The system of protection established by the International Commission on Radiological Protection (ICRP) provides a robust framework for ionizing radiation exposure justification, optimization, and ...dose limitation. The system is built upon fundamental concepts of a
reference person
, defined in ICRP Publication 89, and the radiation protection quantity
effective dose,
defined in ICRP Publication 103. For external exposures to radionuclide-contaminated soil, values of the organ dose rate coefficient (Gy/s per Bq/m
2
) and effective dose rate coefficient (Sv/s per Bq/m
2
) have been computed by several authors and national laboratories using ICRP-compliant reference phantoms—both stylized and voxelized. These coefficients are of great value in post-accident exposure assessments as seen in Japan following the 2011 Fukushima Daiichi nuclear power station disaster. Questions arise, however, among the general public regarding the accuracy of organ and effective dose estimates based upon reference phantom methodologies, especially for those individuals with height and/or total body mass that differ modestly or even substantially from the nearest age-matched reference person. In this pilot study, this issue is explored through use of the extended 351-member UF/NCI hybrid phantom library in which values of organ and detriment-weighted dose rate coefficients are computed for sex/height/mass-specific phantoms, and systematically compared to their values of the effective dose rate coefficient computed using corresponding reference phantoms. Results are given for monoenergetic photons, and then for some 33 different radionuclides, with all dose rate coefficient data provided in a series of electronic annexes. For environmentally relevant radionuclides such as
89
Sr,
90
Sr,
137
Cs, and
131
I, percent differences between the detriment-weighted dose rate coefficient computed using non-reference and the effective dose rate coefficient computed using reference phantoms vary only ± 5% for young children approximated by the reference 1-year-old phantom. With increased body size and age, the range of percent differences in these two quantities increases to + 7% to − 14% for the reference 5-year-old, to + 10% to − 27% for the reference 10-year-old, to + 33% to − 31% for the reference 15-year-old, and to + 15% to − 40% for male and female adults.
The purpose of the study was to evaluate the radiation dose in High-Definition Reference Korean-Man phantom according to the lead equivalent in the protection devices using MCNPX. The tube voltage ...and current are 80–100 kV and 15 mAs, respectively, and the exposure time is 7–10 min. The range of lead equivalent of the protection devices worn by the operator phantom is 0–0.50 mmPb with the internal of 0.05 mmPb. The radiation dose indirect calculation method, the NDD(k), and variance reduction techniques are applied. The average error rate of the absorbed dose in each organ was 12.88% at 80 kV and 7.41% at 100 kV. Among the organs, the doses by the gonads (testis) and bladder accounted for 58.91%, resulting from close proximity to the table height, the origin of the scattered radiation. In case of evenly distributed bone surfaces throughout the body, it was 25.66%. This study quantitatively reports that after 0.25 mmPb lead equivalent of radiation protection devices commonly used in the clinical interventional procedure, TACE, the decrease in effective dose begins to slow down and become constant.
•Impacts of HTO sampler configurations on sampling performance were systematically studied.•A modifiable sampler designs were developed for the first time.•Absorption kinetic curves of samplers were ...calibrated in China and Germany.•A strategy for sampler modification and selection was first proposed.•Custom modification of sampler performance in yet unstudied environments would be enabled.
Anthropogenic release of tritium from nuclear facilities is expected to increase significantly in the coming decades, which may cause radiation exposure to humans through the contamination of water and food chains. It is necessary and urgent to acquire detailed information about tritium in various environments for studying its behavior and assessing the potential radiation risk. In the atmosphere, although the passive sampling technique provides a low-cost and convenient way to characterize the dynamics of tritiated water vapor (HTO), a single, simple sampler configuration makes it difficult to collect sufficient and representative samples within the expected period from different environments. In this study, we systematically studied the impacts of sampler configurations on sampling performance and proposed a modifiable sampler design by scaling sampler geometry and adjusting absorbent to achieve different monitoring demands. The samplers were subsequently deployed at five sites in China and Germany for the field calibration and the measured results exhibited a good agreement between the adsorption process obtained in sites corrected with diffusion coefficient and the one calibrated in Shanghai. This suggests the feasibility of predicting sampling performance in the field based on known data. Finally, we developed a strategy for sampler modification and selection in different environments and demonstrated that using easily obtainable environmental data, our sampler can be optimized for any area without any time-consuming preliminary experiments. This work provides a scientific basis for establishing high-resolution atmospheric HTO database and expands the conventional empirical sampler design paradigm by demonstrating the feasibility of using quantitative indices for sampler performance customization.
The past few decades have witnessed significant variations in the use of shielding materials and ionizing radiation. The use of ceramics as shields for protection against radiation has attracted ...interest in research owing to exceptional properties that distinguish them from other materials that are available to this end. Calcium zirconate (CaZrO3) is a lead-free ceramic material that exhibits good physicochemical properties, and is considered to be a good host for lanthanide elements, such as praseodymium ions, where this makes it a suitable alternative to lead and lead-based compounds as well as a promising candidate for use in radiation protection. In this study, we examine the radiation shielding properties of pristine CaZrO3 and Pr6O11/CaZrO3 ceramic samples by using Monte Carlo simulations. The formation of the desired phase was identified by the XRD technique. The data analysis indicated that the samples crystallized into an orthorhombic structure. The densities of the pristine CaZrO3 and the Pr6O11/CaZrO3 samples were 4.20 g/cm3 and 4.54 g/cm3, respectively. The analysis of their radiation shielding properties indicated an improvement in their linear attenuation coefficient (LAC), with values of 59.3%, 24.4%, 11.3%, and 8.1% at γ-photon energies of 0.121 MeV, 0.356 MeV, 0.662 MeV, and 2.506 MeV, respectively, when Pr6O11 was added to CaZrO3. The improvement in the LAC of the prepared samples was accompanied by a considerable reduction in their half-value thickness, lead-equivalent thickness, and transmission factor.
•Synthesis of pristine CaZrO3 and CaZrO3/Pr6O11 samples via solid-state reaction route.•The synthesized samples crystallized into the orthorhombic structure.•The addition of Pr6O11 affects the physical properties of the prepared CaZrO3 ceramic.•γ-ray attenuation ability of the prepared samples was assessed via Monte Carlo simulation.•The CaZrO3/Pr6O11 sample has better radiation sheilding properties than pristine sample.
This work aims to report the radiation shielding ability of WO3–ZnO–PbO–B2O3 glasses and to understand the effect of WO3 on the shielding behavior of this glass system. Geant4 code was applied to ...calculate the mass attenuation coefficient between 0.1218 and 1.458 MeV. The Phys-X software was used to validate the simulation results. Decrease in the transmission factor (TF) for the selected glasses with an increase in the thickness of the glass from 0.2 to 1 cm has been noticed and discussed. The maximum TF for the glass with composition of 20PbO-80B2O3 occurred for 0.2 cm thickness and equals to 0.44 at 0.1218 MeV and 0.966 at 1.086 MeV. Whereas, the maximum TF for 10WO3-10ZnO-20PbO-60B2O3 sample with a thickness of 0.2 cm varied between 0.256 and 0.95. The TF results emphasize the fact that the sample's power to attenuate the photons becomes weaker with the increase in the energy of the photon. The radiation protection efficiency (RPE) increases with the increase in the thickness of the glass and the amount of WO3. The replacement of 20 mol % of ZnO by 10 mol % of WO3 leads to the increase in the RPE from 8.83 to 12.03% at x = 0.4 cm, from 16.89 to 22.61% at x = 0.8 cm and from 20.64 to 27.42% at x = 1 cm. At 0.444 MeV, the linear attenuation coefficient (LAC) increases by 1.52 due to the increase in the density by 1.46, which indicated that if the density of the glass is doubled, the LAC almost doubles, and the WZPB7 glass with highest density attenuates more photons.
Adoption of interventional endoscopic procedures is increasing with increasing prevalence of diseases. However, medical radiation exposure is concerning; therefore, radiation protection for medical ...staff is important. However, there is limited information on the usefulness of an additional lead shielding device during interventional endoscopic procedures. Therefore, we aimed to determine whether an additional lead shielding device protects medical staff from radiation.An X-ray unit (CUREVISTA; Hitachi Medical Systems, Tokyo, Japan) with an over-couch X-ray system was used. Fluoroscopy-associated scattered radiation was measured using a water phantom placed at the locations of the endoscopist, assistant, nurse, and clinical engineer. For each location, measurements were performed at the gonad and thyroid gland/eye levels. Comparisons were performed between with and without the additional lead shielding device and with and without a gap in the shielding device. Additionally, a clinical study was performed with 27 endoscopic retrograde cholangiopancreatography procedures.The scattered radiation dose was lower with than without additional lead shielding at all medical staff locations and decreased by 84.7%, 82.8%, 78.2%, and 83.7%, respectively, at the gonad level and by 89.2%, 86.4%, 91.2%, and 87.0%, respectively, at the thyroid gland/eye level. Additionally, the scattered radiation dose was lower without than with a gap in the shielding device at all locations.An additional lead shielding device could protect medical staff from radiation during interventional endoscopic procedures. However, gaps in protective equipment reduce effectiveness and should be eliminated.
For traditional spent fuel shielding materials, due to physical and chemical defects and cost constraints, they have been unable to meet the needs. Therefore, this paper carries out the first ...discussion on the application and performance of bismuth in neutron shielding by establishing Monte Carlo simulation on the neutron flux model of shielded spent fuel. Firstly, functional fillers such as bismuth oxide, lead oxide, boron oxide, gadolinium oxide and tungsten oxide are added to the matrices to compare the shielding rates of aluminum alloy matrix and silicone rubber matrix. The shielding rate of silicone rubber mixture is higher than aluminum alloy mixture, reaching more than 56%. The optimal addition proportion of bismuth oxide and lead oxide is 30%, and the neutron radiation protection efficiency reaches 60%. Then, the mass attenuation coefficients of bismuth oxide, lead oxide, boron oxide, gadolinium oxide and tungsten oxide in silicone rubber matrix are simulated with the change of functional fillers proportion and neutron energy. This simulation result shows that the mixture with functional fillers has good shielding performance for low energy neutrons, but poor shielding effect for high energy neutrons. Finally, in order to further evaluate the possibility of replacing lead oxide with bismuth oxide as shielding material, the half-value layers and various properties of bismuth oxide and lead oxide are compared. The results show that the shielding properties of bismuth oxide and lead oxide are basically the same, and the mechanical properties, heat resistance, radiation resistance and environmental protection of bismuth oxide are better than that of lead oxide. Therefore, in the case of neutron source strengths in the range of 0.01–6 MeV and secondary gamma rays produced below 2.5 MeV, bismuth can replace lead in neutron shielding applications.
Optically stimulated luminescent detectors, which are widely used in radiation protection, offer a number of potential advantages for application in radiation therapy dosimetry. Their introduction ...into this field has been somewhat hampered by the lack of information on their radiation response in megavoltage beams. Here the response of a commercially available optically stimulated luminescent detector (OSLD) is determined as a function of energy, absorbed dose to water, and linear energy transfer (LET). The detector response was measured as a function of energy for absorbed doses from 0.5 to 4.0 Gy over the following ranges: 125 kVp to18 MV for photons, 6–20 MeV for electrons, 50–250 MeV for protons, and 290 MeV/u for the carbon ions. For the low LET beams, the response of the detector was linear up to 2 Gy with supralinearity occurring at higher absorbed doses. For the kilovoltage photons, the detector response relative to 6 MV increased with decreasing energy due to the higher atomic number of aluminum oxide (11.2) relative to water (7.4). For the megavoltage photons and electrons, the response was independent of energy. The response for protons was also independent of energy, but it was about 6% higher than its response to 6 MV photons. For the carbon ions, the dose response was linear for a given LET from 0.5 to 4.0 Gy, and no supralinearity was observed. However, it did exhibit LET dependence on the response relative to 6 MV photons decreasing from 1.02 at
1.3
keV
/
μ
m
to 0.41 at
78
keV
/
μ
m
. These results provide additional information on the dosimetric properties for this particular OSL detector and also demonstrate the potential for their use in photon, electron, and proton radiotherapy dosimetry with a more limited use in high LET radiotherapy dosimetry.
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