1,721,343 research outputs found
Cs-137 contamination in wild boars in Sesia Valley, Italy
Full text linkTraces of cesium-137, well above the threshold set out in the Italian regulations, have been found in wild boars in the alpine area of the Sesia Valley, Piedmont, Italy.
We analyzed samples of tongue and diaphragm of animals slaughtered during the hunting season 2012-2013 and in 27 of these the level of cesium was higher than the threshold specified by the Italian Regulation 733 of 2008, dealing with the tolerable limit in the event of a nuclear accident. In fact, 27 samples have values above 600 Bq/kg, reaching up to 5600 Bq / kg in one sample, i.e., about ten times the limit. Cesium-137 is a radioactive isotope released, in 1986 from the Chernobyl disaster. It would seem that the contamination of these boars is so high due to the Chernobyl fallout and not, as it was thought at first, due to a radioactive medical source abandoned and disposed of illegally.
According to ARPA Piemonte (Governmental Regional Agency), the fall-out from Chernobyl was particularly high in certain areas of Piedmont, including the Sesia Valley, and it is not uncommon to find wild boars so contaminated and, in particular, this has already happened in other areas heavily contaminated by Chernobyl fallout as the Sesia Valley was.
A radiological test has been carried out, to assess conclusively that cesium-137 in the boars is "old Cesium" from Chernobyl and nothing something coming from a new contamination. Cs-137 (which has a half-life of 30 years) came from Chernobyl mixed with the shortest-lived isotope Cs-134 (which has half-life of about 2 years). In particular, in May 1986, the ratio of the radioactivity of Cs-137 versus Cs-134 present in the cloud and deposited on Italian soil was equal to about two (1.94): in other words, the radioactivity from Cs- 134 was approximately half that from Cs-137.
But the radioactivity from Cs-134 is halved every two years, while the longest Cs-137 halves every 30 years. So now, 27 years after Chernobyl, the radioactive concentration from Cs-134 has halved more than 13 times, falling to very little, while that of Cs-137 is still a bit 'more than a half of the original one. So, if we analyze the Chernobyl Radioactive cesium today, the ratio of the radioactivity of Cs-137 and Cs-134 is no longer near 2, but it has become, in favor of Cs-137, about 8900.
A further analysis has been performed with more precise measurements: the radioactive contamination of our boars shows a radioactivity of Cs-134 in their flesh almost imperceptible, but in the order - in the maximum case of the 5600 Bq/kg contamination – of 0.6 Bq/kg. Then it is confirmed that it is due to the heritage of the Chernobyl cloud contamination.
However, the wild boars are “sentinel animals” for pollution conditions in the areas where they live, because they provide precise information about the status of the environment. Thus, a contamination of the animals should require investigation and analysis of the environmental, meteorological and hydrological pollution in the areas where they live
Environmental pollution and health effects in the Quirra area, Sardinia Island (Italy) and the Depleted Uranium case
No full textQuirra is a village located in the Italian Sardinia island, close to a big military polygon where ballistic missiles and weapons are tested. Recently, the zone has been driven to the attention of the media due to the so-called 'Quirra syndrome', an apparently off-normal incidence of illnesses in that zone. The media indicated in the military use of depleted uranium a possible cause of the above situation. The paper carries out the following: a statistical assessment, to verify if the 'Quirra syndrome' exists, simulations with an atmospheric dispersion and dose code (HOTSPOT) in order to evaluate health effects of the supposed depleted uranium airborne dispersion. The conclusion is that the 'Quirra syndrome' exists, however it is probably not entirely due to depleted uranium. Other possible causes are briefly accounted fo
Doses due to contamination of the Techa river by the Mayak nuclear complex in Russia
No full textEnvironmental radioactive releases from the "Mayak" military nuclear installation (located in Russia, in southern Urals) have been very high, especially in the early fifties. In particular, releases of Cs-137 and Sr-90 into the Techa river, in the Chelyabinsk region, were extremely high in the years 1950 and 1951. The paper analyses the reasons of those releases, and computes doses to population living in the area. The inhabitants of the village of Metlino, 7 km downstream the release point, are identified as the critical group: the committed dose equivalents for them as so high that, besides a relevant increase of frequency of stochastic radiation effects (leukaemia and other tumors), a new type of disorder (Chronic Radiation Sickness) has been diagnosed in the inhabitants of the are
Impurity activation in magnet structural materials for fusion reactors
No full textNeutron-induced activity in fusion-reactor components can be effectively controlled through materials selection. This primarily applies to in-vessel components (first wall, blanket, etc.). However, some of the other machine components, such as the magnet coils, are also activated. In the Next European Torus (NET) project, for instance, activity in these components is high enough to require remote handling. The role of impurities in determining the activity in first-wall materials has already been investigated. In particular, it turns out that their medium- and long-term activity is remarkable affected by the presence of certain impurities. In order to satisfy currently proposed low-activity criteria, severe limitations have to be imposed on these impurities. In this paper, the authors examines the same problem in magnet structural materials. Specifically, the authors shall determine whether impurities can contribute a significant part of the activity in these material
Italian Foundry Contamination Due To Cs-137
Full text linkIn late October 2005 at the Beltrame plant in Susa Valley (Italy) a radioactive source was accidentally burned in the blast furnace. The source was not discovered by the detectors at the entrance, evidently because of some shielding effect. This caused the contamination of foundry dust, air intake system, and of the filters. There was no dispersion in the environment and risks to workers. All contaminated dust was collected in big bags and placed within containers waiting to know for their destination. The global activity is now estimated at 4 GBq. Five different contamination scenarios, have been analyzed, i.e., possible ways by which such an amount of radioactive material could have been introduced into the foundry. The considered contamination (4 GBq) is compatible with the total activity of some calibration sources. In both cases, Cs-137 is in the form of a quite small radioactive source capsule, sealed and surrounded by a shielding material assembly, such as Pb. The source capsule would have a quite high radioactive concentration, and then a total mass in the order of grams. It has therefore to be classified - for sure - as a High Radioactivity Material, or, once it is inadvertently thrown away, as High Level Waste (HLW), according to the Italian regulation (III Categoria). The lead assembly shielding explains why the assembly passed through the check of the gamma sensor without creating alar
Environmental Advantages of Advanced-fuel Fusion Reactors
No full textThis paper studies the extrapolation of ·compact high-field tokamaks technologies to obtain a DHe fusion power reactor, pointing the attention to the safety and environmental aspects. The main characteristics .of a high magnetic field fusion reactor, using DHe fuel cycle, are presented. The neutron induced .radioactivity in the structural components is calculated: radioactive inventories turn out to be very moderate. The machine has a very low environmental impact. A fusion power reactor based on the DHe cycle can be the correct response to the environmental requirements for future nuclear power plant
Fusion reactor passive safety and ignitor risk-based regulation
No full textPassive design features are more reliable than operator action of successful operation of active safety systems. Passive safety has usually been adopted for fission. The achievement of an inventory-based passive safety is difficult if the fusion reactor uses neutronic reactions. Ignitor is a high-magnetic field tokamak designed to study the physics of ignited plasmas. The safety goal for Ignitor is classification as a mobility-based passively safe machin
The Turin-Lyon High-Speed Rail Opposition: The Commons as an Uncommon Experience for Italy
No full textThe construction of the High Speed Railway (HSR, TAV in Italian) line Turin-Lyon in the Susa Valley (Italy) has long been surrounded by bitter controversies which do not give enough relevance to the most significant and technical aspects of the proposed project. The most relevant critical aspects of the proposed HSR are explored, for going beyond that, pointing out the aspects dealing with the social implications of the anti-HSR (NOTAV in Italian) movement, the leading one in the Commons struggle today in Italy. A brief history of the NOTAV movement is reported. The HSR project brings with it, after more than twenty years of strenuous and continuous reworking, a deal of issues that suggest that this project is not an actual priority for Italy, and its construction should be suspended
A new model for uranium dust health impact
No full textGrowing scientific evidence resulting from both in vivo and in vitro analyses suggests that current models of uranium dust toxicity on humans are not fully satisfactory. They should be refined in order to obtain more effective responses and predictions regarding health effects. A review of recent findings in the field of uranium toxicity is carried out, and a model based on the Toxicity Equivalent Factor approach is outlined. The model takes into account both radiological and chemical toxicity of Uranium, and it will be adopted for a revision of risk assessment due to Depleted Uranium dus
Exploration Of Clearance Strategy for an advanced-fuel fusion device
No full textThe features of Candor, a study of a compact high-magnetic field tokamak, based on advanced fuel cycle have been examined from a neutronics viewpoint. Activation behaviour, focusing on the Clearance Index of materials after service in a Deuterium-Helium-3 advanced fuel fusion experiment has been investigated, showing the possibility of being declassified to nonradioactive material (clearance) after their irradiation in the reactor plasma chamber wall, if a sufficient (55-70 y) interim cooling time is allotted. AISI 316L, on the contrary, suffers the presence of Ni, N, Nb and Mo. Concerning pure elements, it is of particular interest the high Clearance Index of Copper and the moderate one of F
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