Research on engineering procedure and models on buffer materials

Amemiya, Kiyoshi*; TRAN DUC PHI OAN*; Yamashita, Ryo*

JNC TJ8400 2000-055, 49 Pages, 2000/02

JNC-TJ8400-2000-055.pdf:4.15MB

JNC presented the 2 progressive reports on HLW disposal system. The documents impressed the importance of developing the engineering procedures and the model evaluating the thermo-hydro-mechanical phenomena in waste disposal system. In this research, the methods filling the gap between buffer and rock or buffer and overpack were examined. Bentonite pellets were tested as the filling materials. In order to assess the full-scale system performance, the Japanese experiences of buffer mass experiments were compared with the Prototype Repository Project of SKB in Sweden. Father more, the thermo-hydro-mechanical (THM) code named THAMES was validated at the international co-research programs of DECOVALEX II.

Discrete Fracture Modelling of the Aspo LPT-2,Large Scale Pumping and Tracer Test

PNC TN8410 94-269, 77 Pages, 1994/07

PNC-TN8410-94-269.pdf:2.13MB

This report describes FracMan discrete fracture flow transport modelling of the LPT-2, large-scale pumping and tracer test, at the SKB Aspo Hard Rock Laboratory. This work was carried out under the international cooperation program of the AsPo Task Force on Groundwater Flow and Transport of Solutes. The scale of simulation was approximately a one-kilometer cube. The discrete fracture model contains two major fracture types - fracture zones, which were located deterministically according to SKB's conceptual model of the Aspo site, and fractures outside the fracture zones which were generated stochastically. The geometric and hydraulic properties of each group were developed from the SKB modeling database, except for non-zone fracture length which we developed from our own mapping of surface outcrops. Two separate models were prepared for the March and September, 1993, task force meetings respectively. The March model represented the fracture zones as 10-m thick Planar regions containing populations of 30-m radius discrete fractures. The September model represented the fracture zones as single planes, which were discretized on a 20- to 30-m scale for a geostatistical assignment of properties. The September model also included conditioning of the properties to the borehole data. Both models generally reproduce the drawdown and transient pressure interference responses of the experiment. The tracer breakthroughs were simulated using only the September model. Calibration runs of the transport model varied the mean transport aperture, aperture variance, and aperture correlation length. The results of this modelling exercise show that a discrete fracture model can be applied at kilometer scales if the flow is dominated by a small portion of fracture population. The results also show that the SKB conceptual model is consistent with the field measurements.

Research and development of Laser Induced Breakdown Spectroscopy in Collaborative Laboratories for Advanced Decommissioning Science

Wakaida, Ikuo; Oba, Hironori; Miyabe, Masabumi; Akaoka, Katsuaki; Oba, Masaki; Kato, Masaaki; Ruas, A.

no journal, , 

no abstracts in English

Proposition for the future development of the advanced fast reactor cycle (from our experience), 3; Proposition for the high-temperature gas-cooled reactor development

Iyoku, Tatsuo

no journal, , 

Since I got employment in the Japan Atomic Energy Agency in 1979, I have consistently engaged in high-temperature gas-cooled reactor development and experienced from HTTR design to its in-service operation. Based on this experience, I will make recommendations for future high-temperature gas-cooled reactor development at the conference. Typical recommendations are as follows: In future HTGR research and developments, HTTR should be positioned as a COF (center of facility).

Numerical simulation of coupled THM behavior of full-scale EBS in backfilled experimental gallery, Horonobe, Japan

Sugita, Yutaka; Ono, Hirokazu; Beese, S.*; Pan, P.*; Kim, M.*; Lee, C.*; Jove-Colon, C.*; M Lopez, C.*; Liang, S.-Y.*

no journal, , 

This paper presents the results of analytical simulations of in-situ test of engineered barriers system conducted at the Horonobe Underground Research Laboratory. This results is one of the tasks of the current phase "DECOVALEX-2023" of the international joint project DECOVALEX in which JAEA participates. Research teams from 6 countries or region, including JAEA, are participating in this task, Different analytical approaches and their effects on the analytical results are introduced, as well as the factors that affect the evaluation of coupled phenomena in engineered barrier system obtained through the task.