In this investigation, a novel glass system was fabricated via melt quenching. Effect of adding TeO2 on the composition (40-x)B2O3 + (15 + x + y)TeO2 + 25ZnO + (20-y)CaO was stud-ied, where x = 0, 2, 4, 6 mol % and y = 0, 3, 6, and 9 mol % in order to give four fabricated glasses coded by BTZC-1, BTZC-2, BTZC-3, andBTZC-4, respectively. The densities were measured by Archimedes' principle and were 3700, 3860, 4015, and 4166 gcm-3, respec-tively, due to the increasing additives of TeO2. The attenuation properties of the synthesized glass were determined experimentally and theoretically at four energies 0.060, 0.662, 1.173, and 1.333 MeV. A germanium detector was used as a spectrometer, and theoretically the Phy-X software was used, with the findings in agreement between the two techniques. For the BTZC-1 glass at 0.059 MeV, the linear attenuation coefficient was 7.512 cm-1 using the ex-perimental approach and 7.975 cm-1 via Phy-X. The maximum linear attenuation coefficient values were 7.975, 9.826, 11.622, and 13.368 cm-1, respectively for BTZC-1, BTZC-2, BTZC-3 and BTZC-4 at 0.060 MeV, with minimum values of 0.194, 0.201, 0.207, and 0.214 cm-1 at 1.333 MeV.
Ac ti va tion anal y sis and dose as sess ment of re ac tor com po nents are pre req ui sites for de com mis sion ing, cost es ti ma tion, and ra di a tion pro tec tion. At pres ent, im prov ing the ac cu racy of nu clear safety anal y sis re mains the key area of re search. To this end, based on the cou pling method of Monte Carlo code and the fuel de ple tion code, the his tor i cal nu clide de ple tion and ra dio ac tiv ity of de tec tors in spent fuel as sem blies, are cal cu lated and an a lyzed, the law of typ i cal nu clide ac tiv ity with burnup depth is stud ied, and the dose rate dis tri bu tion af ter the cool ing of spent fuel as sem blies, is eval u ated. The re sults of the cal cu la tions are in good agree ment with the ac tual mea sure ments, and the er ror is within an ac cept able range. Cru cially, it was found that af ter a cool ing pe riod of 3 years, with out ap ply ing shield ing mea sures, the dose rate at a dis tance of 30 cm from the sur face drops to be low 1 mSvh-1. On this ba sis, the shield ing de sign scheme of re ac tor de tec tors is pro posed, which pro vides a ref er ence for the re search on the ra di a tion shield ing of a de tec tor in the spent fuel as sem blies.
This study employs computational fluid dynamics methods to analyze bag filters with three structural configurations: non-guided, flat flow-guided, and curved flow-guided systems. The investigation specifically focuses on the influence of these configurations on key parameters, including internal flow field distribution patterns and filter bag load distribution. The evaluation is conducted using indicators such as flow amplitude and the speed variation coefficient. The results indicate that the flow amplitudes for the three structures are 0.41, 0.13, and 0.10, respectively, with notable differences observed in both the flow distribution coefficient and speed variation coefficient. Analysis of flow field uniformity of and particles motion demonstrates that the curved flow guide effectively improves flow field uniformity, providing improved speed distribution and flow allocation at all section heights.
Loss of regulatory control over radioactive sources pose significant threats to public health and environmental safety. This paper proposes a deep-learning-based method for detecting multiple similar radioactive sources. We construct multiple single-source datasets and one multi-source dataset through Geant4. The single-source datasets vary in radiation-pixel-map resolution and in detection-window settings, while the multi-source dataset contains up to three unknown sources. We convert 1-D count-rate data into 2-D image features to generate radiation pixel maps, and we define detection windows to reduce the search space. The YOLOv8n is then employed to detect and locate radioactive sources within these images. Through comparative experiments, we determine the optimal settings for the radiation pixel map and detection windows, achieving an accuracy of over 95 % in detecting multiple un- known radioactive sources. The results demonstrate that the trained deep learning model is able to accurately and effectively detect radioactive sources.
Silicon drift detectors are the core sensors for next-generation space-based X-ray detection, where precise efficiency calibration is crucial for both astronomical observation and radiation monitoring. In this study, calibration was performed using a ground-based monochromatic X-ray calibration facility that employs Bragg diffraction to establish the energy linearity and detection efficiency of an silicon drift detectors detector. A linear relationship between incident energy and channel number was observed, with a correlation coefficient of R² = 0.9987. Monte Carlo simulations were used to model the physical structure of the detector and to calculate its detection efficiency curve across the 2-40 keV range. Comparison with experimental measurements revealed the minimum deviation of 0.53 % at 10 keV and the maximum deviation of 4.77 % at 14 keV. In the 7-32 keV range, measured and simulated detection efficiencies closely matched, with the detector achieving a peak detection efficiency of 94.5 % at approximately 9 keV. The energy resolution of the detector was also calibrated, and a nonlinear curve fitting relationship between intrinsic energy resolution and energy was established, highlighting the variation in monochromaticity with energy. These results validate the feasibility and superiority of using continuously tunable mono-energetic X-rays for silicon drift detectors calibration. This approach lays the groundwork for future space astronomy missions and provides traceable physical references for in-orbit data.
Carbon ion implantation in 4H-SiC eliminates carbon vacancies, enhancing optoelectronic properties without introducing impurities, but excess ions may introduce new defects. Optimizing implantation requires understanding excess carbon's form. In this study, we carried out $ C^{+} $ implantation experiments on 4H-SiC with MEVVA source at 40 keV, with doses of 1×$ 10^{15} $, 5×$ 10^{15} $, 1×$ 10^{16} $, and 5×$ 10^{16} $ ions per cm2. Molecular dynamics simulations analyzed defect evolution, showing Ci2 exhibits greater structural stability than $ \mathrm{C_i1} $ and $ \mathrm{C_i3} $. Ion beam induced luminescence with protons is used to study the defect structures of carbon clusters after implantation. An asymmetric shift in the Donor-Acceptor Pair luminescence peak was ob- served. Gaussian deconvolution analysis revealed that this shift was caused by two new luminescence centers at 2.54 eV and 2.65 eV, respectively. Both of these new centers are induced by Ci2 defects. A single-exponential decay model was employed to study the luminescence evolution of the two centers, demonstrating that the 2.54 eV center exhibits greater stability than the 2.65 eV center. Moreover, DI defect luminescence was only observed at the lowest $ C^{+} $dose of 1×$ 10^{15} $ ions per $ cm^{2} $, corresponding to irradiation damage being below the amorphization threshold.
The issue of pollution in South Eastern Europe lacustrine environments is highly complex, involving industrial inputs, emerging contaminants (including microplastics and heavy metals), diverse chemical compounds and anthropogenic radioactivity-largely resulting from nuclear bomb testing and the Chernobyl disaster. Several methods for radiodating sediment have been developed and refined over the past decades to reconstruct temporal gradients of pollutant deposition. In this context, our study aims to validate Pb-Cs dating procedures for lacustrine environments, with the objective of advancing the understanding of depositional mechanisms and assessing mitigation processes. This paper presents the radiodating procedure applied to cores from a Danube Delta oxbow lake, highlighting both its strengths and limitations. While 210Pb enables the inference of sedimentation rates, 137Cs provides a chronological marker associated with relatively recent nuclear events. The results reinforce the potential of the method, but also reveal weaknesses elated to sampling operations and the need for further detailed explanations regarding recent changes in sedimentation rates. Overall, the findings are promising and offer a positive outlook for radioecological studies in the region.
This study developed a structured framework to evaluate the response capabilities of emergency response organizations in nuclear power plants, grounded in resilience engineering principles. Key response factors were identified and categorized, then analyzed probabilistically by integrating the analytic hierarchy process with Monte Carlo simulation, utilizing expert judgment To determine the relative importance of each evaluation factor while quantitatively addressing the inherent uncertainty in expert responses, weight distributions were derived instead of deterministic point estimates. The probabilistic analysis confirms the significance of practical response-related factors, such as response procedures, decision-making criteria, and risk perception-highlighting the critical role of organizational preparedness and procedural clarity in emergency situations. The identified protection-related factors provide a structured framework for assessing and improving emergency response capabilities, facilitating more reliable resource allocation and enhancing resilience. Future research could analyze the sensitivity of the results by applying alternative probability distribution models or extend this probabilistic framework to strengthen the effectiveness of other emergency response strategies.
This study aims to bridge standardized leaching test data with the underlying radionuclide transport mechanisms in cemented radioactive waste forms. Analysis of experimental data obtained in accordance with the Chinese standard GB 14569.1-2011 reveals that radionuclide release occurs in two distinct stages: an initial fast-release phase, governed by surface reactions, followed by a slow-release phase, controlled by diffusion through the pore structure. In intact cemented systems, matrix dissolution is negligible and can be excluded from long-term predictive models. Fast leaching percentage and fast leaching reaction constant can be derived for the early 14 days leaching data. The slow apparent diffusion coefficient can be derived from the data collected after 35 days, and these derived parameters agree well with dual porosity model. However, radionuclide-specific behavior must be accounted for 60Co and 137Cs. For 60Co since a decrease in leachate pH (e. g., due to carbonation) can enhance the dissolution of Co(OH), thereby increasing its release rate, and for 137Cs, competitive ion effects from Na+/K+ in the pore solution significantly accelerate desorption, indicating that a desorption-controlled diffusion model is more appropriate for long-term performance assessment than a simple Fickian diffusion model. These findings strengthen the mechanistic interpretation of regulatory leaching tests and support more robust safety evaluations of cement-based waste forms in China.
The Monte Carlo code, FLUKA, was used to com pute the in duced ra dio ac tiv ity in treat ment room for pro ton ther apy, car bon ion ther apy, and bo ron neu tron cap ture ther apy. For mod el ing ac tiv ity buildup, a pe ri odic ir ra di a tion ac tiv ity buildup ap proach was em ployed. Re sults show that air ac ti va tion lev els from all three ther a pies are ex tremely low. In pa tients, pro ton/car bon ion ther apy mainly gen er ates short-lived iso topes like 15O, with dose rates at 1 m ther apy, how ever, pro duces lon ger-lived iso topes (24N, 38Cl), lead ing to el e vated dose rates for sev eral hours and re quir ing post-treat ment con trol mea sures. No ta bly, con crete ac ti va tion di verges sig nif i cantly: for pro ton/car bon ion ther apy, the in duced ac tiv ity re mains low (similar to 107 Bq), pos ing min i mal risks to ra di a tion ex po sure or waste dis posal. Bo ron neu tron cap ture ther apy, by con trast, in creases con crete ac ti va tion by two or ders of mag ni tude. Af ter one week of op er a tion, 24Na buildup causes the dose rate at the treat ment room cen ter to reach 39.5 & micro;Svh-1 (af ter 5 min ute cool ing) -15 times the con ven tional limit (2.5 & micro;Svh-1). Af ter 30 years of op er a tion and one month of shut down, the ac tiv ity of 55Fe ex ceeds the ex emp tion limit by a fac tor of 42.1. This study pro vides key guid ance for ra di a tion shield ing de sign, waste man age ment, and clin i cal pro to col op ti mi za tion for ad vanced ra dio ther apy fa cil i ties.
The aim of this work was to es ti mate the eye lens dose equiv a lent at a depth of 3 mm and to eval u ate the ef fec tive ness of shield ing for ra di a tion work ers in nu clear med i cine us ing Monte Carlo sim u la tion with the Monte Carlo N-Par ti cle trans port code, ver sion 5. Pub lished air kerma rate con stants were used to val i date the sim u la tion code for com monly used radionuclides in nu clear med i cine, in clud ing 18F, 99mTc, and 131I. Eye lens dose rates with com mer cially avail able sy ringe shields and vial shields were sim u lated us ing the Monte Carlo N-Par ti cle code with the Pos ture, In di vid ual, and Med i cal Ap pli ca tion Lab o ra tory phan tom. Shielded and un shielded eye lens dose rates based on com mer cially avail able source data were sim u lated for com mon radionuclides at var i ous dis tances. The max i mum num ber of pro ce dures was also es ti mated based on the eye lens dose limit rec om mended by the In ter na tional Com mis sion on Ra dio log i cal Pro tec tion pub li ca tion 118. The sim u lated dose rates may be used to eval u ate ra di a tion safety con sid er ations for work ers in nu clear med i cine. Ap pro pri ate shield ing and eye lens mon i tor ing are par tic u larly rec om mended for pos i tron-emit ting 18F and high-ac tiv ity 131I pro ce dures.
This study investigates the radioactivity concentrations in contaminated soil samples, comprising TENORM-contaminated soil from an oilfield and artificially contaminated soil containing Cs-137. The primary objective was to examine the correlation between soil grain size distribution and radionuclide concentrations within these samples. Radioactivity measure-ments were conducted using a broad-energy HPGe gamma-spectroscopy system with 50 % relative efficiency. Both soil samples were systematically fractionated into seven distinct size categories through mechanical sieving, ranging from <37 & micro;m (400 mesh) to >900 & micro;m (20 mesh) in diameter. Results demonstrate that radionuclide activity concentrations in TENORM samples exhibit significant variation across particle size fractions, with the excep-tion of 40K. The highest activity concentrations were consistently observed in the finest parti-cle fraction (<= 37.5 & micro;m). Similarly, Cs-137 activity in the artificially contaminated soil exhibits fraction-dependent distribution, with peak concentrations in particles <= 63 & micro;m. Statistical analysis revealed strong reverse correlations between particle size and radionuclide concentration: correlation coefficients of r = -0.647 and r = -0.710 were obtained for Ra-228 and 226Ra, respectively (p-value <= 0.008 andp <= 0.04), while 137Cs demonstrated an even stronger reverse correlation (r = -0.930, p <= 0.02). These findings provide essential guidance for ad-vancing targeted soil remediation strategies and optimizing mechanical separation techniques at radioactively contaminated sites, with direct implications for radiation protection practices and environmental risk assessment.
Breast cancer, the most common malignancy in women, accounts for 36 % of cancer cases, with its incidence rising, and ionizing radiation is one of the contributing risk factors. This study aimed to: investigate the link between breast cancer and ionizing radiation through in silico analysis, map the adverse outcome pathway connecting ionizing radiation to breast cancer, and propose additional key events to refine and enhance the adverse outcome pathway. The following publicly available databases, software, and tools were used: Comparative Toxicogenomics Database, ToppGene Suite, GeneMANIA server, and Metascape. Twenty identified genomic biomarkers (ATM, BARD1, BRCA1, BRCA2, CHEK2, E2F1, FBL, H2AX, HRAS, MDM2, RAD51, SIRT1, SNAI2, SFRP1, SFRP2, TANK, TP53, TRP53, TP53BP1, YAPI) were predominantly in physical interactions (57.48 %), or belonged to the same pathway (19.99 %), contributing to molecular functions associated with regulating cellular responses to DNA damage, dou-ble-strand break repair, and DNA integrity checkpoint signaling. These biomarkers exhibit bind-ing capabilities to molecules such as p53, ubiquitin, transcription factors, and chromatin. These findings, combined with the existing breast cancer-ionizing radiation, provide a foundation for future research on ionizing radiation's molecular impact on breast cancer development, with biomarkers supporting early detection and prognosis.
Paediatric interventional cardiology procedures guided by fluoroscopy imaging can impart sub stantial radiation doses, making dose optimisation essential for younger patients. This study aims to establish the first national diagnostic reference levels for common paediatric anal y sis was per formed of 196 pro ce dures in pa tients youn ger than 16 years and weigh ing less than 80 kg, con ducted over 12 months in three Par a guayan hos pi tals. Kerma-area prod uct, Pka, and cu mu la tive air kerma at the pa tient en trance ref er ence point, Ka,r, were ex tracted from sys tem dose re ports. Di ag nos tic ref er ence lev els were de fined as the 75thper cen tile ofPka and Ka,r, strat i fied by rec om mended age and weight groups. The Pka val ues in creased from 4.2-35.8 Gycm2 across age bands and from 4.3-49.8 Gycm2 across weight bands. Cor re sponding Ka,r 75th per cen tile val ues ranged from 83.9-456.1 mGy by age and from 87.7-530.0 mGy by weight. For the most fre quent pro ce dures, Pka 75th percentile values were 8.0-10.2 Gycm2. These na tional val ues were con sis tent with pre vi ously re ported Latin Amer i can data. These val ues pro vide a ba sis for op ti mi sa tion, qual ity as sur ance and re gional com par ison in paediatric interventional cardiology in Paraguay.
This study introduces the process and methodology for determining residual radioactive lev-els in soil at a decommissioned nuclear facility site. Drawing on current research into decom-missioned sites both domestically and internationally, this study reviews the approaches adopted by the International Atomic Energy Agency, the USA, and China for defining de-commissioning end-state targets and establishing dose constraint values. A source investiga-tion of soil pollution was first conducted to identify the types and quantify the activity con-centrations of key pollutants. Subsequently, the radiological assessment defined decommissioning goals and dose constraints, identified exposure pathways and key parame-ters under open, unrestricted land-use scenarios, and developed an assessment model to cal-culate the effective dose using a forward calculation approach. By using the open-limit con-version method for reverse calculation, the residual radioactive level of the decommissioned final soil is ultimately determined. The allowable residual activity concentration values for three nuclides were calculated. The allowable residual activity concentration value for 60Co was 1.9 & centerdot;102 Bgkg-1, the allowable residual activity concentration value for 137Cs was 8.4 & centerdot;102 Bgkg-1, and the allowable residual activity concentration value for 90Sr was 1.1 & centerdot;105Bgkg-1. The final determination of the allowable residual activity concentration values for the three nuclides will provide a basis for implementing, supervising, and accepting decommissioned engineering projects.
This study systematically investigates the thermoluminescent properties of K2GdF5:Tb phos-phor, with an emphasis on determining and comparing kinetic parameters relevant to radia-tion dosimetry. Thermoluminescence glow curves obtained after X-ray irradiation at effective photon energies of 33.3 keV, 65.2 keV, and 100 keV and after mixed neutron-gamma irradia-tion from a 241Am-Be source were analyzed using the initial rise, peak shape, and area peak methods in combination with several kinetic models, including first-order, second-order, general-order, mixed-order, and one-trap-one-recombination-center models. Reference glow curves were employed to verify the stability and reliability of the applied analysis procedures. Experimental results showed that X-ray irradiated K2GdF5:Tb exhibits a single dominant glow peak at approximately 482-484 K, with activation energies in the range of 0.60-0.77 eV. In contrast, mixed neutron-gamma irradiation leads to two partially overlap-ping glow peaks, characterized by lower activation energies in the range of 0.10-0.38 eV, indi-cating the presence of shallow and intermediate trapping components. The extracted kinetic parameters exhibited good consistency within experimental uncertainties and were associated with low figure-of-merit values, thereby confirming the reliability of the applied analysis methods. These results provide provide a deeper understanding of the distinct trapping mechanisms induced by photon and neutron interactions and demonstrate the potential of K2GdF5:Tb for radiation dosimetry applications under X-ray and mixed neutron-gamma fields.
This study investigates the mass stopping power of electrons in various human tissues, includ-ing skin, bone, blood, adipose tissue, soft tissue, eye lens, lungs, breast glands, cartilage, and lymph nodes. Collisional stopping power was calculated using a modified Bethe-Bloch for-mula, while the radiative component was obtained analytically. Calculations were performed for electron energies ranging from 0.01 MeV to 100 MeV. Maximum stopping power values were observed at 0.01 MeV, ranging from 19.986 MeVcm2g-1 in bone to 23.546 MeVcm2g-1 in adipose tissue, while the lowest values occurred at 1 MeV. Results were compared with ESTAR and ICRU databases, showing overall agreement. In the radiotherapy-relevant range, differences in total stopping power reached up to 13.45 % for blood at 20 MeV. These results confirm the reliability of the applied model and provide useful data for applications in medical physics and dosimetry.
Lead aprons are es sen tial for per sonal pro tec tive equip ment used in lab o ra tory en vi ron ments to pro tect work ers from harm ful ra di a tion ex po sure. A lead apron con tains ma te ri als meant to at ten u ate ra di a tion by scat ter ing and ab sorp tion dur ing safety in volv ing di ag nos tic and ther a peu tic ra di a tion pro ce dures. How ever, en sur ing con sis tent lead apron us age pres ents chal lenges be cause many fa cil i ties rely on man ual ob ser va tion and self-re port ing meth ods es pe cially in busy en vi ron ments where con tin u ous mon i tor ing is dif fi cult to main tain. Man ual mon i tor ing of ten fails to pro vide cov er age and doc u men ta tion. There fore, the convolutional neu ral net work method is used to de tect lead apron and pro vide ef fi cient mon i tor ing sys tems that help to en sure with ra di a tion pro tec tion. This re search uses a convolutional neu ral net work model ap proach de signed for small dataset sce nar ios. Lead apron de tec tion in volves bi nary clas si fi ca tion with two cat e go ries such as with apron and with out apron sce nar ios. The dataset com prises 295 grayscale im ages pro cessed at 150 >< 150 pixel res o lu tion and an no tated for bi nary clas si fi ca tion. From the test re sult, the model achieved per for mance with a pre ci sion value of 97 %, re call value of 97 %, and F1-score value of 97 %. The model achiev ing good 95.7 % for lead apron de tec tion and pre ci sion score 98.5 % for with out apron de tec tion sce nar ios.
Elemental analysis and health risk index assessment of leafy vegetables in Hanoi, Vietnam, were conducted using X-ray fluorescence. The identified elements were classified into three groups based on their concentrations: macronutrients (K, Ca, Mg, P, S) with high levels, mesonutrients (Cl, Si, Al), and micronutrients (Fe, Mn, Zn, Cu, Br). Principal component analysis of the elemental concentrations grouped the vegetables into three clusters corre-sponding to their botanical families and distinctive accumulation patterns: Group 1 (Amaranthaceae and Basellaceae) with elevated macronutrient levels, Group 2 (Asteraceae) with preferential micronutrient accumulation, and Group 3 (Brassicaceae) with pronounced accumulation of both nutrients and heavy metals. A close relationship was observed between macronutrients and micronutrients, demonstrating their synergistic roles in regulating plant growth and physiological processes. The calculated health risk indices remained within safe limits (HI<1), indicating no potential health risks exist for consumers.
Physical encryption has long been a focus of research in nuclear material verification due to its ability to protect sensitive technical information. However, enhancing its robustness and re-sistance to cracking remains a significant challenge. This study employs neutron activation analysis with a custom-designed neutron source (low-energy mean: 0.0273 eV, high-energy: 0.12 MeV) to irradiate items and extract their characteristic gamma-ray spectra. For physical encryption, a liquid metal mask is applied to systematically distort this sensitive information before gamma-ray detection. The authenticity of the treaty item can be verified by comparing its characteristic gamma-ray fingerprints with those of the reference item. Simulations of sev-eral representative fraudulent items were conducted using the Geant4 toolkit to assess the ro-bustness and security of the method. In the presence of white noise within 3 % level, the areas under the receiver operating characteristic curves are all above 0.94. Furthermore, when the threshold of real sample differences is set to T = 150, the probability of successfully cracking the liquid metal mask is found to beP approximate to 1.57.10-16. The proposed method enables the tracking and monitoring of nuclear materials while ensuring the protection of sensitive information.
