A radiation transport code based on a Monte Carlo tool is used to simulate a proton therapy beamline designed to treat paediatric patients with intracranial tumours. The treatments are performed using the IBA gantry at the Proton Therapy Centre of the Institut Curie. The treatment is undertaken at 178.16 MeV using the double scattering technique. The aim of this study is to present the Monte Carlo model of the transported proton beam, beamline and treatment room, as well as the experimental validation of the proton dose distributions calculated by this model. The beamline components and the treatment room are accurately modelled using the Monte Carlo code MCNPX. The proton source at the beamline entrance is defined on the basis of IBA data, measurements and calculations. Measured and calculated relative proton dose distributions in a water phantom are compared for the validation. Depth dose profiles, including pristine Bragg peaks and a spread–out Bragg peak, and lateral dose profiles are studied. A general good agreement was found between calculated and measured distributions with discrepancies of less than 2 mm. Relative proton dose distributions are therefore considered to be correctly described by our simulated geometry and proton source parameters. The Monte Carlo simulation will be used subsequently for radiation protection purposes: calculation of secondary neutron doses received by treated patients of different ages.

In 2011 the IRSN conducted several assessments of atmospheric radioactive releases due to the Fukushima Daiichi NPP accident (March 11, 2011) and of their impact on Japan’s terrestrial environment. They were based on the IRSN’s emergency management tools and on the abundant information and technical data gradually published in Japan. According to these assessments, the main release phase lasted from March 12 to 25, 2011 and impacted Japanese land in two events, the first on 15 and 16 March, in which the main radioactive deposits were formed, and the second from March 20 to 23, which was less significant. The highest amounts of radioactive deposits were found in an area extending upwards of several tens of kilometers northwest of the plant. Lower amounts were discontinuously scattered in an area extending up to over 250 km away. Initially composed mainly of short-lived radionuclides, the deposits’ activity sharply decreased in the subsequent weeks. Since the summer of 2011, cesium-134 and cesium-137 have become the residual deposits’ main components. According to IRSN estimates, in the absence of protection, the doses due to exposure to the radioactive plume during the atmospheric release phase may have been potentially higher for people who remained in coastal areas up to several tens of kilometers north and south of the damaged plant. Thereafter, people living up to 50 km northwest of the plant, outside the 20-km emergency evacuation zone, were potentially most vulnerable to residual radioactive deposits over time.

Dans une centrale nucléaire (CNPE), la localisation des points chauds est une préoccupation importante, car ils participent à la dose que reçoivent les intervenants, en particulier lors des opérations de maintenance. Depuis 2010, EDF et le CEA ont entrepris d’adapter une nouvelle génération de caméra gamma, GAMPIX, pour disposer d’un instrument portable dédié à cet usage. Ce système permet de superposer une image gamma à une image visible, afin de localiser les sources radioactives présentes dans un environnement. Des essais sur site au CNPE de Tricastin ont été associés aux développements spécifiques réalisés par le CEA, afin d’appréhender les conditions particulières rencontrées en CNPE, à la fois environnementales et radiologiques : l’énergie relativement élevée des gamma du cobalt 60 (1,17 et 1,33 MeV) et la présence d’un bruit de fond ambiant permanent. Cet article présente les principaux axes du cahier des charges initial, les développements réalisés pour y répondre, et les résultats obtenus lors des campagnes d’essais. Même s’ils étaient uniquement dédiés à la qualification de la caméra gamma, les tests réalisés ont montré des résultats très prometteurs, par exemple la mise en évidence de lignes de fuite le long d’une protection biologique ou le mouvement d’un point chaud dans une tuyauterie (par rapport à sa position identifiée). En dernier lieu, les développements futurs sont évoqués.

The European Platform on Preparedness for Nuclear and Radiological Emergency Response and Recovery (NERIS Platform) was established in June 15, 2010. The Mission of NERIS is to promote the involvement of different stakeholders and improve public confidence in capabilities of the key players in management of nuclear and radiological emergencies in Europe. The NERIS Platform encourages European, national, regional and local authorities, technical support organisations (TSOs), operators, professional organisations, research institutes, universities, non-governmental organisations (NGOs), and national and local stakeholders to co-operate in emergency management, and to facilitate access to expertise and technology in maintaining competence in the field of nuclear and radiological emergency management for the benefit of European countries and citizens. The vision is that by 2015, the self-sustaining NERIS association exists, and by 2020, all European organisations being members of the association are sharing common views and common approaches and are developing and using compatible technology and methods for consequence management of the emergencies. The NERIS Platform has, in September 2012, 43 member organisations representing stakeholders with a wide range of backgrounds, e.g. authorities, emergency centres, research organisations and the academic community. The Strategic Research Agenda (SRA), being under preparation, will provide the basis for priorities of future research and development in order to achieve the vision. The SRA therefore will communicate the future research needs, but will also be an instrument for creating synergies, co-operation and coordination internally between the NERIS participants and externally with activities taking place within other international forums.

Multi-slice computed tomography (MSCT) has proven in several studies to have a high diagnostic accuracy for the detection or exclusion of coronary artery disease. A major concern with coronary MSCT, however, is the associated radiation exposure of patients. Recent studies suggest that use of a 64-slice scanner is associated with a non-negligible lifetime attributable risk of cancer. Several strategies can be used to reduce patient exposure in coronary MSCT. The purpose of this multicenter study was to investigate the effects of the adjustment of tube voltage and current on radiation dose and image interpretability. MSCT with retrospective ECG gating was performed in 315 patients. The dose-length product (DLP) in the patients enrolled with the dose reduction protocol resulted in a 36% overall reduction in the mean radiation dose (911 ± 289 mGy.cm) compared with the standard protocol (1427 ± 226 mGy.cm, p < 0.001). Nevertheless, image interpretability was maintained. This study on coronary MSCT demonstrates that the radiation dose can be significantly reduced by parameter optimization, with maintained image interpretability.

Interventional cardiology procedures (ICPs), while providing important benefits to patients, also contribute to their radiation exposure, in particular for the organs surrounding the heart. This paper addresses the issue of radiation exposure to the lung and bone marrow related to coronary interventions in terms of organ doses for coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA), and risk assessment of potential radiation-induced cancer. Dosimetric information on 2095 ICPs from French patients was collected. The median lung dose for CA alone was 34 mGy for men and 22 mGy for women and the median bone marrow dose was 8 mGy and 4 mGy, respectively; doses were slightly higher for CA and ad hoc PTCA and nearly twice as high for CA and elective PTCA. Based on the French national mortality registry and Biological Effects of Ionising Radiation VII models, spontaneous and radiation-induced lung cancers and leukaemia were estimated. For men and women aged at least 60 years old at the first ICP, excess risk of potentially fatal cancers attributable to radiation ranged from 0.4% to 4%. This study provides evidence of the potential risk of radiation-induced cancer after an ICP. The limitations of such calculations are due to the difficulty of taking into account patients’ possibly shorter life expectancy than in the general population, linked to their comorbidities and coronary disease. Nevertheless, risk estimates can be used to illustrate the beneficial role of optimisation of doses delivered to the patient.

Afin d’évaluer les conséquences des rejets radioactifs provenant des réacteurs accidentés de la centrale nucléaire de Fukushima-Daichi sur l’environnement terrestre français, l’IRSN a renforcé son plan de surveillance en échantillonnant notamment de la végétation de prairie, du lait et de la viande des troupeaux en pâture entre avril et novembre 2011. Ces prélèvements et ces mesures ont, entre autres, permis d’évaluer dans des conditions de dépôts réels la chronologie des transferts du césium-134 de l’herbe au lait et à la viande. Les premières mesures significatives en 134Cs apparaissent dans l’herbe et dans le lait cinq à sept jours après la première mesure significative dans l’air. Les activités maximales atteignent 0,4 Bq.kg–1 d’herbe fraiche et 0,028 Bq.L–1 dans le lait. Dans la viande, les premières mesures significatives apparaissent mi-avril avec une activité maximale mesurée de 0,036 Bq.kg–1, avec de fortes variations d’une espèce animale à une autre. Les coefficients de transfert moyens calculés sont proches de ceux disponibles dans la littérature avec 0,22 j.kg–1 pour la viande de mouton, et de 0,09 et 0,0014 j.L–1 pour le lait de chèvre et de vache, respectivement.

L’utilisation médicale des rayonnements ionisants est devenue la source d’irradiation la plus importante à l’échelle mondiale. Les connaissances et aptitudes des professionnels utilisateurs de ces rayonnements déterminent la mise en œuvre des mesures de radioprotection recommandées par les organismes internationaux et nationaux. La situation de la radioprotection dans les pays africains est préoccupante en raison de la faiblesse des lois, règlements et organismes de radioprotection. Nous rapportons les résultats d’une enquête effectuée dans des services hospitaliers détenteurs de sources de rayonnements ionisants à Yaoundé, capitale du Cameroun. Plus de la moitié des professionnels enquêtés ont un niveau moyen de connaissances des principes et normes de radioprotection et plus de 80 % n’ont jamais bénéficié d’une formation continue en matière de radioprotection.

The European Basic Safety Standards Directive (EU, 1996) contains a chapter on intervention, which, to a large extent, is dedicated to emergency planning and response, but without detailed requirements. A new Directive will consolidate all existing Directives and thus broaden the scope to all exposure situations and categories of exposure, including the protection of the environment. This new text follows the situation-based approach recommended by ICRP (ICRP, 2007). The requirements for emergency preparedness have been worked out in more detail, and the use of reference levels for emergency response is highlighted. The accident in Fukushima prompted reflection on the Euratom legal framework, including the Basic Safety Standards, the arrangements for the early exchange of information (ECURIE) and legislation on the nuclear safety of nuclear installations. A “stress test” of EU nuclear power plants has been undertaken, which includes on-site emergency response. The results of this exercise will allow the Commission to report, by the end of 2012, to the EP and the Council, and to propose new legislation as appropriate. This may extend to the harmonisation of off-site emergency response and communication arrangements among Member States. Meanwhile, an informal coordination mechanism is being set up with the Heads of European Radiation Protection Competent Authorities (HERCA). With regard to the legislation on maximum permitted levels in food, there will be further reflection on the consistency between the controls in place after Chernobyl and after Fukushima, as well as their consistency with the values for the placing on the market of food and feed in the EU in the event of a future accident.

During and after the Fukushima accident, the IRSN collected and interpreted the results of radiological measurements performed on foodstuffs of terrestrial origin published by Japan's Ministry of Health between mid-March 2011 and July 2012. Analysis of the findings shows that the accident's date, livestock-rearing practices and the deposits' characteristics had a decisive influence. The fact that radioactive fallout occurred very early in the growing and breeding season largely explains the moderate contamination of most foodstuffs of terrestrial origin, notably in the areas with the largest deposits. In the case of dairy products and meat, feeding imported fodder to livestock in stables, a common practice in Japan, compounded the calendar effect. Measurements published in Japan have also borne out the particular sensitivity of mushrooms, including cultivated species, and game.

The concentrations of natural radionuclides in 6 different colors of volcanic tuff stones which are derived from the Cappadocia region in Turkey were determined using gamma-ray spectroscopy with a HPGe detector, and the mineralogical composition and formula of stones were determined by an X-ray powder diffractometer. The average activity concentrations of 238U, 232Th and 40K are 50.7, 58.6 and 717.6 Bq.kg–1, which are higher than the world averages of 35, 30 and 400 Bq.kg–1, respectively. The radium equivalent activities (Raeq), external hazard index (Hex), and internal hazard (Hin) associated with the natural radionuclides, alpha (Iα) and gamma indices (Iγ) were calculated to assess the radiation hazard of the natural radioactivity in the volcanic tuff stones. The average indoor annual effective dose equivalent is 0.1 mSv. All values of the indoor effective dose are lower than the exemption dose value of 0.3 mSv. The calculated radium equivalent activity values vary from 60.31 Bq.kg–1 to 281.32 Bq.kg–1 with a mean of 189.78 Bq.kg–1. All values of radium equivalent activity are lower than the world average. The average indoor absorbed dose rate (Din) for volcanic tuff stones, calculated to be 21.18 nGy.h–1, is lower than the world average of 84 nGy.h–1.

An interim edition of the IAEA Safety Requirements document: “Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards” (BSS) was published in November 2011. The revision of the BSS was coordinated by a BSS Secretariat consisting of representatives of the IAEA, FAO, EC, ILO, UNEP, PAHO, WHO and NEA/OECD. The BSS takes into account the Fundamental Safety Principles, the findings of the United Nations Scientific Committee on the Effects of Atomic Radiation and the 2007 recommendations of the International Commission of Radiological Protection (ICRP) and other applicable ICRP statements and publications. This paper provides an overview of the revised BSS, including requirements on preparedness for a nuclear or radiological emergency and to remediation of areas contaminated by residual radioactive material following a nuclear or radiological emergency.

The gamma-ray exposure build-up factors of raw materials of bricks (soils and fly-ashes) in the state of Punjab were investigated for the photon energy range 0.015 to 15 MeV up to 40 mfp penetration depth by the geometrical progression (GP) method. Appreciable variations in the exposure build-up factor (EBF) are noted for the raw materials. The EBFs of the raw materials of bricks change depending on the photon energy, penetration depth and chemical composition. The build-up factors are low at low and high photon energies, whereas they are very high in the medium-energy region. The peak energy of the EBF for soils is 0.3 MeV and 0.2 MeV for fly ashes. The EBFs of the raw materials of bricks are also compared with those of bricks of red mud and common brick materials. Common bricks were found to have the lowest gamma-ray EBF. This study should be useful for emergency preparedness planning and emergency dose estimation for future planned nuclear power plants in the state of Punjab.

The activity concentrations of primordial radionuclides (40K, 226Ra and 232Th) in five different types of commonly used building materials in southwest Nigeria were measured using a low-background NaI(Tl) detector coupled to an IBM-compatible multichannel analyzer. The highest mean concentration of 40K, which was 887.5 ± 101.3 Bq.kg–1, was obtained in gravel. Also, the highest mean concentrations of 226Ra and 232Th were obtained, respectively, in sand and brick samples. The lowest mean concentrations of 40K, 226Ra and 232Th, respectively, were obtained in brick and cement sample. The annual gonadal effective dose (AGED) and other radiological parameters were estimated from the activity concentrations of the radionuclides. The highest mean values of the AGED and radium equivalent activity concentration obtained were 359.1 μSv.y–1 and 110.9 Bq.kg–1, respectively. All these radiological parameters were below the maximum permissible levels recommended for safe use of materials in building construction. It can therefore be concluded that these materials do not pose any radiological hazard to the dwellers of buildings constructed with them.

In France, the activities carried out by the “small-scale holders” of nuclear materials are organized by a specific regulatory system which defines in a detailed way their obligations and the means of control of the government. The first part of the article presents the legal framework relating to the use of nuclear materials by small-scale holders in civilian fields. The importance of the declaration of the nuclear material inventory is clearly emphasized and must be prepared and transmitted to the Institute for Radiological Protection and Nuclear Safety (IRSN) every year. The second part describes how this declaration is used to provide basic information for the competent Ministry and the inspectors to check the correct application of the regulatory requirements relating to physical protection and to the control of nuclear materials. Finally, the last part presents the on-site inspections carried out by sworn and accredited inspectors under the authority of the competent Authority, which provide an overall picture and allow an evaluation of the risks of theft, loss or diversion of these materials.