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Obayashi Corporation*; Kajima Corporation*; Shimizu Corporation*; Taisei Corporation*
PNC TJ1449 91-006, 68 Pages, 1991/01
None
Nagaoka, Toshi; Moriuchi, Shigeru
Hoken Butsuri, 26, p.129 - 137, 1991/00
no abstracts in English
Yusa, Yasuhisa; ; Arai, Takashi
PNC TN8410 91-007, 18 Pages, 1990/12
This paper contains an overview of analogue studies for the assessment of long-term durability of engineered barrier materials at PNC Tokai. Materials of young age and with simple history are the most suitable for study as: (1)properties of the materials tend to deteriorate over longer historical time intervals; and (2) detailed quantitative data on time intervals and environmental conditions are more likely to be available. The following materials and their alteration phenomena were selected: (1)weathering alteration of basaltic glass (as vitrified waste form), (2)corrosion of iron in soil (as overpack), (3)illitization of smectite associated with contact metamorphism (as buffer material), (4)alteration of cement (as buffer or backfill material). (1)Weathering alteration of basaltic glass: Basaltic g1asses, from the Fuji and the Izu-Ohshima pyroclastic fall deposits were studied. The observations were made: (a)Climatological conditions have not varied significantly during the last three thousand years. Therefore, values for temperature, amount, and chemistry of ground water are quantified. (b)The cases studied could be regarded as leaching experiments in groundwater, using mass balances in water-g1ass interaction. (c)Although the groundwater is of Ca(Mg)-HCO
type in the Fuji area and of Na-Cl type in the Izu-Ohshima, similar alteration ratios (2
3
m/1000yr) were obtained. (2)Corrosion of iron in soil: Industrial materials, such as gas/water service pipes of carbon steel or cast iron embedded in soil for 20 110 years, were selected for an analogue study of corrosion of iron in bentonite. The maximum corrosion rates obtained so far fall in the range of 0.040.09 mm/yr. (3)Illitization of smectite associated with contact metamorphism: In the Murakami bentonite deposit in central Japan, lateral variation of smectite to smectite/illite mixed-layer minerals are found in the aureole of the rhyolite intrusion body. Conversion of smectite to the
Hirabayashi, Masaru; Ara, Kuniaki; Hino, Ryutaro
no journal, ,
no abstracts in English
Nagao, Fumiya; Kato, Tomoko; Suzuki, Yuji*; Itazu, Toru*
no journal, ,
The basic matrices were compiled structurally which contain transport and exposure processes in the surface environment. And the method was shown to construct the steady-state biosphere model by combination of the basic matrices. To confirm applicability of the method, a dry run of the biosphere modeling for the hypothetical site was conducted.
Hirabayashi, Masaru; Ara, Kuniaki; Hino, Ryutaro
no journal, ,
no abstracts in English
Takahashi, Yuta; Taniguchi, Takumi; Kuroki, Ryoichiro; Osugi, Takeshi
no journal, ,
no abstracts in English
Koo, Shigeru*; Yamaguchi, Masaaki; Makino, Hitoshi; Tsuchiya, Terumitsu*; Kanzaki, Tametoki*
no journal, ,
A deep borehole disposal has been considered as a disposal option and various technical studies in various countries have been reported in recent years. This study summarizes the main points for discussion on deep borehole disposal and the technical issues for its implementation through research of and comparison among multiple examples in other countries. In addition, we will try to examine the points and issues of deep borehole disposal more specifically through, for example, case studies on the drilling of deep boreholes and the maintenance of the borehole walls, which are one of the important prerequisites for the implementation of deep borehole disposal.
