HFB-1 borehole survey data collection

Miyakawa, Kazuya; Hayano, Akira; Sato, Naomi; Nakata, Kotaro*; Hasegawa, Takuma*

JAEA-Data/Code 2023-009, 103 Pages, 2023/09

JAEA-Data-Code-2023-009.pdf:9.29MB
JAEA-Data-Code-2023-009-appendix1(DVD-ROM).zip:271.51MB
JAEA-Data-Code-2023-009-appendix2(DVD-ROM).zip:883.78MB
JAEA-Data-Code-2023-009-appendix3(DVD-ROM).zip:10.29MB

This borehole investigation was carried out to confirm the validity of the distribution of low flow areas deep underground estimated based on the geophysical survey in FY 2020, as a part of an R&D supporting program titled "Research and development on Groundwater Flow Evaluation Technology in Bedrock" under contract to the Ministry of Economy, Trade and Industry (2021, 2022 FY, Grant Number: JPJ007597). The borehole name is Horonobe Fossil seawater Boring-1 and is referred to as HFB-1 borehole. HFB-1 is a vertical borehole drilled adjacent to the Horonobe Underground Research Laboratory (URL), which was drilled from the surface to a depth of 200 m in FY2021 and from a depth of 200 m to 500 m in FY2022. This report summarizes information related to the drilling of HFB-1 and various data (rock core description, geophysical logging, chemical analysis, etc.) obtained from the borehole investigation.

Application of satellite remote sensing in geological environment investigation; Development of a geobotanical remote sensing method for estimating high water table areas in a humid warm-temperate region

Koide, Kaoru

JAEA-Research 2023-003, 101 Pages, 2023/06

JAEA-Research-2023-003.pdf:14.08MB

This study developed a geobotanical remote sensing method for estimating high water table areas such as groundwater discharge points using differences in the growth conditions of forest trees induced by moisture supply from groundwater in a humid warm-temperate forest area. A new vegetation index (VI) termed AgbNDVI (Added green band NDVI) was proposed to discriminate the differences. The AgbNDVI proved to be more sensitive to water stress on green vegetation than existing VIs: SAVI and EVI2, and possessed a strong linear correlation with the vegetation fraction. To validate the proposed method, a 23 km study area was selected in the Tono region of Gifu Prefecture, central Japan. The AgbNDVI values were calculated from atmospheric corrected SPOT HRV data. To correctly detect high VI points, the influence factors on tree growth were identified using the AgbNDVI values, DEM and forest type data; the study area was then divided into 555 segments according to combinations of the influence factors: elevation, slope gradient, slope aspect and forest type. Thresholds for detecting high VI points were defined for each segment based on a histogram of AgbNDVI values. By superimposing the high VI points on topographic and geologic maps, most of the high VI points are clearly located on the concave/convex slopes and near the geologic boundaries prone to groundwater runoff. In addition, field investigations support the correctness of the high VI points, because the growth increments and biomass of trees () are greater than at points other than the high VI points, and they are located around known groundwater seeps and in a high water table area. Consequently, the proposed method can be expected to provide useful information for characterizing hydrogeological structures by combining with conventional photo-geological interpretation.

Iron-induced association between selenium and humic substances in groundwater from deep sedimentary formations

Terashima, Motoki; Endo, Takashi*; Kimuro, Shingo; Beppu, Hikari*; Nemoto, Kazuaki*; Amano, Yuki

Journal of Nuclear Science and Technology, 60(4), p.374 - 384, 2023/04

https://doi.org/10.1080/00223131.2022.2111376

Dynamic probabilistic risk assessment of seismic-induced flooding in pressurized water reactor by seismic, flooding, and thermal-hydraulics simulations

Kubo, Kotaro; Jang, S.*; Takata, Takashi*; Yamaguchi, Akira*

Journal of Nuclear Science and Technology, 60(4), p.359 - 373, 2023/04

https://doi.org/10.1080/00223131.2022.2100837

Probabilistic risk assessment (PRA) is an essential approach to improving the safety of nuclear power plants. However, this method includes certain difficulties, such as modeling of combinations of multiple hazards. Seismic-induced flooding scenario includes several core damage sequences, i.e., core damage caused by earthquake, flooding, and combination of earthquake and flooding. The flooding fragility is time-dependent as the flooding water propagates from the water source such as a tank to compartments. Therefore, dynamic PRA should be used to perform a realistic risk analysis and quantification. This study analyzed the risk of seismic-induced flooding events by coupling seismic, flooding, and thermal-hydraulics simulations, considering the dependency between multiple hazards explicitly. For requirements of safety improvement, especially in light of the Fukushima Daiichi Nuclear Power Plant accident, sensitivity analysis was performed on the seismic capacity of systems, and the effectiveness of alternative steam generator injection by a portable pump was estimated. We demonstrate the use of this simulation-based dynamic PRA methodology to evaluate the risk induced by a combination of hazards.

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 ...

Effect of radioactive cesium-rich microparticles on radioactive cesium concentration and distribution coefficient in rivers flowing through the watersheds with different contaminated condition in Fukushima

Tatsuno, Takahiro*; Waki, Hiromichi*; Kakuma, Minato*; Nihei, Naoto*; Takase, Tsugiko*; Wada, Toshihiro*; Yoshimura, Kazuya; Nakanishi, Takahiro; Ote, Nobuhito*

Journal of Environmental Management, 329, p.116983_1 - 116983_13, 2023/03

https://doi.org/10.1016/j.jenvman.2022.116983

Development of the continuous monitoring of tritium water by mid-infrared laser spectroscopy (Contract research); FY2021 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; National Institutes of Natural Sciences*

JAEA-Review 2022-059, 34 Pages, 2023/01

JAEA-Review-2022-059.pdf:1.58MB

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 "Development of the continuous monitoring of tritium water by mid-infrared laser spectroscopy" conducted in FY2021. The present study aims to demonstrate the principle of short-time measurement of tritiated water at the "60 Bq/cc level" using a cavity ring-down measurement system with a mid-infrared laser. In order to achieve the above goal, (1) research on the cavity ring-down system and (2) evaluation of hydrogen isotope composition under environmental conditions and preparation of standard samples (subcontractor: Hirosaki University) were conducted this fiscal year. In (1), a mid-infrared cavity ring-down test was conducted. An optical bench (3 m 1.2 m) was set up in the laboratory, …

Arsenic removal from contaminated water utilizing novel green composite and nano zero-valent iron

Islam, M. S.*; Maamoun, I.; Falyouna, O.*; Eljamal, O.*; Saha, B. B.*

Journal of Molecular Liquids, 370, p.121005_1 - 121005_11, 2023/01

https://doi.org/10.1016/j.molliq.2022.121005

Chloramphenicol removal from water by various precursors to enhance graphene oxide-iron nanocomposites

Idham, M. F.*; Falyouna, O.*; Eljamal, R.*; Maamoun, I.; Eljamal, O.*

Journal of Water Process Engineering (Internet), 50, p.103289_1 - 103289_16, 2022/12

https://doi.org/10.1016/j.jwpe.2022.103289

Development of the simplified boiling model applied to the large-scale detailed simulation

Ono, Ayako; Yamashita, Susumu; Sakashita, Hiroto*; Suzuki, Takayuki*; Yoshida, Hiroyuki

Proceedings of 13th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-13) (Internet), 12 Pages, 2022/09

Japan Atomic Energy Agency is developing the computational fluid dynamics code, JUPITER, based on the volume of fluid (VOF) method to analyze detailed thermal-hydraulics in a reactor. The detailed numerical simulation of boiling from a heating surface needs a substantial computational cost to resolve the microscale thermal-hydraulic phenomena such as the bubble generation from a cavity and evaporation of a micro-layer. This study developed the simplified boiling model from the heating surface to reduce the computational cost, which will apply to the detailed simulation code based on the surface tracking method such as JUPITER. We applied the simplified boiling model to JUPITER, and compared the simulation results with the experimental data of the vertical heating surface in the forced convection. We confirmed the degree of their reproducibility, and the issues to be modified were extracted.