巻号一覧
32 巻, 6 号
選択された号の論文の8件中1～8を表示しています
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佐久間 秀樹1992 年 32 巻 6 号 p. 272-280
発行日: 1992/02/10
公開日: 2010/02/23
ジャーナル フリーThere is a worldwide scientific consensus that deep geological disposal is the most feasible option for disposing of high-level radioactive waste. In Japan, these wastes are liquids which are generated by the reprocessing of spent nuclear fuel. High-level radioactive waste will be vitrified and stored for cooling prior to the final disposal.
The concept of geological disposal uses a system of multiple safety barriers. These barriers include engineered barriers (waste form, overpack and backfill) and natural barriers (low permeability, low hydraulic gradient and geochemical retardation, among others). Together engineered barriers and natural barriers will effectively isolate the waste from contact with humans or the environment.
An extensive research and development program on deep geological disposal has been carried out in Japan.
This program includes performance assessment studies on the geological disposal system, development of disposal technologies and an overall evaluation of the geological environment in Japan. The objective of current program is to assess the effectiveness of the geological disposal concept without narrowing down to specific geological environment.抄録全体を表示PDF形式でダウンロード (3301K) -
小出 仁1992 年 32 巻 6 号 p. 281-288
発行日: 1992/02/10
公開日: 2010/02/23
ジャーナル フリーJapan's current research emphasizes the generic validation of geologic disposal and general survey of geologic environment of the Japanese islands. Understanding geologic setting is essential to the assessment of longterm safety of radioactive waste disposal. Scenarios for safety assessment of high level waste disposal should include even natural events of very low probability and very slow geologic processes.
Geologic predictions should be based on extrapolation, natural analog, probability, experiments, conceptual model, numerical simulation and safety-assessment model. The geologic environment at the depth of several hundreds and some 1, 000 meters should be clarified to predict the fate of buried radioactive waste. In situ experiments are planned for the examination of validity of long-term isolation system of high level waste.
Long-term stability of the geologic environment is of primary importance in disposal of radioactive waste in Japan. The nature and behavior of deep groundwater provide key to the modeling and quantitative evaluation of performance of high-level waste isolation system.抄録全体を表示PDF形式でダウンロード (1373K) -
田中 和広, 宮川 公雄1992 年 32 巻 6 号 p. 289-303
発行日: 1992/02/10
公開日: 2010/02/23
ジャーナル フリーRadioactive nuclides are mainly brought by the groundwater flow from the high-level radioactive waste (HLW) disposal facility constructed in deep underground. It is very important to evaluate fractures developed in deep underground, which is thought to be a main groundwater flow path.
Borehole Television (BTV) System can get a variety of 3 dimentional geological information such as strike/dip of bedding and fractures, aperture, spacing, shape and filling minerals of fractures.
Based on the information obtained by BTV, fracture network modelling can be established and finally the mechanism of fracture development will be discussed.
Rock permeability can be discussed with regard to a fracture parameter obtained by BTV observation.
By combining the BTV observation with the core logging and other geophysical measurements, geological and geohydrological information in deep underground could be obtained in detail.
By developing the system, the BTV will be useful technique to explore in deep underground.抄録全体を表示PDF形式でダウンロード (2316K) -
釜石鉱山原位置試験場における調査結果について仙波 毅, 尾方 伸久, 長谷川 健, 岩崎 浩, 渡辺 邦夫1992 年 32 巻 6 号 p. 304-312
発行日: 1992/02/10
公開日: 2010/02/23
ジャーナル フリーPower Reactor and Nuclear Fuel Davelopment Corporation (PNC) has been developing techniques of evaluating groundwater flow in granitic rock. In a link of this purpose, PNC introduced the borehole radar system (RAMAC) which was developed by Swedish Nuclear Fuel and Waste Management Co., because it is critical to investigate the spatial extent and dimensions of fracture zones.
This report describes the results of crosshole measurements which were performed with RAMAC system at the Kamaishi Mine in-situ Experiment Site in the northern part of Honsyu Island, Japan.
The results are summarized as follows:
(1) Spatial extent of some low velocity zones and high velocity zones of electromagnetic waves were delineated.
(2) Almost of the seeping points observed by borehole TV lies in the low velocity zones.
(3) The fracture concentrated zones or fracture zones with groundwater recognized by observing the wall of the gallery, which was dug along the borehole used for crosshole measurements, corresponded to the low velocity zones.
These results indicate that the low velocity zone obtained by the borehole radar measurements corresponds with the fracture concentrated zone or fracture zones with groundwater.抄録全体を表示PDF形式でダウンロード (3044K) -
駒田 広也1992 年 32 巻 6 号 p. 313-320
発行日: 1992/02/10
公開日: 2010/02/23
ジャーナル フリーThe deep underground seismic characteristics which will play an important role in assessing the earthquake resistance of high-level waste geological disposal facilities were examined based on the results of seismic observations conducted at the Shiroyama Underground Hydroelectric Power Station and Hosokawa Mine, and the following results were obtained.
(1) Little amplification is recognized in the acceleration of seismic motion from the deep underground part to the neighborhood of 100m below the surface, but amplification in the seismic motion increases in the surface layer. That is, the maximum acceleration in the underground part deeper than 100m below the surface decreases to about 1/2 of that on the surface part.
(2) The frequency spectra of seismic motion in the underground part have a simplified shape as compared with those in the surface part. Furthermore, the values of the response spectra in the underground part decrease more than those on the ground surface as the epicentral distance becomes shorter.
(3) The vertical angle of incidence of seismic waves in the deep underground part is about 35°max. against the vertical direction. On a seismic design input to geological disposal facilities, therefore, it will be necessary to examine the incidence directin of seismic waves as a parameter.
(4) In the caverns whose size is similar to that of tunnels in the geological disposal facilities, it can be judged that there is little amplification in the seismic motion due to the effect of the caverns.抄録全体を表示PDF形式でダウンロード (890K) -
尾方 伸久, 大澤 英昭, 中野 勝志, 柳澤 孝一, 西垣 誠1992 年 32 巻 6 号 p. 321-332
発行日: 1992/02/10
公開日: 2010/02/23
ジャーナル フリーFor the sake of establishment of a hydrogeological model, the relationships among geological, geophysical and hydraulic properties were discussed, by the use of the data obtained from the rock formation at the Tono area.
Performances of hydraulic test equipments recently were also reviewed.
Results are summarized as follows:
(1) The hydraulic conductivities by PNC Aquifer Test Method (JFT) are quite similar with those by low pressure Lugeon Test Method.
(2) Lithology such as grain size and sorting coefficent correlates with hydraulic conductivity.
(3) Apparent resistivity, measured by electric logging (100cm normal), correlates closely with hydraulic conductivity.
The high correlation between geological and geophygical properties and hydraulic conductivity make possible to estimate hydraulic conductivities by means of Ethology obtained by core logging and electric logging data. The hydrogeological model was successfully constructed by this method.抄録全体を表示PDF形式でダウンロード (1816K) -
北村 孝海, 稲葉 秀雄, 向上 拡美, 塩崎 功, 滝沢 究, 登内 正治1992 年 32 巻 6 号 p. 333-344
発行日: 1992/02/10
公開日: 2010/02/23
ジャーナル フリーRecently, structures of strata and permeability in the rock mass have been investigated with borehole radar systems using electromagnetic waves.
As a result of examinations, the explorative distance of the system was limited from 100 meters in the fractuered granite rock mass under present conditons in Japan, and further improvements are needed to lengthen its explorative distance.
Using the propagative characteristics of electromagnetic waves, high permeability zones (hydraulic pathways) can be estimated by the tomographic data obtained from the results of crosshole measurements before and after salt water injection.抄録全体を表示PDF形式でダウンロード (2554K) -
馬原 保典1992 年 32 巻 6 号 p. 345-355
発行日: 1992/02/10
公開日: 2010/02/23
ジャーナル フリーThe movement of groundwater is the deciding factor in characterization of geological disposal sites for high level radioactive wastes. As radionuclides leaking from a disposal facility will migrate with groundwater, a small groundwater flow velocity is an advantage in safety assessment. There are many methods for investigating groundwater flow. Central Research Institute of Electric Power Industry (CRIEPI) has focused on developing new techniques to reveal macro- and micro-circulations of groundwater in deep strata. We introduce following four new techniques developed by CRIEPI, after reviewing the tracer techniques for groundwater survey.
(1) New dating method of groundwater
CRIEPI has developed and demonstrated the 3H+3He dating method to survey the flow of groundwater in a large geohydrologic catchment area. This method is based on counting the increase of 3He produced by β-decay of 3H in groundwater. This is available for determining the direction and velocity of groundwater flow from dating data.
(2) Development of a point groundwater flow meter to determine the direction and velocity of groundwater crossing a single hole
CRIEPI has developed a technique that can gauge the velocity and direction of groundwater flow to 10-6cm/s in a single hole, which were difficult to detect by conventional methods.
(3) Development of a cross-hole pressure propagation test method
CRIEPI has developed the cross-hole pressure propagation test method among several holes to make an assessment of groundwater flow in fractured bedrock. This is available for measuring a very small hydraulic conductivity 10-8 to 10-9cm/s.
(4) Development of a multi-functional permeability test device equipped with TV-camera.
CRIEPI has developed a test device that can visually observe the movement of groundwater by a TV-camera in the test duration of low and high pressure water injection as well as in that of spring-water test. This device might be a strong weapon for pearmeability test in fractured bedrock.抄録全体を表示PDF形式でダウンロード (1539K)
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