An investigation on the distribution of Radium activity levels in the entire south-eastern coast of Tamilnadu, India, from Chennai to Kanyakumari was carried out. Insitu preconcentration technique was adopted by passing 1000 liters of seawater through MnO2 impregnated cartridge filters at all the locations. In the coastal waters, 226Ra and 228Ra concentration was observed to be in the range of 1 to 1.81 mBq/l and 3.1 to 7.5 mBq/l respectively with an average of 1.52 and 4.53 mBq/l respectively, while the sediment samples showed 226Ra activity levels from 8.1 to 129.0 Bq/kg and 228Ra varied from 14.7 to 430.01 Bq/kg. The concentration of 228Ra was observed to be more than 226Ra in all the locations. The activity ratio of 228Ra/ 226Ra in the Bay of Bengal showed a ratio varying from 0.8 to 2.4 with a mean of 2.1. In the present study, activity ratio varies from 1.9 to 2.4 at Karaikkal. But the regions of Rameswaram and Kanyakumari which comprises the high natural background region reflects different ratio varying from 3.5 to 6.9, reflecting different sources of weathered material for 228Ra. The findings supported the fact that the area also comes under natural high radiation background at the south west of Indian peninsula due to the presence of heavy mineral containing monazite. The spatial distribution of the activity with respect to location is discussed in the paper. The radioactive database obtained represents reference values for coastal environment of Tamil Nadu.

Coal, bottom ash and fly ash samples were collected from three different coal-fired thermal power plants in India and subjected to gamma spectrometry analysis for natural radioactivity contents. The results of present study show that fly ash and bottom ash contains two to five times more natural radionuclides than feed coal. None of the fly-ash and bottom ash samples had radium equivalent activities and external hazard index values more than 370 Bq kg–1 and unity respectively. However the absorbed dose rate at 1 m above the ash pond was 79.19n Gy h–1 (average of 3 plants) higher than the global average value of 55 nGy h–1. The corresponding annual external effective dose is estimated to be 0.68 mSv y–1, which is also more than that (0.46 mSv y–1) in areas of natural background radiation. The 5th percentile, 95th percentile and mean values for total inhalation risk arising from radionuclides (Ra226, Th228, Pb210 and Nat-U) were found to be 3.83 × 10−9, 6.50 × 10−8 and 2.08 × 10−8 respectively.

Traces of short- and long-lived fallout isotopes (131I, 134Cs and 137Cs) were found in environmental samples obtained in northwest Germany (river sediment, rainwater, grass and milk) from March to May 2011, following the radioactivity releases after the nuclear accident in Fukushima, Japan. The found concentration values are consistent with reported concentrations in air, amount of rainfall and expected values applying simple radioecological models. The [134Cs]/[137Cs] ratio reported for air (about 1:1) allows for discrimination between “recent” and “old” 137Cs. Expected 136Cs values fell below the detection limits of the instrumentation, despite large sample masses and long counting times.

An evaluation of the radioecological sensitivity of the coastal marine regions can be used to improve risk management and decision-making systems, especially the development of response strategies, by defining the most sensitive areas. Environmental sensitivity analysis has been carried out for six marine coastal regions for a single deposition of 1000 Bq/m2 for radionuclides 137Cs, 90Sr, 131I and 239Pu. The analysis has been based on dose calculations during the 1st year, 2nd year and 10th year after releases of radionuclides for adults and children of 1 and 10 years of age. The calculations have been carried out by the compartment model, which includes the processes of dispersion of radioactivity in water - sediment environment and accumulation of radionuclides by marine organisms. Doses to man are calculated on the basis of seafood consumption. Results show that for all regions the radiation doses for adults are significantly higher than doses calculated for children. Further, the doses calculated for the first year dominate the doses of the second and tenth year following the releases of radionuclides. Calculations also indicate that doses vary greatly for different radionuclides; and the dose levels for the same radionuclide vary greatly in different marine environments.

The examination of sediment samples collected from the Yenisei River revealed the presence of artificial radionuclides characteristic of radioactive discharges from the MCC facility: isotopes of europium (152Eu, 154Eu, and 155Eu), cesium (137Cs and 134Cs), 60Co,90Sr, and transuranium elements. Radionuclide concentrations in sediment layers remained high as far as 240 km downstream of the MCC. The vertical distribution of radionuclides in sediment cores was very complex, and down-core variations were due to different amounts of radionuclides released by the MCC and due to variations in the hydrologic conditions in the river. Sequential extraction performed on samples of the upper layers of the sediment core showed different degrees of potential environmental availability of artificial radionuclides: the amounts of extracted 90Sr, 152Eu and 241Am were the largest (60–80% of initial activity), then followed 60Co (30%), 238,239,240Pu (15–30%), and, last, 137Cs (5–15%). The distribution of 238U among chemical fractions of sediments was similar to that of 60Co and 238,239,240Pu: 30–40% of 238U initial activity was extracted. In a few samples, 241Am was present in the unextractable form, which may be accounted for by the presence of microparticles of the reactor fuel.

In Finland, Olkiluoto Island on the western coast has been selected as a repository site for spent nuclear fuel disposal. A safety criterion is that typical exposures (dose rates) to flora and fauna should be demonstrated to be lower than those that according to best available knowledge could cause detrimental effect. To increase the confidence of dose assessment to flora, some selected plant species were measured in field conditions. This paper presents the results of the field campaign and discusses on the realism of the common assumption of ellipsoidal geometry applied to the plants in dose assessments of the other biota.

The Søve site is a disused mining complex in Telemark County, Norway, exhibiting enhanced levels of naturally occurring radionuclides from the 238U and 232Th decay series. The nascent General Assessment Methodology Process (‘GAMP’), developed under IAEA’s EMRAS II programme, has been applied at the site. The a priori fixed screening criteria were exceeded in the scenario, precipitating the requirement to undertake a more detailed assessment. The USDOE’s RESRAD-OFFSITE code was employed to investigate potential changes in activity concentrations in various environmental compartments over time and the contribution of various exposure pathways to effective doses. Owing to problems associated with model parameterisation and results interpretation a simple leaching and groundwater migration compartmental model was also applied. This allowed activity concentrations in three waste compartments to be calculated with time. Furthermore, an existing external dose-rate model that correlates information on activity concentrations with depth in soil to dose rates in air above ground has been used to estimate prospective external dose-rates to humans and evaluate the efficacy of applying various remediation options.

Natural radioactivity is associated with the vast mineral resources in South Africa in such concentrations that the radionuclides from the natural uranium and thorium decay series are found to pose concern for public exposure to communities living around these areas. Consumption of water and food is usually the most important route by which natural radionuclides can enter the human body and assessment of natural radionuclide levels in different foods and diets is therefore important to estimate the intake of these radionuclides by man. Sensitive measurement of three major radionuclides (in addition to 238U, 234U, 232Th, 226Ra, 224Ra and 223Ra) is necessary to calculate the estimated annual dose with a high degree of certainty i.e. 230Th, 210Pb and 210Po, while 231Pa, 227Ac and 228Ra also require improved sensitivity. In order to evaluate the yearly dose due to an individual source at a screening level of 25 μSv/a, one is faced with a required lower limit of determination (LLD) of 0.1 to 0.5 Bq/kg for certain foodstuffs. In this study the potential radiological impact of foodstuffs grown in a catchment area influenced by mining and mineral processing industries in South Africa, was determined by measuring the natural radionuclides in a number of foodstuffs collected from the area. The radionuclides were measured by non-destructive techniques such as Instrumental Neutron Activation Analysis (INAA) and low background gamma spectrometry. The assessment of natural radionuclides in foods allowed us to evaluate the items that present the highest risk to the population, and compare this to the limits established by the National Nuclear Regulator (NNR). From the public’s point of view it is important to ensure the population that the contaminant levels in specific food as a result of mining activities, do not exceed the permissible limits. For the majority of the analysed foodstuffs, the estimated dose was less than 250 μSv/a. Overestimation of dose, due to poor measurement detection limits, was clearly indicated for some of the samples. For most of the analysed nuclides, suitable data for evaluation of the yearly dose at the screening level of 25 μSv/a was obtained by broad energy gamma analysis of ashed samples. However, nuclides such as 230Th, 210Po and 231Pa has to be analysed by radiochemical separation through acid destruction of dried foodstuffs followed by individual element separations to provide suitable data with a low enough LLD not to result in an overestimation of the calculated dose.

The European decision support systems ARGOS and RODOS rely on the ECOSYS model for prognoses of ingestion doses. ECOSYS needs an update of various parameter values to provide reliable estimates. This paper reports on some results of a Nordic initiative to derive parameter values that are specific to Nordic conditions, as well as to improve generic parameter values in ECOSYS, taking into account the host of useful measurement data accumulated since ECOSYS was created.

Members of the public are exposed to radiation because of where they live and their habits bring them into contact with sources of radiation. They may be exposed directly by the source, by direct irradiation or inhalation of released activity or indirectly by exposure to contaminated environmental materials such as food. Consequently habit data are an essential part of dose assessment for members of the public [1]. Previously no detailed surveys had been undertaken in Ireland of habit data relevant to the assessment of doses to the population from radioactivity in the marine environment. Instead RPII dose assessments were made on the basis of assumed or notional data inferred from habit surveys undertaken elsewhere and from national average consumption figures. Following a tender process the Centre for Environment, Fisheries & Aquaculture Science, Cefas, UK, were commissioned to undertake a Habits Survey. Its report [2] provides an assessment of aquatic radiation exposure pathways in Ireland relating to anthropogenic radioactivity in the Irish Sea.

In Finland, Olkiluoto Island has been selected for constructing a spent nuclear fuel disposal facility. With the approaching licensing step, submitting the application for nuclear construction licence in 2012, all components of the safety case are becoming more site-specific. In order to assess compliance with regulatory requirements, a prospective deterministic dose assessment methodology based on the ICRP concept of assessing doses to the representative person was developed and implemented in the interim safety case 2009, to be further refined for the safety case 2012. To facilitate the assessment of doses to the most exposed people and other people at the evolving site, full dose distributions are derived, comprising the dose to each potentially exposed person in each generation.

Estimation of 50% lethal doses from nuclear DNA contents and subsequent species sensitivity distribution analysis was performed to derive regional 5% hazardous doses (HD5) for major orders Anura (e.g., frogs) and Caudata (e.g., salamanders) of amphibians inhabiting Japan, Australia, France, Czech Republic, Canada and some US states, where nuclear power plants or uranium mines are located. The HD5 values ranged from 3.0 to 7.7 Gy for the Anura inhabiting there while they ranged from 2.9 to 4.6 Gy for the Caudata. Comparison of these results with the worldwide HD5s (5.3 Gy for the Anura and 3.3 Gy for the Caudata) suggests that benchmark values for the Asian and Oceanic Anura and the European Caudata can be set at higher doses than the global values. Regional differences should be, therefore, considered when benchmark values are derived for some taxonomic groups.

The aim of this work is to develop methods for an assessment of critical doses and dose rates that can result in significant radiation-induced effects in agrocenoses. This is realized on an example of cultivated plants which are one of the main components of agroecosystems. Available information on dose dependences in such umbrella endpoints as reproduction, survival, morbidity, alterations in morphological and biochemical processes, genetic effects in crops, vegetables, fruit trees, etc are gathered from papers issued mainly in Russian scientific press during last 50 years. Data are maintained as database in MS Access that contains about 10000 records at the moment. As critical exposure values, doses are considered producing 50% changes of biological effect at acute impact (ED50), or dose rates resulting in 10% changes at chronic exposure of plants (EDR10). The critical doses and dose rates for agrocenosis estimated from available information on reproduction and survival are presented here. Primary data are assesed for their quality according to several criteria. Three models (linear, logariphmic, logistic) for dose-effect relationship are tested for an applicability to fit a dose-effect dependence taking account of their goodness-of-fit and robustness of ED50 and EDR10 estimates.

In a survey on uranium and 226Ra concentrations in water distributed by Finnish waterworks, 548 samples were analysed that covered drinking water networks servicing 84% of all consumers. Among all consumers, the mean and median uranium concentrations at the point of use were 0.58 and 0.15 μg L–1. The mean uranium concentration in drinking water produced from groundwater was 0.88 μg L–1, and when surface water was used in production the mean concentration was only 0.15 μg L–1. 226Ra concentrations were generally below our detection limit of 0.01 Bq L–1. The annual effective doses to the public arising from these radionuclides were only a few microsieverts, and the 0.1 mSv limit laid down in the EU Drinking Water Directive was not exceeded in any of the studied water distribution networks.

Fine radioactive particulate dispersal in outdoor areas presents significant economic, social, environmental and public health concerns. The interactions of these radioactive particles with urban surfaces need to be well understood to develop optimized decontamination strategies. The major environmental factors influencing these interactions are relative air humidity, temperature and rain. The objective of this work is to investigate the fate and transport of water soluble cesium deposited on conventional urban building materials, especially concrete, brick, asphalt, limestone, and granite, under various environmental conditions (relative humidity (RH), and atmospheric precipitation). The data on the kinetics of 137Cs desorption from building materials by the solution containing 100 mM of Ca2+ and 0.5 mM of K+ have shown that the shape of the 137Cs desorption curves is similar for all building materials. There is a rapid initial decrease in the activity of the sorbed 137Cs. The desorption rate first decreases quickly during 7–10 days and practically does not change later. The remaining 137Cs in building materials that is not desorbed by the solution is 30-40% of the initially sorbed amount. For the building materials of interest, radiocaesium interception potentials (RIP). The RIP(K) value has been shown to range from 20 to 300 mM/kg and increase in the order: limestone > brick > concrete > granite > asphalt. The fine fraction of building materials (<0.125 mm) sorbs 137Cs better than the coarse fraction (0.0125–0.25 mm). Based on RIP(K) value and measured concentration of cations the distribution coefficients Kd(137Cs) were determined. The study of the mechanisms of radiocesium binding by different components of building materials, based on sequential extraction technique, shows that the highest ability to bind 137Cs is characteristic of asphalt which retains 40.9±1.0 % of 137Cs after all extractions. By the ability to bind 137Cs with the residual fraction, the studied materials form the following sequence: concrete > limestone > granite > brick. Method to study radionuclides distribution in depth of building materials using layer-by-layer grinding has been developed.

Surface, intermediate and near-bottom water samples were collected at two of the North East Atlantic radioactive waste dumping sites (47∘ 14’N, 05∘ 33’W and 45∘ 27’N, 06∘ 16’W) in the course of a sampling campaign in June–July 1998. Analysis of 239,240Pu concentrations show no significant differences with respect to measured concentrations in waters taken from control (background) stations well removed from the dumping sites.

A widely applied method of supported lead estimation in sediments using gamma spectrometric 226Ra determination via 222Rn short lived daughter products relies on radioactive equilibrium between 226Ra and 222Rn being established after sealing the samples. Advantages and disadvantages of methods of 226Ra estimation in sediments, using either 226Ra daughter products or direct estimation by the 186.2 keV gamma-emissions are discussed. An equilibrium experiment was performed using test samples and in one case radioactive equilibrium was not reached. On theoretical sediment profiles it is shown how systematic errors in supported 210Pb estimation can lead to wrong interpretations of 210Pbxs profiles and therefore affect 210Pb derived chronologies.

A programme of work, commissioned within the BIOPROTA collaborative forum, has recently been undertaken to assess the quantitative and qualitative elements of uncertainty associated with non-human biota (NHB) dose assessment in relation to the potential long-term release of radionuclides from a geological disposal facility (GDF). This was achieved through combining quantitative sensitivity and qualitative knowledge quality analyses based on the EC ERICA assessment approach and default assessment parameters. The results of the project demonstrate that this combination of approaches may be used to identify important parameters that could be significant in assessments of the impacts of any radionuclide release from a GDF on NHB, and for which there is low confidence. The output is intended to provide information on those parameters that may need to be considered in more detail for site-specific assessments. Such information should help users to enhance the quality of their assessments and build greater confidence in the results.

The evaluation of environmental vulnerability is one of the key factors in need of consideration during the improvement of decision-making systems and the development of response strategies to radionuclide release into marine regions. Environmental marine modelling has to simultaneously describe the dispersion of radionuclides in water and sediment phases; bioaccumulation of radionuclides in biota and finally, dose assessments. It is obvious that such an approach comes up against the problem of complexity and the need for a large set of parameters. The sensitivity analysis of the model parameters can contribute to a better understanding of experimental data as well as define parameters which can play a key role in the evaluation of environmental vulnerability. In the present paper sensitivity analysis has been carried out using the compartment modelling approach for assessment of the environmental vulnerability as dose to man. The sensitivity analysis shows that the influence of model parameters can vary greatly depending on the concrete radionuclude and on the marine region. It is also shown that the results of the sensitivity parameter analysis can contribute to the process of defining which parameters can play an important role in the dose assessment and the evaluation of environmental vulnerability.

Uranium mine Žirovski vrh in Slovenia was closed in the year 1993. In the past years a lot of work was done for restoration of the area around the mine. There are two tailing sites, Jazbec and Boršt, filled with material with high specific activity of 226Ra. Tailings are covered by different layers of clay and soil in depth of 2 m for reducing radon exhalation rate. Gras, growing on the surface of tailing sites has been used as fodder for domestic animals. We were interesting about the amount of the specific activity of natural radionuclides 238U, 226Ra or 210Pb, transferred from the covering soil on the tailing to the grass on the surface area. The transfer factors of naturally occurring radionuclides have not been studied to the same extent as their artificial counterparts, but some comprehensive investigations have been done by various institutions around the world. In case of 226Ra calculated values are two times or four times bigger than measured. For 210Pb measured values are up to hundred times bigger than calculated. The reason for that is radon in the air, decays to the 210Pb, deposited on the grass and not 210Pb coming from the soil.