Authors:Y. Dali, M. Tupin, P. Bossis, F. Valdivieso, and M. Pijolat
The fuel claddings in the Pressurised Water Reactor are corroded in water at high temperature and high pressure. The technical
device ableto follow continuously the corrosion rate in conditions close to this medium does not yet exist. That is the reason
why a high pressure thermogravimetric installation based on magnetic suspension has been designed to study in situ the oxidation
kinetics of the zirconium based alloys under water vapour until 50 bars of pressure at 415°C. The accuracy of measurements
is about 5·10−5 g under 2 bars, and 10−4 g under 50 bars. The reproducibility of measurements was verified and the deviation regarding post test weighing at room
temperature is around 5·10−5 g what is clearly satisfying. Finally, the results presented in this work allow validating the high pressure thermogravimetric
measurements obtained with this magnetic suspension device.
The first aim of our research is to calculate the solar irradiance on roofs assuming clear sky and real (climatologically typical) conditions, respectively, and compare them in a densely built inner city study area in Szeged (Hungary). The second aim is to analyse the shading effect of the tree-crowns on the possible solar energy gain of building roofs. The calculation of the climatologically potential solar energy gain based on an empirical atmospheric transmittance (calculated from the measured global radiation values). The results show that in the case of clear sky condition the urban vegetation (tree-crowns) causes significant potential solar energy loss on the roofs, but in the real situations this effect is less significant. These obtained results clearly illustrate how useful tool could be the presented calculation method at the economical and technical planning stage of the installation of solar systems on roofs.
Authors:V. Nazarov, M. Frontasyeva, P. Lavdanskij, and N. Stephanov
The results of activation studies of concrete ingredients for shielding structures of nuclear installations in the aspect of their decommissioning are given. It is shown that for the long-lived induced radioactivity of construction mineral materials irradiated for 30 years and cooled for more than one year such radionuclides as calcium, iron, cobalt, caesium and europium are responsible. Elemental content of the binding agent and raw material components for their production is obtained by neutron activation analysis. The results show that the type of the binding agent influences to a great extent the concrete shielding activity. The concentration of the above mentioned elements should be taken into account even at the stage of nuclear power plants design. It would allow one to make a prognosis on the volume and radioactivity of wastes as on the radioactivity effect felt by the staff engaged in the decommissioning.
Authors:U. Sansone, Chang Kim, G. Kis-Benedek, R. Schorn, E. Zeiller, A. Qaribov, V. Huseynov, and A. Chupov
In the frame of an International Atomic Energy Agency Technical Cooperation project, a radiological survey was performed in
the Araks and Kura Rivers (Azerbaijan). Sediment samples, and where available, aquatic plants were collected along these two
rivers and their inflow and tributary rivers. 137Cs, 238U, 234U, 239+240Pu, 238Pu, 90Sr and 241Am activity concentrations were measured. The radionuclide levels measured were relatively low, and in most cases below the
detection limit, as compared with those from other areas of the world which have been directly affected by effluents from
nuclear installations or influenced by the Chernobyl accident. The results indicated that the radionuclides are of natural
origin or attributable to the atmospheric fallout from nuclear weapons tests or to the Chernobyl-derived deposition.
The continued erection of nuclear installations which is expected in the future involves a greater production of long-lived
fission products, which result in a concentration increase in the biosphere, the hydrosphere and the atmosphere. In the frame
of a broad survey program, a routine method has been developed with the help of the European Communities to investigate the129I content of thyroid glands of cows. It is the purpose of this project to determine the present concentration situation of
this nuclide, which in the Federal Republic of Germany mainly concerns the North German low plains. Between autumn '76 and
summer '77 18 cows have been investigated with respect to129I, and thyroid glands have been taken at different times in November '76 and August '77. Without exception, the animals were
13-month old bulls, part of which has pastured, while the other part has been fed. The detection limit of the method is 20fCi
Nowadays the PUREX process is the sole accepted reprocessing technique. Its boundary conditions change all the time: former
metallic low burnup fuels have been replaced by present ceramic oxide fuels with high burnups, and tomorrow fast breeder fuels
with high plutonium contents will have to be processed. In addition, more and more restrictive conditions are being imposed
upon waste treatment and more and more stringent safety regulations are being felt. Within these constraints this report presents
a survey of the results of recent developments in process technology and gives some reference to the importance of process
analytical statements with respect to plant operation. Moreover, recommendations are made for the installation and design
of analytical laboratories and some experiences are communicated in the field of process analytical chemistry.
The report considers the results of the development of the automated technique for simultaneous, multielement activation analysis
of plants and fertilizers for the macronutrient elements N, P, K, Ca, Mg, Cl, and Si. On the basis of analytical procedures,
algorithms and software developed, the first automatic (computer based) installation for multielement analyses of plants and
fertilizers has been completed and is in routine use in the agrochemical and plant breeding research program at Soviet Union.
The proposed technique together with the full automatic real time process of measurement and processing of data by computer,
provides a throughput of 250–500 samples (1250–2500 elements determinations) per 8-hour shift, with the accuracy of ±3% for
N and ±5–10% for P, K, Mg, Cl and ±15% for Ca.
In the environment in which we live we are exposed to different kinds of radiation. Radiation is divided into ionising radiation as a result of radioactive decay and into non-ionising radiation, which is the consequence of electromagnetic waves. The use of electric power has penetrated every area of human activities. Its accompanying effects are electromagnetic waves, which expand into the space surrounding the installations for the generation, transmission and use of electric power. The research in the last 20 years has concentrated on the possibly harmful effects of low frequency (0–300 Hz) electromagnetic waves on man and the environment. However, not much research has been conducted into the magnetic fields under the electric overhead traction systems. Therefore, this paper is presenting the results of the calculation of the magnetic field under the electric overhead traction system on Slovenian railways.
Authors:M. Vasconcellos, M. Saiki, D. Fávaro, V. Maihara, A. Figueiredo, and M. Catharino
The Research Reactor Center (CRPQ) of IPEN/CNEN-SP operates the IEA-R1 Research Reactor, at a nominal power of 2 MW thermal,
on a 64 hour per week continuous cycle. The IEA-R1 is a pool type reactor, moderated and cooled by light water, with graphite
as a reflector. One of the main activities of CRPQ is the neutron activation analysis, which is applied to many fields of
research, in collaboration with other institutes and universities. The Research Reactor installations are also intensely used
for human resources development in the field of radiochemistry and neutron activation analysis, at graduate and post-graduate
levels. In the present paper, an overview will be presented of some of the neutron activation analysis research lines that
are being developed, comprising environmental and health-related applications.
The residents of Fremont neighborhood in Seattle Washington, witnessed the installation of a 16 feet, bronze statue of V. I. Lenin in June of 1995. The statue, which had formerly gazed upon the city of Poprad in Slovakia, had been purchased for $13,000 in 1993 by a local English teacher Lewis Carpenter, who came upon it in a scrap heap during his stay in Poprad. The ensuing debates that filled the local papers, questioned the appropriateness of the statue in the heart of Seattle's liberal business sector. What did it mean, they wondered, to have the leader of the October Revolution stride towards the fast food restaurant, Taco Del Mar. My paper argues that the reactivation of the monument's political meaning in Seattle was only possible because it moved outside the traditional channels of the museum and its protective walls.