Klemen Ambrožič, Gašper Žerovnik, Dieter Leichtle
et al.
We present a computational sensitivity and uncertainty analysis of the effect of geometrical uncertainties on the measured reaction rates in the Water Cooled Lithium Lead experimental benchmark, which is a mock-up of a tritium breeding blanket for the future DEMO fusion facility. We used deterministic transport methods to determine the sensitivity of various parts of the geometry and Monte Carlo particle transport methods along with random sampling from geometrical uncertainties, to assess the expected uncertainty and sensitivity profiles, particularly to establish whether tritium self-sufficiency can be achieved within the uncertainty. We have established that most sensitive parts of the geometry are the source position and orientation, as well as the target detector pack position. We have established the uncertainty to be in the range of 8% to 25%, increasing with the distance from the source. We have also established the sensitivity to the displacement of the target detector pack to be roughly 5%mm-1, while the sensitivity to the perturbation of position of other detector packs and source position and orientation is generally below the 1%mm-1.
ZHENG Yulai, WANG Guobao, LI Yong, ZHAO Jiangbin, LIU Yang, LIU Chao, WANG Qiang, HE Gaokui
As a critical means of preventing illicit nuclear material trafficking and nuclear terrorism, nuclear security detection technology has undergone a leapfrog development from traditional radiation monitoring to intelligent multimodal detection. The current technological system, centered on dual-energy X-ray imaging, neutron element analysis, forms a comprehensive protection network covering material identification, behavior monitoring, and data security. This article provides a comprehensive review of the application and development of nuclear detection technology at the China Institute of Atomic Energy in the field of nuclear security. It first elaborates on the developmental trajectory of nuclear detection technology, with a focus on innovative applications by the China Institute of Atomic Energy in nuclear security. It then analyzes the current state of technological advancement and the challenges faced, and finally prospects future trends in intelligence, high sensitivity, and multimodal integration, emphasizing the pivotal role of nuclear detection technology in advancing nuclear security.
Abrrar Abbas Ibrahim, Abdalsattar K. Hashim, Ali Abid Abojassim
GIS ''Geographic Information System'' technology was used to map the specific activity (S.A.) of primordial radionuclides 238U, 232Th, and 40K in selected soil samples for twelve locations at the University of Kufa, Iraq. S.A. values were determined using gamma spectrometry type NaI(Tl) with volume “3 × 3”. Also, the values of radiological parameters such as Raeq ''radium equivalent'', Hex ''external hazard index'', Iγr ''representative gamma risk index'', Dr ''Absorbed Dose rate'', AEDEoutdoor ''Annual Effective Dose Equivalent in outdoor'', and ELCR ''Excess Lifetime Cancer Risk'' were determined. The average value of S.A. for 238U, 232Th, and 40K was 10.35 ± 0.9 Bq/kg, 7.31 ± 1.8 Bq/kg, and 256.19 ± 55.7 Bq/kg, respectively. While, the average values of Raeq (Bq/kg), Hex, Iγr, Dr (nGy/h), AEDEoutdoor (mSv/y), and ELCR were 48.00, 0.130, 0.373, 23.70, 0.029, and 0.102 × 10−3, respectively. The results of S.A. and each radiological parameter of the study area locations were low according to acceptable level reports by UNSCEAR, ICRP, and OCDE. Therefore, it can be concluded that the soil samples of the University of Kufa were safe.
Objective: This systematic review aims to explore the role of MRI-based radiomics combined with machine learning (ML) algorithms in accurately diagnosing and classifying breast cancer subtypes. It emphasizes the performance of advanced ML models, especially deep learning (DL), in comparison with traditional methods like Support Vector Machines (SVM) and Random Forests. The study focuses on how these models improve diagnostic accuracy for subtypes such as Luminal A/B, HER2-enriched, and Triple-Negative Breast Cancer (TNBC). Methods: A comprehensive search was conducted on October 11, 2024, using PubMed, Scopus, and Web of Science with the keywords “MRI AND Radiomics AND breast cancer.” Only peer-reviewed articles in English were included. Citation tracking via PubMed and Google Scholar ensured complete coverage. Studies involving breast cancer patients, using MRI radiomics (e.g., DCE-MRI, DWI) for subtype classification, and applying supervised ML models were selected. Data from 42 eligible studies were extracted, including radiomic features (texture, shape) and performance metrics (accuracy, sensitivity, AUC). Statistical analysis was conducted with Python libraries, focusing on pooled performance metrics and model generalizability. Results: The review reveals that DL models perform better than traditional ML approaches, particularly in identifying aggressive subtypes like TNBC, achieving an AUC of 0.93 compared to 0.85 for SVM. Texture features emerged as the most significant predictors, contributing 40% to the overall accuracy of the models. Across all subtypes, DL consistently outperformed traditional methods, showing higher accuracy, sensitivity, and specificity. Using multiple MRI sequences further enhanced model performance. Conclusion: This review demonstrates that combining MRI-based radiomics with ML can greatly enhance non-invasive breast cancer diagnosis. DL models, with their ability to capture complex tumor characteristics, offer the most potential for clinical use. However, challenges such as the need for standardized MRI protocols and the limited interpretability of some models must be addressed before these tools can be widely adopted. Future research should focus on large, multicenter studies and the integration of radiomic, genomic, and clinical data to develop more comprehensive precision oncology solutions.
Medical physics. Medical radiology. Nuclear medicine, Nuclear engineering. Atomic power
Anna Liski, Marianna Kemell, Tomi Vuoriheimo
et al.
The refractory high entropy alloy, WMoTaNbV, absorbs significant quantities of H directly from the atmosphere. The effective hydrogen absorption has been attributed to the elemental composition of the alloy as well as its highly elaborate lattice structure. In this work, we apply scanning electron microscopy and ion beam analysis tools to investigate the effect of grain size and morphology on hydrogen storage, observing a consistency between the microstructure of WMoTaNbV alloy and hydrogen absorption.
William Chuirazzi, Jayson Bush, Brian Gross
et al.
Nondestructive post-irradiation examination of nuclear fuels and materials is useful in collecting data to inform commercial licensing of new nuclear concepts. This work details the planning, shielding design, and workflow of an X-ray computed tomography examination of an irradiated AGR-5/6/7 tristructural isotropic fuel compact with a dose rate of 1318 R/h on contact from both β and ɤ-ray radiation with 120 R/h of the dose rate coming exclusively from ɤ-rays. Rather than waiting for radioactive decay to reduce the dose rate from the sample, careful implementation of specially developed shielding and work controls enabled some examinations of the irradiated fuel in a timelier manner, which benefits the ongoing qualification and commercialization cases for this fuel by reducing the timeline from irradiated to examination. This timeframe reduction is important as data from these experiments can be more quickly available to inform modeling efforts and subsequent experiments. While this work represents the hottest radiological sample that has been openly transported and examined at Idaho National Laboratory's Irradiated Materials Characterization Laboratory to date, it is anticipated that this work and its lessons learned will facilitate future examinations of similar or even more radioactive specimens.
Mahmoud H. AbuEmira, Khaled ElShahat, Ghada A. Khouqeer
et al.
Background: Pancreatic cancer is a devastating disease with a poor prognosis, and radiation therapy plays a crucial role in its treatment and management. Conventional radiation therapy (RT) techniques have limitations in delivering adequate doses to the tumor while sparing surrounding normal tissues. However, modern RT techniques such as intensity-modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic body radiation therapy (SBRT) have led to the development of novel approaches that can reduce toxicity. The incorporation of advanced imaging modalities, like four-dimensional computed tomography (4D-CT) and magnetic resonance imaging (MRI), enables enhancement of tumor control and improves conformality and treatment outcomes. Additionally, using flattening filter-free (FFF) beams can further enhance treatment efficiency and efficacy. Purpose: This study aims to compare two different VMAT techniques using two different treatment planning systems (TPSs), Monaco and Eclipse, in the treatment of pancreatic cancer II stage infiltrating duct carcinoma patients using an FFF photon beam. Materials and methods: 20 pancreatic cancer II stage infiltrating duct carcinoma patients were retrospectively analyzed, and each patient's plans were designed using the two TPSs. The dose distribution of the target using 6 MV FFF for TrueBeam-Varian and organs at risk (OARs) were compared. The monitor unit (MU), treatment time, conformity (CI), and homogeneity (HI) indices were also evaluated. Results: For pancreatic cancer patients, the mean dose of the planning target volume (PTV) in the Monaco plan was lower than the Eclipse plan. The plan evaluation parameters in Monaco and Eclipse were similar without significant differences (p-value = 0.152). The Monaco plan was better than the Eclipse plan regarding mean dose and V15Gy of the kidneys; the spinal cord was lowest in the Monaco plan, and the maximum dose and V45Gy of the spinal cord were 592.1 cGy and 1.37% lower than the Eclipse plan, respectively. Conclusion: The VMAT Monaco plan is a favorable TPS for pancreatic cancer patients, providing improved sparing of critical organs while maintaining adequate target coverage.
Medical physics. Medical radiology. Nuclear medicine, Nuclear engineering. Atomic power
This paper presents a seismic analysis method that can evaluate a very large number of cases for the free standing dry storage cask by proposing a methodology that has short analysis time as well as accuracy. This study also performed a seismic analysis of a dry storage facility with multiple casks to show a tip-over phenomenon from earthquake accident conditions. The earthquake accident condition is long-term event that occur during about 20 s long, and lots of seismic analysis cases should be performed to consider various real conditions because the free-standing spent-fuel dry storage cask has many nonlinear responses. The soil–concrete pad–cask interaction was considered in the seismic analysis and finite element model was made using concrete pad, soil and cask models. In the reinforced concrete pad, the rebar was excluded to reduce the analysis time, but the thickness was corrected to maintain the bending rigidity. Additionally, the analysis time reduced by modeling the cask as a rigid body rather than a flexible body. 35-cases of seismic analysis were performed to determine a tip-over phenomenon from each earthquake. The analysis revealed that no tip-over phenomenon of the cask was observed in all analyses from 0.2 g to 0.6 g, however the tip-over of the cask were observed from 0.8 g with friction coefficients of 0.8 and 1.0.
Yuxuan Zhang, Kristian G. Myhre, Hassina Z. Bilheux
et al.
Attenuation-based neutron computed tomography (CT) has been used to non-destructively characterize the uncoated tristructural-isotropic (TRISO) nuclear fuel kernels in this work. Particularly, the effect of two different types of carbon blacks (Raven 3500 and Mogul L) on the internal gelation process of UO3-C kernels has been investigated. With 3D reconstructed kernel volumes and digital imaging processing techniques, heterogenous density distributions are mapped in both types of kernels. It is found that the kernels produced with Mogul L are ∼ 20 % denser and ∼ 10 % larger (in equivalent diameter) than the Raven 3500 kernels. Furthermore, less neutron attenuating regions, which are most likely to be carbon agglomerates as scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) results show, are observed in the Mogul L kernels. The size distribution of such carbon agglomerates (ranges from 50 μm to 850 μm with a peak at ∼ 200 μm) has been determined by analyzing the CT data. Furthermore, multiple metrics, including equivalent diameter, surface area, volume, sphericity, have been extracted to evaluate the fuel kernels. This work demonstrates that neutron imaging is an excellent, nondestructive tool to efficiently characterize, understand, and explore fuel materials for nuclear material research and development.
A method for calibrating the energy scale and detection efficiency of stilbene scintillators is presented herein. This method can be used to quantitatively analyze the Compton continuum of gamma-ray spectra obtained using such scintillators. First, channel–energy calibration was conducted by fitting a semiempirical equation for the Compton continuum to the acquired energy spectrum and a new method to evaluate the intrinsic detection efficiency, called intrinsic Compton efficiency, of stilbene scintillators was proposed. The validity of this method was verified by changing experimental conditions such as the number of sources being measured simultaneously and the detector–source distance. According to the energy calibration, the standard error for the estimated Compton edge position was ±1.56 keV. The comparison of the intrinsic Compton efficiencies calculated from the single- and two-source spectra showed that the mean absolute difference and the mean absolute percentage difference are 0.031 %p and 0.557%, respectively, demonstrating reasonable accuracy of this method. The feasibility of the method was confirmed for an energy range of 0.5–1.5 MeV, showing that stilbene scintillators can be used to quantitatively analyze gamma rays in mixed-radiation fields.
RAST-F is a new full-core analysis code based on the two-step approach that couples a multi-group cross-section generation Monte-Carlo code MCS and a multi-group nodal diffusion solver. To demonstrate the feasibility of using MCS/RAST-F for fast reactor analysis, this paper presents the coupled nodal code verification results for the MET-1000 and CAR-3600 benchmark cores. Three different multi-group cross-section calculation schemes are employed to improve the agreement between the nodal and reference solutions. The reference solution is obtained by the MCS code using continuous-energy nuclear data. Additionally, the MCS/RAST-F nodal solution is verified with results based on cross-section generated by collision probability code TULIP. A good agreement between MCS/RAST-F and reference solution is observed with less than 120 pcm discrepancy in keff and less than 1.2% root-mean-square error in power distribution. This study confirms the two-step approach MCS/RAST-F as a reliable tool for the three-dimensional simulation of reactor cores with fast spectrum.
Dewi Nur Riskiana, Anis Rohanda, R Farzand Abdullatif
ESTIMASI PANAS GAMMA PADA PRODUKSI RADIOISOTOP Lu-177, Ir-192, DAN Au-198 DI TERAS MOLIBDENUM RSG-GAS. Panas gamma (Gamma heating) merupakan isu penting terkait keselamatan fasilitas iradiasi suatu reaktor dan sampel iradiasinya. Panas gamma dihasilkan dari interaksi energi gamma dengan material target. Energi gamma yang dihasilkan dari reaktor memiliki karakteristik energi gamma yang berbeda yang salah satunya dipengaruhi oleh jenis bahan bakar (jenis teras). Uranium molibdenum (UMo) merupakan bahan bakar masa depan yang memiliki beberapa keunggulan dibandingkan uranium oksida (UO2) dan silisida (USi) salah satunya dapat meningkatkan operasi reaktor. Untuk itu dilakukan studi komputasi panas gamma RSG-GAS dengan bahan bakar UMo pada beberapa proses produksi radioisotop seperti radioisotop Lu-177, Ir-192, dan Au-198. Penelitian ini menggunakan code ORIGEN untuk menghitung energi gamma yang dihasilkan untuk jenis bahan bakar UMo. Estimasi panas gamma menggunakan program Gamset, suatu program didesain dan sudah teruji untuk menghitung panas gamma di RSG-GAS. Hasil perhitungan panas gamma berbahan bakar UMo di RSG-GAS dalam kisaran 4,85 W/g ~ 8,69 W/g . Hasil ini lebih kecil dibandingkan dengan panas gamma pada uranium silisida (USi) yaitu sekitar 9,27 W/g ~ 13,3 W/g. Radioisotop Lu-177 memiliki panas gamma terbesar sekitar 8,69 W/g, yang diikuti oleh Au-198 dan Ir-192 yang masing-masing sebesar 5,89 W/g dan 7,12 W/g. Panas gamma pada ketiga radioisotop yang diproduksi oleh RSG-GAS berbahan bakar UMo tidak melebihi panas gamma maksimum (20 W/g) yang telah ditentukan sehingga dapat diartikan aman untuk reaktor dan sampel.
Kata kunci: Panas gamma, UMo, RSG-GAS, radioisotop
I. I. Lebedev, D. E. Zolotykh, A. G. Naymushin
et al.
The IRT-T reactor has been conducting research in the field of irradiation of ingots of single-crystal semiconductor materials since 1987. The article describes the existing silicon doping facility. The results of studies on the possibility of creating an additional irradiation channel for neutron-transmutation doping of silicon are presented. It is shown that the use of a graphite reflector and a thermal neutron filter based on boron makes it possible to achieve non-uniformity of irradiation up to 5 %. The principal possibility of irradiating single-crystal silicon ingots with a diameter of up to 203 mm and a length of up to 500 mm is shown. The questions of optimizing the configuration of the core and the regime of reactors operation for increasing the neutron flux in the irradiation channels are discussed. In addition, applying the facility to produce base materials for neutron dosimeter in neutron capture therapy studies is proposed.
An additional low temperature overpressure protection system which relies on the Pressurizer (PRZ) pressure relief valves has been put forward under the situation in which the Residual Heat Removal System (RHRS) is unavailable or isolated. Taking into account the risk of Reactor Pressure Vessel (RPV) brittle fracture and LOCA under cold overpressurization transients, it is urgent to strengthen the low temperature overpressure protection for in-service Pressurized Water Reactors (PWR) in China. In this paper, the simulation and analysis of two types of overpressure transients at low temperature during the shutdown process are carried out through the detailed Relap5 modeling of CPR1000. The results show that the place where the brittle fracture occurs firstly is the lower plenum. The sensitivities of the system temperature and the opening/closing time of the additional protection system's valve are analyzed. The system set point becomes more restrictive at lower coolant temperature. Additional threshold values of the PRZ pressure relief valve are given under different Effective Full Power Years (EFPY). The set point should be less than 5.5 MPa in the case of 5 EFPY and less than 3.7 MPa at 10 EFPY.The results can be applied to engineering practice, which can effectively improve the safety of CPR1000.