The nuclear industry is currently facing a significant demand for well-trained personnel. Due to the high market demand, it is essential to raise awareness among new target groups, including high school pupils and (pre-service) STEM teachers, about the potential and opportunities of pursuing a nuclear career. With this in mind, a new strategic partnership has been established under the Erasmus+ project 'BRAVER' (Blended and Remote teaching Activities supported by Virtual rEality for Radiation sciences). Within this 2-year project, international staff, and students from 7 partners of the CHERNE (Cooperation of Higher Education on Radiological and Nuclear Engineering) network collaborate with industry, regulatory and research institutes in developing educational virtual tools (VR and virtual online escape rooms) for nuclear sciences and engineering. The project aims to develop blended international training programs that incorporate technical, generic, and networking skills for both students and professors. This initiative can serve as a model for other scientific fields, extending its benefits to students and educators across different disciplines.

Knowing the concentration of 226Ra in soil and of 222Rn in soil gas is important for the analysis of indoor radon data and the prediction of radon-prone areas. Except for soil Rn in Ardenne, the data concerning these two radionuclides in Belgian soils are very scarce. In the context of Master theses and international courses, students made 92 measurements of 226Ra in soil samples, 105 of 222Rn in soil gas, and 74 of soil permeability, a significant addition to the existing similar data. The data are analysed in relation with soil texture, geological units and indoor radon risk. There is no clear correlation between radium in soil and indoor radon risk, the most important factor of risk being soil permeability.

The Erasmus project ‘Blended learning in radioecology and radiation protection’ started in Sept 2015 with 8 academic partners from the CHERNE (Cooperation for Higher Education on Radiological and Nuclear Engineering) network in collaboration with a regulatory body and research institute. The total project consists of the development of 12 ECTS ‘distance’ learning activities offered in 6 modules on the project platform and the organisation of 12 ECTS ‘mobility’ training activities offered in 6 themes. In the framework of this Erasmus+ project, UHasselt (Diepenbeek, Belgium) organised a training school in Management of Radioactive Waste ‘MaRaWas’ in November 2016. Twenty students, 3 bachelor and master in nuclear engineering of six project partners, registered for this course. The module comprised a five days training module with lectures, experimental sessions, technical visits and a round table discussion dealing with radioactive waste in different aspects and contexts. Pre-training and tasks were offered using a separate module on the blended learning platform of the project in order to distribute a study guide and background course material, subjects for group tasks and practical information. The enrolled students were divided in groups of 4 students of at least 3 different nationalities. Next to the specialised radioactive waste management skills, communication, collaboration, networking and team building between students with different backgrounds in knowledge, skills and competences were hereby achieved.

For the disposal of high level radioactive waste and for attenuation of the emitted radiation, the Belgian supercontainer concept considers the use of cylindrical concrete containers: the radwaste (encapsulated in a canister and stainless steel overpack) is embedded in a hardened self-compacting concrete buffer, and for closure of the supercontainer the remaining gap is filled by casting a self-compacting mortar (filler and lid). As a consequence, this cementitious layer, surrounding the radwaste, will be exposed immediately to the heat-emitting radioactive waste and gamma radiation with dose rates up to 20 Gy/h during hardening and hydration of the cementitious matrix.In this reearch study, the effect of gamma radiation on the mechanical properties (e.g. compressive strength) and the microstructure of the cementitious samples is investigated thoroughly. By means of compressive strength determination and by analysing the microstructure of the cementitious samples, the effect of gamma radiation during the hardening process of the samples is identified. Small self-compacting mortar cubes were cast and irradiated immediately by gamma rays during hardening. The effect of the total absorbed dose (Gy) and the applied dose rate (Gy/h), in combination with different hardening times at first exposure and total irradiation times is determined. Furthermore, the impact of the composition of the cementitious mortar (e.g. by changing the cement type and the water-to-cement ratio (W/C-ratio)) is investigated.Throughout the test program it was found that a strength loss due to gamma irradiation can be expected, influenced by the total received dose and by the applied dose rate. Furthermore, the age at which irradiation starts (hardening time at first exposure), plays a role in the effect of the gamma irradiation. A correlation between the strength of the mortar samples and its microstructure is found by means of fluorescence microscopy on thin sections and nitrogen adsorption tests: by applying gamma radiation the capillary porosity, the pore volume distribution and the specific surface of the pores is affected. Scanning electron microscopy (SEM) also revealed a change in microstructure due to gamma radiation. (C) 2015 Elsevier Ltd. All rights reserved.

Inside an IBA proton therapy centre, secondary neutrons are produced due to nuclear interactions of the proton beam with matter mainly inside the cyclotron, the beam line, the treatment nozzle and the patient. Accurate measurements of the neutron ambient dose equivalent H*(10) in such a facility require the use of a detector that has a good sensitivity for neutrons ranging from thermal energies up to 230 MeV, such as for instance the WENDI-2 detector. WENDI-2 measurements have been performed at the Westdeutsches Protonentherapiezentrum Essen, at several positions around the cyclotron room and around a gantry treatment room operated in two different beam delivery modes: Pencil Beam Scanning and Double Scattering. These measurements are compared with Monte Carlo simulation results for the neutron H*(10) obtained with MCNPX 2.5.0 and GEANT4 9.6.

The Compton spectrometer is a device in which radiation coming from an X-ray generator is scattered at a known angle in order to reduce the flux and to allow spectrometric measurements without saturating the detector. A small-size prototype Compton spectrometer usable in the range 20–150 keV was developed, using a pen-type NaI detector. The source spectrum is reconstructed by unfolding the measured spectrum, using the response matrix calculated by the Monte-Carlo method. The Monte-Carlo geometrical model was validated with gamma-ray point sources. Unfolding is performed using a modified version of the GRAVEL algorithm. Results are presented for the unfolded spectrum obtained with a test measurement on a medical X-ray device.

Last but not least, an acknowledgment must be due to the support of research centres in the organisation of the intensive programmes (SCK-CEN Mol, JRC-IRMM Geel, FANC, INPCAS Prague, NRPI Prague, INFN-LNS Catania, ITN Lisboa, and several medical centres) and to sponsorship for workshops or intensive courses. In particular: BVS-ABR, Suez, IRE, SCK-CEN, Prince Philippe foundation, Canberra, ECS, Belgoprocess; but also: Ministerio de Educacion y Ciencia, Bancaja, Iberdrola, Generalitat Valenciana, Banca di San Cataldo, Radius, Greek Atomic Energy Commission, … Our warm thanks to all of them.

The Monte Carlo (MC) method can be applied to simulate brachytherapy treatment planning. The MCNP5 code gives, together with results, a statistical uncertainty associated with them. However, the latter is not the only existing uncertainty related to the simulation and other uncertainties must be taken into account. A complete analysis of all sources of uncertainty having some influence on results of the simulation of brachytherapy treatment is presented in this paper. This analysis has been based on the recommendations of the American Association for Physicist in Medicine (AAPM) and of the International Standard Organisation (ISO).

Brachytherapy is a radiotherapy treatment where encapsulated radioactive sources are introduced permanently (interstitial seeds) or temporally (interstitial or intracavitary devices) within a patient. When high dose rate sources (HDR) are used in intracavitary treatments, high doses can be locally imparted within the patient body. In multiple types of gynecological cancer, intracavitary brachytherapy can be used combined with other therapy treatment to give an additional local dose to the tumor. In these cases, different types of applicators can be used in order to increase the dose imparted to the tumor while the effect on healthy tissues is restricted. In order to control both source characteristics and treatment planning evaluation, an independent system must be used by the physicist consisting in experimental devices and/or simulation techniques (i.e. the Monte Carlo method). The aim of this work is to model both applicator and source in order to evaluate the dose distribution and some source characteristics (i.e. air kerma strength). The MCNP5 code based on the Monte Carlo method has been used for the simulation. A gynecological applicator, consisting of a metallic intra-uterine tube with a plastic vaginal applicator and a Microselectron HDR Ir-192 source has been simulated to evaluate the dose distribution. A solid phantom (PMMA) has been designed to perform measurements around the applicator with radiochromic films (type Gafchromic EBT). The dose profile obtained with the F4MESH tally of MCNP5 has been compared with measurements done with radiochromic films and simulation with a treatment planning system.

Brachytherapy is an advanced cancer treatment that is minimally invasive, minimising radiation exposure to the surrounding healthy tissues. Microselectron© Nucletron devices with 192Ir source can be used for gynaecological brachytherapy, in patients with vaginal or uterine cancer. Measurements of isodose curves have been performed in a PMMA phantom and compared with Monte Carlo calculations and TPS (Plato software of Nucletron BPS 14.2) evaluation. The isodose measurements have been performed with radiochromic films (Gafchromic EBT©). The dose matrix has been obtained after digitalisation and use of a dose calibration curve obtained with a 6 MV photon beam provided by a medical linear accelerator. A comparison between the calculated and the measured matrix has been performed. The calculated dose matrix is obtained with a simulation using the MCNP5 Monte Carlo code (F4MESH tally).

A gynaecological applicator consisting of a metallic intra-uterine tube with a plastic vaginal applicator and an HDR Ir-192 source have been simulated with MCNP5 (Monte Carlo code). A solid phantom has been designed to perform measurements around the applicator with radiochromic films. The isodose curves obtained are compared with curves calculated with the F4MESH tally of MCNP5 with a good agreement. A pinpoint ionization chamber has been used to evaluate dose at some reference points.

Brachytherapy is a radiotherapy treatment where encapsulated radioactive sources are introduced within a patient. Depending on the technique used, such sources can produce high, medium or low local dose rates. The Monte Carlo method is a powerful tool to simulate sources and devices in order to help physicists in treatment planning. In multiple types of gynaecological cancer, intracavitary brachytherapy (HDR Ir-192 source) is used combined with other therapy treatment to give an additional local dose to the tumour. Different types of applicators are used in order to increase the dose imparted to the tumour and to limit the effect on healthy surrounding tissues. The aim of this work is to model both applicator and HDR source in order to evaluate the dose at a reference point as well as the effect of the materials constituting the applicators on the near field dose. The MCNP5 code based on the Monte Carlo method has been used for the simulation. Dose calculations have been performed with *F8 energy deposition tally, taking into account photons and electrons. Results from simulation have been compared with experimental in-phantom dose measurements. Differences between calculations and measurements are lower than 5%. The importance of the source position has been underlined.

Two databases of indoor radon measurements in the Walloon region (Belgium), collected respectively by long-term track-etch measurements and by short-term charcoal measurements, are compared at the county level. They are shown to agree reasonably for geometrical mean values, whereas short-term data show a higher variability. Methods to define affected areas from short-term measurements are discussed.

We examine the dosimetric control of Sr-90-Y-90 source trains used for the prevention of restenosis by endovascular irradiation. Beta sources have many advantages in this respect, but their dosimetric control is not easy, because of the very steep dose gradients.Radiochromic films are exposed to the beta radiation in a phantom, at the reference distance of 2 mm. Exposure to Co-60 gamma-rays and 4.5 MeV electron linac beam are used for dose calibration. No significant difference is found between Co-60 and electron calibrations. A bad reproducibility (up to +/-8%) is observed in dose measurements with the source train, attributed to fluctuations of the position of the individual sources in the catheter through which the sources are conveyed. This problem is solved by simultaneously exposing two films, on the two sides of a 4-mm thick phantom, with the catheter at the centre. After film digitisation and conversion to dose, the geometrical mean of the corresponding doses at 2 mm in the two images is calculated. A much better reproducibility is obtained (+/-2%). A software has been written for the analysis and averaging of the images.The results are consistent with Monte-Carlo calculations for a source of the same activity. They disagree with the initial dose calibration of the source train, although traceable to NIST. (C) 2003 Elsevier B.V. All rights reserved.

The indoor radon (222Rn) concentration has been measured by charcoal detectors in 278 buildings in the region of Brussels, Belgium. The correlation with the nature of the subsoil can be studied in detail thanks to the available geotechnical map. With a geometrical mean indoor radon concentration of 19 Bq m(-3), Brussels can be considered as generally unaffected by the radon problem. No value higher than 400 Bq m(-3) (the EU reference level for existing houses) was measured in an occupied room. However, two factors that may enhance the risk are identified: the absence of a basement or a ventilated crawl space, and the presence of loess, under the house. About one third of the houses without basements or ventilated crawl spaces built on loess show an indoor radon concentration above 200 Bq m(-3) (the EU reference level for new houses).

A database of 1724 short-term indoor radon measurements in southern Belgium was analysed to determine the radon-affected areas and their relation with geology. A map of indoor radon in southern Belgium was developed, based on the geometric mean of the measurements in each commune. The radon risk is mainly associated with three Paleozoic series: Cambrian, lower Devonian, and upper Devonian, corresponding to radon-affected areas in the Ardenne Massif (mainly its southern and eastern parts), the synclinorium of Dinant (Condroz), and the Dyle Valley. Special attention was given to the effect of superficial formations, which decrease indoor radon concentrations where an old geological basement is present, but increase it on more recent stages. A detailed study is presented for Brabant, including the measurement of several physical parameters of the subsoil. Although their radium content is not low, no indoor radon problem was found on Holocenic alluvions, presumably because they inhibit radon migration due to their permanent water saturation. Lutetian sand also was not associated with significant indoor radon problems, because its radium and radon content remains rather low, though highly variable. Superficial loess deposits were found to be a significant, though moderate, source of radon risk. This might be explained by their radium and radon content, if a mechanism can be found that increases their permeability under the house.