PANDORA Project for the study of photonuclear reactions below

Tamii, Atsushi*; Pellegri, L.*; Sderstrm, P.-A.*; Allard, D.*; Goriely, S.*; Inakura, Tsunenori*; Khan, E.*; Kido, Eiji*; Kimura, Masaaki*; Litvinova, E.*; et al.

European Physical Journal A, 59(9), p.208_1 - 208_21, 2023/09

https://doi.org/10.1140/epja/s10050-023-01081-w

no abstracts in English

Synthesis report on the R&D for the Horonobe Underground Research Laboratory; Project carried out during fiscal years 2015-2019

Nakayama, Masashi; Saiga, Atsushi; Kimura, Shun; Mochizuki, Akihito; Aoyagi, Kazuhei; Ono, Hirokazu; Miyakawa, Kazuya; Takeda, Masaki; Hayano, Akira; Matsuoka, Toshiyuki; et al.

JAEA-Research 2019-013, 276 Pages, 2020/03

JAEA-Research-2019-013.pdf:18.72MB

The Horonobe Underground Research Laboratory (URL) Project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies for geological disposal of High-level Radioactive Waste through investigations of the deep geological environment within the host sedimentary rock at Horonobe Town in Hokkaido, north Japan. The investigations will be conducted in three phases, namely "Phase 1: Surface based investigations", "Phase 2: Construction phase" (investigations during construction of the underground facilities) and "Phase 3: Operation phase" (research in the underground facilities). According to the research plan described in the 3rd Mid- and Long- term Plan of JAEA, "Near-field performance study", "Demonstration of repository design option", and "Verification of crustal-movement buffering capacity of sedimentary rocks" are important issues of the Horonobe URL Project, and schedule of future research and backfill plans of the project will be decided by the end of 2019 Fiscal Year. The present report summarizes the research and development activities of these 3 important issues carried out during 3rd Medium to Long-term Research Phase.

Experimental evidence of nonthermal acceleration of relativistic electrons by an intensive laser pulse

Kuramitsu, Yasuhiro*; Nakanii, Nobuhiko*; Kondo, Kiminori; Sakawa, Yoichi*; Mori, Yoshitaka*; Miura, Eisuke*; Tsuji, Kazuki*; Kimura, Kazuya*; Fukumochi, Shuji*; Kashihara, Mamoru*; et al.

Physical Review E, 83(2), p.026401_1 - 026401_6, 2011/02

https://doi.org/10.1103/PhysRevE.83.026401

An energy distribution function of energetic particles in the universe or cosmic rays is well represented by a power-law spectrum, therefore, nonthermal acceleration is essential to understand the origin of cosmic rays. A possible candidate for the origin of cosmic rays is wakefield acceleration at relativistic astrophysical perpendicular shocks. Substituting an intensive laser pulse for the large amplitude light waves, we performed a model experiment of the shock environments in a laboratory plasma.

Development of numerical model on the coupled thermo-hydro-mechanical-chemical process for the assessment methodology of chemical effects in the buffer material

Kimura, Makoto*; Sazarashi, Masami; Fujita, Tomoo; Nakama, Shigeo; Suzuki, Hideaki

JAEA-Research 2010-034, 131 Pages, 2010/10

JAEA-Research-2010-034.pdf:16.23MB

Numerical model which can quantify the complex evolution of the coupled thermo-hydro-mechanical-chemical processes in the near-field of a HLW repository has been developed and the outline of the model considering heat flow, fluid flow, mass transport and a variety of chemical reactions such as mineral dissolution/precipitation, gas dissolution/exsolution, ion-exchange and surface complexation are described. The applicability of the numerical model was shown by the following three efforts. (1) Intercomparison analysis against another coupled model, TOUGHREACT which has been developed in the Lawrence Berkeley National Laboratory. (2) Comparison with the measured data in the designed laboratory tests for the salt accumulation/precipitation. (3) Perspective simulation on chemical changes in the near-field involving the radioactive decay heat arising from the vitrified waste and infiltration of ground water into the buffer material.

Numerical simulation of coupled hydro-geochemical behavior induced by tunnel excavation; Preliminary analysis for in-situ test on excavation disturbed zone of the drift in Horonobe URL project

Suzuki, Hideaki; Kimura, Makoto; Fujita, Tomoo

JAEA-Research 2008-110, 29 Pages, 2009/02

JAEA-Research-2008-110.pdf:2.18MB

It is necessary to consider the disturbance around the tunnel caused by the excavation of the realistic numerical simulation regarding the long-term behavior of near-filed after of engineered barrier system. In this paper, it is presented the preliminary analysis for Excavation Disturbed Zone (EDZ) around the horizontal drift at GL.-140m on Horonobe URL project. The coupled analysis, in which the hydraulic disturbance was considered, aiming principally at changes of the geochemical properties in the ground water with excavation was carried out. As a result, changes the pH in the ground water occurred, and it was showed these changes were caused by the gasification of the carbon dioxide in the ground water with enlarging the unsaturated zone, which is reaching up to about 5 meters long from the surface on the drift tunnel.

Description of "Design guideline for gas entrainment prevention using CFD method" (Cooperative research)

Ohshima, Hiroyuki; Sakai, Takaaki; Kamide, Hideki; Kimura, Nobuyuki; Ezure, Toshiki; Uchibori, Akihiro; Ito, Kei; Kunugi, Tomoaki*; Okamoto, Koji*; Tanaka, Nobuatsu*; et al.

JAEA-Research 2008-049, 44 Pages, 2008/06

JAEA-Research-2008-049.pdf:42.3MB

Japan Atomic Energy Agency has conducted a conceptional design study of a sodium-cooled fast reactor in a frame work of the FBR feasibility study. The plant system concept for a commercial step is intended to minimize a vessel diameter to achieve an economical competitiveness. Therefore, the coolant in the vessel has relatively higher velocity and gas entrainment (GE) prevention from a liquid surface in the reactor vessel becomes one of important issues for the thermal-hydraulic design. In order to establish a design criteria for the GE prevention, the GE from vortex dimples at the liquid surface was investigated by a working group. The 1st proposal of "Design Guideline for Gas Entrainment Prevention Using CFD Method" was established based on the knowledge gained from the working group activities. This report introduces each study in the working group to clarify the basis of the design guideline.

Large-scaled non-thermal laser peeling, cutting and drilling in nuclear decommissioning industry

Minehara, Eisuke; Hajima, Ryoichi; Sawamura, Masaru; Nagai, Ryoji; Kikuzawa, Nobuhiro; Nishimori, Nobuyuki; Iijima, Hokuto; Nishitani, Tomohiro; Kimura, Hideaki*; Oguri, Daiichiro*; et al.

Proceedings of 13th International Conference on Nuclear Engineering (ICONE-13) (CD-ROM), 10 Pages, 2005/05

The JAERI FEL has recently discovered the new FEL lasing of 255fs ultra fast pulse, 6-9% high-efficiency, one gigawatt high peak power, a few kilowatts average power, and wide tunability of medium and far infrared wavelength regions at the same time. Using the new lasing and energy-recovery linac technology, we could extend a more powerful and more efficient free-electron laser (FEL) than 10kW and 25%, respectively, for nuclear industry, pharmacy, medical, defense, shipbuilding, semiconductor industry, chemical industries, environmental sciences, space-debris, power beaming and so on. In order to realize such a tunable, highly-efficient, high average power, high peak power and ultra-short pulse FEL, we need the efficient and powerful FEL driven by the JAERI compact, stand-alone and zero boil-off super-conducting RF linac with an energy-recovery geometry. Our discussions on the FEL will cover the application of non-thermal peeling, cutting, and drilling to decommission the nuclear power plants, and to prevent stress-corrosion cracking in nuclear industry and roadmap for the industrial FELs, the JAERI compact, stand-alone and zero-boil-off cryostat concept and operational experience, the new, highly-efficient, high-power, and ultra fast pulse lasing mode, and the energy-recovery geometry.

PARC process for an advanced PUREX process

Uchiyama, Gunzo; Mineo, Hideaki; Hotoku, Shinobu; Asakura, Toshihide; Kamei, Kazushige; Watanabe, Makio; Nakano, Yuji*; Kimura, Shigeru; Fujine, Sachio

Progress in Nuclear Energy, 37(1-4), p.151 - 156, 2000/12

https://doi.org/10.1016/S0149-1970(00)00040-8

no abstracts in English

Dissolution tests of spent fuel in the NUCEF cell including dissolver off-gas treatment

Mineo, Hideaki; Kihara, Takehiro; *; Kimura, Shigeru; *; ; Uchiyama, Gunzo; Hotoku, Shinobu; Watanabe, Makio; ; et al.

JAERI-Conf 99-004, p.498 - 507, 1999/03

https://jopss.jaea.go.jp/pdfdata/JAERI-Conf-99-004-Part1.pdf

no abstracts in English

Derivation methods of clearance levels for nuclear reactors

Okoshi, Minoru; Takahashi, Tomoyuki*; Kimura, Hideo; ; Sakai, Akihiro; Yoshimori, Michiro; Yamamoto, Hideaki

Hoken Butsuri, 34(2), p.187 - 197, 1999/00

https://doi.org/10.5453/jhps.34.187

no abstracts in English