Refine your search:     
Report No.
 - 
Search Results: Records 1-15 displayed on this page of 15
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

JAEA Reports

A Study of the evaluation of the excavation damaged zone in the Horonobe Underground Research Laboratory, 2; Investigation in the 250 m gallery (Joint research)

Aoyagi, Kazuhei; Kubota, Kenji*; Nakata, Eiji*; Suenaga, Hiroshi*; Nohara, Shintaro*

JAEA-Research 2017-004, 91 Pages, 2017/06

JAEA-Research-2017-004.pdf:6.07MB

In this study, we performed seismic tomography, seismic refraction survey, resistivity tomography, and hydraulic tests to investigate the hydro-mechanical property of the excavation damaged zone (EDZ) in the 250 m gallery of the Horonobe Underground Research Laboratory. As a result of seismic tomography, seismic velocity is significantly decreased within 1 m from the gallery wall. The decrease of seismic velocity is related to the density of fracture induced around the gallery wall as a result of the gallery excavation. Thus the extent of the fractures induced by gallery excavation, i.e., EDZ fractures is clarified to be within 1.0 m from the gallery wall. The enhanced hydraulic conductivity was detected within 0.5 to 1.0 m from the gallery wall on the basis of the result of hydraulic tests. This is almost consistent with the extent of the region that seismic velocity is significantly decreased. Therefore, it is estimated that EDZ fractures induced around the gallery leads to the increase of hydraulic conductivity. In addition, the desaturation zone around the gallery is not induced as a result of resistivity tomography. From these results, the hydro-mechanical property of the EDZ is clarified in detail. Also, the in situ tests and evaluation method applied in this study are appropriate to investigate the EDZ in detail.

JAEA Reports

Decommissioning activities and R&D of nuclear facilities in the second midterm plan

Terunuma, Akihiro; Mimura, Ryuji; Nagashima, Hisao; Aoyagi, Yoshitaka; Hirokawa, Katsunori*; Uta, Masato; Ishimori, Yuu; Kuwabara, Jun; Okamoto, Hisato; Kimura, Yasuhisa; et al.

JAEA-Review 2016-008, 98 Pages, 2016/07

JAEA-Review-2016-008.pdf:11.73MB

Japan Atomic Energy Agency formulated the plan to achieve the medium-term target in the period of April 2010 to March 2015(hereinafter referred to as "the second medium-term plan"). JAEA determined the plan for the business operations of each year (hereinafter referred to as "the year plan"). This report is that the Sector of Decommissioning and Radioactive Waste Management has summarized the results of the decommissioning technology development and decommissioning of nuclear facilities which were carried out in the second medium-term plan.

Journal Articles

Current status of decommissioning activities in JAEA; Second midterm plan from FY2010 to FY2014

Tachibana, Mitsuo; Murata, Masato; Tasaki, Tadayuki; Usui, Hideo; Kubota, Shintaro

Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1987 - 1996, 2015/09

230 various types of nuclear facilities were constructed in JAEA's R&D Institutes or Center until the establishment of the JAEA in 2005. The JAEA has efficiently and systematically decommissioned nuclear facilities that would no longer be required after the establishment of the JAEA. Decommissioning of nuclear facilities in each JAEA's R&D Institutes or Center was continued based on the second midterm plan of the JAEA from FY2010 to FY2014. Decommissioning of 2 nuclear facilities was completed during the second midterm. This report describes current status of decommissioning activities in the JAEA during the second midterm and outline of the decommissioning plan in the third midterm.

Journal Articles

Hydrogeomechanical investigation of an excavation damaged zone in the Horonobe Underground Research Laboratory

Aoyagi, Kazuhei; Tsusaka, Kimikazu*; Nohara, Shintaro*; Kubota, Kenji*; Tokiwa, Tetsuya*; Kondo, Keiji*; Inagaki, Daisuke*

Proceedings of 8th Asian Rock Mechanics Symposium (ARMS-8) (USB Flash Drive), 8 Pages, 2014/10

JAEA Reports

Evaluation formulas of manpower needs for dismantling of equipment in FUGEN, 3; Dismantling process of the condenser removal

Kubota, Shintaro; Izumo, Sari; Usui, Hideo; Kawagoshi, Hiroshi; Koda, Yuya; Nanko, Takashi

JAEA-Technology 2014-022, 22 Pages, 2014/07

JAEA-Technology-2014-022.pdf:3.5MB

Japan Atomic Energy Agency (JAEA) has been developing the PRODIA code which supports to make decommissioning plan and has been preparing evaluation functions. Manpower needs for the dismantling the condenser that had conducted from 2010 to 2012 was analyzed and compared with existing evaluation functions. Applicability of evaluation function for a large scale reactor facility was confirmed in dismantling of the heat insulating materials and feed water heaters and reliability of unit productivity factor was improved. Evaluation function of work for clearance was made in dismantling of pipes and supports. Statistically meaningful data was provided from the dismantling of the condenser. Manpower needs for dismantling of a condenser has positive correlation to the weight of equipment and can be described in linear expression. Reliability of each unit productivity factor will be improved with accumulating actual dismantling data in future.

JAEA Reports

Evaluation formulas of manpower needs for dismantling of equipments in uranium refining and conversion plant

Izumo, Sari; Usui, Hideo; Kubota, Shintaro; Tachibana, Mitsuo; Kawagoshi, Hiroshi; Takahashi, Nobuo; Morimoto, Yasuyuki; Tokuyasu, Takashi; Tanaka, Yoshio; Sugitsue, Noritake

JAEA-Technology 2014-021, 79 Pages, 2014/07

JAEA-Technology-2014-021.pdf:22.8MB

Japan Atomic Energy Agency has developed PROject management data evaluation code for DIsmantling Activities (PRODIA) to make an efficient decommissioning for nuclear facilities. PRODIA is a source code which provides estimated value such as manpower needs, costs, etc., for dismantling by evaluation formulas according to the type of nuclear facility. Evaluation formulas of manpower needs for dismantling of equipments about reprocessed uranium conversion in Uranium Refining and Conversion Plant are developed in this report. In the result, 7 formulas for prepare process, 24 formulas for dismantling process and 8 formulas for clean-up process are derived. It is confirmed that an unified evaluation formula can be used instead of 8 formulas about dismantling process of steel equipment for uranium conversion process, and 3 types of simplified formula can be used for preparation process and clean-up process respectively.

JAEA Reports

Development of the clearance level verification evaluation system, 2; Construction of the clearance data management system

Kubota, Shintaro; Usui, Hideo; Kawagoshi, Hiroshi

JAEA-Data/Code 2014-010, 84 Pages, 2014/06

JAEA-Data-Code-2014-010.pdf:19.09MB

Clearance is defined as the removal of radioactive materials or radioactive objects within authorized practices from any further regulatory control by the regulatory body. In Japan, clearance level and a procedure for its verification has been introduced under the Laws and Regulations, and solid clearance wastes inspected by the national authority can be handled and recycled as normal wastes. The most prevalent type of wastes have generated from the dismantling of nuclear facilities, so the Japan Atomic Energy Agency (JAEA) has been developing the Clearance Level Verification Evaluation System (CLEVES) as a convenient tool. The Clearance Data Management System (CDMS), which is a part of CLEVES, has developed to support measurement, evaluation, making and recording documents with clearance level verification. In addition, validation of the evaluation result of the CDMS was carried out by inputting the data of actual clearance activities in the JAEA.

Journal Articles

Fractures distribution around underground gallery in sedimentary rock area

Nohara, Shintaro*; Nakata, Eiji*; Suenaga, Hiroshi*; Tanaka, Shiro*; Kubota, Kenji*; Oyama, Takahiro*; Kondo, Keiji

Nihon Oyo Chishitsu Gakkai Heisei-25-Nendo Kenkyu Happyokai Koen Rombunshu, p.129 - 130, 2013/10

no abstracts in English

Journal Articles

Study on stabilization effect of neutral soft donor on trivalent lanthanide and actinide dicarboxylate complexes by time-resolved laser-induced fluorescence spectroscopy

Sasaki, Takayuki*; Kubo, Shintaro*; Kobayashi, Taishi*; Kirishima, Akira*; Kimura, Takaumi; Kubota, Takumi*; Takagi, Ikuji*; Moriyama, Hirotake*

Journal of Nuclear and Radiochemical Sciences, 6(1), p.51 - 54, 2005/07

no abstracts in English

Oral presentation

Characterization evaluation of the clearance monitor at Fugen

Kubota, Shintaro; Izumo, Sari; Tachibana, Mitsuo; Kawagoe, Shinji; Higashiura, Norikazu

no journal, , 

no abstracts in English

Oral presentation

In-situ dismantling of the liquid waste storage tank LV-1 in JRTF, 1; An Outline of the dismantling program

Nakashio, Nobuyuki; Mimura, Ryuji; Muraguchi, Yoshinori; Nemoto, Koichi; Shiraishi, Kunio; Tachibana, Mitsuo; Kubota, Shintaro; Kawagoshi, Hiroshi

no journal, , 

For the purpose of the development of technology for dismantling and decontamination at the high dose area, ${it in-situ}$ dismantling method is applied for the liquid waste storage tank (LV-1) which is in the concrete cell at the JRTF. This report describes the outline of the program for ${it in-situ}$ dismantling of the LV-1.

Oral presentation

In-situ dismantling of the liquid waste storage tank LV-1 in JRTF, 3; Evaluation of the radioactivity inventory of LV-1

Kubota, Shintaro; Kawagoshi, Hiroshi; Tachibana, Mitsuo; Muraguchi, Yoshinori; Mimura, Ryuji; Nakashio, Nobuyuki; Nemoto, Koichi; Shiraishi, Kunio

no journal, , 

no abstracts in English

Oral presentation

Decommissioning strategy and current status of decommissioning activities in Japan

Murata, Masato; Katano, Yoshiaki; Usui, Hideo; Kubota, Shintaro

no journal, , 

As of October 2014, four Nuclear Power Plants, such as Tokai-1, Hamaoka Power Station Unit 1, Unit 2 and Fugen, have been carried out decommissioning, and JAEA's facilities, such as JRR-2, JRTF, RHL, PFFF, have been decommissioned, too. This presentation shows the decommissioning strategy and current status of decommissioning in Japan at ANUP2014.

Oral presentation

In-situ dismantling of the liquid waste storage tank LV-1 in JRTF, 6; Evaluation of the removal procedure of the radioactive residue in LV-1

Kubota, Shintaro; Tachibana, Mitsuo; Mimura, Ryuji; Nemoto, Koichi; Shiraishi, Kunio

no journal, , 

no abstracts in English

Oral presentation

A Study on the development of excavation damaged zone and desaturation zone in the Horonobe Underground Research Laboratory

Kubota, Kenji*; Oyama, Takahiro*; Suenaga, Hiroshi*; Nohara, Shintaro*; Aoyagi, Kazuhei; Sugita, Yutaka

no journal, , 

no abstracts in English

15 (Records 1-15 displayed on this page)
  • 1