It is very important to evaluate the diameters (activity median aerodynamic diameter) of plutonium dioxide (PuO2) particles for internal exposure dose evaluation. In this study, a method of evaluating PuO2 particle diameters using an alpha-particle imaging detector was developed. PuO2 particles with different diameters were modeled by Monte Carlo simulation, and the change in the shape of the energy spectrum for each particle diameter was evaluated. Two different patterns were modeled, namely, the case of 239PuO2 and the case of PuO2 (including isotopic composition of Pu). Multiple regression analysis was performed to determine the PuO2 particle diameter from the obtained parameters. The simulated diameters and the diameters obtained with the regression model were in good agreement. The advantage of using the alpha-particle imaging detector is to measure the alpha energy spectrum for individual particle, and this allows accurate measurement of particle diameter distribution.

This work aimed to develop and validate software that calculates the shielding thickness required for a radiotherapy room with a linear accelerator utilising geometric and dosimetric data. The software “Radiotherapy Infrastructure Shielding Calculations” (RISC) was developed using MATLAB programming. It does not require the installation of the MATLAB platform, and the user only needs to download and install the application, which displays a graphical user interface (GUI). The GUI includes empty cells to insert numerical values for several parameters to calculate the proper shielding thickness. The GUI comprises two main interfaces, one for the primary and one for the secondary barrier calculation. The interface of the primary barrier is divided into four tabs: (a) primary radiation, (b) patient scattered and leakage radiation, (c) IMRT techniques and (d) the shielding cost calculations. The interface of the secondary barrier includes three tabs: (a) patient scattered and leakage radiation, (b) IMRT techniques and (c) the shielding cost calculations. Each tab consists of two sections: one for input and one for output of the necessary data. The RISC is based on the methods and formulae of the NCRP 151 and calculates the primary and secondary barrier thickness for ordinary concrete with a density of 2.35 g/cm3 and the cost for a radiotherapy room with a linear accelerator that performs conventional or IMRT techniques. Calculations can be performed for photon energies of 4, 6, 10, 15, 18, 20, 25 and 30 MV of a dual-energy linear accelerator, while instantaneous dose rate (IDR) calculations are also performed. The RISC has been validated using all comparative examples of NCRP 151 and the calculations from shielding reports of the Varian IX linear accelerator at Methodist Hospital of Willowbrook and Elekta Infinity at the University Hospital of Patras. The RISC is accompanied by two text files: (a) “Terminology,” extensively describing all parameters, and (b) “User’s Manual,” providing useful instructions to the user. The RISC is user-friendly, simple, fast and precise, providing accurate shielding calculations and quickly and easily reproducing different shielding scenarios for a radiotherapy room with a linear accelerator. Additionally, it could be used during the educational process of shielding calculations by graduate students or trainee medical physicists. As a future work, the RISC will be updated with new features such as skyshine radiation, door shielding, and other types of machines and shielding materials.

The worldwide transformation of electricity production goes hand in hand with increasing use of wind energy. The German ‘Energiewende’ project is no exception and relies heavily on the construction and use of an ever-increasing number of wind turbines. While the operation of wind turbines does not lead to the emission of pollutants (in contrast to, e.g. coal, oil or gas), the production processes of the construction materials do. Since the raw materials’ production primarily takes place outside Germany, radioactivity and doses related to these processes occur at remote places in the world. This effect might be called an ‘export of doses’. In the present paper, we perform a life cycle analysis of wind turbines, investigating the mining and production of the construction materials. We focus on rare-earth elements needed for the generator magnets and assess the associated releases of radioactive materials during mining and processing, primarily in China. Estimates of dose to the public in selected Chinese cities are calculated. Different electricity generation techniques are compared by the use of the quantity (collective) dose per GW per year.

During the early response to large-scale radioactive contamination events, people who are potentially affected need to be screened for radioactive contamination and public health staff need to triage individuals who may need immediate decontamination. This is typically done by screening individuals for external contamination using ionising radiation detection equipment. In this study, spatially and temporally dependent isotopic compositions from a simulated nuclear detonation and Monte Carlo methods were used to relate contamination activity levels to the measurable radiation levels at select distances away from an individual with whole-body contamination. Radionuclide-specific air kerma rate coefficients and Geiger–Mueller instrument response coefficients at five select distances from contaminated individuals are presented for 662 radionuclides. Temporally and spatially dependent incident-specific coefficients are presented for a hypothetical surface detonation of a 235U-fueled device.

The study aimed to estimate threshold doses and their uncertainties for some human health effects after short-term high dose-rate radiation exposure by quantile technique and the effective dose threshold technique based on distribution functions. The relative uncertainty (U) of the threshold dose was estimated using the error propagation technique. The quantile technique provided statistically significant estimates of threshold doses for acute radiation syndrome onset (0.44 ± 0.12 Gy, U = 143%) and lethality (1.84 ± 0.44 Gy, U = 117%) but relative uncertainties were high. The effective threshold dose technique provided statistically significant and more precise threshold dose estimates for acute radiation syndrome onset (0.73 ± 0.02 Gy, U = 18%) and lethality (6.83 ± 0.08 Gy, U = 36%), as well as agranulocytosis (3.51 ± 0.03 Gy, U = 16%) and vomiting onset in the prodromal period (1.54 ± 0.02 Gy, U = 16%). Threshold doses estimated for the change in the peripheral blood neutrophil and leukocyte counts during the first days after short-term high dose-rate radiation exposure were not statistically significant.

We performed an experimental investigation on occupational exposure of the eye lens and the extremity of radiation workers engaged in handling of highly activated materials in a small research accelerator facility. Using a simplified physical phantom to simulate the relevant inhomogeneous radiation exposure situations, the personal dose equivalents obtained at the eye lens and the extremities of radiation workers handling heavily radioactive converters were measured together with the dose measured by personal dosemeters worn on their trunk. Results of mockup experiments and the Monte Carlo calculations suggest that the quantitative estimation of the eye lens doses can be estimated from the trunk dose, while the extremity doses vary considerably from the dose readings from the trunk, depending on the use of simple point-source or volume source geometry.

People exposed to ionising radiation may develop harmful somatic and genetic effects in their anatomical structures. Technological advancements, particularly in radiological devices, research and examinations result in a significant increase in the number of radiological investigations. This large number of radiological examinations increased the number of patients affected by ionising radiation. This study aims to evaluate the medical students’ knowledge of ionising radiation and, examine the level of knowledge of medical students on the awareness and safety of ionising radiation exposure, emphasises the importance of radiation curricula internship programmes. This study is a survey application. The chi-square test is used. As a result, the intern’s knowledge of ionising radiation increased significantly after the internship in a radiology unit. Although it has been significantly increased, it is still insufficient. This gap can be filled by incorporating radiology unit internship programmes into the curriculum of medical faculty education programmes.

In the process of optimisation of radiological protection in long-term radioactive waste management, design options for disposal facilities are assessed from the viewpoint of practical reduction in radiation dose to as low as reasonably achievable (ALARA). In this paper, a probabilistic approach is introduced to evaluate differences in dose distributions between alternative facility designs using the Bayesian inference technique. It is demonstrated by a series of parametric calculations for hypothetic disposal system designs that an additional dose from an disposal facility could be sufficiently reduced from the viewpoint of dose reduction under the ALARA principle if the design option for a disposal facility whose 95th percentile of dose distribution is lower than the target dose of 0.1 mSv/y is provided. Reducing uncertainties of the distribution of dose from disposal options is also an important aspect for the practical reduction in radiation dose to which members of the public are exposed.

The skeleton is a major plutonium retention site in the human body. Estimation of the total plutonium activity in the skeleton is a challenging problem. For most tissue donors at the United States Transuranium and Uranium Registries, a limited number of bone samples is available. The skeleton activity is calculated using plutonium activity concentration (Cskel) and skeleton weight. In this study, latent bone modelling was used to estimate Cskel from the limited number of analysed bone samples. Data from 13 non-osteoporotic whole-body donors were used to develop latent bone model (LBM) to estimate Cskel for seven cases with four to eight analysed bone samples. LBM predictions were compared to Cskel estimated using an arithmetic mean in terms of accuracy and precision. For the studied cases, LBM offered a significant reduction of uncertainty of Cskel estimate.

With the increasing number of decommissioning projects, radioactive waste estimation of biological shielding concretes is becoming more and more important. Simulation tools supporting this activity, like MCNP and Cinder are already available; however, publicly available neutron spectra in shielding concretes are limited. The aim of the study was to present and evaluate possible model arrangements for accurate neutron transport to deeper points of shielding concretes from the reactor pressure vessel. Representation of reality, neutron behavior and activity generation of seven long-lived radioisotopes (54Mn, 60Co, 65Zn, 133Ba, 134Cs, 152Eu and 154Eu) were assessed in each arrangement. After evaluating several model geometries, a conical shape neutron reflecting surface was shown to be the most suitable one to reproduce neutron fields in deeper layers of shielding concretes from a monodirectional initial neutron source.

There are products available on the online market that are claim to contain unique 'energies' that can improve health and wellness by eliminating toxins and pains and energising food and drinking water. We investigated these products by alpha and gamma spectrometry, and the analysis showed that they contained a few to hundreds of kilobecquerels per kilogram of naturally occurring radionuclides from the 232Th and 238U series. The committed effective dose for an adult drinking water that had been in contact with these products just once was estimated to 12 nSv. Considering a worst-case scenario for the workers inhaling the radioactive substance, 1 d of work would result in an effective dose of 0.39 mSv. The product descriptions do not mention the radionuclide content, and concerns are raised for the consumers and workers exposed to these products with no knowledge of the radioactive content.

In this study, an intricate combinatorial geometry model of a Boeing 777-300ER aircraft was constructed for Monte Carlo transport simulations. The aircraft-induced perturbations of the energy spectra and effective doses of secondary cosmic rays at a typical civil aviation altitude (10 km) were investigated on a component-by-component basis, which included neutrons, protons, photons, electrons, positrons, muons and charged pions. Two geomagnetic cutoff rigidities (1.35 and 15.53 GV) and two solar modulation parameters (430 and 1360 MV) were considered in the aforementioned simulations. The characteristics of various cosmic-ray components at six locations along the fuselage were assessed and compared with those of an unperturbed radiation field in the atmosphere. Aircraft structures and contents reduced the effective doses of personnel inside the aircraft to varying degrees, up to an ~32% reduction in the middle section of the passenger cabin. On average, the dose reduction was ~12–16% depending on geomagnetic and solar conditions. Quantifying the aircraft’s self-shielding effects can further improve the estimation accuracy of aircrew and passengers’ exposure to cosmic radiation. Information regarding the perturbed energy spectra of cosmic rays may be useful for designing onboard experiments or analyzing onboard measurement data.

Safety issues are raised from the use of low- and high-power optical radiation sources, both laser and non-laser, by non-experts for aesthetic and entertainment purposes. The Greek Atomic Energy Commission relied on the ISO 31000:2018 framework to manage the public exposure risk to such cases. Risk was evaluated as (1) intolerable for lasers and intense pulsed light sources at aesthetic procedures and in the case of laser pointers, (2) severe for lasers at laser shows and (3) moderate for light-emitting diodes (LEDs) at aesthetic procedures, home-use intense pulsed light sources/LEDs and laser/LED projectors. Operators’ training, public awareness campaigns, intensive market surveillance actions and the enhancement of the regulatory framework have been proposed as risk treatment/control measures and have been prioritised in this order, according to their effectiveness in reducing the exposure risk and their urgency of implementation. The Greek Atomic Energy Commission developed public awareness campaigns regarding exposure safety to laser and non-laser light sources at aesthetic procedures and the use of laser pointers.

The adoption of the Council Directive 2013/59/EURATOM into Austrian national law generated new challenges for businesses, authorities and measurement services. The law defines radon priority regions in which all employers are obliged to hire an authorised radon-monitoring service to determine radon activity concentration at workplaces in basements and on ground floors. In this paper, an overview of our experiences with the process of becoming an accredited and authorised radon-monitoring body using integrating and time-resolved radon measurement equipment is given. The main challenges to overcome, such as determination of measurement uncertainty, conducting metrologically traceable calibration of the track-etch detector system, information not covered by ISO 11665-1, ISO 11665-4 and ISO 11665-5, availability of proficiency tests, etc., are described. This paper aims to be a guideline for laboratories seeking accreditation in the field of radon activity concentration measurements.

The applicability of the ISO slab phantom as calibration phantom for the new ICRU report 95 quantity personal dose should be legitimated by simulations and measurements of backscatter factors on the ISO slab phantom and, comparatively, on a human-like Alderson Rando phantom. An ionization chamber was used to determine backscatter factors for standardized X-ray spectra in the energy range of 16–250 keV and for gamma radiation of 137Cs (662 keV) and 60Co (1250 keV). For the validation of measurement results on the ISO slab, the results were compared with those obtained by means of Monte Carlo simulations using MCNP 6.2. Since the deviations of the backscatter factors on the ISO slab from those on the Alderson Rando were within ±5%, it could be concluded that it is not necessary to develop a new calibration phantom for the assessment of personal dose.

INTRODUCTION We developed a technique including preventing errors management method capable of dealing with the virtual source position delivered by different carbon ion energies from the pattern of spot scanning beam in this study. MATERIALS AND METHODS A homemade large-format complementary metal-oxide-semiconductor (CMOS) sensor and Gaf Chromic EBT3 films were used for the virtual source position measurement. The Gaf films were embedded in a self-designed rectangular plastic frame to tighten the films and set up on a treatment couch for irradiation in the air with the film perpendicular to the carbon ion beam at the nominal source-axis-distance (SAD) as well as upstream and downstream from the SAD. The horizontal carbon ion beam with five energies at a machine opening field size was carried out in this study. The virtual source position was determined mainly with a linear regression by back projecting the full width half maximum (FWHM) to zero at a distance upstream from the various source-film-distance and double checks additionally with a geometric convergent method to avoid any mistakes caused by manual measurement on FWHM. RESULTS The virtual source position for higher carbon ion energy has an obvious longer distance from the SAD since the more carbon ion beam energy, the less spreading affected by the horizontal and vertical magnetism, therefore, the distance of virtual source positions is decreased from SAD with high to low energy. CONCLUSION The method for investigating the virtual source position in the carbon ion beam in this study can also be used for electrons and the proton. We have developed a technique capable of dealing with the virtual source position with a geometric convergent method to avoid any mistakes in spot scanning carbon ion beam.

The Indian Environmental Radiation Monitoring Network continuously monitors, throughout India, the absorbed dose rate in air due to outdoor natural gamma radiation, by using Geiger-Mueller detector-based standalone environmental radiation monitors. The network consists of 546 monitors spread across 91 monitoring locations distributed all over the country. In this paper, the countrywide long-term monitoring results are summarised. The measured mean dose rate of the monitoring locations followed a log-normal distribution and ranged from 50 to 535 nGy.h-1 with a median value of 91 nGy.h-1. Due to outdoor natural gamma radiation, the average annual effective dose was estimated to be 0.11 mSv.y-1.

The paper deals with the determination of the absorbed power density (Sab) in a planar multilayer model of a tissue exposed to the radiation of a dipole antenna, based on the analytical/numerical approach. A derivation of Sab from the differential form of Poynting theorem is presented. The two-layer and three-layer tissue models are used. Illustrative analytical/numerical results for electric and magnetic fields and Sab induced at the tissue surface for various antenna lengths, operating frequencies and antenna-interface distances are presented in the paper. Exposure scenarios of interest pertain to frequencies above 6GHz pertaining to 5G mobile systems.

For homeland security, radiation portal monitors (RPMs) have been widely used to detect illegal radioactive materials at seaports, airports, nuclear facilities and other highly secured establishments. In general, commercial RPMs are based on a large plastic (i.e. PVT-polyvinyl toluene) scintillator detector and the associated electronics. In order to detect radioactive materials passing through the RPM, the alarm criterion should be set according to the background level, which depends on the operating location due to not only composition differences in soil and rocks but also weather variation (i.e. rainfall and temperature). It is well known that RPM background signal level increases with rainfall and that the PVT signal depends on the temperature due to scintillation light yield variation. In this study, the background signal level of two commercial RPMs (models: 4525-3800 and 7000, Ludlum), both of which are installed and operated at the Incheon and Donghae ports in Korea, was analysed by reference to a 3-year database of minute-to-minute RPM background signals and a rainfall-and-temperature database provided by the Korea Meteorological Administration (KMA). In terms of rainfall, the variation of the background signal level was examined with reference to the amount of rainfall. The averaged variation in the background signal level, which was as high as ~20% as a function of the amount of rainfall, was found to be dependent on a region’s specific concentration of 222Rn in the atmosphere. In terms of temperature, the background signal level varied by ~4.7% within the temperature range of −5 to 30°C for the four studied sites (i.e. two sites per region for the Incheon and Donghae regions). Knowledge of the dependency of RPM background signal level on rainfall amount and temperature could be used to achieve more realistic estimation of the background radiation level for optimising commercial RPMs’ alarm criteria.

PyMCGPU-IR is an innovative occupational dose monitoring tool for interventional radiology procedures. It reads the radiation data from the Radiation Dose Structured Report of the procedure and combines this information with the position of the monitored worker recorded using a 3D camera system. This information is used as an input file for the fast Monte Carlo radiation transport code MCGPU-IR in order to assess the organ doses, Hp(10) and Hp(0.07), as well as the effective dose. In this study, Hp(10) measurements of the first operator during an endovascular aortic aneurysm repair procedure and a coronary angiography using a ceiling suspended shield are compared to PyMCGPU-IR calculations. Differences in the two reported examples are found to be within 15%, which is considered as being very satisfactory. The study highlights the promising advantages of PyMCGPU-IR, although there are still several improvements that need to be implemented before its final clinical use.