About the Design of the Cover


The cover is designed with white hexagons similar to the pattern in a tortoise shell, an ancient Japanese symbol of people’s wish for longer lives. Coincidentally, this shape is the same as that of core fuel assemblies for both the prototype fast breeder reactor “MONJU” and the high temperature engineering test reactor “HTTR”.


The images on the cover show detailed molten materials accumulation behavior inside the pedestal by mechanistic numerical simulation code, JUPITER (top left) and visualization result of radioactive substances inside the turbine building of the TEPCO’s Fukushima Daiichi NPS (1F) Unit 3 (bottom right).


The top left image shows the detailed molten materials accumulation behavior inside the pedestal. Melt relocation and accumulation behavior of the main component of core internals such as UO2, SUS and Zry are inflowed and are calculated mechanistically by JUPITER (Chapter 1, Topic 1-1, p.11).


The bottom right image shows the color image of the radioactive substances obtained using the compact Compton camera in the 1F building, which is the high-dose rate environment. We detected the local contamination near the hose crawled on the floor surface (Chapter 1, Topic 1-7, p.17).


JAEA R&D Review 2018

annual report 2017

About the activity status of the whole agency
including CSR, see the annual report
Japan Atomic Energy Agency 2018

JAEA R&D Review 2018–19


Published by
Japan Atomic Energy Agency in January 2019
Editorial Board
Chief editor:Hiroshi Nakashima

Kenji Tatematsu, Tomoaki Suzudo, Ayako Okubo, Shinichi Koyama,
Yutaka Sugita, Fumitaka Esaka, Shinichi Shamoto, Yasuji Morita,
Takamasa Mori, Yukiharu Takeda, Kenji Sakai, Takashi Takata,
Shoji Takada, Hirotsugu Hamada, Takashi Mizuno, Kazuhiko Sato

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