Refine your search:     
Report No.
Search Results: Records 1-20 displayed on this page of 78

Presentation/Publication Type

Initialising ...


Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...


Initialising ...


Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

JAEA Reports

Development of neutron transport calculation codes for 3-D hexagonal geometry, 2; Improvement and enhancement of the MINISTRI code

Sugino, Kazuteru; Takino, Kazuo

JAEA-Data/Code 2019-011, 110 Pages, 2020/01


A deterministic discrete ordinates method (SN method) transport calculation code for three-dimensional hexagonal geometry has been developed as the MINISTRI code (Ver. 7.0). MINISTRI is based on the triangle-mesh finite difference method, which can perform neutron transport calculations with high accuracy for cores of fast power reactors and assemblies of the Russian BFS critical facility. The present study has derived a proper scheme for remarkably improving the convergence of MINISTRI by investigating the issue of previous MINISTRI (Ver. 1.1), which sometimes plays a poor convergence performance in calculations for large-scale power reactor cores. The verification test of improved MINISTRI has been carried out for various cores by setting the reference result as the multi-group Monte-Carlo calculation with the same cross-sections as used in MINISTRI. As a result, it is found that the agreements are within 0.1% for eigenvalues and within 0.7% for power distributions. Thus, the satisfying accuracy of MINISTRI has been confirmed. In order to reduce the calculation time, the initial diffusion calculation scheme and the parallel processing have been implemented. As a result, the calculation time is reduced to the approximately one tenth compared with previous MINISTRI. Furthermore, adoption of the treatment of the anisotropic cell streaming effect, preparation of the perturbation calculation tool, implementation of the function for specification of the triangle-mesh-wise material and merging of the hexagonal-mesh calculation code MINIHEX have been carried out. Thus, the versatility of MINISTRI has been enhanced.

Journal Articles

Simplified calculation method for radiation streaming

Matsuda, Norihiro

Hoshasen Shahei Handobukku; Kisohen, p.229 - 288, 2015/03

no abstracts in English

Journal Articles

Nuclear technology and potential ripple effect of superconducting magnets for fusion power plant

Nishimura, Arata*; Muroga, Takeo*; Takeuchi, Takao*; Nishitani, Takeo; Morioka, Atsuhiko

Fusion Engineering and Design, 81(8-14), p.1675 - 1681, 2006/02

 Times Cited Count:3 Percentile:24.14(Nuclear Science & Technology)

In a fusion reactor plant, a neutral beam injector (NBI) will be operated for a long time, and it will allow neutron streaming from NBI ports to outside of the plasma vacuum vessel. It requires the superconducting magnet to develop nuclear technology to produce stable magnetic field and to reduce activation of the magnet components. In this report, the back ground of the necessity and the contents of the nuclear technology of the superconducting magnets for fusion application are discussed and some typical investigation results are presented, which are the neutron irradiation effect on Nb$$_{3}$$Sn wire, the development of low activation superconducting wire, and the design concept to reduce nuclear heating and nuclear transformation by streaming. In addition, recent activities in high energy particle physics are introduced and potential ripple effect of the technology of the superconducting magnets is described briefly.

Journal Articles

Global profile effects and structure formations in toroidal electron temperature gradient driven turbulence

Idomura, Yasuhiro; Tokuda, Shinji; Kishimoto, Yasuaki

Nuclear Fusion, 45(12), p.1571 - 1581, 2005/12

 Times Cited Count:38 Percentile:75.04(Physics, Fluids & Plasmas)

Using a global gyrokinetic toroidal particle code, the toroidal electron temperature gradient driven (ETG) turbulence is studied in positive and reversed shear tokamaks. In the nolinear turbulent state, the ETG turbulence in the positive and reversed shear configurations show quite different structure formations. In the positive shear configuration, the ETG turbulence is dominated by streamers which have a ballooning type structure, and the electron temperature $$T_e$$ profile is quickly relaxed to the marginally stable state in a turbulent time scale. In the reversed shear configuration, quasi-steady zonal flows are produced in the regative shear region, while the positive shear region is characterized by streamers. Accordingly, the electron thermal diffusivity $$chi_e$$ has a gap structure across the $$q_{min}$$ surface, and the $$T_e$$ gradinet is sustained above the marginal value for a long time in the quasi-steady phase. The results suggest a stiffness of the $$T_e$$ profile in positive shear tokamaks, and a possibility of the Te transport barrier in reversed shear tokamaks.

Journal Articles

Shielding analysis at the upper section of the accelerator-driven system

Sasa, Toshinobu; Yang, J. A.*; Oigawa, Hiroyuki

Radiation Protection Dosimetry, 116(1-4), p.256 - 258, 2005/12

 Times Cited Count:0 Percentile:0.01(Environmental Sciences)

The proton beam duct of the accelerator-driven system (ADS) acts a streaming path for spallation neutrons and photons and causes the activation of the magnets and other devices above the subcritical core. We have performed a streaming analysis at the upper section of the lead-bismuth target/cooled ADS (800MWth). MCNPX was used to calculate the radiation dose from streamed neutrons and photons through the beam duct. For the secondary photon production calculation, cross sections for several actinides were substituted for plutonium because of the lack of gamma production cross section. From the results of this analysis, the neutron dose from the beam duct is about 20 orders higher than that of the bulk shield. The magnets and shield plug were heavily irradiated by streaming neutrons according to the DCHAIN-SP analysis.

Journal Articles

Nuclear analyses of some key aspects of the ITER design with Monte Carlo codes

Iida, Hiromasa; Petrizzi, L.*; Khripunov, V.*; Federici, G.*; Polunovskiy, E.*

Fusion Engineering and Design, 75(1-4), p.133 - 139, 2005/11

The design of the ITER machine was presented in 2001. A nuclear analysis has been performed on ITER by means of the most detailed models and the best assessed nuclear data and codes. As the construction phase of ITER is approaching, the design of the main components has been optimized/finalized and several minor design changes/optimizations have been made, which required refined calculations to confirm that nuclear design requirements are met. Some of the proposed design changes have been made to mitigate critical radiation shielding problems. This paper reviews some of the most recent neutronic work with emphasis on critical nuclear responses in the TF coil inboard legs and vacuum vessel related to design modifications made to the blanket modules and vacuum vessel.

JAEA Reports

Report on the 8th Workshop on the Innovative Water Reactor for Flexible Fuel Cycle; February 10, 2005, Koku-kaikan, Minato-ku, Tokyo

Kobayashi, Noboru; Okubo, Tsutomu; Uchikawa, Sadao

JAERI-Review 2005-029, 119 Pages, 2005/09


The research on Innovative Water Reactor for Flexible fuel cycle (FLWR) has been performed in JAERI for the development of future innovative reactors. The workshop on the FLWRs has been held every year since 1998 aiming at information exchange between JAERI and other organizations. The 8th workshop was held on Feb. 10, 2005 under the joint auspices of JAERI and North Kanto and Kanto-Koetsu branches of Atomic Energy Society of Japan with 75 participants. The workshop began with 3 presentations on FLWRs entitled "Framework and Status of Research and Development on FLWRs", "Long-Term Fuel Cycle Scenarios for Advanced Utilization of Plutonium from LWRs", and "Experiments on Characteristics on Hydrodynamics in Tight-Lattice Core". Then 3 lectures followed: "Development of Evaluation Method for Accuracy in Predicting Neutronics Characteristics of Tight-Lattice Core" by Osaka University, "Development of Cost-Reduced Low-Moderation Spectrum Boiling Water Reactor" by Toshiba Corporation and "Design and Analysis on Super-Critical Water Cooled Power Reactors" by Tokyo University.

Journal Articles

Shielding design of ITER pressure suppression system

Yamauchi, Michinori*; Sato, Satoshi; Nishitani, Takeo; Kawasaki, Hiromitsu*

Proceedings of 21st IEEE/NPSS Symposium on Fusion Engineering (SOFE 2005) (CD-ROM), 4 Pages, 2005/09

no abstracts in English

JAEA Reports

Evaluation on activation activity of reactor in JRR-2 applied 3 dimensional model to neutron flux calculation

Kishimoto, Katsumi; Arigane, Kenji*

JAERI-Tech 2005-016, 83 Pages, 2005/03


Revaluation to activation activity of reactor evaluated at the notification of dismantling submitted in 1997 was carried out in JRR-2 where decommissioning was advanced now. In the revaluation, estimation accuracy on neutron streaming at various horizontal experimental tubes was improved by applying 3 dimensional model to neutron transport calculation that had been carried out by 2 dimensional model, and calculating with TORT. As the result, excessive overestimations on horizontal experimental tubes and biological shield that had greatly contributed to total activation activity in evaluation at the notification of dismantling was revised, sum of their activation activities in the revaluation decreased to 1/18(case after 1 year from the permanent shutdown of reactor) of evaluation at the notification of dismantling, and the structural materials that had large activation activity were changed. By the above, it was shown that introducing 3 dimensional model was effective in evaluation on activation activity of the research reactor that had a lot of various experimental tubes.

JAEA Reports

Results of shielding performance test in rise-to-power test of the HTTR

Ueta, Shohei; Takada, Eiji*; Sumita, Junya; Shimizu, Atsushi; Ashikagaya, Yoshinobu; Umeda, Masayuki; Sawa, Kazuhiro

JAERI-Tech 2004-047, 87 Pages, 2004/06


In the radiation shielding design of the High Temperature Engineering Test Reactor (HTTR), strong attention is needed to avoid especially upward neutron streaming. Shielding performance test have been carried out in the Rise-to-power test up to full power operation of 30MW. The measured dose equivalent rates in unrestricted area were lower than the detection limit for neutron-ray, and background level for $$gamma$$-ray. The neutron dose equivalent rate measured in the stand pipes room was about 120$$mu$$Sv/h at full power operation, which was much lower than the shielding design (330 mSv/h) and the prediction (10 mSv/h).

Journal Articles

Development of environment for remote participation in fusion research on JT-60

Oshima, Takayuki; Naito, Osamu; Hamamatsu, Kiyotaka; Iba, Katsuyuki; Sato, Minoru; Sakata, Shinya; Tsugita, Tomonori; Matsuda, Toshiaki; Iwasaki, Keita*; Karube, Yukihiro*; et al.

Fusion Engineering and Design, 71(1-4), p.239 - 244, 2004/06

 Times Cited Count:5 Percentile:35.33(Nuclear Science & Technology)

In the JT-60 tokamak at JAERI, environment for remote participation is planned to be developed by concentrating experts of nuclear fusion research of another research organizations and universities distributed all over the country. We are constructing a hierarchical remote research system, which consists of remote experiment, remote analysis, and remote diagnostic. In a remote collaboration, it is important to maintain the security of the system, as well as to share the information, atmosphere and presence between the participants. For the latter purpose, we developed a video conferencing system, and a video streaming system that can deliver the images of the JT-60 control room. Furthermore, a development of the remote analysis system called "VizAnalysis" has been started. And to assist the remote analysis, we developed a web based software system called "VizSquare". In the JT-60 tokamak at JAERI, security and authentication methods on a computer network and a new communication tool are developed, and probably they will be applied to the remote participation of ITER.

Journal Articles

Analysis of radiation streaming experiment through a labyrinth at TIARA HIR1

Oguri, Tomomi*; Nakashima, Hiroshi; Tanaka, Susumu; JAERI-University Collaboration Group for Accelerator Shielding Study

Journal of Nuclear Science and Technology, 41(Suppl.4), p.54 - 57, 2004/03

In shielding design of proton accelerator facilities, it applies simplified formulae and Monte Carlo calculation methods to calculation radiation streaming of access way and duct. A radiation streaming experiment was carried out in order to validate accuracy of intermediate energy region in labyrinth of access way connected to the 1st heavy ion room in TIARA at JAERI. In this paper, it is described comparing of measured data and calculations by MCNP-4B Monte Carlo code and simplified formulae. In Monte Carlo calculations, HILO86 constant set and LA150 was used for cross section data. The results of this experimental analysis show the accuracy of 50% errors for Monte Carlo calculations overall and a factor of 3 for simplified formulae. So applicability for these calculation methods in region of intermediate energy is validated.

Journal Articles

3-D shielding calculation method for 1-MW JSNS

Maekawa, Fujio; Tamura, Masaya

Proceedings of ICANS-XVI, Volume 3, p.1051 - 1058, 2003/07

A three-dimensional (3-D) shielding calculation model for MCNPX was produced for shielding design of 1-MW JSNS. The model included simplified target-moderator-reflector assembly, helium-vessel and neutron beam extraction pipes, shutters, shield blocks, gaps and void spaces between these components, and so on, and could treat streaming effects precisely. The particle splitting and kill method with cell importance parameters was adopted as a variance reduction method. The cell importance parameters for such a large target station of about 15 m in diameter and 12 m in hight in which neutron fluxes attenuated more than 12 orders of magnitude could be determined appropriately by automated iteration calculations. This calculation procedure enabled detailed 3-D shielding design calculations for the whole target station in a short time, i.e., within 2 days, and contributed for progress of shielding designs of JSNS.

Journal Articles

Shielding experiments and analyses on proton accelerator facility at TIARA

Nakashima, Hiroshi; Sakamoto, Yukio*; Tanaka, Shunichi; Tanaka, Susumu; Baba, Mamoru*; Nakamura, Takashi*; Hirayama, Hideo*; Shin, Kazuo*; JAERI-Universities Collaboration Working Group for Accelerator Shielding Study

Proceedings of 6th International Meeting on Nuclear Applications of Accelerator Technology (AccApp '03), p.959 - 968, 2003/00

In order to validate shielding design methods on proton accelerator facilities, a series of shielding experiments in several tens of MeV energy region were carried out at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) of Japan Atomic Energy Research Institute (JAERI). The experiments include thick target neutron yield (TTY) measurements by charged particles, deep penetration experiments on concrete, steel and polyethylene shields using p-Li monoenergetic neutron source and radiation streaming experiment at a labyrinth of TIARA using p-Cu white neutron source. These experimental results are compared with calculation results with some high-energy particle transport codes such as MCNPX and NMTC/JAERI. The TTY measurements were analyzed by a code developed by Shin with a moving source model, and the streaming experiment was also analyzed by the DUCT-III code based on Shin's equation. This paper reviews the experimental results and the analyses on the results.

Journal Articles

Evaluation of shutdown $$gamma$$-ray dose rates around the duct penetration by three-dimensional Monte Carlo decay $$gamma$$-ray transport calculation with variance reduction method

Sato, Satoshi; Iida, Hiromasa; Nishitani, Takeo

Journal of Nuclear Science and Technology, 39(11), p.1237 - 1246, 2002/11

 Times Cited Count:27 Percentile:83.32(Nuclear Science & Technology)

no abstracts in English

Journal Articles

An Experimental study on radiation streaming through a labyrinth in a proton accelerator facility of intermediate energy region

Tanaka, Susumu; Nakashima, Hiroshi; Sakamoto, Yukio; Nakane, Yoshihiro; Meigo, Shinichiro; Tanaka, Shunichi; Nakamura, Takashi*; Takada, Masashi*; Kurosawa, Tadahiro*; Hirayama, Hideo*; et al.

Health Physics, 81(4), p.406 - 418, 2001/10

 Times Cited Count:5 Percentile:39.04(Environmental Sciences)

no abstracts in English

Journal Articles

Neutronics experiments for ITER at JAERI/FNS

Konno, Chikara; Maekawa, Fujio; Kasugai, Yoshimi; Uno, Yoshitomo; Kaneko, Junichi; Nishitani, Takeo; Wada, Masayuki*; Ikeda, Yujiro; Takeuchi, Hiroshi

Nuclear Fusion, 41(3), p.333 - 337, 2001/03

 Times Cited Count:3 Percentile:10.97(Physics, Fluids & Plasmas)

no abstracts in English

JAEA Reports

Vectorization, parallelization and porting of nuclear codes (vectorization and parallelization); Progress report fiscal 1999

Adachi, Masaaki*; Ishizuki, Shigeru*; Ogasawara, Shinobu*; Kume, Etsuo; Yatake, Yoichi*; Nemoto, Toshiyuki*; Kawasaki, Nobuo*; Kawai, Wataru*

JAERI-Data/Code 2000-043, 220 Pages, 2001/02


no abstracts in English

Journal Articles

Neutronics analysis of the ITER NB system; Nuclear responses of the components and shutdown dose around the NB injector

Shibata, Keiichiro*; Maki, Koichi*; Inoue, Takashi*; Hanada, Masaya; Okumura, Yoshikazu; Yamashita, Y.*

Fusion Engineering and Design, 51-52, p.357 - 362, 2000/11

 Times Cited Count:1 Percentile:12.1(Nuclear Science & Technology)

no abstracts in English

78 (Records 1-20 displayed on this page)