著者

Osamu Kontani Takashi Okayasu Keishi Kawasumi Shunsuke Ishikawa Hiroshi Masaki Norihiko Tanaka Yasuyuki Goto Shinichi Ishioka

出版者

Japan Concrete Institute

雑誌

Journal of Advanced Concrete Technology (ISSN:13473913)

巻号頁・発行日

vol.20, no.7, pp.444-483, 2022-07-27 (Released:2022-07-27)

参考文献数

46

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The Fukushima Daiichi Nuclear Power Plant lost its core cooling function due to the massive tsunami generated by the 2011 off the Pacific coast of Tohoku Earthquake, which caused core meltdown, resulting in high temperature inside the containment vessel and exposing the RPV pedestal, a reinforced concrete structure, to an unusually high temperature environment. After the earthquake, water was poured into the containment vessel to cool the molten core, and the con-crete structure was gradually cooled in the process. Since it will take at least 40 years to remove the fuel from the core, the integrity of the RPV pedestal is a major concern for the decommissioning of the Fukushima Daiichi Nuclear Power Plant. In order to assess the long-term integrity of the RPV pedestal, a horizontal loading test was conducted using a 1/6 scaled model of the RPV pedestal of Unit 1 considering the effect of the high temperature heating and subsequent wet conditions. And then, the static stress analysis of the RPV pedestal was performed considering the degradation phenomena revealed by the experiments. As a result, it was confirmed that the RPV pedestal of Unit 1 would be structurally sound for 40 years against the current design basis earthquake even if the material degradation due to severe accident and aging was considered.

著者

Ken-ichiro YASUBA Hidehito KUROSAKI Takehiko HOSHI Takashi OKAYASU Yoshiyuki TANAKA Tanjuro GOTO Yuichi YOSHIDA

出版者

Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists

雑誌

Environmental Control in Biology (ISSN:1880554X)

巻号頁・発行日

vol.56, no.3, pp.107-112, 2018 (Released:2018-07-20)

参考文献数

17

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A program library for use on open-source hardware was developed in order to construct a low-cost environmental control system for greenhouses. The library facilitated the development of environmental sensing and control devices that conform to the protocols of the Ubiquitous Environment Control System (UECS). The open-source hardware used was the "Arduino Ethernet" and the "Arduino Mega 2560 with Ethernet Shield" microcontroller boards. UECS is a system for controlling greenhouse environments that communicates information via a local area network, and devices utilizing the library that we developed can perform the UECS defined communication tasks automatically. With the help of this library, device developers no longer need to program the communications aspects of the device and can concentrate on programming setting and control logic of the device. The library occupies about 29 kilobytes of the read only memory area of the target board. The library and associated open-source microcontroller boards are powerful tools for developing low-cost environmental control systems.