Analysis of the radioactivity concentrations in radioactive waste generated from JPDR Facility

Tobita, Minoru*; Haraga, Tomoko; Endo, Tsubasa*; Omori, Hiroyuki*; Mitsukai, Akina; Aono, Ryuji; Ueno, Takashi; Ishimori, Kenichiro; Kameo, Yutaka

JAEA-Data/Code 2021-013, 30 Pages, 2021/12

JAEA-Data-Code-2021-013.pdf:1.47MB

Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed concrete samples generated from JPDR facility. In this report, we summarized the radioactivity concentrations of 21 radionuclides (H, C, Cl, Ca, Co, Ni, Sr, Nb, Ag, Cs, Eu, Eu, Ho, U, U, Pu, Pu, Pu, Am, Am, Cm) which were obtained from radiochemical analysis of the samples in fiscal year 2018-2019.

Status of MONJU decommissioning Phase 2, 1; Reconsideration of performance maintenance facilities in accordance with the transition to Phase 2 of the MONJU decommissioning plan

Ono, Fumiyasu; Fukushima, Tsubasa; Naruse, Keiji; Matsui, Kazuaki; Obata, Ikuhito; Sawazaki, Hiromasa; Goto, Takehiro; Jo, Takahisa; Uchihashi, Masaya

no journal, , 

By storing fuel assemblies in the fuel pond in Phase 1, MONJU eliminates the residual risk of fuel assemblies remaining in the core, which holds chemically active liquid sodium, and from April 2023, Have moved to Phase 2 of decommissioning. As the decommissioning progresses, plant risks will continue to change. Therefore, we will organize the plant status at each Phase of decommissioning and formulate the concept of performance maintenance facilities for MONJU, which will be necessary in Phase 2, and Performance maintenance facilities were Reconsidered.

Uncertainty assessment of environmental fate of radioactive cesium in the river basins of Fukushima Prefecture through long-term simulation

Nittono, Akira*; Ikenoue, Tsubasa; Shimadera, Hikari*; Matsuo, Tomohito*; Kondo, Akira*

no journal, , 

The Fukushima Daiichi Nuclear Power Plant accident caused extensive Cs contamination. Long-term simulations have been conducted to predict the amount of Cs outflow from river basins to the ocean. However, there are uncertainties about the influences of rainfall, tree types and dams to the Cs outflow. This study focused on how much these three factors influence the Cs outflow in eastern Fukushima river basins from 2011 to 2040. The Cs outflow varied by -10 to +17% depending on precipitation, and by -16 to +19% depending on tree species, decreased by 21% by dams.