, Yusuke*; Miyauchi, Yuichiro*; Ida, Yuki*; Takeda, Yuji*; Tonohiro, Chie*; Ozuchi, Yasuhiro*; Yamada, Tsutomu*; Nguyen, D.; Matsuda, Tatsuma; Haga, Yoshinori; et al.

Journal of the Physical Society of Japan, 76(4), p.044708_1 - 044708_11, 2007/04

https://doi.org/10.1143/JPSJ.76.044708

Single crystals of LaIrSi and CeIrSi were grown by the Czochralski pulling method in a tetra-arc furnace and the magnetic and superconducting properties, together with super- conductivity in CeIrCoSi, were clarified by measuring the electrical resistivity, specific heat, magnetic susceptibility, magnetization and de Haas-van Alphen (dHvA) effect. From the results of the dHvA experiment for LaIrSi, the Fermi surface is found to split into two Fermi surfaces due to the spin-orbit interaction arising from the non-centrosymmetric crystal structure. The electronic state of CeIrSi is tuned from the antiferro- magnetic state to the superconducting state by applying pressure. The upper critical field H(0) at a pressure of 2.65 GPa is found to be highly anisotropic. Large magnitude and anisotropy of H(0) in CeIrSi are consistent with the theoretical prediction for superconductivity in the non-centrosymmetric crystal structure.

In situ EXAFS study on GeS glass under high-pressure

Miyauchi, Koichi*; Qiu, J.*; Shojiya, Masanori*; Kawamoto, Yoji*; Kitamura, Naoyuki*; Fukumi, Kohei*; Katayama, Yoshinori; Nishihata, Yasuo

Solid State Communications, 124(5-6), p.189 - 193, 2002/10

https://doi.org/10.1016/S0038-1098(02)00489-1

A GeS glass was compressed up to 8 GPa at room temperature, heated up to 270 C under 8 GPa and then decompressed to ambient pressure at room temperature, using a large volume high-pressure apparatus. The local structural-changes around Ge were examined by means of EXAFS method. The Ge-S bond length became monotonously short with increasing applied-pressure up to 8 GPa at room temperature. When the specimen was heated to 270 C under 8 GPa, however, the vond length became slightly long. The elongated bond lengthe was almost kept even after the temperature was descended to room tempertature. In decompression process, the bond length became gradually long with releasing applied-pressure down to 2 GPa, following a change in compression process. Below 2 GPa, however, the Ge-S bond length was largely elongated, being lnger than the initial one. No significant change of coordination number was found in the compression and decompression processes up to 8 GPa. This change canbe explained by a combined effect of elastic and inelastic structural-changes.

Annual report on analytical works in NUCEF in F.Y. 2000

Tanoue, Takahiro; Gunji, Kazuhiko; Haga, Takahisa*; Fukaya, Hiroyuki; Sonoda, Takashi; Sakazume, Yoshinori; Niitsuma, Yasushi; Miyauchi, Masakatsu; Shirahashi, Koichi; Sato, Takeshi

JAERI-Tech 2001-071, 30 Pages, 2001/11

JAERI-Tech-2001-071.pdf:4.15MB

Analytical results of uranyl nitrate solution are essential data for the operation of the Static Experiment Critical Facility (STACY), the Transient Experiment Critical Facility (TRACY) and the fuel treatment system in the Nuclear Fuel Cycle Safety Engineering Research Facility (NUCEF). Analytical works were carried out for the determination of fuel characteristics before and after criticality experiments, fuel preparation and nuclear material accountancy in FY. 2000. In accordance with handling and dissolution of mixed oxide(MOX) powder in the fuel treatment system of NUCEF ,the preliminary tests for dissolution of the MOX powder in nitric acid solution have started since the end of 2000 ,after the MOX powder transfer to the NUCEF. The analytical works were carried out for the preliminary tests. A total number of analytical samples in FY. 2000 were 483 samples . This report summarizes the data on analytical works in FY.2000.

Annual report of STACY operation in FY.1999; Experiments on two unit neutron-interacting system with slab-shaped core tanks and 10% enriched uranyl nitrate solutions, 1 (Contract research)

Onodera, Seiji; Sono, Hiroki; Hirose, Hideyuki; Tanino, Shuichi; Kaminaga, Jota*; Myomae, Tomoki*; Murakami, Kiyonobu; Sakuraba, Koichi; Miyauchi, Masakatsu; Tonoike, Kotaro; et al.

JAERI-Tech 2000-059, 46 Pages, 2000/11

JAERI-Tech-2000-059.pdf:2.86MB

no abstracts in English

Annual report of STACY operation in F.Y. 1998, 1; 280mm thickness slab core10% enriched uranyl nitrate solution (Contract research)

Onodera, Seiji; Sono, Hiroki; Hirose, Hideyuki; Tanino, Shuichi; Nagasawa, Makoto*; Murakami, Kiyonobu; Sakuraba, Koichi; Miyauchi, Masakatsu; Kikuchi, Tsukasa; Ono, Akio

JAERI-Tech 99-084, p.54 - 0, 1999/12

JAERI-Tech-99-084.pdf:2.7MB

no abstracts in English

Improvement of fuel sampling device for STACY and TRACY

Hirose, Hideyuki; Sakuraba, Koichi; ; ; *; *; ; ; ; Miyauchi, Masakatsu; et al.

JAERI-Tech 98-015, 52 Pages, 1998/05

JAERI-Tech-98-015.pdf:1.68MB

no abstracts in English

Influence of long-term melting on the noble metals shape and glass viscosity, 2

Oyama, Koichi; Morikawa, Yo; Miyauchi, Atsushi; Nakajima, Masayoshi; Yamashita, Teruo; Komamine, Satoshi*; Ochi, Eiji*

no journal, , 

no abstracts in English

Sedimentation behavior of noble metal particles in simulated high-level waste borosilicate glasses

Nakajima, Masayoshi; Oyama, Koichi; Morikawa, Yo; Miyauchi, Atsushi; Yamashita, Teruo; Komamine, Satoshi*; Ochi, Eiji*

no journal, , 

Noble metal elements (NME) contained in high level liquid waste (HLLW) are distributed in a vitrification melter. Some part of them forms sediment which causes negative effects to steady operation of the melter. The formation process and characteristics of the sediment is useful information for considering methods of removing or discharging them. Thus the sedimentation observation was carried out by using simulated glass. Samples with 1.1wt% of initial NME concentration held at 1100C indicated zone settling, and the settling rate of interface is constant; 2.4 mm/h. This sedimentation behavior is the type of rapid settling. Following the rapid settling, the settling rate goes slower gradually, this is the type of compressive settling. The samples whose initial NME concentrations are 3.0wt% and 6.1wt% showed compression settling form the beginning. From the settling curve of interface, the maximum concentration of NME in sediment was estimated as around 23-26wt%. This value can specify the properties of sediment to be removed, Also, growth of NME particles was observed by holding at 1100C for up to 2880 hours.

Elemental analysis of simulated waste glass by laser ablation ICP-AES, 5; Application of LA-ICP-AES for inactive mock-up test of vitrification process

Inose, Takehiko*; Nishizawa, Daiji*; Miyauchi, Atsushi; Oyama, Koichi; Yamakawa, Atsushi*; Nagai, Takayuki

no journal, , 

no abstracts in English