Incorporation of boron into metakaolin-based geopolymers for radionuclide immobilisation and neutron capture potential

Niu, X.*; Elakneswaran, Y.*; Li, A.*; Seralathan, S.*; Kikuchi, Ryosuke*; Hiraki, Yoshihisa; Sato, Junya; Osugi, Takeshi; Walkley, B.*

Cement and Concrete Research, 190, p.107814_1 - 107814_17, 2025/04

https://doi.org/10.1016/j.cemconres.2025.107814

Massive Dirac magnons in the three-dimensional honeycomb magnetic oxide FeTiO

Chung, J.-H.*; Kwangwoo, S.*; Yokoo, Tetsuya R.; Ueta, Daichi*; Imai, Masaki; Kim, H.-S.; Kiem, D. H.; Han, M. J.*; Shamoto, Shinichi

Scientific Reports (Internet), 15, p.5978_1 - 5978_10, 2025/02

https://doi.org/10.1038/s41598-025-90478-2

Study on water stopping, repair and stabilization of lower PCV by geopolymer, etc. (Contract research); FY2022 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*

JAEA-Review 2024-021, 126 Pages, 2024/11

JAEA-Review-2024-021.pdf:6.51MB

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 FY2022. 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 FY2021, this report summarizes the research results of the "Study on water stopping, repair and stabilization of lower PCV by geopolymer, etc" conducted in FY2022. The present study aims to propose a construction method to stop jet deflectors by improved geopolymer and ultra-heavy muddy water, and to repair the lower part of the dry well. In addition, in order to increase the options for on-site construction in unknown situations such as deposition conditions, we will examine a wide range of construction outside the pedestal, and evaluate the feasibility of the construction method by the latest thermal flow simulation method.

Impact of interatomic structural characteristics of aluminosilicate hydrate on the mechanical properties of metakaolin-based geopolymer

Kim, G.*; Cho, S.-M.*; Im, S.*; Suh, H.*; Morooka, Satoshi; Shobu, Takahisa; Kanematsu, Manabu*; Machida, Akihiko*; Bae, S.*

Construction and Building Materials, 411, p.134529_1 - 134529_18, 2024/01

https://doi.org/10.1016/j.conbuildmat.2023.134529

Study on water stopping, repair and stabilization of lower PCV by geopolymer, etc. (Contract research); FY2021 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*

JAEA-Review 2022-062, 121 Pages, 2023/03

JAEA-Review-2022-062.pdf:4.78MB

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 FY2021, this report summarizes the research results of the "Study on water stopping, repair and stabilization of lower PCV by geopolymer, etc." conducted in FY2021. The present study aims to propose a construction method to stop jet deflectors by improved geopolymer and ultra-heavy muddy water, and to repair the lower part of the dry well. In addition, in order to increase the options for on-site construction in unknown situations such as deposition conditions, we will examine a wide range of construction outside the pedestal, and evaluate the feasibility of the construction method by the latest thermal flow simulation method. When widely constructed, fuel debris and deposits discharged out of the pedestal are coated with water stop and repair materials and become waste ...

Safe, efficient cementation of challenging radioactive wastes using alkali activated materials with high-flowability and high-anion retention capacity (Contract research); FY2021 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Hokkaido University*

JAEA-Review 2022-050, 116 Pages, 2023/01

JAEA-Review-2022-050.pdf:11.41MB

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 (1F), 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 FY2019, this report summarizes the research results of the "Safe, efficient cementation of challenging radioactive wastes using alkali activated materials with high-flowability and high-anion retention capacity" conducted from FY2019 to FY2021. Since the final year of this proposal was FY2021, the results for three fiscal years were summarized. The present study aims to explore alkali activated materials with high anionic nuclide retention and flowability and their recipes for safe storage and disposal of iron flocculant from the water treatment facility at 1F, and to propose a design of a solidification device that is feasible as an actual plant. In order to achieve these objectives, the following five items were carried out in this study.

Geopolymer and ordinary Portland cement interface analyzed by micro-Raman and SEM

Cantarel, V.; Yamagishi, Isao

Journal of Nuclear Science and Technology, 59(7), p.888 - 897, 2022/07

https://doi.org/10.1080/00223131.2021.2016510

The Multiaxial creep-fatigue failure mechanism of Mod. 9Cr-1Mo steel under non-proportional loading; Effect of strain energy on failure lives

Ogawa, Fumio*; Nakayama, Yuta*; Hiyoshi, Noritake*; Hashidate, Ryuta; Wakai, Takashi; Ito, Takamoto*

Transactions of the Indian National Academy of Engineering (Internet), 7(2), p.549 - 564, 2022/06

https://doi.org/10.1007/s41403-021-00279-y

The strain energy-based life evaluation method of Mod. 9Cr-1Mo steel under non-proportional multiaxial creep-fatigue loading is proposed. Inelastic strain energy densities were calculated as the areas inside the hysteresis loops. The effect of mean-stress has been experimentally considered and the relationship between inelastic strain energy densities and creep-fatigue lives was investigated. It was found from the investigation of hysteresis loops, the decrease in maximum stress leads to prolonged failure life, while stress relaxation during strain holding causes strength reduction. The correction method of inelastic strain energy density was proposed considering the effect of maximum stress in hysteresis loop and minimum stress during strain holding, and strain energy densities for uniaxial and non-proportional multiaxial loading were obtained. Based on these results, the mechanisms governing creep-fatigue lives under non-proportional multiaxial loading have been discussed.

Evaluation of multiaxial low cycle creep-fatigue life for Mod.9Cr-1Mo steel under non-proportional loading

Nakayama, Yuta*; Ogawa, Fumio*; Hiyoshi, Noritake*; Hashidate, Ryuta; Wakai, Takashi; Ito, Takamoto*

ISIJ International, 61(8), p.2299 - 2304, 2021/08

https://doi.org/10.2355/isijinternational.ISIJINT-2020-780

This study discusses the creep-fatigue strength for Mod.9Cr-1Mo steel at a high temperature under multiaxial loading. A low-cycle fatigue tests in various strain waveforms were performed with a hollow cylindrical specimen. The low cycle fatigue test was conducted under a proportional loading with a fixed axial strain and a non-proportional loading with a 90-degree phase difference between axial and shear strains. The low cycle fatigue tests at different strain rates and the creep-fatigue tests at different holding times were also conducted to discuss the effects of stress relaxation and strain holding on the failure life. In this study, two types of multiaxial creep-fatigue life evaluation methods were proposed: the first method is to calculate the strain range using Manson's universal slope method with considering a non-proportional loading factor and creep damage; the second method is to calculate the fatigue damage by considering the non-proportional loading factor using the linear damage law and to calculate the creep damage from the improved ductility exhaustion law. The accuracy of the evaluation methods is much better than that of the methods used in the evaluation of actual machines such as time fraction rule.

Safe, efficient cementation of challenging radioactive wastes using alkali activated materials with high-flowability and high-anion retention capacity (Contract research); FY2019 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Hokkaido University*

JAEA-Review 2020-054, 72 Pages, 2021/01

JAEA-Review-2020-054.pdf:5.62MB

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 FY2019. 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 FY2019, this report summarizes the research results of the "Safe, efficient cementation of challenging radioactive wastes using alkali activated materials with high-flowability and high-anion retention capacity". The purpose of this study is to find safe, efficient cementation of challenging radioactive wastes using alkali activated materials with high-flowability and high-anion retention capacity, and to propose the concept of a manufacturing apparatus that is established as an actual plant. As a result of study in this year, it was revealed that the K-based alkali activated material has high-flowability and quick curing, and that high-iodine retention capacity is achieved by incorporating silver ions during manufacturing of solidified waste.