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Uchida, Masahiro; Yoshino, Naoto
JNC TN8410 2001-015, 35 Pages, 2001/05
JNC-TN8410-2001-015.pdf:1.73MB
This technical report summarizes excavation and preparation of the natural rock block sample used in LABROCK. This report was originally compiled by PNC in March, 1993.
Chijimatsu, Masakazu*; Sugita, Yutaka; Fujita, Tomoo; Amemiya, Kiyoshi*
JNC TN8400 99-034, 177 Pages, 1999/07
It is an important part of the near field perfformance assessment of nuclear waste disposal to evaluate coupled thermo-hydro-mechanical (T-H-M) phenomena, e.g., thermal effects on groundwater flow through rock matrix and water seepage into the buffer material, the generation of swelling pressure of the buffer material, and thermal stresses potentially affecting porosity and fracture apertures of the rock. An in-situ T-H-M experiment named 'Engineered Barrier Experiment' has been conducted at the Kamaishi Mine, of which host rock is granodiorite, in order to establish conceptual models of the coupled T-H-M processes and to build confidence in mathematical models and computer codes. In 1995, fourteen boreholes were excavated in order to install the various sensors. After the hydraulic tests, mechanical tests were carried out to obtain the rock properties. After that, a test pit, 1.7m in diameter and 5.0m in depth, was excavated. During the excavation, the change of pore pressure, displacement and temperature of rock mass were measured. In 1996, the buffer material and heater were set up in the test pit, and then coupled thermo-hydro-mechanical test was started. The duration of heating phase was 250 days and that of cooling phase was 180 days. The heater surface was controlled to be 100
C during heating phase. Measurment, was carried out by a number pf sensors installed in both buffer and rock mass during the test. The field experiment leads to a better understanding of the behavior of the coupled thermo-hydro-mechanical phenomena in the near field.
Sugita, Yutaka; Chijimatsu, Masakazu*; Fujita, Tomoo; Tranduc, P.*
JNC TN8430 99-009, 45 Pages, 1999/06
It is an important part of the near field performance assessment of nuclear waste disposal to evaluate coupled thermo-hydro-mechanical (T-H-M) phenomena, e.g., thermal effects on groundwater flow through rock matrix and water seepage into the buffer material, the generation of swelling pressure of the buffer material, and thermal stresses potentially affecting porosity and fracture apertures of the rock. An in-situ T-H-M experiment named "Engineered Barrier Experiment" was conducted at the Kamaishi Mine, in which the host rock is granodiorite, in order to establish conceptual models of the coupled T-H-M processes and to build confidence in mathematical models and computer codes. This report summarizes the results of the in-situ direct compaction technique to evaluate the appropriate conditions for this technique. The in-situ direct compaction technique is one of the major candidate emplacement techniques for the buffer material. This experiment consisted of the mock-up tests and the in-situ test. The mock-up tests showed the appropriate conditions for the in-situ direct compaction technique. For the in-situ experiment, the manufactured OT-9607 achieved dry density averaged 1.65 g/cm
, which matched the demand for the thermo-hydro-mechanical experiment.
Chijimatsu, Masakazu*; Fujita, Tomoo; Kobayashi, Akira*; Onishi, Yuzo*
JNC TN8400 99-031, 61 Pages, 1999/06
It is an important part of the near field performance assessment of nuclear waste disposal to evaluate couples thermo-hydro-mechanical (T-H-M) phenomena, e.g., thermal effects on groundwater flow through rock matrix and water seepage into the buffer material, the generation of swelling pressure of the buffer material, and thermal stresses potentially affecting porosity and fracture apertures of the rock. An in-situ T-H-M experiment naned 'Engineered Barrier Experiment' has been oonducted at the Kamaishi Mine, of which host rock is granodiorite, in order to establish conceptual models of the coupled T-H-M processes and to build confidence in mathematical models and computer codes. The coupled T-H-M experiment is one of tasks in DECOVALEX (DEvelopment of COupled models and their VALidation against EXperiments) project which is an international co-operative project and it is defined as Task 2. The Task 2 for the DECOVALEX project are divided into three subtasks (A-C) in accordance with the programme and availability of data, called subtasks. This note describes the results of subtask C. Subtask C is a coupled thermo-hydro-mechanical analysis in the near field.
Sato, Haruo; ; ; *; *; Yui, Mikazu
PNC TN8410 97-127, 57 Pages, 1997/08
Retardation of key nuclides is one of the most important mechanisms to be examined specifically and modelled for the performance assessment of geological disposal of radioactive waste. We have been studing diffusion of nuclides into the pore spaces of the rock matrix, sorption of nuclides on the rock pore surfaces and pore properties to quantify the degree of nuclide retardation in fractured crystalline rock. The work has concentrated on predominant water conducting fracture system in the host granodiorite in the Kamaishi In Situ Test Site, which consists of fracture fillings and altered granodiorite. Through-diffusion experiements to obtain effective and apparent diffusion coefficients (Da and De, respectively) for Na, Cs, HTO, Cl and Se as a function of ionic charge at 22 
25C and batch sorption experiments for Cs, Sr, Se, 
U and 
Pu were conducted on fracture fillings, altered and intact granodiorite. The experiments only for Se, a redox sensitive element, were done in an N2-atmospheric glove box (O
1 ppm) to keep the chemical species. In situ groundwater (pH8.79.5) sampled from the same place as rock samples was used for the experiments. Porosity and density of cach rock sample were determined by both water saturation method and mercury porosimetry, and pore-size distribution and specific surface area of pores were measured by mercury porosimetry. The porosity is in the order; fracture fillings (5.6%) 
altered rock (3.2%) intact rock (2.3%). The pore-size distribution of the intact and altered granodiorite is ranging from 10 nm to 0.2 mm, and the fracture fillings have that of 50 nm to 0.2 mm, but a lot of pores were found around 100 nm and 0.2 mm in the fracture fillings. The effective diffusion coefficients for all species (Na
, Cs, HTO, Cl
, Se0
) are in the order of fracture fillings altered rock intact rock in proportion to these porosities. Effective diffusion ...
Mano, Tadashi; Ishikawa, Hirohisa; Fujita, Tomoo; Sugita, Yutaka
PNC TN8020 95-001, 50 Pages, 1995/01
None
Kawabata, Kuniaki; Mori, Fumiaki; Tanifuji, Yuta; Shirasaki, Norihito; Hanari, Toshihide
no journal, ,
This paper describes about development of modular style test field for Remotely Operated Mobile Robots. Our motivation is to provide test methods for development of the robots and operator proficiency to contribute decommissioning works of Fukushima Daiichi Nuclear Power Station (FDNPS). We currently design prototypes of modular style test fields based on analysis of emergency response tasks at FDNPS and construct them. Developed prototypes including a pile-shape obstacle that is three mutually perpendicular elements, steps with iron surface, grating floor and so on were reported in this paper. Developed modules are capable of reconfiguring kinds of the test fields by arranging their layout utilizing modular mobile carts.
Kawabata, Kuniaki; Mori, Fumiaki*; Shirasaki, Norihito; Tanifuji, Yuta; Hanari, Toshihide
no journal, ,
This paper describes the development of test fields for decommissioning works by remotely operated machines. Especially, prototypes that imitate penetrations for accessing inside of the Primary Containment Vessel were designed. Penetrations are the pipes; three types of penetration with different inner diameter are developed by referring to real size. Some elbow-type pipes are also prepared to configure various piping route. The prototypes and some peripheral facilities for testing the machines are described.
Kawabata, Kuniaki; Ishiyama, Hiroki; Shirasaki, Norihito; Ono, Takahiro; Hanari, Toshihide; Tanifuji, Yuta
no journal, ,
Ota, Ryosuke*; Mitsuyama, Kazuaki*; Tachi, Yukio; Yotsuji, Kenji*; Sato, Tomofumi*; Sato, Hisao*; Martin, A.*
no journal, ,
The radionuclide migration model representing heterogeneities in distributions of minerals and pores was developed for Grimsel granodiorite. This model was applied to quantify the impact of heterogeneities on radionuclide migration and was validated by comparing with the measured data.