Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2011

Kunimaru, Takanori; Mikake, Shinichiro; Nishio, Kazuhisa; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Ishibashi, Masayuki; Sasao, Eiji; Hikima, Ryoichi; Tanno, Takeo; Sanada, Hiroyuki; et al.

JAEA-Review 2013-018, 169 Pages, 2013/09

JAEA-Review-2013-018.pdf:15.71MB

Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) Project in crystalline rock environment in order to construct scientific and technological basis for geological disposal of High-level Radioactive Waste (HLW). The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). The MIU Project has been ongoing the Phase II and the Phase III in 2011 fiscal year. This report shows the results of the investigation, construction and collaboration studies in fiscal year 2011, as a part of the Phase II and Phase III based on the MIU Master Plan updated in 2010.

Fission fragment mass distribution for nuclei in the r-process region

Tatsuda, Sayuki*; Hashizume, Kazuaki*; Wada, Takahiro*; Ota, Masahisa*; Sumiyoshi, Kosuke*; Otsuki, Kaori*; Kajino, Toshitaka*; Koura, Hiroyuki; Chiba, Satoshi; Aritomo, Yoshihiro*

AIP Conference Proceedings 891, p.423 - 426, 2007/03

https://doi.org/10.1063/1.2713548

We investigate the fission-fragment mass distribution on about 2000 nuclides, which should have a critical impact on the r-process nucleosynthesis through fission (). The mass distribution of fission fragment is thought to be one of the most important elements on some astrophysical conditions for the theoretical estimation of the r-process abundance pattern. We calculated the potential energy surface (PES) by means of the liquid-drop model with the shell energy correction by the Two-Center shell model in 3-dimensional parameter space. We derive fission-fragment mass distribution by considering the location and the depth of the valley of PES near the saddle point and the scission point of nuclei with the use of the Langevin calculation. We determine the fission asymmetry by examining the valley depth and its location in the deformation parameter space. The consistency of our mass asymmetry with available experimental data is discussed.