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Tsuji, Masakuni*; Kobayashi, Shinji*; Sato, Toshinori; Mikake, Shinichiro; Matsui, Hiroya
Proceedings of 8th Nordic Grouting Symposium, p.171 - 185, 2016/09
This paper presents the application of a durable liquid-type colloidal silica grout (CSG), to the great depth of the Mizunami Underground Research Laboratory (MIU). The CSG had been invented decades ago in Japan for the purpose of the ground improvement. A post-grouting experiment with the CSG carried out in 300 m depth of MIU confirmed its applicability and good durability at a great depth more than 3 years. Furthermore, a comparison study of applying the CSG between this experiment and a Swedish project indicated good applicability of the Swedish theoretical design to MIU. The CSG with the Swedish design were applied to the post-grouting campaign in a gallery at 500 m depth for further reducing water ingress and for developing the latest grouting methodology. The grouting was successful in reducing the abundant inflow from the rock with many fractures. The conductivity of the grouted rock mass of the latter fans is estimated to be lower than 10
m/s.
Sato, Tatsuhiko; Niita, Koji*; Matsuda, Norihiro; Hashimoto, Shintaro; Iwamoto, Yosuke; Furuta, Takuya; Noda, Shusaku; Ogawa, Tatsuhiko; Iwase, Hiroshi*; Nakashima, Hiroshi; et al.
Annals of Nuclear Energy, 82, p.110 - 115, 2015/08
Times Cited Count：34 Percentile：93.49(Nuclear Science & Technology)The general purpose Monte Carlo Particle and Heavy Ion Transport code System, PHITS, is being developed through a collaboration of several institutes in Japan and Europe. The Japan Atomic Energy Agency is responsible for managing the entire project. PHITS can deal with the transport of nearly all particles, including neutrons, protons, heavy ions, photons, and electrons, over wide energy ranges using various nuclear reaction models and data libraries. This paper briefly summarizes the physics models implemented in PHITS, and introduces some important functions useful for particular purposes, such as an event generator mode and beam transport functions.
sp
Hard Rock Laboratory in Sweden and Mizunami Underground Research Laboratory in JapanTsuji, Masakuni*; Funehag, J.*; Kobayashi, Shinji*; Sato, Toshinori; Mikake, Shinichiro
Proceedings of 8th Asian Rock Mechanics Symposium (ARMS-8) (USB Flash Drive), 10 Pages, 2014/10
Silica sol is a material that seems to fulfill the non-hazardous requirement and capable of penetrating into narrow fractures. The rock grouting strategy with silica sol has been studied and applied for some recent projects in Sweden. The design methodology is based on the determination of the fracture transmissivity distribution and the theoretical penetration length. In 2008, grouting with silica sol was applied in the construction of a short tunnel at 450 m depth in the sp Hard Rock Laboratory, the TASS-tunnel. In 2010, a grouting experiment with silica sol was performed in a gallery at 300 m depth in the Mizunami Underground Research Laboratory (MIU experiment). It can be suggested that Swedish methodology can be applied to design and evaluate the grouting works in Japanese rock with higher intensity of fractures in general. Furthermore, an additional pumping time or the use of Japanese silica sol might improve the grouting quality in Sweden.
El-Jaby, S.*; Tomi, L.*; Sihver, L.*; Sato, Tatsuhiko; Richardson, R. B.*; Lewis, B. J.*
Advances in Space Research, 53(5), p.810 - 817, 2014/03
Times Cited Count：2 Percentile：18.83(Engineering, Aerospace)This paper describes a methodology for assessing the pre-mission exposure of space crew aboard the International Space Station (ISS) in terms of an effective dose equivalent. In this approach, the PHITS Monte Carlo code was used to assess the particle transport of galactic cosmic radiation (GCR) and trapped radiation for solar maximum and minimum conditions through an aluminum shield thickness. From these predicted spectra, and using fluence-to-doseconversion factors, a scaling ratio of the effective dose equivalent rate to the ICRU ambient doseequivalent rate at a 10 mm depth was determined. Only contributions from secondary neutrons, protons, and alpha particles were considered in this analysis.
Sato, Tatsuhiko; Niita, Koji*; Matsuda, Norihiro; Hashimoto, Shintaro; Iwamoto, Yosuke; Noda, Shusaku; Ogawa, Tatsuhiko; Iwase, Hiroshi*; Nakashima, Hiroshi; Fukahori, Tokio; et al.
Journal of Nuclear Science and Technology, 50(9), p.913 - 923, 2013/09
Times Cited Count：561 Percentile：99.98(Nuclear Science & Technology)An upgraded version of the Particle and Heavy Ion Transport code System, PHITS 2.52, was developed and released to public. The new version has been greatly improved from the previous released version, PHITS 2.24, in terms of not only the code itself but also the contents of its package such as attached data libraries. Owing to these improvements, PHITS became a more powerful tool for particle transport simulation applicable to various research and development fields such as nuclear technology, accelerator design, medical physics, and cosmic-ray research.
El-Jaby, S.*; Lewis, B. J.*; Tomi, L.*; Sihver, L.*; Sato, Tatsuhiko; Lee, K. T.*; Johnson, A. S.*
Proceedings of IEEE Aerospace Conference 2013 (Internet), 18 Pages, 2013/03
A semi-empirical model is derived from operational data collected aboard the International Space Station (ISS) with the U.S. tissue equivalent proportional counter (TEPC). The model provides daily and cumulative mission predictions of the operational dose equivalent that space-crew may receive from galactic cosmic radiation (GCR) and trapped radiation (TR) sources as a function of the ISS orbit.
Maeyama, Takuya*; Yamashita, Shinichi; Baldacchino, G.*; Taguchi, Mitsumasa; Kudo, Hisaaki*; Sihver, L.*; Murakami, Takeshi*; Katsumura, Yosuke
no journal, ,
Yield of hydroxyl radical (
OH) has been measured near the Bragg peak of therapeutic heavy ions. Such a highly energetic heavy ions go through fragmentation reactions and its contribution has been quantitatively estimated with computer simulation. There are two kinds of simulation codes. One it deterministic 1D code, which needs only a few minutes for single calculation, and the other is stochastic 3D code, which can be extended to wide variety of beam configurations and more close to real situation. However, comparison of them has not been attempted intensively. In this study, measured OH yield has been reproduced by considering fragmentations based on these code and results were compared to extract advantages and disadvantages of them.
Sato, Tatsuhiko; Niita, Koji*; Matsuda, Norihiro; Hashimoto, Shintaro; Iwamoto, Yosuke; Iwase, Hiroshi*; Noda, Shusaku; Ogawa, Tatsuhiko; Nakashima, Hiroshi; Fukahori, Tokio; et al.
no journal, ,
Recently, we released PHITS version 2.5, which has the following new features: (1) Incorporation of the latest intra-nuclear cascade model such as INCL 4.6, (2) Implementation of the statistical multi-fragmentation model and high-energy photo-nuclear reaction model, (3) Re-evaluation of the Kerma factors contained in the neutron nuclear data library based on JENDL-4.0, (4) Access to shared-memory parallelism using the OpenMP architecture, (5) Implementation of the uncertainty-estimation function on the basis of history and batch variances, (6) Improvement of the user support tools such as the installers for Windows and MacDetails of these new features will be presented at the meeting.
Sato, Tatsuhiko; Nagamatsu, Aiko*; Takeda, Kazuo*; Niita, Koji*; Puchalska, M.*; Sihver, L.*; Reitz, G.*
no journal, ,
Estimation of organ doses and their mean quality factors for astronauts due to cosmic-ray exposure has been an essential issue in the planning of long-term space missions. We therefore performed simulation for calculating the organ doses and their mean quality factors inside the MATROSHKA phantom, using a realistic geometry of the Kibo module in combination with the NUNDO phantom, which was constructed based on the CT image of the phantom. The particle and heavy ion transport code system PHITS was employed in the simulation. From preliminary results, it is found that the calculated organ doses and their mean quality factors inside the MATROSHKA phantom agree with the corresponding experimental data fairly well.
Tsuji, Masakuni*; Kobayashi, Shinji*; Sato, Toshinori; Mikake, Shinichiro; Johan, F.*
no journal, ,
Silica sol is a material that seems to fulfill the non-hazardous requirement of final repository and capable of penetrating into narrow fractures. The rock grouting strategy with silica sol has been studied and applied for some recent projects in Sweden. The design methodology is based on the determination of the distribution of fracture transmissivity and the theoretical penetration length. In 2008, grouting with silica sol was applied in the construction of a short tunnel at 450 m depth in the Aspo Hard Rock Laboratory, the TASS-tunnel. In 2010, a grouting experiment with silica sol was performed at a niche of 300 m depth in the Mizunami Underground Research Laboratory, the MIU-300-niche. Despite the fact that silica sol has been used for a couple of decades for soil consolidation or sealing of fractures, it has seldom been applied as a material for rock grouting during tunneling.
