New data on abundance and isotope composition of “hot” and active particles in alluvial soils and sediments of the Yenisei river (Krasnoyarsk region, Russia), located in a near influence zone of the Krasnoyarsk Mining and Chemical Processing Plant (KMCPP), are presented in this study. On a set of gamma-emitting radioisotopes all “hot” particles can be divided on three groups: 1. monoisotopic (137Cs, 60Co); 2. two-isotopic (137Cs and 134Cs); 3. polyisotopic (137Cs, 134Cs, 60Co, 154Eu, 155Eu and 241Am). Very significant is the absence of 152Eu in all polyisotopic particles whereas in soils this isotope is often predominant. The active particles are presented by the several polyisotopic types, containing: 1. 154Eu, 155Eu, 137Cs, 60Co and 241Am; 2. 154Eu, 155Eu, 137Cs and 241Am; 3. 152Eu, 154Eu, 155Eu, 60Co and 241Am and monoisotopic (60Co and 137Cs). Presence of the active particles containing all isotopes, except of 137Cs, and particles without 152Eu and 60Co is interesting. Some active particles due to their set of radioisotopes can be referred to the finely dispersed fragments of the “hot” particles. However, the majority of them have the nature distinct from the “hot” particles.

The French Decree of 25 May 2005 [4] relative to activities using naturally occurring radioactive materials (NORM) not used because of their radioactive properties imposes that the operators assess effective doses received by workers and populations. To date, about sixty studies have been submitted to the French public authorities. Within this context, the French public authorities asked IRSN to develop a tool for evaluating the quality and the comprehensiveness of these studies and for identifying industrial plants with radiological protection problems. This tool is aimed at helping the regional representatives of French public authorities in their duty to analyse these studies. The aim of this presentation is to illustrate the application of the tool developed by IRSN and to present the French feedback.

The Angra dos Reis nuclear power plant site is located 130 km south from Rio de Janeiro city. Seawater is used as cooling water for both units; the cooling water is pumped from Itaorna Bay and discharged into Piraquara de Fora Bay, together with the liquid effluents from the two NPPs. Piraquara de Fora Bay belongs to a large bay system, Ilha Grande Bay and, therefore, conservative radionuclides in seawater will reach this bay with the tidal movement and, at the end, exported to open sea. Radium isotopes behave conservatively in seawater and can be applied as natural tracers to carry out dispersion studies. Two transets involving eight sampling points each were performed in Ilha Grande bay and 228Ra, 226Ra, 224Ra and 223Ra determination realized. The results have shown that the conservative radionuclide dispersion is controlled by eddy diffusion with negligible net offshore advection. The calculated eddy diffusion coefficient was 26 km2 ⋅ d-1 and 25 km2 ⋅ d-1, based on 223Ra and 224Ra respectively.

Three sediment cores were sampled at Sepetiba bay and four cores at Ribeira bay, Rio de Janeiro State, Brazil. Sedimentation rates were determined applying 210Pb dating. In the Ribeira Bay, the sedimentation rate increases in the direction from sampling point RB1 (0.15 cm y-1), in the inner part of the bay, to 0.34 cm y-1 in the sampling point RB4, close to its entrance. For the Sepetiba Bay, two sedimentation rates were observed: a lower rate of 0.3 cm y-1, for the period before the 60's, and a more recent rate of 0.75 cm y-1. These findings agree with the construction of the Santa Cecília impoundment (1955) that brings water from the Paraíba do Sul Basin into the Guandu River, increasing its flow from the original 20 m3 s-1 to 160 m3 s-1. In order to determine the elemental concentrations, aliquot from the SB1 and RB4 cores were taken, totally dissolved and analyzed by ICP-MS. The hypothesis that Ribeira Bay could constitute a reference database for metal concentrations in the neighboring Sepetiba Bay is valid for several elements as K, Ti, Mn, Zn, Ga, Rb, Sr among others, but it isn't for other elements as V, Cr and Cd. Applying to the mean elemental concentration, of the upper contaminated 45 cm sediment layer, and to the elemental concentration of the deepest analyzed sediment layer a normalization to iron, a double ratio was calculated and it was concluded that the Sepetiba Bay sediments are, particularly, contaminated with Cr, may be, from a leather tanning plant existing in this region and Cd and Zn from the former Ingá Metais.

Advisability of using risks as indicators for estimating radiation impacts on environmental objects and humans has been justified. Results are presented from identification of dose burdens distribution to various cohorts of the population living within the Semipalatinsk Test Site (STS) and consuming contaminated farm products. Parameters of dose burden distributions are estimated for areas of livestock grazing and the most contaminated sectors within these areas. Dose distributions to meadow plants for the above areas have been found. Regulatory radiation risks for the STS population and meadow ecosystem components have been calculated. Based on the parameters estimated, levels of radiation exposure of the population and herbaceous plants have been compared.

An algorithm and formulas to estimate non-regulatory stochastic risks (for biota and humans) have been derived. These were used to assess radiation risks for meadow plants within the Semipalatinsk Test Site (STS). It has been shown that on small plots with relatively high radiation levels (∼ 0.25 mGy/h) the radiation risks of death of radiosensitive plants (leguminous and coniferous shrubs) have a noticeable value (> 2%). In the other STS area, radiation is not a danger to the vegetation.

The natural radioactivity due to presence of 238U, 232Th and 40K in zirconium minerals used in the Iranian ceramic industry, tiles and waste sludges has been measured. The measurements were made by gamma spectrometry system with a high pure germanium (HPGe) detector connected to multichannel analyzer (MCA). The average concentrations of 238U and 232Th determined in the mineral samples (3000, 500 Bq kg-1 respectively) are much higher than concentrations found in the earth's crust. The specific activity of 238U and 232Th in tiles (62,54 Bq kg-1 respectively) are not higher than in other building materials.

The 238U concentration of sludges (150 Bq kg-1) is higher than the mean value for the earth's crust. The results are examined on the basis of the existing national limit.

A small-scale decommissioning concept was applied with staff from an earlier project with strong knowledge of radiation protection, minimized radiation doses and environmental pollution. The project was therefore initiated with less than 10 people involved using standard handheld equipment. The aim of the decommissioning project was to set free as much material as possible, i.e. remove waste from the regulatory control regime and also free the remaining structures and buildings for conventional demolition and subsequent reuse of the property. A final decommissioning plan was drafted together with a safety assessment covering the planned activities and abnormal events that may occur during decommissioning. Applications and contacts were made with five different authorities to obtain permits pursuant to national safety standards and requirements, including the areas of safety (Swedish Nuclear Power Inspectorate), radiation protection (Swedish Radiation Protection Institute), environmental protection (County Administrative Board), construction (Swedish Work Environment Authority) and building demolition (Municipality of Nyköping). Sufficient funds were available for decommissioning. Complete decommissioning will be concluded at the end of 2008 when all waste is taken care of. This is the fourth in a series of important decommissioning projects in Studsvik since the 1980s.

In 1985, at Novovoronezh NPP (NVNPP), liquid radioactive waste leaked from the storage facility No2 (SLW-2). The leakage took place along the perimeter of the storage facility from the underpan closed with soil; therefore the leakage has been discovered in about half year, during water sampling from the test boreholes. According to the assessments, a volume of liquid waste released in soil was about 480 m3 with ∼76 and 15 TBq activities of 60Co and 137Cs, respectively. Up to now, the majority of 137Cs amount has been localized at the place of the leakage – in the unsaturated zone at the level of the underpan; 60Co was infiltrated into the aquifer and spread through – ground waters at about 700 meters up to Don River. 60Co occurrence in the river was registered in 1995. The ground water discharge into Don River caused contamination of some part of bottom sediments up to the level of solid radioactive waste. This paper presents the calculation results of 60Co migration via ground waters.

A new assessment of the nuclear dumping sites of Novaya Zemlya was performed in 2003/4. 137Cs contamination levels within both Stepovogo and Abrosimova Bays are similar to background environmental levels and there has been no detectable leakage from objects in Tsivolki Bay. Near-surface sediment 137Cs contamination levels in 2003/04 are 1–11 Bq/kg, 4–268 Bq/kg, and 13–20 Bq/kg in Tsivolki, Stepovogo and Abrosimova Bays respectively. These conclusions are further supported by the data for 238Pu and 239+240Pu. Hence, leakages from the low-level waste containers on the seafloor have diminished appreciably after ten years while sediment reworking (e.g. mixing, burial, resuspension and transport) and radioactive decay has reduced to negligible the elevated radionuclide levels previously detected in surface sediments. Furthermore, there is no indication that nuclear fuel from the dumped reactors or submarine has been or is presently releasing detectable quantities of radioactivity into the marine environment.

Lead-210 is a natural radioactive isotope and a decay product of the Uranium-238 decay chain found in the natural environment along with Radon-222 and Polonium-210. Lead-210 contribution to the internal exposure of man through ingestion is 20% but represents 70% of the internal exposure of man through inhalation due to the uranium and thorium decay series.

Transfer of lead-210 in the environment has been relatively poorly studied when compared to other radionuclides (Caesium-137, Strontium-90, Cobalt-60, Tritium, Carbon-14, etc.) even if we register a recent increase in the number of scientific publications. Therefore, this study reviews experimental data concerning the transfers of Lead-210 in the different compartments (atmosphere, freshwaters, sediments, soils, plants, animals) of continental environments (terrestrial and freshwater) from its natural sources.

Moreover, it compares these data with those concerning the stable isotopes of lead. Indeed, stable lead is found in all the terrestrial and freshwater ecosystems but with an important variation in its concentration according to location and sampling type. Such a global contamination of the environment is mainly due to its industrial use. Lead toxicity is coming from its physiological behaviour similar to those of essential elements such as calcium and magnesium. A list of transfer factors for Lead-210 and stable isotopes of lead between the different compartments of the terrestrial and freshwater ecosystems is provided.

The main conclusion of this review is that the behaviours of Lead-210 and stable isotopes of lead are quite similar in terrestrial environments although some discrepancies are noted in freshwater environments. The nature of these discrepancies is discussed.

The assessment of cyto- and genotoxicity of water samples from a regional radioactive waste repository using the Allium-test was carry out. Biotesting of natural waters from the site has demonstrated that negative biological effects are generated under the influence of water from well, located near the source of contamination. The percentage of aberrant cells in water samples from this well 4 is 2 times higher than in the control or other sources. Effects of water composition at the genome level are season independent. The Allium-test was shown to be highly sensitive and effective in testing a combined effect from radiation and chemical factors in field conditions.

In 2003 IAEA launched the EMRAS Programme aiming at evaluating the predictive power of radiological models. The programme continued work of previous international radioecological modelling programmes and comprised several working groups focusing on different aspects of environmental modelling. The Iodine Working Group reassessed the impact of the release of 131I during the Chernobyl accident with the aim of comparing model predictions with environmental data and inter-comparing the model predictions. Measurement data and detailed geographic and demographic descriptions were available for three regions: Plavsk, Warsaw and Prague. As for the Prague Scenario, milk supply regions of three big dairies were chosen for the model validation. Apart from geographic, demographic and agricultural descriptions (e.g. gathering regions of the dairies, feeding regime), the modellers were provided with information on the weather conditions and measurement data of iodine contamination. The most important peculiarities of Prague Scenario were keeping milk cattle in sheds and a special feeding regime during May 1986. The modellers were asked to assess the 131I content in the thyroid of the local population and the resulting dose. The assessments were compared with measurement data. The results of these model calculations and their comparison with experimental data are presented.

The paper presents a simple technique for determination of the Equilibrium Equivalent Thoron Concentration (EETC). A solid-state nuclear alpha track detector (SSNATD) named CR-39 manufactured by BARYOTRAK is used as the detector. This technique can be utilized anywhere, provided that air sampling is carried out with a DC driving pump. Although the measurement of Thoron concentrations is useful enough for screening high Thoron exposure, it is still necessary to determine Thoron progeny concentrations in order to complete dose assessment. After applying this technique for determining the EETC in some selected areas in southern Thailand, it has been found that the obtained EETC values are consistent with the values presented in the report compiled by UNSCEAR in 2000.

The data on assessment of the irradiation doses of the Chernobyl 239,240Pu to the Black Sea hydrobionts of different trophic levels are presented. The rates of adsorbed doses of internal irradiation from the alpha-radiation of incorporated 239,240Pu to the Black Sea hydrobionts varied from 0.01 to 0.354 µGy ⋅ years-1 Comparative analysis of dose levels formed with 239,240Pu to studied hydrobionts of the Black Sea in this work and doses formed with natural alpha-emitting radionuclide of 210Po showed that 239,240Pu irradiation doses are 103–104 times lower, than irradiation doses with 210Po. Hence, doses created with 239,240Pu to the Black Sea hydrobionts were in n ⋅ 106–107 times less than the dose level offered by International Atomic Energy Agency (IAEA), at which there are no negative consequences in populations of aquatic organisms.

Numerous studies have considered whether run-off from large Siberian rivers, in particular the Ob River, has the potential to transport radioactive contaminants from the nuclear sites – SPA “Mayak” and Siberian Chemical Combine (SCC), located in the vicinity of these rivers, to distant locations including the Kara Sea.

The plutonium-producing radiochemical plant of SPA ''Mayak'' stored a lot of radioactive wastes in LakeKarachai. Radioelements are carried to the rivers with flood and ground waters [1]. As contaminationis transported, radioactivity is removed through Techa-Iset’-Tobol-Ob river system but has the potentialto reach the Kara Sea and further to other seas within the Arctic basin via ocean currents. The SiberianChemical Combine, is located in Seversk city on the bank of Tom River, that drains into the Ob network.SCC liquid wastes were detected in the Tom River, which flows into the Ob River [2].

In this paper the data of our investigations during last years on studying the radioecological situation in twoparts of the Ob river-Kara Sea aquatic system Ob-Irtysh river’s system and Ob Bay and adjacent part ofthe Kara Sea, with a main focus on the behavior and migration pathways of man-made radionuclides arepresented.

Coal mine Tusnica is located in South-West part of Bosnia and Herzegovina in the municipality Livno. Coal mine Tusnica consists of two surface coal mines. The first one is brown coal surface deposit called Drage and second one is lignite deposit called Table. The brown coal deposit shows increased levels of natural radionuclides. The highest absorbed dose rate is recorded in the center of the surface coal mine Tusnica-Drage (500 nGy h-1) as result of the increased content of uranium and radium in coal (average specific activity of U-238 is 623 ± 23 Bq kg-1 and Ra-226 is 1191 ± 5 Bq kg-1). Levels of natural radionuclides in the vicinity of the surface deposit Drage in agricultural soil (about 3 km of the centre mine) are slightly increased due to the use of the coal ash and coal dust for fertilization of the land (U-238 is 142 ± 11 Bq kg-1 and Ra-226 is 197 ± 2 Bq kg-1). Obtained results in soil-plant-animal products chain does not show significantly increased levels of natural radionuclides due to the fact that mentioned radionuclides, in general, have a low transfer factors in soil-plant-animal products chain.

This study evaluates distribution and dynamics of suspended matter, strontium 90 and caesium 137 in Orlík reservoir. In the case of suspended matter and caesium 137, 85.8% and 60.6% respectively was deposited in the reservoir during the period 2000–2006 while during the period 1997–2006 the outflow of strontium 90 from the reservoir exceeded the inflow by 31%.

Airborne 137Cs level in France is not decreasing significantly anymore (mean yearly value around 0,25 µ Bq.m-3 contrarily to what was noticed in the past decades. This observation points out the role of processes that delay the atmospheric cleaning and participate to the persistence of radionuclide in the air at ground-level after a deposit, in the frame of medium as well as long-dated post-accidental contexts. The current background level also yields to consider 137Cs in the atmosphere as a tracer of atmospheric processes like resuspension and re-emission from biomass burnings. This allows us to explain 2/3 of the peaks observed over the last six years. The remaining 1/3 is mainly noticed in winter when spreading of pollutants in the atmosphere is often weak due to temperature gradient inversion. On average, continental air masses are responsible for increases by a factor of 3 while oceanic air masses are characterised by levels 3 times lower, compared to the mean value. Feeding of 137Cs in air at ground-level is the result of both local resuspension that signs 137Cs activity levels in soils to which is added a remote contribution from time to time (resuspension of Saharan dust or re-emission from fires occurring in eastern territories with high 137Cs deposition level). Finally, 137Cs activity levels in air masses crossing over France can be described on average by a longitudinal gradient.

Quaternary sediments and soils at the Forsmark site (Sweden) would constitute the last barrier for radionuclide migration interposed between a deep repository of high level nuclear wastes (HLNW) and surface ecological systems. The retention capacity of these sediments is evaluated by means of reactive transport simulations. Two different scenarios have been modelled: (1) Inflow of deep fluids carrying radionuclides into shallow aquifers hosted in the carbonate glacial till, and (2) Inflow of deep fluids carrying radionuclides into organic matter-bearing clays. The model results predict that caesium is very efficiently retained in both scenarios for periods longer than 3000 years due to the strong affinity of this ion with the frayed edge sites of the illite layers. Strontium is also retained via cation exchange in illite and, in a lesser extent, via co-precipitation in calcite. The retention efficiency for strontium, however, quickly decreases to 0 after 1000 years. Uranium is retained in both scenarios with retention efficiencies higher than 40% at long term (>3000 years) due to precipitation of amorphous uraninite and adsorption on Fe(III) oxyhydroxides. Radium is only retained in the till aquifer since co-precipitation with barium sulphate does not occur in the clay porewater.