Japan - IAEA Joint Nuclear Energy Management School 2016

Yamaguchi, Mika; Hidaka, Akihide; Ikuta, Yuko; Murakami, Kenta*; Tomita, Akira*; Hirose, Hiroya*; Watanebe, Masanori*; Ueda, Kinichi*; Namaizawa, Ken*; Onose, Takatoshi*; et al.

JAEA-Review 2017-002, 60 Pages, 2017/03

JAEA-Review-2017-002.pdf:9.41MB

Since 2010, IAEA has held the NEM School to develop future leaders who plan and manage nuclear energy utilization in their county. Since 2012, JAEA together with Japan Nuclear HRD Network, University of Tokyo, Japan Atomic Industrial Forum and JAIF International Cooperation Center have cohosted the school in Japan in cooperation with IAEA. Since then, the school has been held in Japan every year. In 2006, Japanese nuclear technology and experience, such as lessons learned from the Fukushima Daiichi Nuclear Power Plant accident, were provided to offer a unique opportunity for the participants to learn about particular cases in Japan. Through the school, we contributed to the internationalization of Japanese young nuclear professionals, development of nuclear human resource of other countries including nuclear newcomers, and enhanced cooperative relationship with IAEA. Additionally, collaborative relationship within the network was strengthened by organizing the school in Japan.

Development of displacement damage model in PHITS and comparison with other codes in a high-energy region

Iwamoto, Yosuke; Niita, Koji*; Sawai, Tomotsugu; Ronningen, R. M.*; Baumann, T.*

Proceedings of 11th Meeting of the Task Force on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-11), p.91 - 98, 2013/10

http://www.oecd-nea.org/science/pubs/2013/7157-satif-11.pdf

We have developed the displacement damage model in PHITS using the screened Coulomb scattering and the nuclear reaction model to evaluate the energy of the target PKA created by the projectile and the "secondary particles" which include all particles created from the sequential nuclear reactions. For the high-energy proton and neutron incident reactions, it was found that a target PKA created by the "secondary particles" is more dominant than a target PKA created by the projectile in DPA calculations. Recently, radiation damage models in other codes such as FLUKA, MARS, MCNP have also been developed. As there is few experimental data in a high energy region, an intercomparison of Monte Carlo codes used in the radiation damage calculation is very important for the improvement of models. In the meeting, we will also discuss the comparison between PHITS and FLUKA for the high-energy proton and neutron irradiation.

Radiation damage calculation in PHITS for materials irradiated with neutrons, protons and deuterons over a wide energy range

Iwamoto, Yosuke; Iwamoto, Hiroki; Harada, Masahide; Niita, Koji*; Sawai, Tomotsugu

Robutsuri No Kenkyu (Internet), (65), p.1 - 3, 2013/03

http://rpg.jaea.go.jp/else/rpd/annual_report/pdf65/No65-7.pdf

The displacement cross sections for common structural materials were calculated using the radiation damage model in PHITS. The displacement cross sections with the defect production efficiency gave good agreement with experimental data. For application to the DPA calculations at 400 MeV proton and 40 MeV deuteron, calculated cross sections were folded into calculated particle fluxes in PHITS. Thus the PHITS including the displacement cross sections can be useful to calculate the DPA values in materials used at accelerator facilities that will be exposed to intense primary and secondary particle irradiation. It will also be useful at fission and fusion reactor facilities.

Improvement of radiation damage calculation in PHITS and tests for copper and tungsten irradiated with protons and heavy-ions over a wide energy range

Iwamoto, Yosuke; Niita, Koji*; Sawai, Tomotsugu; Ronningen, R. M.*; Baumann, T.*

Nuclear Instruments and Methods in Physics Research B, 274, p.57 - 64, 2012/03

https://doi.org/10.1016/j.nimb.2011.11.038

The radiation damage model in the PHITS has been improved using the screened Coulomb scattering to evaluate the energy of the target PKA (Primary Knock on Atom) created by the projectile and the secondary particles from the nuclear reactions. For the high-energy proton and He incident reactions, a target PKA created by the secondary particles was more dominant than a target PKA created by the projectile in DPA calculations. Therefore, the improved PHITS can calculate DPA values at high energies and TRIM leads to severe underestimation where projectile energy is high enough to create nuclear reactions. Thus improved PHITS is applicable to evaluate the displacement cross sections for the various particles and over a wide energy range and to calculate DPA values determined by different particles and fluxes in an irradiation environment.

DPA calculations for heavy-ion and proton incident reactions in high-energy region using the PHITS code

Iwamoto, Yosuke; Niita, Koji*; Sawai, Tomotsugu; Ronningen, R. M.*; Baumann, T.*

JAEA-Conf 2011-002, p.157 - 162, 2011/09

https://jopss.jaea.go.jp/pdfdata/JAEA-Conf-2011-002.pdf

Radiation damage measured as a function of DPA is one of the critical issues for high-intensity beams, especially heavy-ions. The DPA model in PHITS has recently been extended to include contributions from Coulomb elastic scattering of transported charged particles. For the Coulomb elastic scattering, a universal one-parameter differential scattering cross section equation introduced by J. Lindhard et al. is employed instead of the differential Rutherford cross section which is a function of six parameters; charge and mass number of incident and produced particles, kinetic energy of incident particle and scattered angle. In this work, we compare PHITS results for the 130 MeV/u 6Ge+W reaction with calculated results of TRIM which is two-dimensional damage calculation code. Then we calculate DPA for different ions, targets and energies in the energy region from 100 MeV/u to 1 GeV/u and evaluate the systematics of DPA.

Extra-irradiation hardening of reduced activation ferritic/martensitic steel by multi-ion irradiation

Ando, Masami; Wakai, Eiichi; Okubo, Nariaki; Ogiwara, Hiroyuki; Sawai, Tomotsugu; Onuki, Somei*

Nihon Kinzoku Gakkai-Shi, 71(12), p.1107 - 1111, 2007/12

https://doi.org/10.2320/jinstmet.71.1107

no abstracts in English

Impact of N-isotope composition control of ferritic steel on classification of radioactive materials from fusion reactor

Hayashi, Takao; Kasada, Ryuta*; Tobita, Kenji; Nishio, Satoshi; Sawai, Tomotsugu; Tanigawa, Hiroyasu; Jitsukawa, Shiro

Fusion Engineering and Design, 82(15-24), p.2850 - 2855, 2007/10

https://doi.org/10.1016/j.fusengdes.2007.01.007

The impact of increasing the enrichment of N in low activation ferritic steel, F82H, of a fusion reactor has been investigated in order to increase the fraction of low level material (LLM), which can be disposed by shallow land burial. Carbon-14, mainly produced from nitrogen, is one of the most critical nuclei for qualifying as a LLM. The concentration of nitrogen in F82H is 200 ppm in the calculations. The enrichment of N was varied from natural abundance of 0.37% to 95%. The concentration of C at the outboard first wall decreased from 7.8 10 to 3.2 10 Bq/g by enriching N, which is lower than the C regulation (3.7 10 Bq/g) for LLM in Japan. In the permanent blanket, the highest C concentration with 95% N enriched nitrogen was 1.0 10 Bq/g. The C concentration on the inboard side was lower than the outboard side. Therefore, with regard to the C concentration, the F82H used in the inboard and outboard blankets can qualify as a LLM by enriching N.

Creep behavior of reduced activation ferritic/martensitic steels irradiated at 573 and 773K up to 5dpa

Ando, Masami; Li, M.*; Tanigawa, Hiroyasu; Grossbeck, M. L.*; Kim, S.-W.; Sawai, Tomotsugu; Shiba, Kiyoyuki; Kono, Yutaka*; Koyama, Akira*

Journal of Nuclear Materials, 367-370(1), p.122 - 126, 2007/08

https://doi.org/10.1016/j.jnucmat.2007.03.157

Irradiation creep behavior of the F82H and several JLF-1 steels have been measured up to 5 dpa, using helium-pressurized creep tubes irradiated in HFIR. These tubes were pressurized with helium to hoop stress levels of 0 to 400 MPa for irradiation temperature. The results of F82H and JLF-1 with 200 MPa hoop stress showed small creep strains ( 0.15%) after irradiation. Irradiation creep rate in these steels is linearly dependent on the applied stress less than 200 MPa. However, at higher hoop stress level, the creep rate of them is nonlinear. The creep compliance coefficient for F82H and JLF-1 at 300 C is very small values. These data contribute to a part of materials database for ITER Test blanket design work.

Effect of helium and hydrogen production on irradiation hardening of F82H steel irradiated by ion beams

Wakai, Eiichi; Ando, Masami; Sawai, Tomotsugu; Onuki, Somei*

Materials Transactions, 48(6), p.1427 - 1430, 2007/06

https://doi.org/10.2320/matertrans.MBW200611

Effects of helium and hydrogen production on irradiation hardening of martensitic steel F82H (Fe-8Cr-2W-0.2V-0.04Ta-0.1C) were examined by dual or triple beam experiments. The effects of tempering and cold working were also examined. The irradiations were performed at about 500C to 50 dpa under simultaneous dual beams of 10.5 MeV-Fe and 1.05 MeV-He or triple beams of those and 380keV-H ions. The value of appm-He/dpa for the dual ion beams was about 15, and the values of appm-He/dpa and appm-H/dpa for the triple ion beams were 15 and 15 (or 150), respectively. The hardness of the irradiated specimens measured at room temperature using a micro indentation after the irradiations. Irradiation softening and hardening was observed in F82H-std, F82H+CW and a non-tempered F82H steels irradiated at about 500C to 18 and 50 dpa, respectively, by dual ion beams. The hardness of the specimens irradiated at about 500C to 18 dpa under triple ion beams was harder than that under dual ion beams.

Fabrication of 8Cr-2W ferritic steel tile for reduction in toroidal magnetic field ripple on JT-60U

Kudo, Yusuke; Sawai, Tomotsugu; Sakurai, Shinji; Masaki, Kei; Suzuki, Yutaka; Sasajima, Tadayuki; Hayashi, Takao; Takahashi, Ryukichi*; Honda, Masao; Jitsukawa, Shiro; et al.

Journal of the Korean Physical Society, 49(96), p.S297 - S301, 2006/12

http://www.kps.or.kr/jkps/abstract_view.asp?articleuid=71E58E92-124F-41B0-899D-B0C585DA073B&globalmenu=3&localmenu=10

Installation of ferritic steel tiles was proposed in JT-60U to reduce the toroidal magnetic field ripple and to improve the fast ion loss, which degrades heating efficiency and increases heat load on plasma facing component under large volume plasma operations. We selected a 8Cr-2W-0.2V ferritic steel with the cost-effectiveness, in which concentration limits of activation elements in F82H were relaxed because of the less number of neutron generations from deuterium operations on JT-60U. The fabricated ferritic steel has clear tempered martensitic microstructure, and sufficient magnetic and mechanical properties. The saturated magnetization was estimated to 1.7 Tesla at 573 K, lower than expected, but effectiveness in JT-60U was confirmed by numerical analyses. To research the effect of material conditions, such as microstructure and heat treatment, on saturated magnetization of the ferritic steel based on 8-9Cr is important for the future fusion reactors which will be planned to install the ferritic steel as the in-vessel components.