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.

A numerical model has been applied to simulate the fate of 226Ra radionuclides in the ocean, generated from discharges of produced water in the Norwegian Sector of the North Sea. The model simulates the transport, dilution and the (possible) deposition on the sea floor of 226Ra. Figures are presented for the concentration levels and deposition rates of 226Ra in the ambient for various assumptions for the fate of the 226Ra in the ocean (as dissolved, as adsorbed to ambient organic particles that sink down on the sea floor, and as forming Ba(Ra)SO4 particles). Concentration levels and deposition rates are compared with natural levels and fluxes of 226Ra in the ocean and to the sediment, respectively. The added concentration levels/fluxes are found to be generally relatively small, compared to natural levels/fluxes. The reason for this is attributed to the presence of fairly high natural levels/fluxes of 226Ra.

En dosimétrie des neutrons, les situations pratiques rencontrées couvrent un large domaine d'énergie s'étendant sur plus de 10 décades. En outre, les grandeursdosimétriques utilisées en radioprotection ne sont pas directement accessibles à la mesure. Ce dernier point est principalement dû à la variation de la "qualité" du rayonnement neutronique, exprimé au moyen des facteurs de pondération radiologiques (pour le calcul de la dose efficace) et des facteurs de qualité (pour le calcul de l'équivalent de dose). En dépit des progrès considérablesréalisés dans le domaine de la dosimétrie des neutrons, il n'y a pas encore aujourd'hui de dosimètre susceptible de mesurer la dose due aux neutrons avec une précision acceptable quel que soit le spectre en énergie. Cet article présente les grandeurs dosimétriques utilisées en radioprotection. Il traite également des méthodes et des procédures d'étalonnages adaptées à la détermination de ladose aux postes de travail avec les appareils actuels dont les performances sont limitées. Les propriétés de ces instruments, incluant les dosimètres de zone, lesdosimètres individuels et les ensembles de spectrométrie, sont décrites et les améliorations nécessaires exposées. En conclusion, la situation actuelle requiert des recherches complémentaires pour le développement des techniques de dosimétrie et l'étude des postes de travail.

La dosimétrie individuelle des neutrons constitue une des difficultés actuelles de la radioprotection des travailleurs. La dosimétrie dite active (opérationnelle) est réglementaire depuis mars 1999 ; les valeurs des seuils recommandées par la CIPR 60 applicables en mai 2000 rendent nécessaire la mise en place d'une nouvelle génération de dosimètresneutrons. L'Institut de protection et de sûreté nucléaire (IPSN) a mené, au cours de ces dernières années, l'étude d'un dosimètre électronique individuel pour les neutrons satisfaisant aux spécifications d'un cahier des charges défini par le groupe de travail " dosimétrie neutrons " réunissant les principaux acteurs du cycle nucléaire français. Courant1998, l'IPSN a engagé un transfert de technologie vers la société Saphymo ; celle-ci commercialisera fin 2000 le premier dosimètre individuel électronique pour les neutrons, le Saphydose-n, répondant à la norme CEI 1323. Ce dosimètre,d'un encombrement réduit, permettra d'évaluer l'équivalent de dose individuel Hp(10) dans des champs mixtes neutron-gamma. Il pourra être utilisé dans toutes les installations du cycle électronucléaire, sans connaissance préalable de l'énergie moyenne du spectre des neutrons et du rapport neutron-gamma. Le dosimètre Saphydose-n pourra être raccordé aux bornes existantes des dosimètres gamma pour la lecture des informations et pour la charge des accumulateurs.

Population of small rodents in radiocontaminated environment is compelled to include more energy-intensive way of maintenance its ability to live — increasing of the proportion of mature young of the year (first pathway of ontogeny). Their reproductive characteristics — actual fecundity was higher, whereas embryonic mortality and the proportion of females with embryonic losses were significantly lower compared with neighboring areas. Abundance of mice in the impact zone was higher, age cross was revealed, which improves the adaptive possibility of the population. Preconditions for acceleration of evolutionary transformations of a population are created, but this process is restrained by both the local configuration of the polluted territory and migration of murine rodents. As a consequence, the population decreases the probability that certain changes will be fixed and inherited in a series of generations. Chronic low-dose radiation (stress) can be considered as the mechanism of switching of life history of cyclomorphic mammals. Thus, ontogenetic multiversality of small mammals is an important mechanism of protection strategy of population and decreasing the damaging action on biota in radiocontaminated environment. Functional approach makes it possible to reduce errors in assessing the radiological consequences and hence, can provide a reliable methodological basis for organization of biological monitoring.

In Finland, Olkiluoto Island on the western coast has been selected as a repository site for spent nuclear fuel. Due to the shallow sea areas around the island, the postglacial land uplift is going to change the landscape within the next millennia. For instance, new lakes and mires will develop on the present offshore areas. Concerning radionuclide transport models, the properties of the future ecosystems surrounding Olkiluoto Island can be forecast based on the properties of present lakes and mires. Due to the lack of site-specific data, lakes and mires of various successional stages were selected within a larger geographical area as analogues of the future ones. Here we present an example of a systematic process for selection of appropriate analogue sites.

The study addresses accumulation of radionuclides by mushrooms and berry shrubs from the forest soil in the 30-km area around the MCC (the Krasnoyarskii Krai, Russia). The Suillus granulatus and S. luteus mushrooms have been found to be the best bioindicators in this area. The level of 137Cs concentration in these species can reach 10 kBq/kg dry mass. The 137Cs transfer factor (TF) by the mushrooms varies 5-fold among the sites that receive radionuclides from different sources. The level of radionuclide activities accumulated by berry shrubs is 2–3 orders of magnitude lower than the activities accumulated by mushrooms. No relationship has been found between the TFs of radionuclides to the shrubs and the pathway via which the radionuclides enter the soil. The contribution of the dose due to intake of mushrooms and berries to the annual effective dose of internal exposure to residents does not exceed 150 μSv/year and 1.4 μSv/year, respectively, estimated from the registered levels of accumulated 137Cs.

Health Canada maintains detector networks across Canada. One of these networks consists of NaI(Tl) detectors that measure air KERMA [1]. Located beside the NaI(Tl) detector in Ottawa is a radioxenon analyzer [2] that measures the activity concentration of 131m, 133m, 133, 135Xe directly. The ICRU-accepted KERMA to activity concentration conversion factor for 133Xe, for a semi-infinite cloud measured 1 m off the ground, is 9.68 pGy/hr per Bq/m3 [3]. However, on various dates, the two detectors in Ottawa reported a conversion value of 2.6 ± 0.2 pGy/hr per Bq/m3; we have resolved this discrepancy [4] and have expanded on the study of other isotopes by focusing on the NaI(Tl) detector. Greater accuracy in the conversion value between the air KERMA and activity concentration will assist meteorological modellers in verifying their models [1]. Two Monte Carlo methods were used in this investigation. The first is the analogue geometry where the detector is immersed in a semi-infinite radioactive source. A second method is to apply a reciprocal transform of the analogue geometry. This expedited the calculation of larger clouds. By using these two methods together, we have calculated new values for KERMA rate to activity concentration for 4 of isotopes of noble gases, namely 131mXe, 133mXe, 85Kr, 85mKr, 135Xe.

The post-depositional reactivity of the plutonium was investigated in bottom sediments collected in the central English Channel using an experimental approach. Medium to coarse grained surficial sediments and fine-grained undisturbed sediment cores were spiked with 238Pu. After a one-month incubation, pore waters were extracted under strictly anoxic conditions and dissolved plutonium was analysed by liquid scintillation techniques. Kd values ranged from 102 to 105 in surficial sediments undergoing oxic diagenesis, and were shown to be grain-size dependant. In fine-grained sediments undergoing anoxic diagenesis, Kd values ranged between 103 and 105. Kd profile suggests an active recycling of the plutonium in the topmost sediment layers, and subsequent efficient uptake process at depth, tentatively acido-volatile sulphide (AVS) precipitation. This hypothesis was further confirmed by a correlation between the AVS content and the loosely bound plutonium extracted using an oxidising/complexing solution from sediment subsamples. In surficial sediments, by contrast, loosely bound plutonium was likely to be associated with the carbonate phase as surface complexes.

Some 3×109 kg of phosphogypsum (PG) wastes are annually generated by two fertiliser-production factories in Huelva (south-western Spain). PG has relatively high concentrations of 226Ra and other radionuclides, with an special concern due to the 222Rn emissions. These wastes could be used to improve the fertility of agriculture soils in a large former marsh area of the Guadalquivir river. Thus, it is interesting to study the levels and behaviour of natural radionuclides within this system to evaluate the radioactive impact of this amendment. An agronomical test is being conducted by one of the authors in an experimental farm in Lebrija (Seville). The soils are treated with 13 and 26 t ha-1 of PG, 30 t ha-1 of manure. Each treatment was repeated twice and continued for two years with beetroot and cotton plant production. We are measuring 226Ra (by alpha counting and gamma spectrometry) and U isotopes (by alpha spectrometry and ICP-MS analysis) in drainage waters, soils and vegetal-tissues samples. The PG used in the treatment has 620 ± 70 Bq kg-1 of 226Ra. The drainage waters have 226Ra contents similar to those from non-contaminated natural waters, but the uranium concentrations are one order of magnitude higher. Our results are suggesting that the major uranium input comes from the application of phosphate-fertiliser. No significant levels of radionuclides were found in the vegetal tissues.

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.

The paper deals with a specific aspect of a general survey, that is being carried out during last ten years in several regions of Serbia (former Yugoslavia, former Serbia and Montenegro) to assess population exposure to natural radioactivity based on geochemical and integrative pattern research approach. The originality regarding this work is related to the facts such as follows: the first identification and assessment of high areas of natural radiation in Serbia which provides insight into its regional characteristics, the interpretation of the results in terms of geological aspects, building types and human habits, the first introduction and field applicability of both (surface and volume trap) retro techniques in Serbia and assessment of doses and risks to the population in investigated high natural radiation rural communities.

A project to compare the response of different detector types was started in 1996 at the Schauinsland mountain (1200 m above sea level) close to Freiburg, Germany, where the German office for radiation protection (BfS) runs a trace analysis laboratory since about 50 years. The aim of this inter-calibration experiment is to compare different gamma dose rate detector types over long periods and under rather unfavorable climatic conditions. This allows to characterise different probe types under environmental conditions and it complements the EURADOS inter-comparison exercises, which a carried out every 2 to 3 years. Both projects dealing with the harmonization of gamma dose rate data in the EU are used to derive terrestrial dose rate from the raw data. Using interpolation techniques provided by INTAMAP seasonal maps of the terrestrial dose rate could be generated. It is shown, that this information can be used for the calibration of satellite based soil moisture methods as well for the calculation of radon emission maps on the European scale, which are of interest for the research community, since Radon is used as a passive tracer in atmospheric research to examine transport processes on synoptic time scales.

Le but de cet article est de donner un bref aperçu sur les principes de base et uneapproche théorique de la thermoluminescence. Après une présentation dumodèle classique de base et des divers types de recombinaison électron-trou,l'application à la dosimétrie des rayonnements ionisants est développée.

It is well known that the bioavailability of artifical radionuclides such as 90Sr, 137Cs and 239+240Pu in contaminated soils depends on the source term origin of the contamination. Altough the behaviour of the mentioned radionuclides in the soil is also influenced by the time passed from the contamination event and the characteristics of the contamination receiving soils. The objective of the present work is to analyse the different bioavailability and possible chemical-physical associations of 90Sr, 137Cs, and 239+240Pu in soils located in different Spanish ecosystems (Almeria and Cáceres provinces) by application of a sequential extraction procedure based on the NIST standard sequential extraction protocol. The resulting fractions obtained are: a) water soluble and exchangeable, b) associated to organic matter, and c) residual fraction. They will be studied jointly with the polluting sources (deposit of nuclear fallout-50s and 60s, Palomares accident in 1966 and the cesium release by Acerinox in 1998) in each ecosystem to interpret the observed behaviour of radionuclides.

Le paramètre le plus simple et le plus commun pour modéliser la mobilité d’un radionucléide dans un sol est le coefficient de distribution, Kd. Réciproquement, la valeur empirique de Kd est supposée représenter différents mécanismes biochimiques et physiques eux-mêmes influencés par de nombreuses variables. Les valeurs de Kd varient avec les sols et les radionucléides. En conséquence, l'utilisation de valeurs de Kd « par défaut » dans un modèle d'évaluation du comportement d’un radionucléide dans des sols peut aboutir à une incertitude non négligeable. L’étude systématique de cinq radionucléides (Cs, I, Sr, Se, Tc) est faite en termes de comportement dans les sols, mécanismes principaux, cinétiques, réversibilité/irréversibilité de la sorption... Pour chaque radionucléide, une base de données de Kd est constituée, comprenant les données primaires utilisées pour établir les valeurs par défaut les plus communes et de nouvelles données issues des publications récentes. Une fiche synthétique récapitule les paramètres les plus importants influençant significativement leur mobilité, propose une valeur par défaut pour le Kd et suggère les expériences minimales qui pourraient être utiles pour acquérir des valeurs de Kd plus appropriées au comportement du radionucléide.

Based on the framework for post-accident rehabilitation preparedness elaborated in theEURANOS project (Dubreuil et al., 2010), a Norwegian Pilot Study wasconducted in spring 2008 to test the suggested method. This article describes the methodused in the Norwegian Pilot Study and the outcomes of the co-expertise meetingsarranged.

The radionuclide contents of sediment samples collected from 20 surface-water dams in southwestern Nigeria have been determined by low-level gamma-spectroscopy. The average concentration of 40K in each of the dams varied between 110.9 ± 11.9 Bq kg-1 and 1025.9 ± 36.8 Bq kg-1 with an overall mean (± SD) of 549.3 ± 247.6 Bq kg-1 while that of 238U varied from 17.1 ± 3.6 to 51.9 ± 8.7 Bq kg-1 with an overall mean (± SD) of 27.6 ± 8.5 Bq kg-1 and that of 232Th varied from 26.2 ± 3.6 Bq kg-1 to 130.1 ± 23.7 Bq kg-1 with overall mean (± SD) of 62.0 ± 26.1 Bq kg-1. The variability of the values shows the wide disparity in the measured activity concentrations. The mean radium equivalent of 158.9 Bq kg-1 was calculated for the sediments in the dams. No artificial gamma emitting radionuclide was detected in the samples.

The development and application of a new detection system is described for autonomously working radioactivity measurements, usable in seawater and river environment. The system is based on a NaI scintillator with specifications for use in the marine environment and for real time acquisition. It is simple, stable for long-term monitoring, and of low consumption. The sensor was energy and efficiency calibrated in the laboratory. Many tests were made for the linearity and the stability of the electronics. The energy resolution calibration of the sensor was performed prior to its location into the tank, using various reference point sources. The system was deployed in open sea in order to measure background and low volumetric activity of 137Cs (19 Bq/m3). The field measurements in the Aegean Sea offer very promising results concerning the use of the whole system in the marine environment to be used as continuous monitoring and alarm system.

L’objectif de ce document est de décrire le comportementdu tritium dans l’environnement à partir des données de surveillanced’un centre de recherche français. Depuis la fin des années 60,le centre de Valduc a rejeté du tritium gaz et de l’eau tritiéedans l’atmosphère. Ces rejets ont conduit à des transferts aux nappesphréatiques et rivières voisines. Un bilan de la migration de l’eautritiée à travers le système hydrogéologique est présenté sur la période1969-2009. Les données de surveillance de l’environnement de surfaceapportent également de nombreuses informations sur les transfertspour la voie atmosphérique. Ceci concerne les différents compartiments :l’air, la pluie, les sols, les végétaux et les animaux. Les rapportsentre les différentes concentrations des différents compartimentsmontrent que le transfert air-feuilles est important, que la pluieet le dépôt atmosphérique sont du même ordre de grandeur, et qu’il existeun certain équilibre entre l’eau libre et l’eau de combustion desvégétaux. À l’extérieur du centre, les eaux sont toujours restéesen deçà des limites actuelles de l’OMS pour la qualité des eauxde boisson. L’impact radiologique a été évalué et est actuellementinférieur à 1 µSv.an-1 pour un individu de la population voisine.