Upgrade of seismic design procedure for piping systems based on elastic-plastic response analysis

Nakamura, Izumi*; Otani, Akihito*; Okuda, Yukihiko; Watakabe, Tomoyoshi; Takito, Kiyotaka; Okuda, Takahiro; Shimazu, Ryuya*; Sakai, Michiya*; Shibutani, Tadahiro*; Shiratori, Masaki*

Dai-10-Kai Kozobutsu No Anzensei, Shinraisei Ni Kansuru Kokunai Shimpojiumu (JCOSSAR2023) Koen Rombunshu (Internet), p.143 - 149, 2023/10

https://doi.org/10.60316/jcossar.10.0_143

In 2019, the JSME Code Case for seismic design of nuclear power plant piping systems was published. The Code Case provides the strain-based fatigue criteria and detailed inelastic response analysis procedure as an alternative design rule to the current seismic design, which is based on the stress evaluation by elastic response analysis. In 2022, it was approved to revise the Code Case with improving the cycle counting method for fatigue evaluation to the Rain flow method. In addition, the discussion to incorporate the elastic-plastic behavior of support structures is now in progress for the next revision of the Code Case. This paper discusses the contents and background of the 2022 revision, the progress of the next revision, and future tasks.

Long-term observation of fog chemistry and estimation of fog water and nitrogen input via fog water deposition at a mountainous site in Hokkaido, Japan

Yamaguchi, Takashi*; Katata, Genki; Noguchi, Izumi*; Sakai, Shigekatsu*; Watanabe, Yoko*; Uematsu, Mitsuo*; Furutani, Hiroshi*

Atmospheric Research, 151, p.82 - 92, 2015/01

https://doi.org/10.1016/j.atmosres.2014.01.023

To evaluate water and nitrogen input via fog water deposition, fog chemistry and deposition around a crater lake (Mashu) in northern Japan were investigated in the growing seasons of trees in 2006-2012. The fog samples were collected using an active fog collector and droplet size distribution was measured by a droplet size spectrometer. Compared to previous iterature of exposure experiments of acid mist on plants, fog acidity in this study did not seem to injure plant leaves. The visibility (VIS)-liquid water content of fog (LWC) relationship differed between summer and autumn. Fog water deposition was calculated from LWC empirically derived from past VIS data and deposition velocity estimated using wind speed and vegetation parameters. The water and nitrogen inputs via fog water deposition accumulated for each growing season were estimated as 107-161 mm and 20-41 meq m, respectively.

Report on decontamination pilot projects to establish guidelines for environmental remediation of residential areas contaminated with radioactive materials discharged from the Fukushima Daiichi Nuclear Power Station Accident

Kihara, Shinji; Amazawa, Hiroya; Sakai, Akihiro; Nakata, Hisakazu; Kugo, Teruhiko; Matsuda, Norihiro; Oizumi, Akito; Sasamoto, Hiroshi; Mitsui, Seiichiro; Miyahara, Kaname

JAEA-Research 2013-033, 320 Pages, 2014/07

JAEA-Research-2013-033.pdf:119.17MB

JAEA performed decontamination experiments at two test sites that combined a range of buildings and different types of land use, located in Date and Minami Soma municipalities as field pilot projects in order to accumulate knowledge and data for full-scale decontamination activities performed by local governments. In the pilot projects, we established its plan using practical decontamination methods that can be easily implemented, according to decontamination targets (e.g., forests, agricultural land, residential house and roads) at each site. As a result of the decontamination, the average air dose rates were reduced to approximately one half of the values before decontamination.

Insulation and impregnation test for ITER toroidal field coils

Hemmi, Tsutomu; Matsui, Kunihiro; Koizumi, Norikiyo; Nakajima, Hideo; Iijima, Ami*; Sakai, Masahiro*

Teion Kogaku, 47(3), p.172 - 177, 2012/03

https://doi.org/10.2221/jcsj.47.172

The manufacturing process for the ITER Toroidal Field (TF) coil has to be demonstrated for the qualification. Since the impregnation of its insulation system is one of the qualifications, the authors performed impregnation test using cyanate-ester and epoxy blended resin, which is a candidate among resins because of its excellent resistance to radiation. To establish the insulation and impregnation procedure of the TF coil manufacturing, three types of trials were performed. (1) Impregnation tests using an acrylic model to fix the impregnation conditions; (2) Impregnation test using a metallic model to confirm that no void remains in the insulation layer after the curing in the D-shaped configuration; and (3) Insulation and impregnation trials using 1/3 scale double pancake (DP) to establish the insulation and impregnation procedure for the TF coil manufacturing, The procedure of the insulation and impregnation for the ITER TF coil was established from the results of these trials.

Research on glass cells for He neutron spin filters

Sakaguchi, Yoshifumi; Kira, Hiroshi; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sakai, Kenji; Nakamura, Mitsutaka; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; et al.

Physica B; Condensed Matter, 406(12), p.2443 - 2447, 2011/06

https://doi.org/10.1016/j.physb.2010.12.020

Characterization of glasses for He neutron spin filter cells

Sakaguchi, Yoshifumi; Kira, Hiroshi; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sakai, Kenji; Nakamura, Mitsutaka; Suzuya, Kentaro; Arai, Masatoshi; Takeda, Masayasu; et al.

Nuclear Instruments and Methods in Physics Research A, 634(1, Suppl.), p.S122 - S125, 2011/04

Simplified evaluation guideline for thermal fatigue damage due to random fluctuation of fluid temperature

Okajima, Satoshi*; Honda, Kei*; Sakai, Shinsuke*; Izumi, Satoshi*; Oishi, Kunio*; Kasahara, Naoto

Nihon Kikai Gakkai M&M 2007 Zairyo Rikigaku Kanfarensu Koen Rombunshu (CD-ROM), p.262 - 263, 2007/10

It is well known that fatigue damage accumulates around T-junctions of piping system where two kinds of fluid with different temperatures are mixed. Kasahara et al. have proposed the thermal fatigue evaluation method based on power spectrum density (PSD). However, this method is too complex to practical use in the design stage. In this paper, a simplified damage evaluation guideline is proposed based on the Kasahara et al. method. The damage evaluation procedure from stress PSD is simplified in this guideline.

Design of the injection bump system of the 3-GeV RCS in J-PARC

Takayanagi, Tomohiro; Kamiya, Junichiro; Watanabe, Masao; Yamazaki, Yoshishige; Irie, Yoshiro; Kishiro, Junichi; Sakai, Izumi*; Kawakubo, Toshimichi*

IEEE Transactions on Applied Superconductivity, 16(2), p.1358 - 1361, 2006/06

https://doi.org/10.1109/TASC.2005.864361

The injection bump system of the 3-GeV RCS in J-PARC consists of the pulse bending magnets for the injection bump orbit, which are four horizontal bending magnets (shift bump), four horizontal painting magnets (h-paint bump), and two vertical painting magnets (v-paint bump). In this paper, the design of the magnets and power supply of the injection bump system are reported.

Direct evaluation method of thermal fatigue damage due to random fluctuation of fluid temperature

Okajima, Satoshi*; Sakai, Shinsuke*; Izumi, Satoshi*; Kasahara, Naoto

Nihon Zairyo Gakkai Dai-21-Kai Zairyo, Kozo Shinraisei Shimpojiumu Koen Rombunshu, p.132 - 137, 2005/12

no abstracts in English

Design of the pulse bending magnets for the injection system of the 3-GeV RCS in J-PARC

Takayanagi, Tomohiro; Irie, Yoshiro; Kamiya, Junichiro; Watanabe, Masao; Watanabe, Yasuhiro; Ueno, Tomoaki*; Noda, Fumiaki*; Saha, P. K.; Sakai, Izumi*; Kawakubo, Toshimichi*

Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.1048 - 1050, 2005/00

The pulse bending magnets for the injection system of the 3-GeV RCS in J-PARC has been designed. The injection system consists of the pulsed bending magnets, which are four horizontal bending magnets (shift bump) and four horizontal painting magnets (h-paint bump) for the injection bump orbit, and two vertical painting magnets (v-paint magnet). The injection beam energy and the extraction beam power are 400 MeV and 1 MW at 25 Hz repetition rate, respectively. The acceptance to include the injection beam, the painting beam and the circulating beam at the shift bump points is a 388 mm wide and a 242 mm high. The shift bump has been designed using a 3D magnetic analysis code, which accomplished less than 0.4 % field deviation under 0.26 T excitation level.