Pub Date : 2026-05-01Epub Date: 2026-01-17DOI: 10.1016/j.net.2026.104136
Luis A. Montejo
While matching input motions to a design response spectrum (DRS) is standard practice, the US-NRC Standard Review Plan (SRP) 3.7.1 also mandates a minimum power spectral density (PSD) check to prevent power deficiencies that can lead to unconservative in-structure response spectra (ISRS). However, existing methodologies for constructing the required target PSD functions are designed for single-component analysis and do not accommodate the modern orientation-independent spectra (e.g., RotDnn) toward which bidirectional analysis is moving. This article addresses this gap by introducing an iterative algorithm to generate duration-dependent, orientation-independent PSD and Fourier Amplitude Spectra (FAS) functions compatible with any target RotDnn spectrum. The algorithm iteratively adjusts the target FAS of two orthogonal components until their combined RotDnn response spectrum provides a close match to the target DRS, from which a large set of synthetic motions is generated to define the final orientation-independent target spectra. The accuracy and robustness of the proposed methodology is demonstrated by successfully reproducing the FASRotD100 and PSDRotD100 from a benchmark dataset of 50 historical earthquake records, providing an essential tool for reliable seismic assessments consistent with modern hazard definitions.
{"title":"Generation of Fourier amplitude spectra and power spectral density functions compatible with orientation-independent design spectra for bidirectional seismic analyses of nuclear facilities","authors":"Luis A. Montejo","doi":"10.1016/j.net.2026.104136","DOIUrl":"10.1016/j.net.2026.104136","url":null,"abstract":"<div><div>While matching input motions to a design response spectrum (DRS) is standard practice, the US-NRC Standard Review Plan (SRP) 3.7.1 also mandates a minimum power spectral density (PSD) check to prevent power deficiencies that can lead to unconservative in-structure response spectra (ISRS). However, existing methodologies for constructing the required target PSD functions are designed for single-component analysis and do not accommodate the modern orientation-independent spectra (e.g., RotDnn) toward which bidirectional analysis is moving. This article addresses this gap by introducing an iterative algorithm to generate duration-dependent, orientation-independent PSD and Fourier Amplitude Spectra (FAS) functions compatible with any target RotDnn spectrum. The algorithm iteratively adjusts the target FAS of two orthogonal components until their combined RotDnn response spectrum provides a close match to the target DRS, from which a large set of synthetic motions is generated to define the final orientation-independent target spectra. The accuracy and robustness of the proposed methodology is demonstrated by successfully reproducing the FASRotD100 and PSDRotD100 from a benchmark dataset of 50 historical earthquake records, providing an essential tool for reliable seismic assessments consistent with modern hazard definitions.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 5","pages":"Article 104136"},"PeriodicalIF":2.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2025-12-30DOI: 10.1016/j.net.2025.104111
Sung-Jun Lim , Sung-Hun Jo
This paper proposes a voltage-booster read-decoupled radiation-hardened 14T (BDRH14T) SRAM cell. In harsh environments such as space, radiation can flip the stored data in memory cells, resulting in soft errors, including single-event upset (SEU) and single-event multi-node upset (SEMNU). Moreover, with the continued scaling of CMOS technology, the reduced spacing between transistors lowers the critical charge, increasing the vulnerability of SRAM cells to radiation-induced faults. The proposed BDRH14T cell is designed to recover its original stored data at all sensitive nodes even under a high injected charge of 150 fC. Additionally, it is capable of self-recovery from SEMNU occurring at storage node pairs. In addition to its radiation hardness, the BDRH14T exhibits enhanced read stability and reduced power consumption, achieving high read static noise margin (RSNM) and hold static noise margin (HSNM), along with low hold power (HPWR). All simulations were conducted using a 90 nm CMOS technology, considering variations over a wide range of supply voltages (0.9–1.1 V) and temperatures (−30 °C–120 °C). The superior performance of BDRH14T is attributed to the adoption of a voltage booster, a read-decoupled architecture, and deliberate a trade-off in read and write access times (RAT and WAT).
{"title":"A multi-node-upset-resilient 14T SRAM with high read stability for space applications","authors":"Sung-Jun Lim , Sung-Hun Jo","doi":"10.1016/j.net.2025.104111","DOIUrl":"10.1016/j.net.2025.104111","url":null,"abstract":"<div><div>This paper proposes a voltage-booster read-decoupled radiation-hardened 14T (BDRH14T) SRAM cell. In harsh environments such as space, radiation can flip the stored data in memory cells, resulting in soft errors, including single-event upset (SEU) and single-event multi-node upset (SEMNU). Moreover, with the continued scaling of CMOS technology, the reduced spacing between transistors lowers the critical charge, increasing the vulnerability of SRAM cells to radiation-induced faults. The proposed BDRH14T cell is designed to recover its original stored data at all sensitive nodes even under a high injected charge of 150 fC. Additionally, it is capable of self-recovery from SEMNU occurring at storage node pairs. In addition to its radiation hardness, the BDRH14T exhibits enhanced read stability and reduced power consumption, achieving high read static noise margin (RSNM) and hold static noise margin (HSNM), along with low hold power (HPWR). All simulations were conducted using a 90 nm CMOS technology, considering variations over a wide range of supply voltages (0.9–1.1 V) and temperatures (−30 °C–120 °C). The superior performance of BDRH14T is attributed to the adoption of a voltage booster, a read-decoupled architecture, and deliberate a trade-off in read and write access times (RAT and WAT).</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 5","pages":"Article 104111"},"PeriodicalIF":2.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-09DOI: 10.1016/j.net.2026.104128
Susana Petisco-Ferrero , Raquel Idoeta , Ander Nafarrate , Saroa Rozas , Jon Sáenz , Alain Ulazia , Gabriel Ibarra-Berastegui
This study analysed the weekly 210Pb and 40K concentrations from four Spanish laboratories located in urban areas recorded during the period of 2006–2022. The application of cluster analysis allowed the identification of two distinct clusters: one with lower values and the other with higher values. In the second stage, the wind and accumulated precipitation data were analysed for both clusters. The results indicated that accumulated precipitation was the main driving mechanism responsible for the observed weekly concentration patterns. The recorded precipitation in low-concentration clusters, was typically twice that of high-concentration weeks.
{"title":"Cluster analysis of weekly 210Pb and 40K concentrations and cumulative meteorological effects in urban Spain (2006–2022)","authors":"Susana Petisco-Ferrero , Raquel Idoeta , Ander Nafarrate , Saroa Rozas , Jon Sáenz , Alain Ulazia , Gabriel Ibarra-Berastegui","doi":"10.1016/j.net.2026.104128","DOIUrl":"10.1016/j.net.2026.104128","url":null,"abstract":"<div><div>This study analysed the weekly <sup>210</sup>Pb and <sup>40</sup>K concentrations from four Spanish laboratories located in urban areas recorded during the period of 2006–2022. The application of cluster analysis allowed the identification of two distinct clusters: one with lower values and the other with higher values. In the second stage, the wind and accumulated precipitation data were analysed for both clusters. The results indicated that accumulated precipitation was the main driving mechanism responsible for the observed weekly concentration patterns. The recorded precipitation in low-concentration clusters, was typically twice that of high-concentration weeks.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 5","pages":"Article 104128"},"PeriodicalIF":2.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-29DOI: 10.1016/j.net.2026.104165
Gehad M. Saleh , Basma A. El-Badry , Mabrouk Sami , Tamader Alhazani , Omnia T. Amer , Ioan V. Sanislav , El Saeed R. Lasheen
The present research aims to evaluate the radiation dosages in the Magal Gebreel granitic phases, which encompass monzogranites, alkali feldspar granites, and altered granites (widely exposed along the shear zone). The former rocks have an average of 89.28 ± 23.85 Bqkg−1 for 238U, 51.71 ± 9.65 Bqkg−1 for 232Th, and 995.34 ± 160.21 Bqkg−1 for 40K utilizing the NaI (Tl) analyzer. Alkali feldspar granites have an average of 146.32 ± 46.73 Bqkg−1 for 238U, 77.57 ± 11.21 Bqkg−1 for 232Th, and 1120.54 ± 26 Bqkg−1 for 40K. The later (altered granites) have the highest activity concentrations of 232Th (avg. 360.57 ± 58.02 Bqkg−1), 40K (avg. 1197.23 ± 106.53 Bqkg−1), and 238U (avg. 3797.50 ± 725.68 Bqkg−1), as well as their summation (avg. 2201.60 ± 250.62 Bqkg−1). It is obvious that the investigated rocks contain increased activity concentrations and therefore fall above the widely accepted worldwide requirements. The results of microscopic and ESEM analysis revealed large assemblages of significant minerals enclosed in the Magal Gebreel rocks such as precious, base metals, accessories, radioactive-bearing, REE-bearing, and Nb-Ta- bearing minerals. Radium equivalent, dose of human body, absorbed dose rate and annualized dosage, excess life-time cancer, coupled with extra radiological characteristics were inferred for these rocks. Given that the measures of most of these criteria are higher than the international average, it is distinct that the tested rocks (certainly altered granites) have a considerable effect on the natural gamma emission released.
{"title":"Mineralization and radioactive potential of Magal Gebreel rocks, South Eastern Desert, Egypt: Health risk evaluation","authors":"Gehad M. Saleh , Basma A. El-Badry , Mabrouk Sami , Tamader Alhazani , Omnia T. Amer , Ioan V. Sanislav , El Saeed R. Lasheen","doi":"10.1016/j.net.2026.104165","DOIUrl":"10.1016/j.net.2026.104165","url":null,"abstract":"<div><div>The present research aims to evaluate the radiation dosages in the Magal Gebreel granitic phases, which encompass monzogranites, alkali feldspar granites, and altered granites (widely exposed along the shear zone). The former rocks have an average of 89.28 ± 23.85 Bqkg<sup>−1</sup> for <sup>238</sup>U, 51.71 ± 9.65 Bqkg<sup>−1</sup> for <sup>232</sup>Th, and 995.34 ± 160.21 Bqkg<sup>−1</sup> for 40K utilizing the NaI (Tl) analyzer. Alkali feldspar granites have an average of 146.32 ± 46.73 Bqkg<sup>−1</sup> for <sup>238</sup>U, 77.57 ± 11.21 Bqkg<sup>−1</sup> for <sup>232</sup>Th, and 1120.54 ± 26 Bqkg<sup>−1</sup> for <sup>40</sup>K. The later (altered granites) have the highest activity concentrations of <sup>232</sup>Th (avg. 360.57 ± 58.02 Bqkg<sup>−1</sup>), <sup>40</sup>K (avg. 1197.23 ± 106.53 Bqkg<sup>−1</sup>), and <sup>238</sup>U (avg. 3797.50 ± 725.68 Bqkg<sup>−1</sup>), as well as their summation (avg. 2201.60 ± 250.62 Bqkg<sup>−1</sup>). It is obvious that the investigated rocks contain increased activity concentrations and therefore fall above the widely accepted worldwide requirements. The results of microscopic and ESEM analysis revealed large assemblages of significant minerals enclosed in the Magal Gebreel rocks such as precious, base metals, accessories, radioactive-bearing, REE-bearing, and Nb-Ta- bearing minerals. Radium equivalent, dose of human body, absorbed dose rate and annualized dosage, excess life-time cancer, coupled with extra radiological characteristics were inferred for these rocks. Given that the measures of most of these criteria are higher than the international average, it is distinct that the tested rocks (certainly altered granites) have a considerable effect on the natural gamma emission released.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 5","pages":"Article 104165"},"PeriodicalIF":2.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2025-12-30DOI: 10.1016/j.net.2025.104110
Sehwan Seol, Jae Chang Kim, Junehyung Lee Bernaski, Yong Kyun Kim, Ser Gi Hong
This study presents a novel method for estimating the masses of uranium-235 and total plutonium in spent nuclear fuel assemblies using only Differential Die-Away (DDA) analysis results and cooling time without relying on passive or delayed neutron measurements. A database of DDA signals was generated through MCNP6 simulations based on spent nuclear fuel compositions derived from ORIGAMI depletion calculations under a wide range of initial enrichments, burnups, and cooling times. The correlations were developed between DDA results (i.e., die-away time and total neutron counts) and the isotopic masses. For 235U, a linear function of the signal ratio was used with the coefficients depending on cooling time. For Pu, a separate correlation was introduced using the die-away time difference between spent and fresh fuels, which required an estimation of initial enrichment. A Gaussian Process Regression (GPR) model was trained for this purpose, achieving high accuracy. Validation with 50 independent SNFs showed high prediction performance with maximum relative errors of 7.52 % and 2.41 % for 235U and Pu, respectively. This method provides a non-destructive and efficient technique for characterizing spent nuclear fuel assemblies, offering potential applications in nuclear safeguards, spent fuel management, and nuclear material accountancy.
{"title":"New method for estimating uranium and plutonium masses using differential die-away signals","authors":"Sehwan Seol, Jae Chang Kim, Junehyung Lee Bernaski, Yong Kyun Kim, Ser Gi Hong","doi":"10.1016/j.net.2025.104110","DOIUrl":"10.1016/j.net.2025.104110","url":null,"abstract":"<div><div>This study presents a novel method for estimating the masses of uranium-235 and total plutonium in spent nuclear fuel assemblies using only Differential Die-Away (DDA) analysis results and cooling time without relying on passive or delayed neutron measurements. A database of DDA signals was generated through MCNP6 simulations based on spent nuclear fuel compositions derived from ORIGAMI depletion calculations under a wide range of initial enrichments, burnups, and cooling times. The correlations were developed between DDA results (i.e., die-away time and total neutron counts) and the isotopic masses. For <sup>235</sup>U, a linear function of the signal ratio was used with the coefficients depending on cooling time. For Pu, a separate correlation was introduced using the die-away time difference between spent and fresh fuels, which required an estimation of initial enrichment. A Gaussian Process Regression (GPR) model was trained for this purpose, achieving high accuracy. Validation with 50 independent SNFs showed high prediction performance with maximum relative errors of 7.52 % and 2.41 % for <sup>235</sup>U and Pu, respectively. This method provides a non-destructive and efficient technique for characterizing spent nuclear fuel assemblies, offering potential applications in nuclear safeguards, spent fuel management, and nuclear material accountancy.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 5","pages":"Article 104110"},"PeriodicalIF":2.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-10DOI: 10.1016/j.net.2026.104126
Haluk Yücel, Ege Can Karanfil, Bahadır Saygı
Radioisotope identification devices(RID) play a crucial role in detection and identification of illicit trafficking of radioactive/nuclear materials in nuclear security and nuclear safeguards. These devices utilize various algorithms for automated isotope identification(ID) without the need for expert intervention. In this study, an automated algorithm for real-time isotope identification is presented. The algorithm employs a second-derivative-based peak detection and a Bayesian-statistics-peak based ID approach. To demonstrate the suitability of the developed algorithm, it was applied to the gamma-ray spectra acquired with a medium energy -resolution LaBr3(Ce) detector. In addition to point sources 60Co, 109Cd, 22Na, 137Cs, 241Am, 152Eu, and 133Ba, the algorithm was also tested on the more complex gamma-ray spectra obtained from low enriched uranium reference materials 171 (EC-NRM171), and natural uranium and thorium minerals such as BL-2, BL-3, BL-4A, BL-5, RGU and OKA-2. To evaluate the performance of the algorithm, total scoring (ST) is calculated. For identification of 22Na, 60Co, and 137Cs isotopes, the posterior probabilities were estimated to be greater than 99 %. For 133Ba, 152Eu, and 241Am, the isotopes they were also correctly identified with higher posterior probabilities ranged from 92 % to 95 %. The developed algorithm successfully identified the isotopes contained in U-Th ore samples with a 100 % total score. Additionally, the performance evaluation of the results obtained with Certified Reference Uranium Materials also demonstrated 100 % score. For automatic ID, the photopeak-based Bayesian method, combined with the Mariscotti's peak detection method has great potential for real-time ID when implemented in RID devices.
{"title":"Development of an automated isotope identification algorithm based on second derivative and Bayesian statistics methods using medium energy resolution scintillation detectors","authors":"Haluk Yücel, Ege Can Karanfil, Bahadır Saygı","doi":"10.1016/j.net.2026.104126","DOIUrl":"10.1016/j.net.2026.104126","url":null,"abstract":"<div><div>Radioisotope identification devices(RID) play a crucial role in detection and identification of illicit trafficking of radioactive/nuclear materials in nuclear security and nuclear safeguards. These devices utilize various algorithms for automated isotope identification(ID) without the need for expert intervention. In this study, an automated algorithm for real-time isotope identification is presented. The algorithm employs a second-derivative-based peak detection and a Bayesian-statistics-peak based ID approach. To demonstrate the suitability of the developed algorithm, it was applied to the gamma-ray spectra acquired with a medium energy -resolution LaBr<sub>3</sub>(Ce) detector. In addition to point sources <sup>60</sup>Co, <sup>109</sup>Cd, <sup>22</sup>Na, <sup>137</sup>Cs, <sup>241</sup>Am, <sup>152</sup>Eu, and <sup>133</sup>Ba, the algorithm was also tested on the more complex gamma-ray spectra obtained from low enriched uranium reference materials 171 (EC-NRM171), and natural uranium and thorium minerals such as BL-2, BL-3, BL-4A, BL-5, RGU and OKA-2. To evaluate the performance of the algorithm, total scoring (ST) is calculated. For identification of <sup>22</sup>Na, <sup>60</sup>Co, and <sup>137</sup>Cs isotopes, the posterior probabilities were estimated to be greater than 99 %. For <sup>133</sup>Ba, <sup>152</sup>Eu, and <sup>241</sup>Am, the isotopes they were also correctly identified with higher posterior probabilities ranged from 92 % to 95 %. The developed algorithm successfully identified the isotopes contained in U-Th ore samples with a 100 % total score. Additionally, the performance evaluation of the results obtained with Certified Reference Uranium Materials also demonstrated 100 % score. For automatic ID, the photopeak-based Bayesian method, combined with the Mariscotti's peak detection method has great potential for real-time ID when implemented in RID devices.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 5","pages":"Article 104126"},"PeriodicalIF":2.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-13DOI: 10.1016/j.net.2026.104143
Thi Yen Hong Huynh , Huu Ngan Thy Truong , Ngoc Ba Vu
Accurate characterization of the HPGe detector dead layer is crucial for reliable Monte Carlo simulations in gamma-ray spectrometry. This study investigates the impact of source geometry on the determination of the effective dead layer thickness. Experimental measurements and MCNP6 simulations were conducted using a p-type coaxial HPGe detector with three geometries: a cylindrical source (S1), a 3π source (S2), and a Marinelli beaker (S3). Results show that while the physical dead layer distribution is intrinsic to the crystal, the determined effective dead layer parameter is strongly dependent on the irradiation geometry. The on-axis source (S1) indicated a stable frontal dead layer of approximately 0.60 mm. Conversely, volumetric sources (S2 and S3) revealed a thicker lateral dead layer (∼1.10–1.21 mm) with a significant transition zone at low energies due to the geometric weighting of photon interactions. Crucially, the study demonstrates that applying a uniform dead layer thickness derived from point-source calibration (S1) to volumetric geometries (S3) results in a systematic overestimation of efficiency across the energy range. These findings highlight the inadequacy of uniform dead layer models for complex geometries and the necessity of multi-region characterization for high-accuracy environmental monitoring.
{"title":"Impact of non-uniform dead layer distribution on efficiency calibration for volumetric sources in HPGe detectors","authors":"Thi Yen Hong Huynh , Huu Ngan Thy Truong , Ngoc Ba Vu","doi":"10.1016/j.net.2026.104143","DOIUrl":"10.1016/j.net.2026.104143","url":null,"abstract":"<div><div>Accurate characterization of the HPGe detector dead layer is crucial for reliable Monte Carlo simulations in gamma-ray spectrometry. This study investigates the impact of source geometry on the determination of the effective dead layer thickness. Experimental measurements and MCNP6 simulations were conducted using a p-type coaxial HPGe detector with three geometries: a cylindrical source (S1), a 3π source (S2), and a Marinelli beaker (S3). Results show that while the physical dead layer distribution is intrinsic to the crystal, the determined effective dead layer parameter is strongly dependent on the irradiation geometry. The on-axis source (S1) indicated a stable frontal dead layer of approximately 0.60 mm. Conversely, volumetric sources (S2 and S3) revealed a thicker lateral dead layer (∼1.10–1.21 mm) with a significant transition zone at low energies due to the geometric weighting of photon interactions. Crucially, the study demonstrates that applying a uniform dead layer thickness derived from point-source calibration (S1) to volumetric geometries (S3) results in a systematic overestimation of efficiency across the energy range. These findings highlight the inadequacy of uniform dead layer models for complex geometries and the necessity of multi-region characterization for high-accuracy environmental monitoring.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 5","pages":"Article 104143"},"PeriodicalIF":2.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-12DOI: 10.1016/j.net.2026.104138
Siyoung Choi , Sung-Woo Kim , Sangtae Kim , Minsung Hong
In this study, the rupture disk corrosion test (RDCT) was employed to measure the initiation time of primary water stress corrosion cracking (PWSCC) in Alloy 600. The applied stress was controlled by the disk specimen thickness, and the PWSCC initiation times were measured experimentally according to the controlled applied stress. Additionally, an optimized finite element analysis (FEA) model was selected to evaluate the applied stress and calculate the stress distribution on the specimen. A clear correlation was established between the applied stress and the PWSCC initiation time; specifically, the initiation time decreased as the applied stress increased. To improve the accuracy and reliability of PWSCC initiation time measurement by RDCT and the stress calculation by FEA, the experimental apparatus was modified, with the computational models were optimized, respectively. This study demonstrates that the integrated RDCT–FEA approach can effectively predict PWSCC initiation under simulated PWR conditions.
{"title":"Integrated the Rupture Disk Corrosion Test (RDCT) and Finite Element Analysis (FEA) approach for evaluating PWSCC initiation in Alloy 600 under simulated pressurized water reactors conditions","authors":"Siyoung Choi , Sung-Woo Kim , Sangtae Kim , Minsung Hong","doi":"10.1016/j.net.2026.104138","DOIUrl":"10.1016/j.net.2026.104138","url":null,"abstract":"<div><div>In this study, the rupture disk corrosion test (RDCT) was employed to measure the initiation time of primary water stress corrosion cracking (PWSCC) in Alloy 600. The applied stress was controlled by the disk specimen thickness, and the PWSCC initiation times were measured experimentally according to the controlled applied stress. Additionally, an optimized finite element analysis (FEA) model was selected to evaluate the applied stress and calculate the stress distribution on the specimen. A clear correlation was established between the applied stress and the PWSCC initiation time; specifically, the initiation time decreased as the applied stress increased. To improve the accuracy and reliability of PWSCC initiation time measurement by RDCT and the stress calculation by FEA, the experimental apparatus was modified, with the computational models were optimized, respectively. This study demonstrates that the integrated RDCT–FEA approach can effectively predict PWSCC initiation under simulated PWR conditions.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 5","pages":"Article 104138"},"PeriodicalIF":2.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-09DOI: 10.1016/j.net.2026.104131
Tao Liu , Chongdou Yang , Xiangrong Fan , Di Yun , Wenguan Liu , Miroslav Popovic , Bingyao Zhao , Haiqing Xia , Zhongbo Liu , Jie Qiu
The corrosion behavior of SIMP steel in liquid lead-bismuth eutectic was investigated to elucidate the degradation mechanism of Fe-based protective oxide film in LBE when the temperature exceeds the critical threshold of 550 °C. Results show that a three-layer oxide film structure is formed on the surface of SIMP steel, consisting of an outer oxidation layer of Fe3O4, an inner oxidation layer of Fe-Cr spinel, and an internal oxidation zone. At 550 °C, SIMP steel forms a stable oxide layer and exhibits excellent resistance to LBE corrosion. However, at 600 °C, the increased diffusion coefficients of elements and their higher solubility in LBE accelerate elemental depletion, leading to the dissolution of the outer oxidation layer. The formation of a Cr2O3 band protects the matrix but also impedes elements diffusion from matrix to the oxides, promoting the formation of nanoscale voids and pores in the inner oxidation layer, resulting the failure of oxide film to resist lead-bismuth eutectic corrosion at 600 °C. The failure of the inner oxidation layer further accelerates the corrosion of the matrix.
{"title":"Degradation mechanism of oxide film on SIMP steel in LBE at temperatures above 550 °C","authors":"Tao Liu , Chongdou Yang , Xiangrong Fan , Di Yun , Wenguan Liu , Miroslav Popovic , Bingyao Zhao , Haiqing Xia , Zhongbo Liu , Jie Qiu","doi":"10.1016/j.net.2026.104131","DOIUrl":"10.1016/j.net.2026.104131","url":null,"abstract":"<div><div>The corrosion behavior of SIMP steel in liquid lead-bismuth eutectic was investigated to elucidate the degradation mechanism of Fe-based protective oxide film in LBE when the temperature exceeds the critical threshold of 550 °C. Results show that a three-layer oxide film structure is formed on the surface of SIMP steel, consisting of an outer oxidation layer of Fe<sub>3</sub>O<sub>4</sub>, an inner oxidation layer of Fe-Cr spinel, and an internal oxidation zone. At 550 °C, SIMP steel forms a stable oxide layer and exhibits excellent resistance to LBE corrosion. However, at 600 °C, the increased diffusion coefficients of elements and their higher solubility in LBE accelerate elemental depletion, leading to the dissolution of the outer oxidation layer. The formation of a Cr<sub>2</sub>O<sub>3</sub> band protects the matrix but also impedes elements diffusion from matrix to the oxides, promoting the formation of nanoscale voids and pores in the inner oxidation layer, resulting the failure of oxide film to resist lead-bismuth eutectic corrosion at 600 °C. The failure of the inner oxidation layer further accelerates the corrosion of the matrix.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 5","pages":"Article 104131"},"PeriodicalIF":2.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-05-01Epub Date: 2026-01-20DOI: 10.1016/j.net.2026.104150
Dong Liu , Chao Wu , Qi-Long Chen , Kang-Jun He , Jin-Chao Zhang , Qian Zhang , Kai Wang , Chen Zhao , Yang Liu
Resonance self-shielding calculation in complex heterogeneous geometries is essential for reactor physics and core design. While the ultra-fine group method solves the neutron slowing-down equation with high accuracy, its adoption has been limited by low computational efficiency and geometric constraints. Recent progress in deep learning has demonstrated strong potential in neutron transport calculations, offering new solutions to longstanding challenges in resonance self-shielding. This paper proposes a novel deep learning method termed “Frequency-Reduction and Order-Elevation(FROE)." First, frequency reduction is achieved by defining a composite function as the product of the slowing-down spectrum and the total cross-section. This transformation effectively smooths high-frequency oscillations induced by resonance peaks, facilitating neural network approximation. Second, order elevation involves reformulating the integro-differential slowing-down equation into an exact differential form by converting integral terms into their corresponding antiderivatives, thereby improving computational efficiency. Deep neural networks are then employed to represent the composite function and the antiderivatives. The slowing-down equation is solved by training the networks through an alternating iterative scheme to minimize this loss function. Numerical results for several heterogeneous problems, including cases with multi-nuclide resonance interference, validate the proposed method. Our approach accurately yields continuous slowing-down spectra in both space and energy. This work opens a promising new avenue for tackling the enduring challenge of resonance self-shielding in reactor physics.
{"title":"Frequency Reduction and Order Elevation (FROE): A physics-informed deep learning method for ultra-fine group resonance self-shielding in heterogeneous systems","authors":"Dong Liu , Chao Wu , Qi-Long Chen , Kang-Jun He , Jin-Chao Zhang , Qian Zhang , Kai Wang , Chen Zhao , Yang Liu","doi":"10.1016/j.net.2026.104150","DOIUrl":"10.1016/j.net.2026.104150","url":null,"abstract":"<div><div>Resonance self-shielding calculation in complex heterogeneous geometries is essential for reactor physics and core design. While the ultra-fine group method solves the neutron slowing-down equation with high accuracy, its adoption has been limited by low computational efficiency and geometric constraints. Recent progress in deep learning has demonstrated strong potential in neutron transport calculations, offering new solutions to longstanding challenges in resonance self-shielding. This paper proposes a novel deep learning method termed “Frequency-Reduction and Order-Elevation(FROE).\" First, frequency reduction is achieved by defining a composite function as the product of the slowing-down spectrum and the total cross-section. This transformation effectively smooths high-frequency oscillations induced by resonance peaks, facilitating neural network approximation. Second, order elevation involves reformulating the integro-differential slowing-down equation into an exact differential form by converting integral terms into their corresponding antiderivatives, thereby improving computational efficiency. Deep neural networks are then employed to represent the composite function and the antiderivatives. The slowing-down equation is solved by training the networks through an alternating iterative scheme to minimize this loss function. Numerical results for several heterogeneous problems, including cases with multi-nuclide resonance interference, validate the proposed method. Our approach accurately yields continuous slowing-down spectra in both space and energy. This work opens a promising new avenue for tackling the enduring challenge of resonance self-shielding in reactor physics.</div></div>","PeriodicalId":19272,"journal":{"name":"Nuclear Engineering and Technology","volume":"58 5","pages":"Article 104150"},"PeriodicalIF":2.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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