Estimation on the change of the condition of the impervious plug during groundwater recovery experiment

Matsui, Hiroya; Mikake, Shinichiro; Ikeda, Koki; Tsutsue, Jun

Dai-46-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koenshu (CD-ROM), p.286 - 291, 2019/01

Japan Nuclear Energy Agency (JAEA) has been conducting the groundwater recovery experiment to develop a methodology to estimate the geological environment recovery after closure of the drift at GL-500m in Mizunami Underground Research Laboratory, Japan. For the experiment, an impervious concrete plug was constructed to maintain a recovered water pressure and its functions were assessed based on the monitoring results and interpretation of several kinds of measurements performed inside and outside of the plug during groundwater recovery test. This report summarized the change of the condition of the plug due to groundwater recovery estimated based on the different kinds of monitoring data.

Preliminary examination about the seal leak using the photocoagulation resin (Joint research)

Ooka, Makoto; Maekawa, Yasunari; Tomizuka, Chiaki; Murakami, Tomoyuki*; Katagiri, Genichi*; Ozaki, Hiroshi*; Kawamura, Hiroshi

JAEA-Technology 2015-003, 31 Pages, 2015/03

JAEA-Technology-2015-003.pdf:3.95MB

An action for the decommissioning of the Fukushima Daiichi Nuclear Power Station (Tokyo Electric Power Company) is pushed forward now. For fuel debris Remove, it is necessary to fill the Primary Containment Vessel (PCV) with water. Because a coolant leaks out from the PCV, it becomes the most important problem to seal leak the coolant. Nuclear Plant Decommissioning Safety Research Establishment has examined the method of seal leak using the photocoagulation resin. However, originally the photocoagulation resin is used as coating or the painting, and the applicability to seal leak water is unknown. This report describes the result that examined the applicability to seal leak using photocoagulation resin.

Static mechanical properties of buffer material

Takachi, Kazuhiko; Suzuki, Hideaki*

JNC TN8400 99-041, 76 Pages, 1999/11

JNC-TN8400-99-041.pdf:4.49MB

The buffer material is expected to maintain its low water permeability, self-sealing properties, radionuclides adsorption and retardation properties, thermal conductivity, chemical buffering properties, overpack supporting properties, stress buffering properties, etc. over a long period of time. Natural clay is mentioned as a material that can relatively satisfy above. Among the kinds of natural clay, bentonite when compacted is superior because (1)it has exceptionally low water permeability and properties to control the movement of water in buffer, (2)it fills void spaces in the buffer and fractures in the host rock as it swells upon water uptake, (3)it has the ability to exchange cations and to adsorb cationic radioelements. In order to confirm these functions for the purpose of safety assessment, it is necessary to evaluate buffer properties through laboratory tests and engineering-scale tests, and to make assessments based on the ranges in the data obtained. This report describes the procedures, test conditions, results and examinations on the buffer material of unconfined compression tests, one-dimensional consolidation tests, consolidated-undrained triaxial compression tests and consolidated-undrained triaxial creep tests that aim at getting hold of static mechanical properties. We can get hold of the relationship between the dry density and tensile stress etc. by Brazillian tests, between the dry density and unconfined compressive strength etc. by unconfined compression tests, between the consolidation stress and void ratio etc. by one-dimensional consolidation tests, the stress pass of each effective confining pressure etc. by consolidated-undrained triaxial compression tests and the axial strain rate with time of each axial stress etc. by consolidated-undrained triaxial creep tests.

None

PNC TJ1559 95-001, 218 Pages, 1995/03

PNC-TJ1559-95-001.pdf:7.0MB

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PNC TN8410 92-332, 69 Pages, 1992/10

PNC-TN8410-92-332.pdf:4.03MB

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Fujita, Tomoo; ;

PNC TN8410 92-170, 84 Pages, 1992/06

PNC-TN8410-92-170.pdf:1.38MB

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; Sasaki, Noriaki; Ishikawa, Hirohisa; Fujita, Tomoo; Sato, Shinji*

PNC TN8410 92-043, 31 Pages, 1992/03

PNC-TN8410-92-043.pdf:0.95MB

None

Research for the erosion of buffer material with the vertical disposal concept, 4; Numerical analysis of inflow control into the disposal pits using discrete fracture network model

Atsumi, Hiroyuki*; Masumoto, Kazuhiko*; Ishii, Tomoko*; Jo, Mayumi*; Nakayama, Masashi; Ono, Hirokazu

no journal, , 

In the vertical disposal concept of high level radioactive waste, it is important to evaluate influence of the groundwater inflow into the disposal pits against performance of buffer material as an artificial barrier because the inflow might cause the erosion of buffer material. The target of this study was to estimate the inflow control technique (e.g. grouting) around the disposal pits using numerical analysis. The model for the simulation should be a discrete fracture network model when the groundwater mainly flows along the fractures in the rock mass, therefore, the discrete fracture network model was selected to estimate the inflow control technique in this study. The results of numerical flow analysis showed that the effectiveness of grouting for the disposal pits and the impact of grouting for the other disposal pits or surrounding disposal tunnel could be evaluated quantitatively.

Applicability examination for water stoppage using the photo-curable resin; Development of water stoppage technique by the improved photo-curable resin

Shimada, Kozue; Tomizuka, Chiaki; Shibata, Takuya; Ooka, Makoto; Maekawa, Yasunari*; Aoyagi, Katsuhiro*; Shinoki, Masatoshi*; Katagiri, Genichi*; Ozaki, Hiroshi*; Koyama, Shinichi

no journal, , 

no abstracts in English

Experiments of bentonite spraying method for the clay plug, 1; Investigation of sprayed bentonite properties

Kimura, Shun; Takeda, Masaki; Motoshima, Takayuki*; Dan, Hanae*

no journal, , 

no abstracts in English