Air kerma to H-P(3) conversion coefficients for IEC 61267 RQR X-RAY radiation qualities: application to dose monitoring of the lens of the eye in medical diagnostics

Recent studies highlight the fact that the new eye lens dose limit can be exceeded in interventional radiology procedures and that eye lens monitoring could be required for these workers. The recommended operational quantity for monitoring of eye lens exposure is the personal dose equivalent at 3 mm depth Hp(3) (ICRU 51). However, there are no available conversion coefficients in international standards, while in the literature coefficients have only been calculated for monoenergetic beams and for ISO 4037-1 X-ray qualities. The aim of this article is to provide air kerma to Hp(3) conversion coefficients for a cylindrical phantom made of ICRU-4 elements tissue-equivalent material for RQR radiation qualities (IEC-61267) from 40 to 120 kV and for angles of incidence from 0 to 180°, which are characteristic of medical workplace. Analytic calculations using interpolation techniques and Monte Carlo modelling have been compared.Postprint (author's final draft

Dose calculations in aircrafts after Fukushima nuclear power plant accident – Preliminary study for aviation operations

There is little information to decision support in air traffic management in case of nuclear releases into the atmosphere. In this paper, the dose estimation due to both, external exposure (i.e. cloud immersion, deposition inside and outside the aircraft), and due to internal exposure (i.e, inhalation of radionuclides inside the aircraft) to passengers and crew is calculated for a worst-case emergency scenario. The doses are calculated for different radionuclides and activities. Calculations are mainly considered according to International Commission on Radiological Protection (ICRP) recommendations and Monte Carlo simulations. In addition, a discussion on potential detectors installed inside the aircraft for monitoring the aerosol concentration and the ambient dose equivalent rate, H*(10), for during-flight monitoring and early warning is provided together with the evaluation of a response of a generic detector. The results show that the probability that a catastrophic nuclear accident would produce significant radiological doses to the passengers and crew of an aircraft is very low. In the worst-case scenarios studied, the maximum estimated effective dose was about 1¿mSv during take-off or landing operations, which is the recommended yearly threshold for the public. However, in order to follow the ALARA (As Low As Reasonably Achievable) criteria and to avoid aircraft contamination, the installation of radiological detectors is considered. This would, on one hand help the pilot or corresponding decision maker to decide about the potential change of the route and, on the other, allow for gathering of 4D data for future studiesPostprint (published version

Experimental verification of acuros XB in the presence of lung-equivalent heterogeneities

Acuros XB (AXB) is a deterministic algorithm that directly accounts for the effects of heterogeneities and improves the accuracy of photon dose calculations in radiotherapy. Nevertheless, the accuracy of AXB inside lung has not been yet fully examined by means of experimental measurements. The aim of this study was to evaluate the accuracy of AXB in the presence of lung using 7Li-based thermoluminescent dosimeters (TLD-700). Percentage depth-dose distributions (PDD) obtained by AXB on a slab water-equivalent phantom with a lung-equivalent heterogeneity were compared with the TLD-700 measurements for 6 MV and 18 MV photon beams and a set of field sizes ranging from View the MathML source2×2cm2to20×20cm2. Dose distributions obtained by the Anisotropic Analytical Algorithm (AAA) were also included in the comparison as a reference to a non-deterministic dose calculation algorithm. The agreement between AXB and the TLD results was kept within clinical tolerance levels (3%) for all beam configurations. On the contrary, AAA failed at correctly predicting the absorbed dose when the lateral electronic equilibrium was lost. AXB is capable of providing reliable dose estimations in the presence of lung and clearly outperforms AAA.Postprint (author's final draft

Master’s degree in Nuclear Engineering UPC-ENDESA. Creating synergy at industrial and academic levels

The Master’s degree in Nuclear Engineering, born from the alignment of objectives of Academy and Industry, aims to prepare competent engineers to assume managerial positions within the Nuclear Industry. MNE is completely taught in English. Synergies are established at both industrial and academic levels.MNE syllabus has been designed (and is being continuously improved) with the help of industrial partners and the Spanish Regulatory Body (CSN). One half of the lectures are delivered by professionals external to the university. Besides ENDESA, other companies (ANAV, AREVA, ENRESA, ENSA, ENUSA, IDOM, Nuclenor, Tecnatom, Westinghouse) collaborate in the master. Lecturers from CSN and CIEMAT (the major Spanish research centre) participate in the Master as well. A large portion of the master contents is delivered as Project Based Learning, In general, active learning and team work activities are thoroughly used so as to help the students achieve the learning objectives and acquire a number of soft skills required by industry.MNE is embedded in EMINE, the European Master in Nuclear Energy (European Institute of Technology, KIC-InnoEnergy). As well, MNE is part of a double degree in the Barcelona Engineering School (ETSEIB) with the official Master in Industrial Engineering (MUEI). Having in the same classroom EMINE and MNE students creates a good working atmosphere, while allowing the future engineers work in a multicultural and international environment. The double degree MNE-MUEI allows students to acquire the MNE competencies and, at the same time, legal engineering attributions. It has been useful to attract good engineering students to the master.Postprint (published version

Master’s degree in Nuclear Engineering UPC-ENDESA. A consolidated international program

The Master’s degree in Nuclear Engineering (MNE) UPC-ENDESA offers a unique and practical oriented training, with the aim to prepare competent engineers so that they can assume managerial positions within the Nuclear Industry. The program combines science, technology and management in the nuclear energy field, including the elements of the safety culture. MNE is embedded in EMINE, the European Master in Nuclear Energy (KIC InnoEnergy) and is completely taught in English. Its 90 credits (each credit implies 25 hours of student’s work) are divided into one year of subjects (60 credits), and one semester of internship plus final project (30 credits). MNE has a strong industrial implication: lecturers from companies, research institutes and the Spanish Regulatory Authority (cover about one half of the lectures; companies accept students in internships and organize technical visits. The participation of professionals external to the University in the definition and revision of the Program is one of MNE’s assets. A large portion of the contents of the MNE are organized in the form of Problem and Project Based Learning: real industrial problems are brought into the classroom to be solved by students, most of the time assisted by experts from the nuclear industry. MNE is in continuous evolution, seeking for a continuous improvement of the contents and learning methods. Starting the sixth edition, the master is firmly consolidated and the alumni value it positively.Postprint (published version

Monte Carlo simulation of the total dose distribution around the 12 MeV UPC race-track microtron and radiation shielding calculations

The Technical University of Catalonia is building a miniature 12 MeV electron race-track microtron for medical applications. In the paper we study the leakage radiation caused by beam losses inside the accelerator head, as well as the bremsstrahlung radiation produced by the primary beam in the commissioning setting. Results of Monte Carlo simulations using the PENELOPE code are presented and two shielding schemes, global and local, are studied. The obtained shielding parameters are compared with estimates based on DIN 6847 part 2 as international recommendation of the radiation safety standards.Postprint (published version

Measurements of eye lens doses in interventional cardiology using OSL and electronic dosemeters

The purpose of this paper is to test the appropriateness of OSL and electronic dosemeters to estimate eye lens doses at interventional cardiology environment. Using TLD as reference detectors, personal dose equivalent was measured in phantoms and during clinical procedures. For phantom measurements, OSL dose values resulted in an average difference of 215% vs. TLD. Tests carried out with other electronic dosemeters revealed differences up to +/- 20% versus TLD. With dosemeters positioned outside the goggles and when TLD doses were > 20 mu Sv, the average difference OSL vs. TLD was 29%. Eye lens doses of almost 700 mu Sv per procedure were measured in two cases out of a sample of 33 measurements in individual clinical procedures, thus showing the risk of high exposure to the lenses of the eye when protection rules are not followed. The differences found between OSL and TLD are acceptable for the purpose and range of doses measured in the survey.Postprint (published version

Impact of region-of-interest delineation methods, reconstruction algorithms, and intra- and inter-operator variability on internal dosimetry estimates using PET

Purpose Human dosimetry studies play a central role in radioligand development for positron emission tomography (PET). Drawing regions of interest (ROIs) on the PET images is used to measure the dose in each organ. In the study aspects related to ROI delineation methods were evaluated for two radioligands of different biodistribution (intestinal vs urinary). Procedures PET images were simulated from a human voxel-based phantom. Several ROI delineation methods were tested: antero-posterior projections (AP), 3D sub-samples of the organs (S), and a 3D volume covering the whole-organ (W). Inter- and intra-operator variability ROI drawing was evaluated by using human data. Results The effective dose estimates using S and W methods were comparable to the true values. AP methods overestimated (49 %) the dose for the radioligand with intestinal biodistribution. Moreover, the AP method showed the highest inter-operator variability: 11 ± 1 %. Conclusions The sub-sampled organ method showed the best balance between quantitative accuracy and inter- and intra-operator variability.Postprint (author's final draft

Intercomparison IC2021area of passive area dosimetry systems

The EURADOS intercomparison IC2021area was carried out between May 2021 and April 2022 for 66 participating passive H*(10) area dosimetry systems from 47 different institutes and monitoring services. Three measurement conditions were provided at locations of the Karlsruhe Institute of Technology: 3-months indoor, 3-months outdoor and 6-months outdoor. The challenge of this intercomparison was measuring additionally irradiated low dose radiation. Six dosemeters of each participating system were irradiated with Cs-137 gamma reference radiation: Three dosemeters with 150 µSv and three dosemeters with 300 µSv. Another six dosemeters of each participating system were not irradiated and were used for background dose subtraction. Typical values of the measured background dose were between 200 µSv and 450 µSv with a few significantly higher values up to 1.6 mSv. Despite the challenge of the low reference dose values, more than 90 % of the resulting response values of the irradiated dosemeters were within the recommended ISO 14146 trumpet curve response limits.Peer ReviewedPostprint (published version

Systematic influences on the areas of peaks in gamma-ray spectra that have a large statistical uncertainty

A method is presented for calculating the expected number of counts in peaks that have a large relative peak-area uncertainty and appear in measured gamma-ray spectra. The method was applied to calculations of the correction factors for peaks occurring in the spectra of radon daughters. It was shown that the factors used for correcting the calculated peak areas to their expected values decrease with an increasing relative peak-area uncertainty. The accuracy of taking the systematic influence inducing the correction factors into account is given by the dispersion of the correction factors corresponding to specific peaks. It was shown that the highest accuracy is obtained in the peak analyses with the GammaVision and Gamma-W software.Postprint (author's final draft