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JAEA Reports

Study of groundwater sampling casing for monitoring device

Okihara, Mistunobu*; Yahagi, Ryoji*; Iwatsuki, Teruki; Takeuchi, Ryuji; Murakami, Hiroaki

JAEA-Technology 2019-021, 77 Pages, 2020/03

JAEA-Technology-2019-021.pdf:5.33MB

One of the major subjects of the ongoing geoscientific research program, the Mizunami Underground Research Laboratory (MIU) Project in the Tono area, central Japan, is accumulation of knowledge on monitoring techniques of the geological environment. In this report, the conceptual design of the monitoring system for groundwater pressure and water chemistry was carried out. The currently installed and used system in research galleries at various depths was re-designed to make it possible to collect groundwater and observe the water pressure on the ground.

JAEA Reports

Compilation of previous studies on secondary effects induced by earthquake and fault activity (Contract research)

Goto, Akira; Murakami, Masaki*; Sakai, Ryutaro*; Terusawa, Shuji*; Sueoka, Shigeru

JAEA-Review 2020-003, 60 Pages, 2020/03

JAEA-Review-2020-003.pdf:4.43MB

One of the natural phenomena that may affect the geological disposal system are earthquake and fault activity. Fault displacement due to the earthquake and fault activity will be considered the direct effects. In addition to it, it is necessary to consider the secondary effects include secondary faults formed by the seismic fault activity as well as spring water and mud volcanoes that are generated by fluid movement attributed to the fault activity. This paper introduces previous studies performed focused on the hydraulic effects (spring water and mud volcanoes) and mechanical effects (secondary faults) in order to understand the effects of these secondary phenomena on the geological disposal system. We were able to collect 142 literatures from Japan and overseas by searching for related keywords in Japanese and English. As a result, we compiled case studies of each secondary impact. From the viewpoint of geological disposal, we extracted the following issues for future research and development. As for the sump water induced by earthquakes and faulting, accumulation of information related to its mechanism, affected area, and activity history is required. As for the mud volcanoes, reviewing of the mechanism of anomalous pore water pressure that causing the formation, also development of estimation technique are required. And for the secondary faults, accumulation of the detailed spatial distribution and reviewing of formation mechanism are required.

JAEA Reports

Mizunami Underground Research Laboratory Project Annual Report for Fiscal Year 2018

Takeuchi, Ryuji; Iwatsuki, Teruki; Matsui, Hiroya; Nohara, Tsuyoshi; Onoe, Hironori; Ikeda, Koki; Mikake, Shinichiro; Hama, Katsuhiro; Iyatomi, Yosuke; Sasao, Eiji

JAEA-Review 2020-001, 66 Pages, 2020/03

JAEA-Review-2020-001.pdf:7.6MB

The Mizunami Underground Research Laboratory (MIU) Project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of geological disposal technologies through investigations of the deep geological environment in the crystalline rock (granite) at Mizunami City, Gifu Prefecture, central Japan. On the occasion of JAEA reformation in 2014, JAEA identified three remaining important issues on the geoscientific research program based on the synthesized latest results of research and development (R&D): "Development of countermeasure technologies for reducing groundwater inflow", "Development of modeling technologies for mass transport" and "Development of drift backfilling technologies". The R&D on three remaining important issues have been carrying out in the MIU Project. In this report, the current status of R&D and construction activities of the MIU Project in fiscal year 2018 is summarized.

JAEA Reports

Annual report for FY2018 on activities of decommissioning and radioactive waste management

Sector of Nuclear Fuel, Decommissioning and Waste Management Technology Development

JAEA-Review 2019-021, 149 Pages, 2020/03

JAEA-Review-2019-021.pdf:9.51MB

This annual report summarizes the activities of decommissioning and radioactive waste management in JAEA in the period from April 1, 2018 to March 31, 2019. Decommissioning activities and radioactive waste treatment activities were carried out according to the annual plan. Decommissioning plan of Tokai Vitrification Facility of Tokai Reprocessing Plant (TRP) of Nuclear Fuel Cycle Engineering Laboratories (NCL) was approved by Nuclear Regulation Authority (NRA) in June 2018. Uranium Enrichment Demonstration Plant of Ningyo-toge Environmental Engineering Center (Ningyo-toge), application for approval of decommissioning plan was submitted to NRA in September 2018. The dismantling cost of JAEA facilities were evaluated by DECOST Code, and the results were reflected by Facilities Management Plan. Radioactive waste generated from R&D activities in JAEA were treated and managed safety. Also, the construction of Oarai Waste Reduction Treatment Facility (OWTF) of Oarai Research and Development Institute was completed in March, 2019. As technology development pertaining to treatment and radioactive wastes activities were carried out according to the annual plan. Sampling technology of the reactor component and laser cutting technology have been developed towards reactor decommissioning in Fugen Decommissioning Engineering Center. In Ningyo-toge, a uranium measurement technology has been developed to verify the clearance level.

JAEA Reports

Annual report for FY2017 on activities of decommissioning and radioactive waste management

Sector of Nuclear Fuel, Decommissioning and Waste Management Technology Development

JAEA-Review 2019-020, 153 Pages, 2020/03

JAEA-Review-2019-020.pdf:10.84MB

This annual report summarizes the activities of decommissioning and radioactive waste management in JAEA in the period from April 1, 2017 to March 31, 2018. Decommissioning activities and radioactive waste treatment activities were carried out according to the annual plan. To reduce a risk of storage of high-level radioactive liquid waste, produced 34 vitrified wastes at Tokai Vitrification Facility of Tokai Reprocessing Plant (TRP) of Nuclear Fuel Cycle Engineering Laboratories (NCL). JRR-4 and Transient Experiment Critical Facility (TRACY) of Nuclear Science Research Institute (NSRI), each decommissioning plan was approved by Nuclear Regulation Authority (NRA) in June 2017. Radioactive waste generated from R&D activities in JAEA were treated and managed safety. Also, the construction of Oarai Waste Reduction Treatment Facility (OWTF) of Oarai Research and Development Center was carried out. As technology development pertaining to treatment and radioactive wastes activities were carried out according to the annual plan. Sampling technology of the reactor component and laser cutting technology have been developed towards reactor decommissioning in Fugen Decommissioning Engineering Center. In Ningyo-toge Environmental Engineering Center, a uranium measurement technology has been developed to verify the clearance level.

JAEA Reports

Annual report for FY2015 - 2016 on activities of decommissioning and radioactive waste management

Sector of Nuclear Fuel, Decommissioning and Waste Management Technology Development

JAEA-Review 2019-019, 118 Pages, 2020/03

JAEA-Review-2019-019.pdf:8.57MB

This annual report summarizes the activities of decommissioning and radioactive waste management in JAEA in the period from April 1, 2015 to March 31, 2017. Decommissioning activities and radioactive waste treatment activities were carried out according to the annual plan. To reduce a risk of storage of high-level radioactive liquid waste, produced 25 vitrified wastes at Tokai Vitrification Facility of Tokai Reprocessing Plant (TRP) of Nuclear Fuel Cycle Engineering Laboratories (NCL). Radioactive waste generated from R&D activities in JAEA were treated and managed safety. Also, the construction of Oarai Waste Reduction Treatment Facility (OWTF) of Oarai Research and Development Center was carried out. As technology development pertaining to treatment and radioactive wastes activities were carried out according to the annual plan. Laser cutting technology have been developed towards reactor decommissioning in Fugen Decommissioning Engineering Center. In Ningyo-toge Environmental Enginnering Center, a uranium measurement technology has been developed to verify the clearance level.

JAEA Reports

Synthesis report on the R&D for the Horonobe Underground Research Laboratory; Project carried out during fiscal years 2015-2019

Nakayama, Masashi; Saiga, Atsushi; Kimura, Shun; Mochizuki, Akihito; Aoyagi, Kazuhei; Ono, Hirokazu; Miyakawa, Kazuya; Takeda, Masaki; Hayano, Akira; Matsuoka, Toshiyuki; et al.

JAEA-Research 2019-013, 276 Pages, 2020/03

JAEA-Research-2019-013.pdf:18.72MB

The Horonobe Underground Research Laboratory (URL) Project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies for geological disposal of High-level Radioactive Waste through investigations of the deep geological environment within the host sedimentary rock at Horonobe Town in Hokkaido, north Japan. The investigations will be conducted in three phases, namely "Phase 1: Surface based investigations", "Phase 2: Construction phase" (investigations during construction of the underground facilities) and "Phase 3: Operation phase" (research in the underground facilities). According to the research plan described in the 3rd Mid- and Long- term Plan of JAEA, "Near-field performance study", "Demonstration of repository design option", and "Verification of crustal-movement buffering capacity of sedimentary rocks" are important issues of the Horonobe URL Project, and schedule of future research and backfill plans of the project will be decided by the end of 2019 Fiscal Year. The present report summarizes the research and development activities of these 3 important issues carried out during 3rd Medium to Long-term Research Phase.

JAEA Reports

Mizunami Underground Research Laboratory Project; Synthesis report on the R&D concerning important issues

Matsuoka, Toshiyuki; Hama, Katsuhiro

JAEA-Research 2019-012, 157 Pages, 2020/03

JAEA-Research-2019-012.pdf:11.91MB

The Mizunami Underground Research Laboratory (MIU) Project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies for geological disposal of High-level Radioactive Waste through investigations of the deep geological environment within the host crystalline rock at Mizunami City in Gifu Prefecture, central Japan. The project proceeds in three overlapping phases, "Phase I: Surface-based investigation Phase", "Phase II: Construction Phase" and "Phase III: Operation Phase". The MIU Project has been ongoing the Phase III, as the Phase II was concluded for a moment with the completion of the excavation of horizontal tunnels at GL-500m level in February 2014. The present report summarizes the research and development activities carried out mainly in the GL-500m stage during Third Medium to Long-term Research Phase.

JAEA Reports

Visualization of fractures in an excavation damaged zone in the Horonobe Underground Research Laboratory, 2 (Joint research)

Aoyagi, Kazuhei; Chen, Y.*; Ishii, Eiichi; Sakurai, Akitaka; Miyara, Nobukatsu; Ishida, Tsuyoshi*

JAEA-Research 2019-011, 50 Pages, 2020/03

JAEA-Research-2019-011.pdf:3.48MB

In this research, we performed the resin injection experiment at the 350 m Gallery of Horonobe Underground Research Laboratory in order to identify the distribution of fractures induced around the gallery owing to excavation. We also observed the rock cores obtained around the resin injection borehole under ultraviolet light. As a result, the extent of the development of EDZ fracture was 0.9 m from the gallery wall. In the depth within 0.4 m from the gallery wall, the density of the EDZ fracture is higher than the depth more than 0.4 m from the gallery wall. As a result of the analysis on the fracture aperture by image processing, the fractures with a large aperture (1.02 mm in maximum) were observed within 0.3 m from the gallery wall, while the maximum aperture was 0.19 mm in the depth more than 0.3 m from the gallery wall.

JAEA Reports

Data of groundwater chemistry obtained in the Horonobe Underground Research Laboratory Project (FY2017-FY2019)

Miyakawa, Kazuya; Mezawa, Tetsuya*; Mochizuki, Akihito; Sasamoto, Hiroshi

JAEA-Data/Code 2020-001, 41 Pages, 2020/03

JAEA-Data-Code-2020-001.pdf:3.75MB
JAEA-Data-Code-2020-001-appendix(CD-ROM).zip:0.34MB

Development of technologies to investigate properties of deep geological environment and model development of geological environment have been pursued in "Geoscientific Research" in the Horonobe Underground Research Laboratory (Horonobe URL) project. A geochemical model which is a part of geological environment model requires the data of groundwater chemistry around the Horonobe URL for the development. This report summarizes the data obtained for 3 years from the fiscal year 2017 to 2019, especially for the results for measurement of physico-chemical parameters and analysis of groundwater chemistry, in the Horonobe URL project.

JAEA Reports

Development of JAEA sorption database (JAEA-SDB); Update of sorption/QA data in FY2019

Sugiura, Yuki; Suyama, Tadahiro*; Tachi, Yukio

JAEA-Data/Code 2019-022, 40 Pages, 2020/03

JAEA-Data-Code-2019-022.pdf:2.22MB

Sorption behavior of radionuclides (RNs) in buffer materials, rocks and cementitious materials is one of the key processes in a safe geological disposal. This report focuses on updating of JAEA sorption database (JAEA-SDB) as a basis of integrated approach for the performance assessment (PA)-related distribution coefficient (K$$_{rm d}$$) setting and development of mechanistic sorption models. K$$_{rm d}$$ data and their quality assurance (QA) results were updated by focusing on the following systems as potential needs extracted from our recent activities on the K$$_{rm d}$$ setting and development of mechanistic models, i.e., clay minerals, sedimentary rocks and cementitious materials. As a result, 6,702 K$$_{rm d}$$ data from 60 references were added and the total number of K$$_{rm d}$$ values in JAEA-SDB reached 69,679. The QA/classified K$$_{rm d}$$ data reached about 72% for all K$$_{rm d}$$ data in JAEA-SDB.

JAEA Reports

Data acquisition for radionuclide sorption on barrier materials for performance assessment of geological disposal of TRU wastes

Tachi, Yukio; Suyama, Tadahiro*; Mihara, Morihiro

JAEA-Data/Code 2019-021, 101 Pages, 2020/03

JAEA-Data-Code-2019-021.pdf:4.05MB

Sorption of radionuclides in cement and bentonite as engineered barrier materials, and rocks as natural barrier is the one of key processes in the performance assessment of geological disposal of TRU and highlevel waste. The magnitude of sorption, expressed normally by a distribution coefficient (K$$_{rm d}$$), needs to be measured and determined taking into account the properties of barrier materials and geochemical conditions and associated uncertainty in the performance assessment. The basic concept for TRU waste disposal contains cementitious materials as an engineered barrier materials, in addition to bentonite and rock. It is therefore needed to consider the effects of the cement degradation and co-existing substances such as nitrates on radionuclide sorption. This report focused on data acquisition of distribution coefficient (K$$_{rm d}$$) by batch sorption experiments for the systems coupling barrier material-chemical condition-radionuclides that are needed to consider for the performance assessment of geological disposal of TRU waste. The barrier materials considered are ordinary Portland cement (OPC), degraded OPC and tuff rock. The chemical conditions are distilled water and synthetic seawater equilibrated with OPC and those containing nitrates and ammonium salts, etc. The radionuclides considered are organic carbon, inorganic carbon, Cl, I, Cs, Ni, Se, Sr, Sn, Nb, Am and Th. Although K$$_{rm d}$$ values have been partly reported previously as RAMDA (Radionucldie Migration Datasets) for the performance assessment in the TRU-2 report, these results and addition K$$_{rm d}$$ data are reported with the details of experimental methods and conditions.

JAEA Reports

Hydraulic tests for the excavation damaged zone around the 350m niches in the Horonobe Underground Research Project, 2

Samata, Yoichi; Ishii, Eiichi

JAEA-Data/Code 2019-020, 69 Pages, 2020/03

JAEA-Data-Code-2019-020.pdf:4.0MB
JAEA-Data-Code-2019-020-appendix1(DVD-ROM).zip:86.89MB
JAEA-Data-Code-2019-020-appendix2(DVD-ROM).zip:232.04MB
JAEA-Data-Code-2019-020-appendix3(DVD-ROM).zip:369.23MB

In Horonobe Underground Research Laboratory Project, hydraulic tests for the excavation damaged zone have been performed in order to characterize the hydrological properties of the zone. This report summarized the results of the hydraulic tests and pore-pressure monitoring which have been done from April 2016 to March 2019.

JAEA Reports

Hydrochemical investigation at the Mizunami Underground Research Laboratory; Compilation of groundwater chemistry data in the Mizunami group and the Toki granite (fiscal year 2018)

Fukuda, Kenji; Watanabe, Yusuke; Murakami, Hiroaki; Amano, Yuki; Aosai, Daisuke*; Kumamoto, Yoshiharu*; Iwatsuki, Teruki

JAEA-Data/Code 2019-019, 74 Pages, 2020/03

JAEA-Data-Code-2019-019.pdf:3.53MB

Japan Atomic Energy Agency has been investigating groundwater chemistry to understand the influence of excavation and maintenance of underground facilities as part of the Mizunami Underground Research Laboratory (MIU) Project in Mizunami, Gifu, Japan. In this report, we compiled data of groundwater chemistry and microbiology obtained at the MIU in the fiscal year 2018. In terms of ensuring traceability of data, basic information (e.g. sampling location, sampling time, sampling method and analytical method) and methodology for quality control are described.

JAEA Reports

Preliminary study on radiation effects of monitoring equipment

Nakayama, Masashi; Tanai, Kenji

JAEA-Review 2019-032, 32 Pages, 2020/02

JAEA-Review-2019-032.pdf:1.84MB

There are various types of monitoring in the geological disposal of high-level radioactive waste, such as monitoring for confirmation of construction quality and the status of engineered barrier, and monitoring to help manage construction, operation and closure activities, etc. Among these monitoring methods, monitoring related to the confirmation of the state of engineered barrier has been studied in international joint research on monitoring concepts and specific methods. Since monitoring equipment is affected by temperature, humidity, pressure, radiation, water quality, etc., it is important to consider geological environmental conditions and radiation effects. This report compares the radiation resistance of the materials used in the monitoring equipment with the absorbed dose in the buffer material obtained by analysis, and qualitatively examines the effects of radiation on the monitoring equipment. As a result of the examination, it was estimated that the dose did not affect the monitoring equipment. However, it is necessary to verify the possibility of reliable data acquisition by irradiation tests for monitoring devices with built-in electronic components.

JAEA Reports

A Study for a fire gas behavior by using a vertical shaft model (Contract research)

Abe, Hironobu; Hatakeyama, Nobuya; Yamazaki, Masanao; Okuzono, Akihiko*; Sakai, Tetsuo*; Inoue, Masahiro*

JAEA-Research 2009-019, 192 Pages, 2020/02

JAEA-Research-2009-019.pdf:8.07MB

Construction of the underground facility is on going at the Horonobe Underground Research Center, a division of the Japan Atomic Energy Agency. The facility is consisted of three shafts and horizontal drifts at the completion of construction and it is excavated in geological environment with methane gas, so it is important to secure the workers and visitors security in case of fire in the underground. However, it is known that the fire gas such as methane shows a complicated behavior by drift effect and so on and very difficult to predict its behavior, even if under enforced ventilation. In order to construct new prediction method of the fire gas behavior, the model scaled experiments were conducted by using the basic model which consists of shafts and drifts. As a results, fundamental data of the fire gas behavior was grasped and complicated behavior of the fire gas such as three-dimensional backflow and main flow inversion phenomena at the underground structure were ascertained. A new fire gas behavior analysis system has been designed and a prototype system has been programmed which is able to simulate the phenomena noted above. Coupling analysis method is adapted to the system, which consists of mainly one-dimensional ventilation network analysis and simplified computational fluid dynamics program named M-CFD. To minimize calculation time, M-CFD was designed as two-dimensional calculation with simulators multi area analysis system. Using the prototype system, several experimented models representing typical behavior of fire gas have been simulated for model scaled experiments. The system qualitatively reappeared the phenomena such as back flow or main flow inversion, and most of calculations completed in expected time. This indicates appropriateness of the prototype system, but some upgrade such as heat conductivity analysis in the wall rock mass transfer calculation, user friendly interface system and others will be required.

JAEA Reports

Analysis of the radioactivity concentrations in low-level radioactive waste generated from JRR-2, JRR-3 and hot laboratory facilities

Tobita, Minoru*; Haraga, Tomoko; Sasaki, Takayuki*; Seki, Kotaro*; Omori, Hiroyuki*; Kochiyama, Mami; Shimomura, Yusuke; Ishimori, Kenichiro; Kameo, Yutaka

JAEA-Data/Code 2019-016, 72 Pages, 2020/02

JAEA-Data-Code-2019-016.pdf:2.67MB

In the future, radioactive wastes which generated from research and testing reactors in Japan Atomic Energy Agency are planning to be buried for the near surface disposal. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes by the time it starts disposal. In order to contribute to this work, we collected and analyzed the samples generated from JRR-2, JRR-3 and Hot laboratory facilities. In this report, we summarized the radioactivity concentrations of 25 radionuclides ($$^{3}$$H, $$^{14}$$C, $$^{36}$$Cl, $$^{60}$$Co, $$^{63}$$Ni, $$^{90}$$Sr, $$^{94}$$Nb, $$^{93}$$Mo, $$^{99}$$Tc, $$^{108m}$$Ag, $$^{126}$$Sn, $$^{129}$$I, $$^{137}$$Cs, $$^{152}$$Eu, $$^{154}$$Eu, $$^{233}$$U, $$^{234}$$U, $$^{238}$$U, $$^{238}$$Pu, $$^{239}$$Pu, $$^{240}$$Pu, $$^{241}$$Pu, $$^{241}$$Am, $$^{243}$$Am, $$^{244}$$Cm) which were obtained from radiochemical analysis of those samples.

JAEA Reports

Groundwater pressure records by geochemical monitoring system in the 350 m gallery of the Horonobe Underground Research Laboratory (FY 2016-2018)

Mochizuki, Akihito; Miyakawa, Kazuya; Sasamoto, Hiroshi

JAEA-Data/Code 2019-014, 56 Pages, 2020/02

JAEA-Data-Code-2019-014.pdf:6.56MB
JAEA-Data-Code-2019-014-appendix(CD-ROM).zip:5.81MB

Japan Atomic Energy Agency (JAEA) has been conducting "geoscientific study" and "research and development on geological disposal" in the Horonobe Underground Research Laboratory (URL) for safe geological disposal of high-level radioactive waste. Groundwater pressure and geochemical parameters such as pH and oxidation-reduction potential in the deep groundwater have been continuously monitored with monitoring systems which were developed in the Horonobe URL Project. This report presents the data of groundwater pressure which have been obtained by the monitoring systems installed at the 350 m gallery. The data obtained from April 1, 2016 until March 31, 2019 was summarized along with related information such as the specifications of boreholes and the excavation of the URL.

JAEA Reports

Analysis of the radioactivity concentrations in low-level radioactive waste generated from Post Irradiation Examination Facility

Mitsukai, Akina; Haraga, Tomoko; Ishimori, Kenichiro; Kameo, Yutaka

JAEA-Data/Code 2019-012, 70 Pages, 2020/02

JAEA-Data-Code-2019-012.pdf:3.86MB

It is necessary to establish practical evaluation methods to determine radioactivity concentration of radioactive wastes which generated from research and testing reactors in Japan Atomic Energy Agency are planning to be buried for the near surface disposal. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes by the time it starts disposal. In order to contribute to this work, we collected and analyzed the samples generated from Post Irradiation Examination Facility. In this report, we summarized the radioactivity concentrations of 19 radionuclides which were obtained from radiochemical analysis of those samples.

Journal Articles

Influence of mixing solution on characteristics of calcium aluminate cement modified with sodium polyphosphate

Irisawa, Keita; Garcia-Lodeiro, I.*; Kinoshita, Hajime*

Cement and Concrete Research, 128, p.105951_1 - 105951_7, 2020/02

 Times Cited Count:0 Percentile:100(Construction & Building Technology)

This study investigated characteristics of a calcium aluminate cement modified with a phosphate (CAP) by changing an amount and concentration of mixing solution with sodium polyphosphate. When the amount of mixing solution was increased with a constant amount of sodium polyphosphate, an enhanced consumption of monocalcium aluminate was observed compared with gehlenite in calcium aluminate cement (CAC). Formation of gibbsite, Al(OH)$$_{3}$$, was also increased as a hydration product in the CAP and the possible reduction of water in the amorphous gel phase. When the amount of mixing solution was increased with a constant concentration of sodium polyphosphate, the enhanced consumption of monocalcium aluminate was not observed. Neither gibbsite nor any other crystalline hydration products were identified in this series. In addition, unreacted sodium polyphosphate remained in the system. The increased formation of gibbsite and the possible reduction of water from the amorphous gel phase appears to contribute to the improvement of the microstructure in the products.

10550 (Records 1-20 displayed on this page)