The study presented here, being its main goal to evaluate the behaviour of natural radionuclides in coal combustion, is part of a wider study carried out by CIEMAT and the University of Extremadura (UEX). The research is addressed to the radiological evaluation of the workers and the public as a result of the operation of the four biggest Spanish Coal-Fired Power Plants (CFPPs). Some generally used effects were confirmed in this study, as the difference in concentration of 210Po in fly and bottom-ashes. Enrichment factors relative to 40K as defined by UNSCEAR were found to be a little different than expected. 210Po enrichment was found in gypsum (material obtained as a by-product in the desulphuration process). In order to confirm the assumption considered to explain difference in 232Th activity concentration between bottom and fly ashes, carbon content was measured, obtaining that it should be reviewed.

The Spanish law that transposes the European Directive 29/96 is based on the recommendations established by ICRP in 1991. This law requires that estimations of the doses due to radioactive emissions, from practices or installations in which ionising radiation sources are used, must be performed in a regular base and in the more realistic possible way. More recently, the ICRP, as well as the European Union, recommended that, in order to reach a realistic estimation, a gradual approach made by consecutive iterations should be made. However, in spite of the huge amount of documentation, realistic dose assessments are usually treated just for artificial radionuclides, being Naturally Occurring Radioactive Materials (NORM) industries only considered by regulation, regarding to the necessity of performing studies to determine if there is or is not a significant increase in the exposition to the workers or to the public. In this paper an adaptation of the general criteria used to carry on realistic dose assessments for the particular case of NORM is presented. Also the difficulties and implications, that applying such criteria involve, are analysed. In addition the main parameters, which could influence the uncertainty of the assessment, are discussed.

In some regions of Germany radiocaesium contamination of wild boar (Sus scrofa) is either staying fairly constant or slightly increasing on average, concurrently exhibiting an extraordinary variability. The reasons for this peculiar contamination pattern were investigated from 2002 to 2004 in an area located in the Bavarian forest. The microscopic analyses of 70 stomachs gave detailed information on the food composition. Potential food items sampled in the investigation area were measured for their radiocaesium level. Deer truffles (Elaphomyces granulatus), a preferred delicacy of wild boar, turned out to play a key role. This fungus showed contamination levels exceeding those of edible mushrooms and other food components by an order of magnitude and more. Despite their low weight proportion of about 6% of the stomach content on average, more than three quarters of the radiocaesium uptake can be ascribed to deer truffles. Their irregular consumption and the dynamics of radiocaesium in forest soil explain the peculiar contamination pattern of wild boar. Predictive modelling of radiocaesium contamination of wild boar should always take into account deer truffles, especially their occurrence, contamination levels and irregular consumption.

The Arctic environment is unique in terms of many factors that may influence the behaviour and fate of contaminants including the presence of permafrost, low temperatures, slow breakdown of organic compounds, short food chains and long recovery times for some species. This study introduces the issues surrounding the development of a bespoke environmental impact assessment methodology specifically for the consideration of radiation impacts on Arctic ecosystems. The approach allows for the impact on plants and animals from exposure to radiation to be quantified in a robust manner through integration of our current knowledge concerning transfer in the environment, resultant dose-rates from the presence of radioactivity within biota and their media and information concerning radiobiological effects on endpoints of concern from an environmental protection perspective.

Environmental risk assessment methodologies often require background dose-rates for wild flora and fauna to be derived in a robust and transparent way. To facilitate this task, information can be organised around reference organisms (ROs), entities that can be used as representatives of the broader ecosystem. In this study, generic datasets have been collated on levels of naturally occurring radionuclides in sediments, seawater and ROs for marine ecosystems. In some cases, data gap filling methods have been required owing to a paucity of information. Once full datasets have been acquired, dose conversion coefficients (DCCs) can be applied and dose-rate calculations can be performed probabilistically allowing the variability in the underlying datasets to be accounted for. Unweighted absorbed dose-rates for marine reference organisms lie between 0.02–1.2 µGy h-1, whereas weighted dose-rates fall in the range 0.08 µGy h-1 to 8.8 µGy h-1. Except for the special case of sea anemones/corals, the most important nuclides for the total dose-rates are 210Po and 226Ra for heterotrophic ROs (i.e. all vertebrate and invertebrate animals), whereas 226Ra and 228Th contribute most for autotrophic ROs (i.e. macroalgae, phytoplankton and aquatic plants). In addition, 40K has a considerable impact on unweighted dose-rates for all ROs. Non-parametric statistical tests have been applied to show whether there are differences between activity concentrations data for ROs and ICRP-defined Reference Animals and Plants (RAPs).

During a radiological emergency (RE) a large area may be non-uniformly contaminated with a number of radionuclides, the ratios of which will change in course of time. At the beginning the contaminated area, where consumption and distribution of foodstuffs will be prohibited, will be delimitated in a very conservative manner. So it will be necessary to specify and locate more accurate borders defining areas with contamination significantly higher, significantly lower and “close” to the limits for ruling out distribution and consumption of commodities. This task can be fulfilled mainly by laboratories equipped with semiconductor gamma spectrometry. The sample throughput of laboratories with semiconductor gamma spectrometry depends on many factors. The paper is dedicated to the questions of adequate sample throughput of the laboratories equipped with gamma spectrometry, factors witch influence the throughput including human capacity for 24 hours working regime, and to the optimization of the work in the laboratories. The capacity and the organization chart of laboratories in the frame of the Radiation monitoring network of the Czech Republic are shown, too.

STUK was established in spring 1958 with the main policy to keep research and regulatory activities under the same roof. Radioecological research focused first on environmental surveillance and effects of nuclear weapon tests in the environment and agricultural foodstuffs. The earlier experiences on environmental behaviour of artificial radionuclides helped greatly the management of the fallout situation after the Chernobyl accident in 1986. As a consequence of the accident, amounts of 137Cs in natural produce vary largely still in 2000s. Indoor radon, however, is the greatest source of radiation exposure in Finland. Future challenges of radioecology at the national level are prioritised taking into account the basic need for new information and contribution to radiation safety, emergency preparedness, food safety and security research. Radiation protection of living organisms demands improvement of dosimetric models for risk assessment. Involvement of the stakeholders' opinions in practical work as well as in decision making is important. Maintenance and enhancement of competence in radioecology in the Europe-wide context including close cooperation both with national and international universities and research institutes, as well as networking and compiling all resources and expertise within the areas may be a new challenge also for STUK.

The results of the low-level performance of an anti-Compton device are presented. The anti-coincidence action of the NaI detectors lowers the total background of the HPGe detector integrated on the energy range 30 keV to 2730 keV by a factor 8.1 and suppresses the continuum above 300 keV by a factor larger than 10. Qualitative and quantitative results on environmental samples are described to illustrate the improvement of uncertainties determination and the significant reduction of detection limits. This provides ever more accurate and precise data on natural and anthropogenic radionuclides often used as tracers for environmental studies.

Aim of the work was analysis of the modern and rapid data acquisition methods for agricultural countermeasures, feedstuff restrictions and clean-up of large contaminated areas (104–105 km2) after accident in a nuclear power reactor. Acquiring and generating agricultural reliable data especially based on satellite technology and analysis of landscape contamination (computer code vs. in situ measurements, airborne and/or terrestrial mapping of contamination) are discussed.

In common with the assessment of chemical stressors many of the methods used for the assessment of risk of non-human biota exposed to radiation use tiered approaches. The initial tier within these approaches is designed to be simple and conservative with the aim to identify sites of negligible concern which can be excluded from more detailed assessment with a high degree of confidence. In this paper we compare the outputs of the screening tiers of three tools which are freely available as software packages. Outputs were compared for terrestrial and freshwater ecosystems assuming 1 Bq per unit media. Considerable variability between the risk quotients (RQ) estimated by the three approaches used was seen for some radionuclide-organism-ecosystem combinations. Reasons for this are explored with differences in transfer parameters used by the models being a common contributor. The large variation within RQ values estimated by the approaches requires further investigation as it does not promote the level of confidence required by the user. The practicalities of applying a single generic screening dose rate in assessments are also explored.

An assessment of the natural radiation dose to wildlife in England and Wales was made to determine the contribution it may make to the total radiation dose estimated during environmental impact assessments. Significant use was made of systematic datasets for environmental media (stream sediments, stream waters and soils), in particular those produced by the Geochemical Baseline Survey of the Environment (G-BASE) project. This provided extensive, although variable, coverage for different elements and sample types after normalisation of data to account for changes in sampling and analysis over time. Almost complete coverage for K in stream sediments was achieved by merging G-BASE and Wolfson Atlas data. This required normalisation of the Wolfson data to the G-BASE results. Coverage was improved greatly for U and Th in sediments, and K, U and Th in soils, by using the strong relationship between soils and sediments and geology (both solid and superficial) to extrapolate the data. The total U, Th and K data were used to derive activity concentrations of 238U and 232Th series radionuclides and 40K. External dose rates to wildlife were then estimated from derived media concentrations; internal dose rates were estimated from measured activities in biota or activities predicted using recommended concentration ratios.

The extent of radiocaesium in soil is very important to appreciate the risk of its recycling by the vegetation and thus the risk of food chain contamination. An intrinsic soil parameter, the radiocaesium interception potential (RIP), could be used to measure this retention. In this study, we tested the possibility to predict the RIP starting from a simple acid extraction in widely different soils coming from the whole world and pertaining to various soil reference groups of the WRB/FAO world soil classification. Our results show that a simple acid extraction could be used as an operational test to estimate the RIP whatever the soil type.

We present the main results of our more than decade-long monitoring of 137Cs content in berry plants and medical herbs growing in the Shatsk National Natural Park (Volyn Region, Ukraine). It is shown that the 137Cs content for most of the medical herbs has significantly decreased during the monitoring time period and now it meets the demands of Ukrainian sanitary standards (less than 200 Bq/kg d. w.). The decreasing rate is much higher than that for the corresponding soils. This is because the radionuclide available in the soil becomes less accessible for digesting by the plant rootage in the course of time. The 137Cs content in the vegetative and generative organs of bilberry shows essential seasonal variations. The corresponding content for the foliage reveals almost double decrease during the period when the berries ripen and an increase occurring after fructification.

This study presents and implements a screening methodology for assessing the potential postclosure radiological impact of a deep geological repository (DGR) for used nuclear fuel on non-human biota. This screening methodology is designed for hypothetical sites representative of selected Canadian conditions under both present and potential future climate conditions. The screening is carried out by comparing estimated radionuclide concentrations to derived “No Effect Concentrations” (NECs). The NECs are screening or threshold criteria; the conservative nature of the assumptions used to derive the NECs ensures that as long as the NECs are not exceeded, there is confidence that, despite uncertainty in modelled environmental concentrations, there will be no significant ecological effect on non-human biota. In the event NECs are exceeded in screening calculations, a site-specific Ecological Risk Assessment would be required to determine whether this is due to conservatism in the assumptions, lack of sufficient data or potential real impact. The NECs derived in this study were compared to other threshold criteria from U.S. and international literature.

In the paper it demonstrates that for more precise and comprehensive interpretation under the framework of biospheric concept, the anthropocentric paradigm, being now the one of the basic principles in radiation protection, should be reformulated and amended (an immediate switch to ecological concept involves significant changes and calls for solution of very complicated scientific problems). It is suggested that application of the biospheric approach within the bounds of the modified hygienic principle allows resolving the majority of contradictions between anthropocentric and ecological approaches. This may represent a more perspective course of the radiation protection system development compared to a simple change of fundamental paradigms.

The RESRAD-OFFSITE code provides expanded state-of-the art, cost-effective, and user-friendly methods for evaluating the radiological consequences to a receptor located onsite or outside the area of primary contamination. It calculates radiological dose and excess lifetime cancer risk with the predicted radionuclide concentrations in the environment, and derives soil cleanup guidelines corresponding to a specified dose limit. The RESRAD-OFFSITE code is an extension of the RESRAD (onsite) code, which has been widely used for calculating doses and risks from exposure to radioactively contaminated soils. The development of RESRAD-OFFSITE started more than 10 years ago, but new models and methodologies have been developed, tested, and incorporated since then. Some of the new models have been benchmarked against other independently developed (international) models. The databases used have also expanded to include all the radionuclides (more than 830) contained in the International Commission on Radiological Protection (ICRP) 38 database. Detailed information on the design and application of the RESRAD-OFFSITE code is presented in its recently published User's Manual.

Radio-caesium is an important radionuclide released considering food and feed products. In aquatic environments caesium tends to accumulate in fish, both through its diet and its gills. This presentation discusses the caesium accumulation in fish living in estuaries. The aim of this work is to conclude on the importance of potential uptake routes: via the gills, diet or ingested with water. It is suggested that the magnitude of caesium accumulation in fish is related to waterborne potassium concentrations. Based on this theory, fish living in seawater should show a suppressed caesium accumulation compared to fish that stays in freshwater. However, to compensate for water losses, seawater fish are constantly drinking, adding an alternative route of entry for caesium. Apart from these two possible uptake routes of waterborne caesium, fish may take up caesium via their diet. Separate uptake-and-elimination studies were performed to measure the waterborne and dietary caesium uptake and elimination rate constants in fully acclimated Sea Bass at six different salinities (ranging from 1‰ to 35‰). Short-term uptake studies were performed as well to evaluate the effect of the waterborne potassium concentration. A toxicokinetic model evaluated several scenarios to conclude on the importance of each uptake route.

To document the tritium uptake following chronic atmospheric exposure, potted lettuces (Lactuca sativa L.) were cultivated outdoors in the vicinity of a nuclear facility. During two sets of experiments performed in spring and autumn, the plants were continually exposed to low tritium levels throughout growth. These experiments factored in meteorological data, tritium monitoring in air (HT and HTO) and analysis of Tissue Free Water Tritium (TFWT) and Organically-Bound Tritium (OBT) in biological material. The global conversion rate of HTO to OBT in plants averaged 0.16% ⋅ h-1 over the growing period, but marked variations were observed during growth. In particular, a significant increase appeared at the exponential growth stage. Consequently, the usual predictive models (for cases of accidental or chronic exposure to tritium) should factor in the conversion rate according to the biological stage. Moreover, as plant growth is closely correlated to total energy received, meteorological parameters (temperature, light intensity) may be considered reliable indicators of growth.

Scaling factors, used to predict radionuclide uptake as a function of mass, have tremendous potential to provide a more transparent approach to risk assessment. Although the historical literature might seem to offer a wealth of data for the purposes of testing these scaling relationships, a more defensible alternative may be to conduct new site-specific data collection efforts. Trace element analysis was conducted on 16 plant species from a single location in Oregon. Results for ten elements and six species exhibit mass dependence on trace-element uptake. Transfer factors calculated for several elements spanned only an order of magnitude across all plant species. Conversely, radionuclide data taken from the open literature was inconclusive in the analysis for mass effects.

In the mid-long-term after a nuclear accident, the contamination of drinking water sources, fish and other aquatic foodstuffs, irrigation supplies and people's exposure during recreational activities may create considerable public concern, even though dose assessment may in certain situations indicate lesser importance than for other sources, as clearly experienced in the aftermath of accidents like Chernobyl. The MOIRA system is designed to allow for a reliable assessment of the long-term evolution of the radiological situation and of possible alternative rehabilitation strategies, including an objective evaluation of their social, economic and ecological impacts in a rational and comprehensive manner. MOIRA also features a decision analysis methodology, making use of multi-attribute analysis, which can take into account the preferences and needs of different types of stakeholders. A decision-making exercise regarding such problems, in which MOIRA has been be used as a decision support tool, was organised in Spain involving the organizations responsible for emergency management and the affected services, as well as local and regional stakeholders and several international observers. The system resulted very helpful in assessing the overall situation and the alternative management strategies and also facilitated the interaction between agencies which reached a better common understanding of all related issues.