[en] This project involves two related activities directed toward understanding respiratory carcinogenesis in radon-exposed former uranium miners. The first activity involves a continuation of the tissue resource of lung cancer cases from former underground uranium miners and comparison cases from non-miners. The second activity is a pilot study for a proposed longitudinal study of respiratory carcinogenesis in former uranium miners. The objectives are to facilitate the investigation of molecular changes in radon exposed lung cancer cases and to develop methods for prospectively studying clinical, cytologic, cytogenetic, and molecular changes in the multi-event process of respiratory carcinogenesis, and to assess the feasibility of recruiting former uranium miners into a longitudinal study that collects multiple biologic specimens

[en] The proposed measurements of the magnetic field maps of the six HRS quadrupoles in Hall A at CEBAF is summarized. The basis of the measurement using rotating coils and a preliminary design of the apparatus are presented. (author)

[en] The goal of the conference was to give the opportunity to identify and discuss low-level radioactive waste management issues, share lessons learned, and hear about some of the latest advances in technology. Abstracts of the presentations are arranged into the following topical sections: (1) Performance Management Track: Performance assessment perspectives; Site characterization; Modeling and performance assessment; and Remediation; (2) Technical Track: Strategic planning; Tools and options; Characterization and validation; Treatment updates; Technology development; and Storage; (3) Institutional Track: Orders and regulatory issues; Waste management options; Legal, economic, and social issues; Public involvement; Siting process; and Low-level radioactive waste policy amendment acts

[en] This is the seventh report prepared by the National Conference of State Legislatures (NCSL) on developments in radioactive materials transportation. It updates information contained in the April 1993 report on Legislative Developments in Radioactive Materials Transportation and describes activities for the period April 1, 1993--August 31, 1993. NCSL currently is updating an on-line data base that contains abstracts of federal, state and local laws and regulations relating to the transportation of radioactive materials. The data base will be operated by NCSL under a cooperative agreement with the Department of Energy's (DOE) Office of Civilian Radioactive Waste Management. Limited availability of on-line capability is anticipated by the end of 1993. Users approved by DOE and NCSL will have access to the data base. A copy of any legislation listed in this report can be obtained by contacting the people listed below. This report contains the current status of legislation introduced in the 1993 state legislative sessions, not previously reviewed in past reports. Bills that address nuclear materials transportation and the broader area of hazardous materials transportation are grouped by state according to their status--enacted, pending or failed. In addition, bills that deal with emergency preparedness are described. (General nuclear waste legislation with no transportation element is no longer tracked.) Also included are Federal Register notices pertinent to radioactive waste and hazardous materials transportation

[en] Full text. Recently, new microstructures based on a high mobility two-dimensional (2D) electron gas in GaAs/AlGaAs heterostructures have been fabricated, in which electron transport is ballistic; electron collide with the sidewall of microstructures, but not with the impurities. One version of this electron billiard is a 2D electron gas in a lattice of antidote: holes with submicron diameter etched in heterostructures Ga As/Al Ga As. In this system electrons are scattered by the antidote strong repulsive potential. In this work we measured magnetoresistance in mesoscopic samples with artificially created scatter ( antidotes) arranged in a disordered configurations. Samples had a size 4 x 4 μm², the averaged period of the disordered antidote lattice was 0.7 μm, diameter of antidote 0.1-0.15 μm. Magnetoresistance fluctuations of this mesoscopic conductor due to the interference of the ballistic electron trajectories have been found. From calculation of the correlation function and Fourier spectrum of these fluctuations we determined correlation magnetic field. We suggested that our billiard consists of a series of elementary billiard with 3-4 antidotes. Amplitude of the conductivity fluctuations 0.1 e²/h has been found. Change in the pattern of conductivity fluctuations as a function of magnetic field after irradiation by the light has been observed. We believe that this change was due to variation in the width of the depletion region around antidotes. Since our system is a chaotic billiard, the close electron trajectories are diverged after several collisions. Therefore interference of these trajectories has a high sensitivity to radius variation of the depletion zone around antidotes. (author)

[en] Full text. Although in most of the theoretical works on semiconductor heterostructures the optical phonon are treated as bulk modes only the presence of interfaces tend to form both confined modes and interface modes. Wendler (Phys. Status Solidi B141,129(1985) and Mori and Ando (Phys. Rev. B41, 3572(1987) calculated the spectrum of phonon by using a continuous dielectric model. They also have obtained the electron-phonon interaction potential for hetero junctions and quantum wells. By now it is well known that the electron interaction with the interfaces phonon play an important role in the properties of the semiconductor structures such as in the cyclotron resonance. In this sense, corrections to the cyclotron resonance energy and electron effective mass due to electron-interface LO-phonon modes interaction in semiconductor heterostructures, are calculated as a function of the magnetic field perpendicular to the surface through the second order of the Improved Wigner-Brillouin Perturbation Theory. The Froehlich model describing this system is employed throughout. Numerical results for Ga As-Ga Sb and Ga As-Al As heterojunctions are obtained and shown important contribution due to the interface modes on near the resonance region. In the case where the interface mode is close to the bulk mode a three branches splitting appears int he cyclotron energy and effective mass. We also have found that the resonance frequencies are shifted from its original positions due to the presence of other modes. For Ga As-Al As heterostructures in the region below the resonance where the experiment are usually carried on the electron interaction with the interface phonon can be neglected. The inclusion of the bulk phonon of Ga As only give good enough results. (author)

[en] The paper brings basic information on geological and seismic characteristics of the site of NPP Jaslovske Bohunice, Slovakia. Western Carpathians and Trnava, bay geological properties are briefly introduced. The most important macroseismic data and data obtained from field measurements are analysed. Main features of the expected strong seismic motion are discussed. The attention is devoted to local soil characteristics just under the site of NPP. (author)

[en] The final design seismic characteristics of Kozloduy NPP site; envelope response spectra for free field and a respective three component accelerograms were investigated and determined by probabilistic and deterministic methods. The investigations were based on tectonics, geological, seismological data, earthquake records and characteristics in a region of 320 km radius, as well as physicomechanical and acoustic site-soil characterises of the base rock

[en] Belgian nuclear power amounts to about 6,000 MW, generated by seven plants that started operation as early as 1967. The latest plant started in 1985. Some of these plants were designed with no seismic requirements whatsoever. Even for those that had seismic requirements at the design stage, seismic demand was raised after design had been frozen (late during construction or at the 10 years revision). As a consequence all the plants had to undergo, to a variable extent, a seismic reevaluation and/or backfitting. Civil structures were concerned as well as electro-mechanical equipment and piping systems. The present paper deals with the mechanical aspect of the problem (equipment and piping). In order to minimize hardware modifications, advanced analytical techniques were used throughout the process, starting with the elaboration of a site specific spectrum, and using a full soil-structure interaction in order to get as 'realistic' as possible floor response spectra. In some instances, non linear elasto-plastic time history analysis was performed on piping-systems in order to qualify them without hardware modifications. In other cases a 'Load Coefficient Method' was used. Sometimes stresses or displacements taken from the original stress reports and scaled by comparison of applicable spectra, allowed to assess the seismic validity of the system under investigation. Seismic acceptability of installed active equipment is more difficult to demonstrate, as this is usually done by testing. This problem is a generic issue in the US, identified under the label USI-A-46 (Unresolved Safety Issue). It is treated by. a group of Utilities (SQUG = Seismic Qualification Utilities Group). The Belgian Utility is member of that group since 1985. The application of this program is starting in the US. SQUG methodology has been applied to three Belgian plants starting in 1988 and is now completed. The required fixes are being implemented. Experience gained in the process has been applied to other Belgian units. General conclusions can be drawn. They are presented in the paper. Among them is the necessity of performing 'seismic markdowns' at regular intervals during the plant life in order to restore the seismic adequacy of vital equipment possibly degraded by 'maintenance drift'. Among the required seismic upgrades is the necessity, in a near future, to define accurate measures to be taken in the case of occurrence of an earthquake close to the OBE level. It has become clear that the input for defining these actions is readily available as a result of the SQUG walkdowns. (author)

[en] Fault model has been developed to estimate a strong ground motion in consideration of characteristics of seismic source and propagation path of seismic waves. There are two different approaches in the model. The first one is a theoretical approach, while the second approach is a semi-empirical approach. Though the latter is more practical than the former to be applied to the estimation of input motions, it needs at least the small-event records, the value of the seismic moment of the small event and the fault model of the large event