The radioactivity concentrations of 226Ra, 232Th and 40Kwere measured using gamma-ray spectroscopy with NaI (Tl) detectors in four tantalitemining sites in the Oke-Ogun area, South-Western Nigeria. The measured values of theactivities of 40K, 226Ra and 232Th in the soil sampleswere found to lie in the ranges 123.7 ± 3.8 – 1372.3 ± 8.6, 16.8 ± 1.6 – 71.1 ± 2.53 and3.0 ± 0.7 – 31.9 ± 1.0 Bq kg–1, respectively. These samples were also found to have radiumequivalent activity in the range 74.2–121.0 Bq kg-1. Values of 0.2–0.3 for the externaland 0.3–0.4 for the internal hazard indices were estimated for the samples and the annualeffective dose varied from 70.3 ± 13.5 to 100.8 ± 42.8 µSv with a mean of 87.5 ± 18.6 µSvy–1. The annual effective dose is higher than the world average.

Radon-222 exhalation from different ceramic tiles depends upon the radium(226Ra) concentration and porosity. Raw zirconium sand is one of thesubstances widely used in the ceramic industry and it is naturally radioactive. This canproduce unjustified concern and subsequently perturb the market of these products. Theradon exhalation rates for all ceramic tile companies were in the ranges 28-44mBq.m-2.h-1 and 2.0 to 4.8 mBq.kg-1 .h-1.The porosity of ceramic tiles is in the range 0.19-0.28. The radium activity of ceramictiles was found to be in the range 16-38 Bq.kg-1 for the glazed surface and23-64 Bq.kg-1 for the clay surface, respectively. The average equivalent dosein contact with the ceramic surface was found to be 22 mSv.y-1. The exposure atworking level at the ceramic tile surface was in the range 2.4-3.8 WL. This gives a riskindication to people who spend a long time in closed ceramic tile stores, who should avoidstaying for a long time in such places.

Accurate dose calculations are very important in radiotherapytreatment planning. The Monte Carlo method has proven to be an accurateand reliable method for simulation of the dose distributions fromelectron beams and can provide theoretically more accurate distributionsthan conventional planning system algorithms (e.g. theGeneralized Gaussian Pencil Beam algorithm) for more complex targetconfigurations. The aim of this work was to assess the parametersand spectrum of a given electron beam (Varian CLINAC 2100 C/D) from experimentaldepth dose distribution and then simulate dose distributions inan experimental arrangement with a 3D polymer gel dosimeter. Thecomparison of data from experimental measurements, Monte Carlo calculationsand the planning system enabled us to verify experimentally thesimulation model and technique as well as the planning system results. Bothsimple and more complex systems (e.g. dose distributions closeto different material interfaces) can be studied. The generationand influence of the “bremsstrahlung” photons in the electron beamswas also analyzed using the simulation technique. The computations,experimental methods used and results obtained are presented anddiscussed.

In order to study the vertical migration of anthropogenic 137Cs, soil inventories ofthis radionuclide were measured in two regions selected on the basisof a previous comprehensive survey in the northern Iranian provinceof Guilan located in the South Caspian region. Ten sampling stations were randomly chosen in these regions and split-level samplingwas carried out to a depth of 30 cm. Sample analysis was performedusing a HPGe detector system. In situ gamma measurementsin both regions were als o carried out with the aid of a portable germanium spectrometer.The experimental data were then compared with the solution of theconvection-dispersion equation (CDE) with the proper initial and boundary conditions to evaluate initialdeposition as well as transport parameter values. The solution,including the effects of both considered sources, i.e. global falloutand Chernobyl releases, fits the measured data well. The effectiveconvection velocity and dispersion coefficients of 137Cslie in the range of 0-0.25 cm·y-1 and 0.32-0.75 cm2·y-1, respectively, indicating a very slow migration rate in the area. Most of the deposited 137Cs still remainedin the top 10-cm layer. Moreover, the fitted depth profiles werethen employed to correct the surface activities of 137Csestimated by in situ measurements.

We performed an Environmental Risk Assessment (ERA) to evaluate the impact on non-humanbiota from liquid radioactive effluents discharged by the Belgian Nuclear Power Plants(NPPs) of Doel and Tihange. A deterministic risk assessment for aquatic and terrestrialecosystems was performed using the ERICA tool and applying the ERICA screening value of 10µGy.h-1. The ERA was performed for the radioactive discharge limits and forthe actual releases (maxima and averages over the last 10 years, 1999-2008). All ERICAreference organisms were considered and depending on the assessment situation, additionalreference organisms were included in the analysis. It can be concluded that the currentdischarge limits for the Belgian NPPs do not result in significant risks to the aquaticand terrestrial environment and that the actual discharges, which are a fraction of theliquid discharge limits, are unlikely to harm the environment.

In pediatric radiology, radiological protection isof vital importance due to the great radio-sensitivity of body tissuesin childhood, which can come to present stochastic effects as childrenhave a longer life expectancy. The objective of this research isto establish diagnostic reference levels in chest exam pediatricpatients. The study, carried out in one of the largest pediatriccenters of the city of Medellin, the capital of the Department ofAntioquia, consisted of the calculation of the Entrance Skin Dose(ESD) for a sample of 814 chest radiographic studies in the anteroposterior(AP) and left lateral (L LAT) projections, and it was compared withthe doses obtained with the computational program PCXMC 2.0. Forthe estimate of the Entrance Skin Dose, data were collected from theexams, including the size of the radiation field, mAs and kVp. TheESD in chest exams for 5-year-old children was the only one thatexceeded the international reference levels, giving evidence ofthe need to optimize the techniques used in this type of study inthe institution under evaluation.

Interventional cardiology procedures can involve potentiallyhigh doses of radiation to the patients. Stochastic effects of ionisingradiation – radiation-induced cancers in the long term – may occur.We analysed clinical characteristics and dosimetric data in a populationof patients undergoing interventional cardiology. In all, 1 591patients who had undergone coronarography and/or angioplasty inthe course of a year at the Saint-Gatien Clinic in Tours (France)were included. Information on patients’ individual clinical characteristicsand Dose-Area Product values were collected. Organ doses to thelung, oesophagus, bone marrow and breast were mathematically evaluated.The median age of patients was 70 years. Their median cumulativedose-area product value was 48.4 Gy.cm2 for the wholeyear and the median effective dose was 9.7 mSv. The median organdoses were 41 mGy for the lung, 31 mGy for the oesophagus, 10 mGyfor the bone marrow and 4 mGy for the breast. Levels of doses closeto the heart appear to be rather high in the case of repeated interventionalcardiology procedures. Clinical characteristics should be takeninto account when planning epidemiological studies on potential radiation-inducedcancers.

Inhalation of indoor radon has been recognized as thelargest contributor to the total effective dose received by humanbeings. Indoor radon data were collected from the dwellings lyingon the sedimentary rocks (sandstones, siltstones and clays) ofthe Murree Formation, Nagri Formation, Dhok Pathan Formation, Mirpurconglomerate and surficial deposits of the Kotli area in Azad Jammuand Kashmir, Pakistan. Radon measurements were made using the passivetime-integrated method using Kodak CN-85 Solid-State Nuclear Track Detectors.The radon concentration in dwellings varied from 13 ± 6 Bq.m-3 to185 ± 23 B. qm-3, with an average of 73 ± 15 Bq.m-3.Theradon concentration in the Murree Formation, Nagri Formation, riverterrace and Dhok Pathan Formation were 89.7 ± 16.5, 72 ± 15, 68.5and 69 Bq.m-3, respectively. The average value of allthe measured concentrations (73 ± 15 Bq.m-3) within theframework of this study is more than the world average value of40 Bq.m-3 given by UNSCEAR (United Nations ScientificCommittee on the Effects of Atomic Radiation, report to the GeneralAssembly, United Nations, New York, 2000) and is within the actionlevel of 200-600 Bq.m-3 fixed by the ICRP(InternationalCommission on Radiological Protection, ICRP publication65, Protectionagainst radon at home and at work, 1993). The ambient gamma doserates both indoors and outdoors in different parts of Kotli werealso measured. The average value of gamma absorbed dose rates prevailingin the indoor environment was 131.2 ± 16.6 nGy/h. The gamma exposurerates recorded outdoors were 35% lower than in the indoor environment.The measured gamma dose rates have a weak positive correlation withindoor radon concentration. The annual effective dose for inhabitantsin Kotli due to radon ranged from 0.32 to 4.7 mSv.y-1,with an average value of 1.8 mSv.y-1. This dose is relativelyhigher than the world mean dose of 1.15 mSv/y. That is explainedby the particular geology of the state of Azad Jammu and Kashmir,and the method of construction of the dwellings.

The accident at the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) in March 2011 led toan unprecedented direct input of artificial radioactivity into the marine environment. TheInstitute for Radioprotection and Nuclear Safety was requested by the French authoritiesto investigate the radioecological impact of this input, in particular the potentialcontamination of products of marine origin used for human consumption. This articledescribes the close link between the responses provided and the availability of the data,as well as their nature and ability to meet the requirements of expert investigation.These responses were needed: (i) to evaluate the inputs of radionuclides into the marineenvironment, (ii) to understand their dispersion in seawater, and (iii) to estimate theirtransfer to the biota and sediments. Three phases can be distinguished which characterisethese processes during the accident and post-accident periods. The first phase correspondsto an emergency phase during which no measurements were available on samples from themarine environment. It involved the formulation of hypotheses based solely on theexpertise of the Institute for Radioprotection and Nuclear Safety. The second phasestarted when the Japanese authorities provided measurements of the concentrations ofradionuclides in seawater. Although these data were not yet adapted to addressing theproblems of radioecology, the scenarios could then be refined and the estimates developedin more detail. During the third phase, the accumulation of data over the course of timemade it possible to study the phenomena in an appropriate way. The chronology of theevents shows that it is essential to have (i) significant measurements of concentrationfrom samples collected in the various matrices of the marine environment, regularlyupdated and sufficiently well-documented, (ii) samples of seawater collected at theearliest opportunity as close as possible to the damaged site to characterise the sourceterm, and (iii) a numerical tool allowing rapid modelling of the dispersion ofradionuclides in seawater, as well as their transfer to sediments and the biota,ultimately for the purpose of estimating the dose to humans.

The study of radiation fields around the cyclotron roomwas carried out for the Proton-Therapy-Center in Prague (Czech Republic).The 230 MeV proton cyclotron will be installed there as well asadditional components located along the beampath. The ambient doseswere computed by taking into account 3 major sources of secondaryradiation (neutron and photon) – the cyclotron, energy degraderand its collimator. The fluxes of neutrons/photons produced by protonswere computed using Monte Carlo code MCNPXTM 2.5.0. Energyand angular distributions were computed for various targets and protonbeam energies. Different physical models of high-energy proton interactionswere studied as well. The annual charge at the cyclotron exit wasbased on the “patient model” (distribution of treatment type) establishedfor a similar therapy center in Essen (Germany). Calculated datawere used as an approximation of the radiation field of the most significantsources of radiation (graphite degrader, tantalum collimator). Fluence-to-doseconversion factors from ICRP-74 were used for the annual dose equivalentevaluation. With these results, the shielding analysis in the Therapy-Centerwas performed in the context of the current legislation requirements.

Calculations are presented of the effective dosesper unit neutron fluence according to the ICRP publications 60 and 103.Monte Carlo N-Particle (MCNPX) code was used for six geometricalconditions of irradiation (Anterior-Posterior, Posterior-Anterior,Left-Lateral, Right-Lateral, Rotation and Isotropic) on Oak RidgeNational Laboratory (ORNL) modified mathematical adult phantomsfor monoenergetic neutrons from 10-9 MeV to 20 MeV. The conversioncoefficients were compared with the results of an analytical phantom(Medical Internal Radiation Dose (MIRD-5)) and some voxel model(ICRP/ICRU Reference Voxel Phantom (ICRP/ICRU RVP), HANAKO, TAROand Visible Human Project (VIPMAN)). From these comparisons, one canconclude that large discrepancies between data sets appear whenwR and different sizes of the phantoms have been used for calculations.Furthermore, the differences in applied Monte Carlo codes or simulatedbody models could make some discrepancies less than 15%.

The natural γ-radiation in samples of a variety of marblesimported into Bangladesh for use in building construction was measured,employing γ-ray spectrometry with a HPGe detector. From the measuredγ-ray spectra, activity concentrations were determined for 226Ra(29.31 ± 2.06 to 46.99 ± 2.97 Bq.kg–1), 232Th (42.91± 2.53 to 62.92 ± 3.37 Bq.kg–1) and 40K (824.42± 15.42 to 1071.58 ± 20.14 Bq.kg–1). The measured activityconcentrations for these natural radionuclides were compared withthe reported data of other countries and with the world averageactivity of soil. The radium equivalent activity (Raeq),the hazard indices, the gamma activity concentration index, theindoor absorbed dose rate and the corresponding annual effectivedose were estimated for the potential radiological hazard of themarble. The Raeq values of all marble samples are lowerthan the limit of 370 Bq.kg–1, equivalent to a dose of1.5 mSv.y–1. The average values of the external and internalhazard indices are less than unity. The average indoor absorbeddose rate (121.25 nGy.h–1) is higher than the population-weightedaverage of 84 nGy.h–1, whereas the corresponding annualdose limit falls within an average value of 0.60 mSv, which is anorder of magnitude below the limit specified for building materialsin the literature. The present results indicate that using marblein building construction in Bangladesh does not pose any significant radiologicalhazard.

In the framework of assistance for Japan, the ACTIFLORAD project for liquid wastedecontamination mobilized over 200 AREVA collaborators and 47 people who led their missionin the damaged site. Led between May 18th and July 6th, 2011, the French mission aimed atsupervising the ACTIFLORAD process building and assisting Japanese teams in performing it.The post-accidental situation and emergency led to setting up a radiation protectionorganization in agreement with French regulation as well as integrated into the Japaneseorganization. This text establishes a testimony of the everyday life of the mission andits preliminary preparation.

L’acquisition du mouvement est de plus en plus souventeffectuée pour améliorer la balistique des traitements en radiothérapieexterne. Cependant, elle est source d’une exposition supplémentairepour le patient. Le développement de la plate-forme de simulationnumérique NEMOSIS (NEural NEtwork MOtion SImulation System)ouvre la voie à l’optimisation de la dose en imagerie. Elle permetde générer un mouvement pulmonaire localisé et personnalisé à partirdu modèle 3D du patient. Pour 3 patients test, 5 à 6 points anatomiquesont été simulés puis comparés aux tracés du radiothérapeute. Dansle cas le plus défavorable, les résultats ont montré une précisionmoyennée sur l’ensemble des points d’un patient et sur toutes lesphases d’environ 3 mm avec une incertitude élargie de tracé égaleà 1,5 mm (intervalle de confiance de 95 %) et une incertitude maximalede phase atteignant 6,53 mm. Une autre étude comparant les GTV (Gross Tumor Volume) d’un radiothérapeute et ceuxcalculés par NEMOSIS a été également menée. Un indice de Dice stipulant unecorrespondance minimale de 0,80 a été calculé entre les deux typesde volumes. Ces résultats font de NEMOSIS un outil très prometteuren tant qu’alternative aux imageries irradiantes.

The assessment of the radiological impact of a decommissionednuclear power plant is presented here through the results of anenvironmental monitoring survey carried out in the area surroundingthe Garigliano Power Plant. The levels of radioactivity in soil,water, air and other environmental matrices are shown, in whichα, β and γ activity and the γ equivalent dose rate are measured.Radioactivity levels of the samples from the Garigliano area areanalyzed and then compared with those from a control zone situatedmore than 100 km away. Moreover, a comparison is made with a previous surveycarried out in 2001. The analyses and comparisons show no significantalteration in the radiological characteristics of the area surroundingthe plant, with the overall radioactivity depending mainly on theglobal fallout and natural sources.

A workshop dedicated to cancer risks associated withlow-dose internal contamination was organised in March 2011, inParis, in the framework of the DoReMi (Low Dose Research towardsMultidisciplinary Integration) European Network of Excellence. Theaim was to identify the best epidemiological studies that providean opportunity to develop a multidisciplinary approach to improvethe evaluation of the cancer risk associated with internal contamination.This workshop provided an opportunity for in-depth discussions betweenresearchers working in different fields including (but not limitedto) epidemiology, dosimetry, biology and toxicology. Discussionsconfirmed the importance of research on the health effects of internalcontamination. Several existing epidemiological studies providea real possibility to improve the quantification of cancer riskassociated with internal emitters. Areas for future multidisciplinary collaborationswere identified, that should allow feasibility studies to be carriedout in the near future. The goal of this paper is to present anoverview of the presentations and discussions that took place duringthis workshop.

En France, les effluents générés par des personnes traitéeset hospitalisées en médecine nucléaire doivent être collectés dansdes cuves de décroissance avant leur rejet dans le réseau d’assainissement,en accord avec les limites règlementaires définies. Un modèle utilisantune série d’exponentielle décroissante a été mis au point permettantde simuler l’évolution de l’activité volumique dans les cuves de décroissance.Ainsi son utilisation permet d’optimiser le nombre et la capacitédes cuves par rapport à l’activité médicale actuelle ou future.En outre, ce modèle est très modulable puisqu’il intègre comme variables :la période physique du radioélément, le volume total de chaque cuve,l’activité excrétée par patient, le volume total d’effluents généréspar patient durant son séjour en chambre blindée, le nombre de patientspris en charge lors de chaque semaine et le nombre de semaines avantla mise en décroissance de la cuve. Par ailleurs, les simulationsavec ce modèle montrent qu’à activité médicale équivalente, il estpossible de travailler soit avec 2 grandes cuves soit avec 3 cuvesayant une capacité réduite de 50 %. L’utilisation de plusieurs petitescuves permet en outre de maintenir la rotation des cuves de décroissanceen cas de mise hors service d’une d’entre elles.

Après le passage du tsunami les sous-sols des bâtiments de la centrale étaient envahispar de l’eau de mer plus ou moins contaminée. L’eau d’arrosage des réacteurs accidentéss’y ajoutant, l’opérateur de la centrale s’est trouvé face à la menace d’un débordementgénéral à brève échéance. Les groupes français AREVA et Veolia ainsi que la sociétéaméricaine Kurion sont intervenus pour réaliser sur site et dans l’urgence uneinstallation de décontamination de grande capacité. Kurion a fourni le premier étage dutraitement, par échangeurs minéraux en cartouches blindées. AREVA et Veolia ont associéleurs compétences pour mettre en œuvre le procédé chimique de décontamination de Marcouleet La Hague dans des machines Veolia prévues pour le traitement d’effluents nonradioactifs. Malgré l’ampleur des innovations nécessaires, et les conditions de travailsur site difficiles et changeantes, le traitement des effluents est devenu opérationnel enmoins de trois mois, et a permis d’éviter le débordement.