Development of the treatment method for difficult wastes aimed at decommissioning of JMTR; Structural materials of reactor and used ion-exchange resins

Seki, Misaki; Nakano, Hiroko; Nagata, Hiroshi; Otsuka, Kaoru; Omori, Takazumi; Takeuchi, Tomoaki; Ide, Hiroshi; Tsuchiya, Kunihiko

Dekomisshoningu Giho, (62), p.9 - 19, 2020/09

Japan Materials Testing Reactor (JMTR) has been contributing to various research and development activities such as the fundamental research of nuclear materials/fuels, safety research and development of power reactors, and radioisotope production since the beginning of the operation in 1968. JMTR, however, was decided as a one of decommission facilities in April 2017 and it is taken an inspection of a plan concerning decommissioning because the performance of JMTR does not confirm with the stipulated earthquake resistance. As aluminum and beryllium are used for the core structural materials in JMTR, it is necessary to establish treatment methods of these materials for the fabrication of stable wastes. In addition, a treatment method for the accumulated spent ion-exchange resins needs to be examined. This report describes the overview of these examination situations.

Fabrication and hydrogen generation reaction with water vapor of prototypic pebbles of binary beryllides as advanced neutron multiplier

Nakamichi, Masaru; Kim, Jae-Hwan

Fusion Engineering and Design, 98-99, p.1838 - 1842, 2015/10

https://doi.org/10.1016/j.fusengdes.2015.04.026

Advanced neutron multipliers with high stability at high temperatures are desired for the pebble bed blankets of DEMO reactors. Beryllium intermetallic compounds (beryllides) are the most promising material for this purpose. To fabricate the beryllide pebbles, a new granulation process has been established that combines a plasma sintering method for beryllide synthesis and a rotating electrode method using a plasma-sintered electrode for granulation. In granulation examinations, prototypic pebbles 1 mm in diameter of Be-V beryllide as well as Be-Ti beryllide were successfully fabricated. This study performed not only granulation of binary beryllides but also its characterization of the hydrogen generation reaction with water vapor compared with those of pure Be pebbles.

New approach to measure double-differential charged-particle emission cross sections of several materials for a fusion reactor

Kondo, Keitaro; Takagi, Satoshi*; Murata, Isao*; Miyamaru, Hiroyuki*; Takahashi, Akito*; Kubota, Naoyoshi; Ochiai, Kentaro; Nishitani, Takeo

Fusion Engineering and Design, 81(8-14), p.1527 - 1533, 2006/02

https://doi.org/10.1016/j.fusengdes.2005.08.070

In a fusion reactor development, double-differential charged-particle emission cross sections(DDXc) are necessary to estimate nuclear heating and material damages of candidate materials irradiated with neutrons. Especially in light nuclei such as Be, Li, and C, nuclear reactions are complicated and difficult to estimate energy spectra of emitted particles based only on theoretical calculations Therefore development of a new technique for precise measurements of DDXc is quite important. Recently we successfully developed a new spectrometer for measurement of DDXc using a pencil-beam DT neutron source of FNS in JAERI. In the present study we carried out measurements of DDXc of Be, C, F, and Al using the spectrometer. The present technique was valid from the result of measurement for the Al(n,x) reactions. Slight differences appeared between measured data and evaluation or previous experimental values for Be(n,x) reactions at backward scattering angle and in lower energy region.

Experimental studies on tungsten-armour impact on nuclear responses of solid breeding blanket

Sato, Satoshi; Nakao, Makoto*; Verzilov, Y. M.; Ochiai, Kentaro; Wada, Masayuki*; Kubota, Naoyoshi; Kondo, Keitaro; Yamauchi, Michinori*; Nishitani, Takeo

Nuclear Fusion, 45(7), p.656 - 662, 2005/07

https://doi.org/10.1088/0029-5515/45/7/014

no abstracts in English

Present status of beryllide R&D as neutron multiplier

Kawamura, Hiroshi; Takahashi, Heishichiro*; Yoshida, Naoaki*; Mishima, Yoshinao*; Ishida, Kiyohito*; Iwadachi, Takaharu*; Cardella, A.*; Van der Laan, J. G.*; Uchida, Munenori*; Munakata, Kenzo*; et al.

Journal of Nuclear Materials, 329-333(1), p.112 - 118, 2004/08

https://doi.org/10.1016/j.jnucmat.2004.04.297

no abstracts in English

Preliminary survey for recycle of beryllium reflector frames used in the JMTR

Ishitsuka, Etsuo; Nakamichi, Masaru*; Uchida, Munenori*; Kawamura, Hiroshi; Kaminaga, Katsuo; Tsuboi, Kazuaki; Kusunoki, Hidehiko

JAERI-Conf 2004-006, p.262 - 264, 2004/03

https://jopss.jaea.go.jp/pdfdata/JAERI-Conf-2004-006.pdf

no abstracts in English

Microstructure and mechanical properties of BeTi/(Be) and BeV/(Be) two-phase alloys

Mishima, Yoshinao*; Yamamoto, Keisuke*; Kimura, Yoshisato*; Uchida, Munenori*; Kawamura, Hiroshi

JAERI-Conf 2004-006, p.184 - 189, 2004/03

https://jopss.jaea.go.jp/pdfdata/JAERI-Conf-2004-006.pdf

no abstracts in English

Trial fabrication of BeTi electrode for pebble production by rotating electrode method

Uda, Minoru*; Iwadachi, Takaharu*; Uchida, Munenori*; Nakamichi, Masaru*; Kawamura, Hiroshi

JAERI-Conf 2004-006, p.190 - 195, 2004/03

https://jopss.jaea.go.jp/pdfdata/JAERI-Conf-2004-006.pdf

no abstracts in English

Elemental development of beryllide electrode for pebble production by rotating electrode method

Uchida, Munenori*; Uda, Minoru*; Iwadachi, Takaharu*; Nakamichi, Masaru; Kawamura, Hiroshi

Journal of Nuclear Materials, 329-333(Part2), p.1342 - 1346, 2004/00

https://doi.org/10.1016/j.jnucmat.2004.04.195

In this paper, an elemental technology to fabricate beryllide rods by the vacuum casting was researched. Furnace material study to prevent the chemical reaction with beryllide and casting procedure study to cast durable ingot without any shrinkages and cracks were performed. From the results of the reactivity test of refractory material with BeTi, it was clear that the BeO crucible had less reactivity with melt and no contamination. From the results of casting tests with a MgO cylindrical mold in a vacuum chamber, it was revealed that the mold dimension was critical to minimize shrinkages and cracks. It was also found that the forced cooling by the MgO cylindrical sleeve with water-cooled copper mold on the bottom was efficient to improve the shrinkages and the cracks.

Summary of the Symposium on Beryllides as an Advanced Nuclear Functional Material

Department of JMTR, Oarai

JAERI-Review 2003-026, 163 Pages, 2003/09

JAERI-Review-2003-026.pdf:16.05MB

no abstracts in English