[en] The borehole radar method has been developed and applied to the localization and characterization of fracture zones in crystalline rock. In a geological medium such as crystalline rock there is a significant attenuation of the radar waves, increasing with frequency. There is, however, a frequency window from a few MHz to a few hundred MHz where the wave aspect of the radar dominates and acceptable ranges can be achieved. A new borehole radar system has been designed, built and tested. The system consists of borehole transmitter and receiver probes, a signal control unit for communication with the borehole probes, and a computer unit for storage and display of data. The system can be used both in singlehole and crosshole modes and probing ranges of 115 m and 300 m, respectively, have been obtained at Stripa. The borehole radar is a short pulse system which uses center frequencies in the range 20 to 60 MHz, corresponding to wavelengths of a few meters in the rock. Single hole reflection measurements have been used to identify fracture zones and to determine their position and orientation. The zones often cause strong and well defined reflections originated from the resistivity change at the edges of the zones. The exact orientation of the zones can be determined by combining data from several boreholes. Reflections are also observed in crosshole measurements. A new technique has been developed for the analysis of crosshole reflection data which in principle allows the orientation to be uniquely determined if the boreholes are not in the same plane. The travel time and amplitude of the first arrival measured in a crosshole experiment can be used as input data in a tomographic analysis. Tomographic inversion has given detailed information about the extent of fracture zones in the plane spanned by the boreholes as well as a quantitative estimate of their electrical properties. 28 refs., 165 figs., 6 tabs

[en] Published in summary form only

[en] It is reported that 5-year construction of a tunnel for electron-positron collider at CERN is finished. The tunnel is placed so that the may passing under the Yurassic rocks is minimum. The tunnel was driven by shields and head-roaders under neath the plain and by explosions underneath mountains. Main difficulties occured when driving the tunnel underneath the Yurassic rocks were connected with water break. Total volume of the spoil was 1.4x10⁶m³

[en] During 1984 and 1985 the SLC alignment group established and measured a system of elevation benchmarks (BM's) over the whole of the SLAC site, ranging from the injector area to the NGS horizontal control point (surface monument) AA on the hill to the east of the collider hall outside the radiation fence. Precise elevations are needed in general for survey, alignment, placement, and monitoring of SLC tunnels and components. In particular, precise elevations of the survey instruments, mounted over penetrations to the tunnels and over the horizontal control points, are needed for the reductions of measured distances on the surface. Precise elevations were also needed at several other locations, like sector 1, 10, 19, and 30 along the LINAC (for the Global Positioning System measurements), outside of the IR 8 access to PEP (to connect the run from the SLC Master Benchmark R306 close to LINAC station 100 + 00 through the PEP SIT tunnel), and at the south-west adit to the SLC tunnel (to connect the BSY run). Permanent benchmarks were, therefore, installed close to these locations. To minimize errors and simplify re-leveling, turning points were also permanently installed. Figure 1 shows the locations of the elevation benchmark east of LINAC sector 30 and the course of the premanently installed leveling runs

[en] The purpose of this paper is to summarize the general nature of the geology and rock and soil formations of the PEP site as they relate to the design and construction of the project; to describe site investigation programs and to catalog the geotechnical information presently available about the site. The recently-completed investigation of subterranean conditions around the PEP ring when coupled with previous surveys gives us a good understanding of what to expect with regard to tunneling, undertaking larger underground excavations and constructing research halls are the interaction areas. It bears out the predictions made in Jacobs and Associates' report of 1973; i.e., that the ring housing construction is classified as soft-ground tunneling and that large underground openings, such as region 10 and the injection junction structures, will require great attention to support. A shield or shields will probably be required. On the positive side, the site affords very good conditions for soft-ground tunneling. Water will be a problem in some areas, but not an unsolvable one. The possibility of encountering lethal or explosive gases, almost always the case in tunneling in California's coastal formations, exists but has not been ascertained. Finally, no reasons to change current cost estimates or schedules have merged from the investigation. 13 refs., 1 fig

[en] The Atmospheric Turbulence and Diffusion Division (ATDD) of the National Oceanic and Atmospheric Administration (NOAA) and the Divisao de Seguranca Ambiental (DSEA.N) of Furnas Centrais Eletricas S.A. (FURNAS) have undertaken a joint field study to characterize atmospheric transport and diffusion at the complex site of the Angra Nuclear Power Plant (Angra 1) operated by FURNAS. Phase 1 experiments were designed to address questions of site representativeness with respect to the present meteorological monitoring system. Experiment teams undertook two week intensive measurement program consisting of tethersonde sounding coupled with neutral-lift balloon tracking. The data showed the site meteorology to be dominated by the local land/sea breeze effects. Daytime trajectories follow the local onshore flow until ridge top then indicate transport out to the ocean. Trajectories during the evening hours followed the drainage flow out to sea ending some distance from the shore or showing a tendency to follow the upper level onshore flow. (Author)

[en] Through the analysis of Radon concentration distribution in five geothermal energy fields in Mexico, it has been observed that high Radon emanation occurs near the active faults. Crosschecking data of Radon distribution, Geochemical and Geophysical information allow us to locate areas for flow testing in deep drill wells and so to evaluate the potentiality of geothermal energy reservoirs for electricity production. (author). 7 refs, 3 figs

[en] For the purpose of research and development of the measurement technique concerning in-situ experiments for geological disposal of high level waste, several field tests were carried out in Japan Atomic Energy Research Institute (JAERI). This paper is a short introduction of JAERI work on in-situ experiments. 2 refs.; 3 figs

[en] Published in summary form only

[en] The Radiological Survey Activities group of the Health and Safety Research Division at Oak Ridge National Laboratory is the Inclusion Survey Contractor (ISC) for the Uranium Mill Tailings Remedial Action (UMTRA) project in Grand Junction, Colorado. The ISC is responsible for performing any required radiological surveys and data analyses for the recommendation of inclusion or exclusion of designated properties in the UMTRA project. One of the responsibilities of the ISC is to obtain consent from the property owners to conduct radiological surveys. In Grand Junction, Colorado 30-40% of the owners of designated properties have not responded to the consent-for-access requests sent by certified mail. A questionnaire was designed to identify and study this nonresponse through personal interviews with 100 randomly selected nonrespondents. A profile of the population of nonrespondents, reasons for nonresponse, as well as suggestions to encourage response were identified and analyzed