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[en] A survey is given on the results in hand on the natural radioactivity of building materials. It is shown that only a small percentage of building materials has an increased content of radioactive materials. The results are compared with approximate values given in a Russian publication. (orig./AK)
[de]Es wird eine Zusammenfassung ueber die bisher vorliegenden Ergebnisse der natuerlichen Aktivitaeten in Baumaterialien gegeben. Es zeigt sich, dass nur in einem kleinen Teil der Baumaterialien erhoehte Gehalte an radioaktiven Stoffen vorhanden sind. Die Ergebnisse werden mit Richtwerten verglichen, die einer russischen Arbeit entstammen. (orig.)
[en] This report presents the status of the problem with release of materials from decommissioned nuclear power plants in the European countries and Bulgaria and activities for adoption of standards in this area. The principles applied in developing of internationally approved criteria for releasing are discussed with regard of minimal impact on the environment
[en] The factors affecting the energy of neutrons produced in generators with sealed tubes are presented. The change in the energy of neutrons interacting with the structural materials of the generator is not examined. The analysis will be useful to specialists doing practical work with neutron generators.
[en] The contents of natural radionuclides (235 U, 226 Ra; 232 Th, 40 K ) in row building materials (simple and quartz sand, cement, unhydrated lime, aluminium powder) and final product (siporex extended concrete) were determined on two HPGe detectors by standard gamma spectrometry. The detectors have different relative efficiencies and are placed in differently constructed Pb shieldings. (author)
[en] The importance of gypsum as a building material increases nowadays because of its environmental friendliness, excellent fire properties and good workability. Since the gypsum is mostly used in the form of the paste, the influence of aggregates on properties of gypsum mortars is not investigated very often. The article deals with some basic and mechanical properties of gypsum mortars with different aggregates and compares them with the properties of gypsum paste. Type of the aggregates influences the properties of gypsum mortars significantly. The presence of aggregate does not worsen the adhesive strength of the gypsum material in comparison with gypsum paste and the adhesive strength was even improved for some type of aggregates. (paper)
[en] The radioactive substances in building materials, which are used in the construction and repair of buildings, have a serious negative effect on human health. Consequently, the radiation background of the buildings territory are being built should be pre-measured, and construction sites should not be allowed to live in areas where the radiation background is above of normal. The effective radiation dose rate should not exceed the average value for residential and public buildings.
[en] The rates of radon exhalation from building materials available on the Serbian market were measured using RAD7 device. Fitting the growth curves of radon activity concentration provided the information on radon exhalation rates from the samples. The results were quite low and they ranged from 1.4 to 855 mBq m-2 h-1 for surface exhalation rate and from 1.3 to 11.4 mBq kg-1 h-1 for mass exhalation rate. The effect of moisture on radon exhalation was confirmed. For powdered samples with dimensions smaller than radon diffusion length, the mass exhalation rate is independent of sample mass and its exhalation area. (author)