Study on rational treatment/disposal of contaminated concrete waste considering leaching alteration (Contract research); FY2021 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Hokkaido University*

JAEA-Review 2022-038, 102 Pages, 2023/01

JAEA-Review-2022-038.pdf:4.76MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2020, this report summarizes the research results of the "Study on rational treatment/disposal of contaminated concrete waste considering leaching alteration" conducted in FY2021. The present study aims to understand migration behaviors of radionuclides in relation to the properties of concrete altered by leaching, to develop a model to predict concentration profiles, and to analyze waste management scenarios, with a focus on underground concrete structures in contact with contaminated water. Migration behaviors depend on radionuclides and their chemical species. Sorption of I is less significant on C-S-H and C-A-S-H than on hardened cement paste with two orders of magnitude smaller distribution coefficient , while of U was the same …

Progress Report on Safety Research of High-Level Waste Management for the Perical April,1981 to May,1982

JAERI-M 82-145, 73 Pages, 1982/10

JAERI-M-82-145.pdf:2.53MB

no abstracts in English

Characterization of sludge generated from decontamination device in Fukushima Daiichi NPS

Hinai, Hiroshi; Sato, Daisuke; Shibata, Atsuhiro; Myodo, Masato; Koma, Yoshikazu; Nomura, Kazunori

no journal, , 

We have been analyzing and characterizing the contaminated water generated in Fukushima Daiichi Nuclear Power Station (NPS) and secondary waste of the contaminated water treatment system for investigation of their waste management. As one of the contaminated water treatment system, Decontamination Device was operated from June until September 2011. The operation of this device generated secondary waste of sludge that have a high dose rate. In this device, the contaminated water was mixed with several reagents to remove some radioactive nuclides. As the result, the sludge was generated as a complex of chemically stable substances. This sludge has been stored in a concrete pit and is required to transport to another place of the site and treat for further storage. For the purposes and upcoming disposal, a small amount of the sludge was analyzed for its radioactivity, particle size distribution and others. For radiochemical analysis, the sludge was successfully dissolved into solutions and was measured for its radioactivity composition; the main nuclides were Sr-90 and Cs-137. The concentration of Sr-90 (6.6E7 [Bq/cm]) was about 10 times higher than that of Cs-137 in the sludge. And small amount of Pu-238 as alpha-ray emitting nuclide was determined. The sludge mainly contained small particles of 10 micro meter or less in diameter. The rate of sedimentation and behavior of mixing also investigated.