
@article{lee_multilevel_2021,
	title = {Multilevel modeling of diametral creep in pressure tubes of {Korean} {CANDU} units},
	volume = {53},
	copyright = {All rights reserved},
	issn = {17385733},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S1738573321003405},
	doi = {10.1016/j.net.2021.06.019},
	abstract = {In this work, we applied a multilevel modeling technique to estimate the diametral creep in the pressure tubes of Korean Canada Deuterium Uranium (CANDU) units. Data accumulated from in-service inspections were used to develop the model. To conﬁrm the strength of the multilevel models, a 2-level multilevel model considering the relationship between channels for a CANDU unit was compared with existing linear models. The multilevel model exhibited a very robust prediction accuracy compared to the linear models with different data pooling methods. A 3-level multilevel model, which considered individual bundles, channels, and units, was also implemented. The inﬂuence of the channel installation direction was incorporated into the three-stage multilevel model. For channels that were previously measured, the developed 3-level multilevel model exhibited a very good predictive power, and the prediction interval was very narrow. However, for channels that had never been measured before, the prediction interval widened considerably. This model can be sufﬁciently improved by the accumulation of more data and can be applied to other CANDU units.},
	language = {en},
	number = {12},
	urldate = {2022-02-26},
	journal = {Nuclear Engineering and Technology},
	author = {Lee, Gyeong-Geun and Ahn, Dong-Hyun and Jin, Hyung-Ha and Song, Myung-Ho and Jung, Jong Yeob},
	month = dec,
	year = {2021},
	pages = {4042--4051},
	annote = {cited By 2},
	file = {Lee et al. - 2021 - Multilevel modeling of diametral creep in pressure.pdf:files/967/Lee et al. - 2021 - Multilevel modeling of diametral creep in pressure.pdf:application/pdf},
}

@article{lee_machine_2021,
	title = {Machine learning modeling of irradiation embrittlement in low alloy steel of nuclear power plants},
	volume = {53},
	copyright = {All rights reserved},
	issn = {17385733},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S1738573321003351},
	doi = {10.1016/j.net.2021.06.014},
	abstract = {In this study, machine learning (ML) techniques were used to model surveillance test data of nuclear power plants from an international database of the ASTM E10.02 committee. Regression modeling was conducted using various techniques, including Cubist, XGBoost, and a support vector machine. The root mean square deviation of each ML model for the baseline dataset was less than that of the ASTM E900-15 nonlinear regression model. With respect to the interpolation, the ML methods provided excellent predictions with relatively few computations when applied to the given data range. The effect of the explanatory variables on the transition temperature shift (TTS) for the ML methods was analyzed, and the trends were slightly different from those for the ASTM E900-15 model. ML methods showed some weakness in the extrapolation of the ﬂuence in comparison to the ASTM E900-15, while the Cubist method achieved an extrapolation to a certain extent. To achieve a more reliable prediction of the TTS, it was conﬁrmed that advanced techniques should be considered for extrapolation when applying ML modeling.},
	language = {en},
	number = {12},
	urldate = {2022-02-26},
	journal = {Nuclear Engineering and Technology},
	author = {Lee, Gyeong-Geun and Kim, Min-Chul and Lee, Bong-Sang},
	month = dec,
	year = {2021},
	pages = {4022--4032},
	annote = {cited By 4},
	file = {Lee et al. - 2021 - Machine learning modeling of irradiation embrittle.pdf:files/968/Lee et al. - 2021 - Machine learning modeling of irradiation embrittle.pdf:application/pdf},
}

@article{lee_modeling_2019,
	title = {Modeling of {Flow}-{Accelerated} {Corrosion} using {Machine} {Learning}: {Comparison} between {Random} {Forest} and {Non}-linear {Regression}},
	volume = {18},
	copyright = {All rights reserved},
	shorttitle = {Modeling of {Flow}-{Accelerated} {Corrosion} using {Machine} {Learning}},
	url = {https://doi.org/10.14773/CST.2019.18.2.61},
	doi = {10.14773/CST.2019.18.2.61},
	abstract = {Flow-Accelerated Corrosion (FAC) is a phenomenon in which a protective coating on a metal surface is dissolved by a flow of fluid in a metal pipe, leading to continuous wall-thinning. Recently, many countries have developed computer codes to manage FAC in power plants, and the FAC prediction model in these computer codes plays an important role in predictive performance. Herein, the FAC prediction model was developed by applying a machine learning method and the conventional nonlinear regression method. The random forest, a widely used machine learning technique in predictive modeling led to easy calculation of FAC tendency for five input variables: flow rate, temperature, pH, Cr content, and dissolved oxygen concentration. However, the model showed significant errors in some input conditions, and it was difficult to obtain proper regression results without using additional data points. In contrast, nonlinear regression analysis predicted robust estimation even with relatively insufficient data by assuming an empirical equation and the model showed better predictive power when the interaction between DO and pH was considered. The comparative analysis of this study is believed to provide important insights for developing a more sophisticated FAC prediction model.},
	language = {ko},
	number = {2},
	urldate = {2022-02-26},
	journal = {Corrosion Science and Technology},
	author = {Lee, Gyeong-Geun and Lee, Eun Hee and Kim, Sung-Woo and Kim, Kyung-Mo and Kim, Dong-Jin},
	month = apr,
	year = {2019},
	pages = {61--71},
	annote = {cited By 2},
	file = {Lee et al. - 2019 - Modeling of Flow-Accelerated Corrosion using Machi.pdf:files/970/Lee et al. - 2019 - Modeling of Flow-Accelerated Corrosion using Machi.pdf:application/pdf},
}

@article{lee_observation_2014,
	title = {Observation and rate theory modeling of grain boundary segregation in Σ3 twin boundaries in ion-irradiated stainless steel 316},
	volume = {449},
	copyright = {All rights reserved},
	issn = {00223115},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022311513012014},
	doi = {10.1016/j.jnucmat.2013.10.049},
	abstract = {Radiation-induced segregation (RIS) is the phenomenon of compositional change at point defect sinks in alloys irradiated at a moderate temperature. Owing to the potential relevance of RIS by way of the susceptibility of structural materials to irradiation-assisted stress corrosion cracking, basic research on austenitic stainless steels used in nuclear reactors has been carried out in recent years. In this work, commercial stainless steel 316 specimens were irradiated with Fe ions, and the resulting changes in Cr and Ni compositions were characterized using transmission electron microscopy and energy-dispersive X-ray spectroscopy. The samples with various grain boundary orientations, including the special R3 orientation, were analyzed. The ledges of a few special R3 twin boundaries showed signiﬁcantly higher RIS compared to the coherent regions. The RIS behavior of a parallel twin pair was observed, and two proﬁles of RIS were found in them. The inner twins in multi-twins showed considerably lower RIS compared to the outer twins. For the calculation of RIS, time-dependent differential equations based on the rate theory were established and numerically integrated. An additional variable, representing the sink strength of the grain boundary, was introduced in the differential equations, and the concentration proﬁles of the R3 twins were calculated. The calculated results were in good agreement with the experimental results.},
	language = {en},
	number = {1-3},
	urldate = {2022-02-26},
	journal = {Journal of Nuclear Materials},
	author = {Lee, Gyeong-Geun and Jin, Hyung-Ha and Lee, Yong-Bok and Kwon, Junhyun},
	month = jun,
	year = {2014},
	pages = {234--241},
	annote = {cited By 11},
	file = {Lee et al. - 2014 - Observation and rate theory modeling of grain boun.pdf:files/975/Lee et al. - 2014 - Observation and rate theory modeling of grain boun.pdf:application/pdf},
}

@article{lee_microstructural_2013,
	title = {Microstructural {Investigation} of {Alloy} 617 {Creep}-ruptured at {High} {Temperature} in a {Helium} {Environment}},
	volume = {29},
	copyright = {All rights reserved},
	issn = {10050302},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S1005030213002272},
	doi = {10.1016/j.jmst.2013.09.024},
	language = {en},
	number = {12},
	urldate = {2022-02-26},
	journal = {Journal of Materials Science \& Technology},
	author = {Lee, Gyeong-Geun and Jung, Sujin and Park, Jae-Young and Kim, Woo-Gon and Hong, Sung-Deok and Kim, Yong-Wan},
	month = dec,
	year = {2013},
	pages = {1177--1183},
	annote = {cited By 15},
	file = {Lee et al. - 2013 - Microstructural Investigation of Alloy 617 Creep-r.pdf:files/976/Lee et al. - 2013 - Microstructural Investigation of Alloy 617 Creep-r.pdf:application/pdf},
}

@article{lee_relationship_2012,
	title = {{RELATIONSHIP} {BETWEEN} {RADIATION} {INDUCTED} {YIELD} {STRENGTH} {INCREMENT} {AND} {CHARPY} {TRANSITION} {TEMPERATURE} {SHIFT} {IN} {REACTOR} {PRESSURE} {VESSEL} {STEELS} {OF} {KOREAN} {NUCLEAR} {POWER} {PLANTS}},
	copyright = {All rights reserved},
	abstract = {The decrease in the fracture toughness of ferritic steels in a reactor pressure vessel is an important factor in determining the lifetime of a nuclear power plant. A surveillance program has been in place in Korea since 1979 to assess the structural integrity of RPV steels. In this work, the surveillance data were collected and analyzed statistically in order to derive the empirical relationship between the embrittlement and strengthening of irradiated reactor pressure vessel steels. There was a linear relationship between the yield strength change and the transition temperature shift change at 41 J due to irradiation. The proportional coefficient was about 0.5°C/MPa in the base metals (plate/forgings). The upper shelf energy decrease ratio was non-linearly proportional to the yield strength change, and most of the data lay along the trend curve of the US results. The transition regime temperature interval, ∆TT, was less than the US data. The overall change from irradiation was very similar to the US results. It is expected that the results of this study will be applied to basic research on the multiscale modeling of the irradiation embrittlement of RPV materials in Korea.},
	language = {en},
	journal = {NUCLEAR ENGINEERING AND TECHNOLOGY},
	author = {Lee, Gyeong-Geun and Lee, Yongbok and Kwon, Junhyun},
	year = {2012},
	pages = {8},
	annote = {cited By 2},
	file = {Lee et al. - 2012 - RELATIONSHIP BETWEEN RADIATION INDUCTED YIELD STRE.pdf:files/977/Lee et al. - 2012 - RELATIONSHIP BETWEEN RADIATION INDUCTED YIELD STRE.pdf:application/pdf},
}

@article{lee_microstructural_2011,
	title = {Microstructural {Investigation} of {Alloy} 617 {Creep}-{Ruptured} in {Pure} {Helium} {Environment} at 950℃},
	volume = {21},
	copyright = {All rights reserved},
	issn = {1225-0562},
	url = {http://koreascience.or.kr/journal/view.jsp?kj=GJRHBQ&py=2011&vnc=v21n11&sp=596},
	doi = {10.3740/MRSK.2011.21.11.596},
	abstract = {The very high temperature gas reactor (VHTR) is one of the next generation nuclear reactors for its safety, longterm stability, and proliferation-resistance. The high operating temperature of over 800oC enables various applications with high energy efficiency. Heat is transferred from the primary helium loop to the secondary helium loop through the intermediate heat exchanger (IHX). The IHX material requires creep resistance, oxidation resistance, and corrosion resistance in a helium environment at high operating temperatures. A Ni-based superalloy such as Alloy 617 is considered as a primary candidate material for the intermediate heat exchanger. In this study, the microstructures of Alloy 617 crept in pure helium and air environments at 950oC were observed. The rupture time in helium was shorter than that in air under small applied stresses. As the exposure time increased, the thickness of outer oxide layer of the specimens clearly increased but delaminated after a long creep time. The depth of the carbide-depleted zone was rather high in the specimens under high applied stress. The reason was elucidated by the comparison between the ruptured region and grip region of the samples. It is considered that decarburization caused by minor gas impurities in a helium environment caused the reduction in creep rupture time.},
	language = {ko},
	number = {11},
	urldate = {2022-02-26},
	journal = {Korean Journal of Materials Research},
	author = {Lee, Gyeong-Geun and Jung, Su-Jin and Kim, Dae-Jong and Kim, Woo-Gon and Park, Ji-Yeon and Kim, Dong-Jin},
	month = nov,
	year = {2011},
	pages = {596--603},
	annote = {cited By 4},
	file = {Lee et al. - 2011 - Microstructural Investigation of Alloy 617 Creep-R.pdf:files/978/Lee et al. - 2011 - Microstructural Investigation of Alloy 617 Creep-R.pdf:application/pdf},
}

@article{lee_kinetic_2009,
	title = {A kinetic {Monte} {Carlo} approach for the analysis of trapping effect on the defect accumulation in neutron-irradiated {Fe}},
	volume = {267},
	copyright = {All rights reserved},
	issn = {0168583X},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0168583X09007599},
	doi = {10.1016/j.nimb.2009.06.063},
	abstract = {The trapping effect of self-interstitial atom (SIA) clusters in neuron-irradiated Fe was analyzed in terms of generic traps. The effect of the cut-off size between sessile and glissile SIA clusters was investigated. The accumulation of SIA clusters decreased drastically as the cut-off size increased, which originated from the elimination of the SIA clusters at a grain boundary through its one-dimensional motion. When the immobile generic traps were introduced to the kinetic Monte Carlo simulation model, the effect of trap parameters was assessed. An increase in the binding energy between the trap and SIA-species resulted in a decrease in the number of mono-SIAs that were dissociated from the trap and a corresponding delay in visible SIA clusters. The size-dependent prefactor for the dissociation rate of trapped SIA clusters was necessary for a realistic accumulation behavior of SIA clusters. The trap density affects the density and size of the accumulated SIA cluster density during irradiation. This parameterization of generic traps provided insight into the mechanism of accumulation of SIA and SIA cluster.},
	language = {en},
	number = {18},
	urldate = {2022-02-26},
	journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
	author = {Lee, Gyeong-Geun and Kwon, Junhyun and Kim, Duk Su},
	month = sep,
	year = {2009},
	pages = {3214--3217},
	annote = {cited By 3},
	file = {Lee et al. - 2009 - A kinetic Monte Carlo approach for the analysis of.pdf:files/980/Lee et al. - 2009 - A kinetic Monte Carlo approach for the analysis of.pdf:application/pdf},
}

@article{lee_novel_2007,
	title = {A novel process for fabrication of {SnO2}-based thick film gas sensors},
	volume = {123},
	copyright = {All rights reserved},
	issn = {09254005},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0925400506005752},
	doi = {10.1016/j.snb.2006.08.029},
	abstract = {A centrifugal coating technique has been developed for SnO2 thick ﬁlm gas sensors. The thickness of the ﬁlms was controlled by changing the concentration of the SnO2 suspension. For thicknesses above 10 ␮m, the sensitivity was stabilized. A cold isostatic pressing of the ﬁlms before sintering resulted in a slight reduction of the sensitivity and a considerable reduction in resistivity, showing the applicability of the process. Centrifugally coated samples showed a much higher sensitivity than screen-printed samples. This result was attributed to the stacking of ﬁne powder at the surface which showed a lower resistivity and a higher sensitivity compared to coarse powder.},
	language = {en},
	number = {1},
	urldate = {2022-02-26},
	journal = {Sensors and Actuators B: Chemical},
	author = {Lee, Sora and Lee, Gyeong-Geun and Kim, Joosun and Kang, Suk-Joong L.},
	month = apr,
	year = {2007},
	pages = {331--335},
	annote = {cited By 14},
	file = {Lee et al. - 2007 - A novel process for fabrication of SnO2-based thic.pdf:files/982/Lee et al. - 2007 - A novel process for fabrication of SnO2-based thic.pdf:application/pdf},
}

@article{lee_formation_2005,
	title = {Formation of large pores and their effect on electrical properties of {SnO2} gas sensors},
	volume = {107},
	copyright = {All rights reserved},
	issn = {09254005},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0925400504007257},
	doi = {10.1016/j.snb.2004.10.032},
	abstract = {The effect of large pores on electrical properties of SnO2 gas sensors has been investigated. Large intergranular pores of 10–20 ␮m diameter were created in SnO2 gas sensors by adding starch powder in concentrations from 0 to 15 wt.\%. Addition of starch powder did not change sintering behavior and resultant microstructure except for the formation of large pores. Gas sensitivity increased with starch addition. This result was attributed to enhanced diffusion of gases into the bulk SnO2 through the created large pores. Introduction of large pores in a bulk SnO2 matrix by adding starch can be a simple and useful way of microstructure control and sensitivity enhancement.},
	language = {en},
	number = {1},
	urldate = {2022-02-26},
	journal = {Sensors and Actuators B: Chemical},
	author = {Lee, Gyeong-Geun and Kang, Suk-Joong L.},
	month = may,
	year = {2005},
	pages = {392--396},
	annote = {cited By 13},
	file = {Lee and Kang - 2005 - Formation of large pores and their effect on elect.pdf:files/993/Lee and Kang - 2005 - Formation of large pores and their effect on elect.pdf:application/pdf},
}

@article{koo_measurement_2005,
	title = {Measurement of reduction kinetics in {Nb2O5}-doped {SrTiO3} by use of a new technique of liquid film migration},
	volume = {66},
	copyright = {All rights reserved},
	issn = {00223697},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0022369704002720},
	doi = {10.1016/j.jpcs.2004.06.026},
	abstract = {To investigate the reduction kinetics of Nb2O5-doped SrTiO3, which has previously been difﬁcult because of its low diffusivity, we have developed a new technique for the measurement of chemical diffusivity using the phenomenon of liquid ﬁlm migration. 0.2 mol\%-Nb2O5doped SrTiO3 powder compacts were sintered in air and then annealed at various temperatures and for various periods of time in 95N2/5H2. During the annealing the surface of individual grains was reduced and the thickness of the reduced layer varied with the annealing temperature and time. As a CuO melt was inﬁltrated into the annealed samples, liquid ﬁlm migration occurred and eventually stopped when the reduced layer was swept. It was therefore possible to measure the thicknesses of the reduced layers under different annealing conditions. Based on the measured migration thicknesses, the chemical diffusion coefﬁcient, Dchem, during reduction of 0.2 mol\%-Nb2O5-doped SrTiO3 was determined to be Dchem Z 4:6 !104 exp½Kð489G118 kJÞ=RT (cm2 sK1). Comparing the diffusion coefﬁcient and activation energy with previous data showed that the reduction was governed by the diffusion of Sr ions. The present investigation demonstrates a new technique for the study of oxidation/reduction kinetics in systems where the lattice parameter varies with oxygen partial pressure.},
	language = {en},
	number = {2-4},
	urldate = {2022-02-26},
	journal = {Journal of Physics and Chemistry of Solids},
	author = {Koo, Sang-Yoon and Lee, Gyeong-Geun and Kang, Suk-Joong L.},
	month = feb,
	year = {2005},
	pages = {498--503},
	annote = {cited By 4},
	file = {Koo et al. - 2005 - Measurement of reduction kinetics in Nb2O5-doped S.pdf:files/1206/Koo et al. - 2005 - Measurement of reduction kinetics in Nb2O5-doped S.pdf:application/pdf},
}

@article{koo_suppression_2004,
	title = {Suppression of {Liquid} {Film} {Migration} and {Improvement} of {Dielectric} {Properties} in {Niobium}-{Doped} {Strontium} {Titanate}},
	volume = {87},
	copyright = {All rights reserved},
	issn = {00027820, 15512916},
	url = {https://onlinelibrary.wiley.com/doi/10.1111/j.1551-2916.2004.01483.x},
	doi = {10.1111/j.1551-2916.2004.01483.x},
	language = {en},
	number = {8},
	urldate = {2022-02-26},
	journal = {Journal of the American Ceramic Society},
	author = {Koo, Sang-Yoon and Lee, Gyeong-Geun and Kang, Suk-Joong L. and Nowotny, Janusz and Sorrell, Chris},
	month = aug,
	year = {2004},
	pages = {1483--1487},
	annote = {cited By 2},
	file = {Koo et al. - 2004 - Suppression of Liquid Film Migration and Improveme.pdf:files/1207/Koo et al. - 2004 - Suppression of Liquid Film Migration and Improveme.pdf:application/pdf},
}

@article{lee_atom_2017,
	title = {Atom probe tomography analysis of nanostructure evolution in {Ni}-{Cr}-{Mo} low alloy steel under neutron irradiation},
	volume = {31},
	copyright = {All rights reserved},
	issn = {1738-494X, 1976-3824},
	url = {http://link.springer.com/10.1007/s12206-017-0708-x},
	doi = {10.1007/s12206-017-0708-x},
	abstract = {Ni-Cr-Mo low alloy steels are being considered as alternative materials to replace the Mn-Mo-Ni low alloy steels used in reactor pressure vessels in nuclear power plants, because of their higher strength and toughness. However, the neutron irradiation occurring during reactor operation causes degradation of Ni-Cr-Mo low alloy steel. In this study, irradiation-induced clusters in a Ni-Cr-Mo model alloy irradiated in the High-flux advanced neutron application reactor (HANARO) research reactor were investigated via Atom probe tomography (APT). The irradiated specimens showed irradiation-induced hardening and embrittlement. The neutron irradiation caused Si clustering, and these spherical clusters were homogeneously distributed within the matrix. Ni was also clustered at the Si clusters. However, the other elements did not clearly exhibit clustering behavior. Si and Ni atoms were also located at the dislocations. To quantify the nano-sized clusters, a method based on the Density-based spatial clustering of applications with noise (DBSCAN) algorithm was implemented. The total number of clusters was calculated to be {\textasciitilde}7 × 10-4 n/nm3 and the average cluster radius was less than 2 nm. The APT approach was demonstrated to be well suited for discovering the irradiation defect structures.},
	language = {en},
	number = {8},
	urldate = {2022-02-26},
	journal = {J Mech Sci Technol},
	author = {Lee, Gyeong-Geun and Jin, Hyung-Ha and Chang, Kunok and Lim, Sangyeob and Kim, Min-Chul and Lee, Bong-Sang and Kwon, Junhyun},
	month = aug,
	year = {2017},
	pages = {3675--3678},
	annote = {cited By 2},
	file = {Lee et al. - 2017 - Atom probe tomography analysis of nanostructure ev.pdf:files/974/Lee et al. - 2017 - Atom probe tomography analysis of nanostructure ev.pdf:application/pdf},
}

@article{lee_statistical_2017,
	title = {Statistical analysis on the fluence factor of surveillance test data of {Korean} nuclear power plants},
	volume = {49},
	copyright = {All rights reserved},
	issn = {17385733},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S1738573317301304},
	doi = {10.1016/j.net.2017.02.005},
	abstract = {The transition temperature shift (TTS) of the reactor pressure vessel materials is an important factor that determines the lifetime of a nuclear power plant. The prediction of the TTS at the end of a plant’s lifespan is calculated based on the equation of Regulatory Guide 1.99 revision 2 (RG1.99/2) from the US. The ﬂuence factor in the equation was expressed as a power function, and the exponent value was determined by the early surveillance data in the US. Recently, an advanced approach to estimate the TTS was proposed in various countries for nuclear power plants, and Korea is considering the development of a new TTS model. In this study, the TTS trend of the Korean surveillance test results was analyzed using a nonlinear regression model and a mixed-effect model based on the power function. The nonlinear regression model yielded a similar exponent as the power function in the ﬂuence compared with RG1.99/ 2. The mixed-effect model had a higher value of the exponent and showed superior goodness of ﬁt compared with the nonlinear regression model. Compared with RG1.99/2 and RG1.99/3, the mixed-effect model provided a more accurate prediction of the TTS.},
	language = {en},
	number = {4},
	urldate = {2022-02-26},
	journal = {Nuclear Engineering and Technology},
	author = {Lee, Gyeong-Geun and Kim, Min-Chul and Yoon, Ji-Hyun and Lee, Bong-Sang and Lim, Sangyeob and Kwon, Junhyun},
	month = jun,
	year = {2017},
	pages = {760--768},
	annote = {cited By 0},
	file = {Lee et al. - 2017 - Statistical analysis on the fluence factor of surv.pdf:files/973/Lee et al. - 2017 - Statistical analysis on the fluence factor of surv.pdf:application/pdf},
}

@article{lee_effect_2010,
	title = {Effect of a sintering process on the electrical properties of {SnO} 2 gas sensors},
	volume = {10},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77951915291&doi=10.1166%2fjnn.2010.1499&partnerID=40&md5=288240c29305c1546836f07077dd41cb},
	doi = {10.1166/jnn.2010.1499},
	number = {1},
	journal = {Journal of Nanoscience and Nanotechnology},
	author = {Lee, G.-G. and Kang, S.-J.L. and Kwon, J. and Kim, D.S.},
	year = {2010},
	pages = {68--73},
	annote = {cited By 7},
}

@inproceedings{lee_microstructure_2010,
	title = {Microstructure observation of {Inconel} alloy 617 creep-tested in he environment at 950°{C}},
	volume = {6},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80155145626&doi=10.1115%2fPVP2010-25152&partnerID=40&md5=6a7e105ad8f9868c7abada60f98dbb73},
	doi = {10.1115/PVP2010-25152},
	booktitle = {American {Society} of {Mechanical} {Engineers}, {Pressure} {Vessels} and {Piping} {Division} ({Publication}) {PVP}},
	author = {Lee, G.-G. and Kim, W.-G. and Kim, Y.-W. and Park, J.Y.},
	year = {2010},
	pages = {793--800},
	annote = {cited By 1},
}

@article{lee_microstructural_2014,
	title = {Microstructural investigation of {Alloy} 617 corroded in high-temperature helium environment},
	volume = {271},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899423354&doi=10.1016%2fj.nucengdes.2013.11.051&partnerID=40&md5=c987155d3210cccb7d93e3ee6ee68ede},
	doi = {10.1016/j.nucengdes.2013.11.051},
	journal = {Nuclear Engineering and Design},
	author = {Lee, G.-G. and Jung, S. and Kim, D. and Jeong, Y.-W. and Kim, D.-J.},
	year = {2014},
	pages = {301--308},
	annote = {cited By 13},
}

@article{lee_high-temperature_2012,
	title = {High-temperature corrosion behavior of alloy 617 in helium environment of very high temperature gas reactor},
	volume = {50},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84866895075&doi=10.3365%2fKJMM.2012.50.9.659&partnerID=40&md5=36d7f9c4f18a83a76f555eddeac89b9c},
	doi = {10.3365/KJMM.2012.50.9.659},
	number = {9},
	journal = {Journal of Korean Institute of Metals and Materials},
	author = {Lee, G.-G. and Jung, S. and Kim, D. and Jeong, Y.-W. and Kim, D.-J.},
	year = {2012},
	pages = {659--667},
	annote = {cited By 2},
}

@article{lee_study_2014,
	title = {Study of the evolution of defects in the structure of reactor pressure vessel by rate theory},
	volume = {10},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84894081720&doi=10.2174%2f1573413709666131109001431&partnerID=40&md5=6af850db8d19199403e26e9b64d01f6c},
	doi = {10.2174/1573413709666131109001431},
	number = {1},
	journal = {Current Nanoscience},
	author = {Lee, G.-G. and Lee, Y.-B. and Kim, M.-C. and Kwon, J.},
	year = {2014},
	pages = {123--127},
	annote = {cited By 1},
}

@article{lee_atomistic_2015,
	title = {Atomistic analysis of radiation-induced segregation in ion-irradiated stainless steel 316},
	volume = {60},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938082984&doi=10.1515%2famm-2015-0093&partnerID=40&md5=90d263d3f4b2935fa08fb53f90e148bb},
	doi = {10.1515/amm-2015-0093},
	number = {2},
	journal = {Archives of Metallurgy and Materials},
	author = {Lee, G.-G. and Jin, H.-H. and Chang, K. and Lee, B.H. and Kwon, J.},
	year = {2015},
	pages = {1179--1184},
	annote = {cited By 4},
}

@article{lee_effects_2017,
	title = {Effects of temperature and pressure on {Henry}'s law constant for hydrogen in the primary water of a simulated pressurized-water reactor},
	volume = {106},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85017195645&doi=10.1016%2fj.anucene.2017.04.001&partnerID=40&md5=9f1930ba42b3d542518351403df37e8d},
	doi = {10.1016/j.anucene.2017.04.001},
	journal = {Annals of Nuclear Energy},
	author = {Lee, E.-H. and Lee, G.-G. and Kim, K.-M.},
	year = {2017},
	pages = {136--142},
	annote = {cited By 2},
}

@article{lee_atom_2018,
	title = {Atom probe tomography analysis of radiation-induced solute clustering in austenite stainless steels},
	volume = {173},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050531735&doi=10.1080%2f10420150.2018.1499736&partnerID=40&md5=c9dc908107ea9e67f57c52f4e9ce3b56},
	doi = {10.1080/10420150.2018.1499736},
	number = {7-8},
	journal = {Radiation Effects and Defects in Solids},
	author = {Lee, G.-G. and Jin, H.-H. and Chang, K. and Kwon, J.},
	year = {2018},
	pages = {694--704},
	annote = {cited By 2},
}

@article{lee_determining_2023,
	title = {Determining the adjusting bias in reactor pressure vessel embrittlement trend curve using {Bayesian} multilevel modelling},
	volume = {55},
	issn = {1738-5733},
	url = {https://www.sciencedirect.com/science/article/pii/S1738573323002206},
	doi = {10.1016/j.net.2023.04.042},
	abstract = {A sophisticated Bayesian multilevel model for estimating group bias was developed to improve the utility of the ASTM E900-15 embrittlement trend curve (ETC) to assess the conditions of nuclear power plants (NPPs). For multilevel model development, the Baseline 22 surveillance dataset was basically classified into groups based on the NPP name, product form, and notch orientation. By including the notch direction in the grouping criteria, the developed model could account for TTS differences among NPP groups with different notch orientations, which have not been considered in previous ETCs. The parameters of the multilevel model and biases of the NPP groups were calculated using the Markov Chain Monte Carlo method. As the number of data points within a group increased, the group bias approached the mean residual, resulting in reduced credible intervals of the mean, and vice versa. Even when the number of surveillance test data points was less than three, the multilevel model could estimate appropriate biases without overfitting. The model also allowed for a quantitative estimate of the changes in the bias and prediction interval that occurred as a result of adding more surveillance test data. The biases estimated through the multilevel model significantly improved the performance of E900-15.},
	language = {en},
	number = {8},
	urldate = {2023-07-15},
	journal = {Nuclear Engineering and Technology},
	author = {Lee, Gyeong-Geun and Lee, Bong-Sang and Kim, Min-Chul and Kim, Jong-Min},
	month = aug,
	year = {2023},
	keywords = {Embrittlement trend curve, Markov chain Monte Carlo, Bayesian multilevel model, Irradiation embrittlement, Reactor pressure vessel},
	pages = {2844--2853},
	file = {ScienceDirect Full Text PDF:files/2881/Lee et al. - 2023 - Determining the adjusting bias in reactor pressure.pdf:application/pdf;ScienceDirect Snapshot:files/2882/S1738573323002206.html:text/html},
}

@article{lee_refinement_2024,
	title = {Refinement {MRP}-135 constitutive equation model for tensile properties of austenitic stainless steel},
	volume = {421},
	issn = {0029-5493},
	url = {https://www.sciencedirect.com/science/article/pii/S0029549324001912},
	doi = {10.1016/j.nucengdes.2024.113091},
	abstract = {This study focuses on analyzing and enhancing MRP-135 constitutive models, which are crucial for assessing the tensile properties of irradiated stainless steels in the reactor vessel internals of pressurized water reactors. The newly developed model, named M1, incorporates parameters from MRP-135, while minimizing modifications to ensure high compatibility with existing models. A significant improvement in M1 is the resolution of the inversion phenomenon observed between the yield strength and ultimate tensile strength at low temperatures in Type 316 stainless steel, a challenge previously identified in MRP-135 Rev. 2. M1 integrates the temperature effects from the earlier version, MRP-135 Rev. 1, to address this issue effectively. Additionally, for Type 316, M1 refined the equations to represent the cold work factor more accurately, enabling precise interpolation of strength variations across different levels of cold work from solution-annealed to cold-worked conditions. A comparative analysis of the M1 and the MRP-135 models against actual irradiated tensile test data for Type 304 and 316 stainless steel demonstrated the superior accuracy of M1, as indicated by a lower root-mean-square deviation. This study highlights the importance of continuous improvements in constitutive models, with future work aimed at further refining these models based on comprehensive irradiation test data.},
	urldate = {2024-04-09},
	journal = {Nuclear Engineering and Design},
	author = {Lee, Gyeong-Geun and Ahn, Dong-Hyun and Kim, Ji-Su and Kim, Min-Chul and Kim, Jong-Mim},
	month = may,
	year = {2024},
	keywords = {Austenitic stainless steel, Constitutive equation model, Reactor pressure vessel (RPV), Reactor vessel internal (RVI), Tensile property},
	pages = {113091},
	file = {1-s2.0-S0029549324001912-main.pdf:files/3660/1-s2.0-S0029549324001912-main.pdf:application/pdf;ScienceDirect Snapshot:files/3610/S0029549324001912.html:text/html},
}

@article{lee__2024,
	title = {혼합효과 모델을 이용한 원자로 압력용기 조사취화 경향곡선의 실용적 조정},
	volume = {20},
	url = {https://doi.org/10.20466/KPVP.2024.20.2.001},
	doi = {10.20466/KPVP.2024.20.2.097},
	abstract = {Cast austenitic stainless steels (CASS) and austenitic stainless steel weldments with a ferrite-austenite duplex structure are widely used in nuclear power plants, incorporating ferrite phase to enhance strength, stress relief, and corrosion resistance. Thermal aging at 290-325°C can induce embrittlement, primarily due to spinodal decomposition and G-phase precipitation in the ferrite phase. This study evaluates the effects of thermal aging by collecting and analyzing various mechanical properties, such as Charpy impact energy, ferrite microhardness, and tensile strength, from various literature sources. Different model expressions, including hyperbolic tangent and phase transformation equations, are applied to calculate activation energy (Q) of room-temperature impact energies, and the results are compared. Additionally, predictive models for Q based on material composition are evaluated, and the potential of machine learning techniques for improving prediction accuracy is explored. The study also examines the use of ferrite microhardness and tensile strength in calculating Q and assessing thermal embrittlement. The findings provide insights for developing advanced prediction models for the thermal embrittlement behavior of CASS and the weldments of austenitic steels, contributing to the safety and reliability of nuclear power plant components.},
	language = {ko},
	number = {2},
	journal = {Transactions of the Korean Society of Pressure Vessels and Piping},
	author = {Lee, Gyeong-Geun and Lee, Bong-Sang and 김민철 and Kim, Jong-Min},
	year = {2024},
	pages = {1--10},
	file = {20(2) 097-106 이경근:files/4000/20(2) 097-106 이경근.pdf:application/pdf},
}

@article{lee_development_2024,
	title = {Development of a {Magnetic} {Rope} {Testing} {System} {Using} {Hall} {Sensors} and {Its} {Wire}-{Break} {Signal} {Analysis}},
	volume = {44},
	issn = {1225-7842, 2287-402X},
	url = {http://www.dbpia.co.kr/Journal/ArticleDetail/NODE11960747},
	doi = {10.7779/JKSNT.2024.44.5.361},
	language = {en},
	number = {5},
	urldate = {2024-12-26},
	journal = {JKSNT},
	author = {Lee, Gyeong-Geun and Park, Jun-Kue and Han, Soonwoo and Kang, To and Moon, Seongin and Maeng, WanYoung and Jeong, Jaehwan and Jeong, Hun and Kim, Seong-Ha and Lee, See-Hyoung},
	month = oct,
	year = {2024},
	pages = {361--370},
	file = {PDF:files/3999/Lee et al. - 2024 - Development of a Magnetic Rope Testing System Using Hall Sensors and Its Wire-Break Signal Analysis.pdf:application/pdf},
}

@article{lee_denoising_2023,
	title = {Denoising {Magnetic} {Flux} {Leakage} {Signals} for {Wire} {Ropes} {Inspections} using {Discrete} {Wavelet} {Transform}},
	volume = {43},
	issn = {1225-7842, 2287-402X},
	url = {http://www.dbpia.co.kr/Journal/ArticleDetail/NODE11561813},
	doi = {10.7779/JKSNT.2023.43.5.339},
	language = {en},
	number = {5},
	urldate = {2024-12-26},
	journal = {JKSNT},
	author = {Lee, Gyeong-Geun and Han, Soon-Woo and Moon, Seongin and Maeng, WanYoung and Kang, To and Jeong, Jaehwan},
	month = oct,
	year = {2023},
	pages = {339--348},
	file = {1-JKSNT Vol. 43, No. 5, pp. 339-348.pdf:files/3258/1-JKSNT Vol. 43, No. 5, pp. 339-348.pdf:application/pdf},
}

@article{lee__2024-1,
	title = {주조 오스테나이트 스테인리스강의 열취화 활성화에너지 분석},
	volume = {20},
	url = {https://doi.org/10.20466/KPVP.2024.20.1.056},
	doi = {10.20466/KPVP.2024.20.1.056},
	number = {1},
	urldate = {2024-12-26},
	journal = {Transactions of the Korean Society of Pressure Vessels and Piping},
	author = {Lee, Gyeong-Geun and Hong, Suk-Min and Kim, Ji-Su and Ahn, Dong-Hyun and Kim, Jong-Min},
	month = jun,
	year = {2024},
	pages = {56--65},
	file = {Lee et al. - 2024 - Analysis of Activation Energy of Thermal Aging Emb.pdf:files/3717/Lee et al. - 2024 - Analysis of Activation Energy of Thermal Aging Emb.pdf:application/pdf},
}

@article{lee_adjustment_2025,
	title = {Adjustment of reactor pressure vessel embrittlement trend curves using a mixed-effects model},
	volume = {57},
	issn = {17385733},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S1738573325002220},
	doi = {10.1016/j.net.2025.103654},
	abstract = {This study presents a novel approach for adjusting the generic reactor pressure vessel embrittlement trend curve (ETC), ASTM E900-15, using a mixed-effects model based on Baseline22, a compiled dataset of surveillance test data from nuclear power plants worldwide. Using this statistical framework, systematic deviations owing to initial material properties, notch orientations, and other plant-specific factors were separated from measurement errors, providing a more accurate assessment of embrittlement trends. Two types of adjustment models were explored: an intercept-only model (AM3) and a combined intercept-slope model (AM6). The AM3 model, which estimates only group-specific intercepts, effectively reduces prediction errors compared to ASTM E900-15 model while maintaining interpretability and simplicity, making it particularly suitable for regulatory applications. AM6, which incorporates group-specific slopes and covariance terms, further improves predictive accuracy, but introduces estimation complexities, so its suitability for conservate regulatory applications requires further discussion. To facilitate the practical implementation of AM3, closed-form expressions for group-specific intercept adjustments were derived, enabling the estimation of adjustment factors without the need for Bayesian Markov chain Monte Carlo models or complex statistical tools. Additionally, the standard deviations of the intercept means and prediction intervals were formulated as functions of the group size, providing a straightforward method for assessing embrittlement trends as new surveillance test results became available. This study demonstrates that existing generic ETC models can be dynamically refined and updated using plant-specific surveillance test data, while maintaining robustness and regulatory applicability. These findings lay the groundwork for the future refinement of standard ETC models, potential integration with regulatory frameworks, and improved long-term integrity assessments of reactor pressure vessels in aging nuclear power plants.},
	language = {en},
	number = {9},
	urldate = {2025-05-07},
	journal = {Nuclear Engineering and Technology},
	author = {Lee, Gyeong-Geun and Lee, Bong-Sang and Kim, Min-Chul and Kwon, Junhyun and Kim, Jong-Min},
	month = sep,
	year = {2025},
	pages = {103654},
	file = {PDF:files/4210/Lee et al. - 2025 - Adjustment of reactor pressure vessel embrittlement trend curves using a mixed-effects model.pdf:application/pdf},
}

@incollection{server_analysis_2023,
	title = {Analysis of {Radiation} {Embrittlement} {Trend} {Curves}: {Machine} {Learning} and {Multilevel} {Modeling}},
	isbn = {978-0-8031-7741-3 978-0-8031-7742-0},
	shorttitle = {Analysis of {Radiation} {Embrittlement} {Trend} {Curves}},
	url = {https://asmedigitalcollection.asme.org/astm-ebooks/book/310/chapter/27751970/Analysis-of-Radiation-Embrittlement-Trend-Curves},
	doi = {10.1520/STP164720220042},
	abstract = {Machine learning (ML) has been a widely used tool for recognizing patterns in an extensive database with increasing computing power. This study applied three ML techniques—Cubist, support-vector machine (SVM), and XGBoost (XGB)—to fit the BASELINE surveillance test database. The rule-based Cubist and tree-based XGB models showed a significantly lower root-mean-square deviation than the SVM and ASTM E900-15 nonlinear model. ML showed a good capability for prediction in the interpolation region of the dataset. However, there were significant errors in the extrapolation region in predicting the effect of large fluence on the transition temperature shift (TTS). ML can be very useful in the development of a preliminary model because it can quickly capture the trend of the dataset. To improve the prediction of the TTS trend with fluence in the grouped data with the same initial Charpy impact property, a varying intercept model was introduced into the ASTM E900-15 trend curve, and the model coefficients were estimated by a multilevel modeling procedure. This model considered both the trend of all data and the trend of each group. It then provided more reliable intercepts in each group for TTS prediction with fluence. The multilevel modeling of the grouped datasets can increase the predictive power of the embrittlement trend model for commercial power plants.},
	language = {en},
	urldate = {2025-06-25},
	booktitle = {Radiation {Embrittlement} {Trend} {Curves} and {Equations} and {Their} {Use} for {RPV} {Integrity} {Evaluations}},
	publisher = {ASTM International100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959},
	author = {Lee, Gyeong-Geun and Kim, Min-Chul and Lee, Joonho and Lee, Bong-Sang},
	editor = {Server, William L. and Brumovský, Milan and Kirk, Mark},
	month = jun,
	year = {2023},
	pages = {336--353},
	file = {PDF:files/4308/Lee et al. - 2023 - Analysis of Radiation Embrittlement Trend Curves Machine Learning and Multilevel Modeling.pdf:application/pdf},
}

@article{lee_evaluation_2026,
	title = {Evaluation of embrittlement models for regulatory use: {Comparing} {RG} 1.99 {Rev}. 2 and an intercept-adjusted {ASTM} {E900}-15 approach},
	volume = {58},
	issn = {1738-5733},
	shorttitle = {Evaluation of embrittlement models for regulatory use},
	url = {https://www.sciencedirect.com/science/article/pii/S1738573325006060},
	doi = {10.1016/j.net.2025.104038},
	abstract = {This study evaluated the regulatory applicability of embrittlement trend curve models for reactor pressure vessel (RPV) steels by comparing RG 1.99 Rev. 2 with an intercept-adjusted ASTM E900-15 model. A statistically grounded additive adjustment was applied to the E900-15 model to improve its prediction accuracy using plant-specific surveillance data. The analysis utilized a combined dataset of 1034 data points from Korean and U.S. nuclear power plants, encompassing a broad range of product forms, notch orientations, and fluence levels. Quantitative comparisons with and without model-specific margins were performed to assess the predictive performance and conservatism of each model within the established regulatory upper-bounds for RPV embrittlement. The adjusted E900-15 model significantly reduced the residual bias and root-mean-square deviation, particularly at high fluence levels. Its marginal behavior remained stable and statistically conservative without excessive overestimation, whereas RG 1.99 Rev. 2 tended to underestimate the embrittlement in the long-term fluence regime. Even though RG 1.99 Rev. 2 is widely adopted for its simplicity, the findings indicate that the intercept-adjusted E900-15 model provides a more accurate and adaptable framework for regulatory applications, particularly for long-term operations and life-extension assessments.},
	number = {3},
	urldate = {2025-12-08},
	journal = {Nuclear Engineering and Technology},
	author = {Lee, Gyeong-Geun and Lee, Bong-Sang and Kim, Min-Chul and Kwon, Junhyun and Kim, Jong-Min},
	month = mar,
	year = {2026},
	keywords = {Irradiation embrittlement, ASTM E900-15 adjustment, Embrittlement Trend Curve (ETC), Reactor Pressure Vessel (RPV), Regulatory guide 1.99 rev. 2, Regulatory margin evaluation},
	pages = {104038},
	file = {ScienceDirect Full Text PDF:files/5003/Lee et al. - 2026 - Evaluation of embrittlement models for regulatory use Comparing RG 1.99 Rev. 2 and an intercept-adj.pdf:application/pdf;ScienceDirect Snapshot:files/5002/S1738573325006060.html:text/html},
}

@misc{noauthor_kaeri-_nodate,
	title = {{KAERI}-외부메일},
	url = {https://mail.kaeri.re.kr/mail/#mboxes/unseen/mails?currentPage=1&perPage=20&sortField=M_TIME&sortOrder=DESC&specialUseMailbox=unseen},
	urldate = {2026-02-24},
	file = {KAERI-외부메일:files/6132/mail.html:text/html},
}

@article{lee_empirical_2025,
	title = {Empirical {Modeling} of {Swelling} in {Cold}-{Worked} {SS316} {Stainless} {Steel} under {Molten} {Salt} {Reactor} {Conditions}},
	volume = {21},
	url = {https://doi.org/10.20466/KPVP.2025.21.2.171},
	doi = {10.20466/KPVP.2025.21.2.171},
	abstract = {Accurate prediction of irradiation-induced swelling in 316 stainless steel (SS316) is important for the structural design and lifetime assessment of Molten Salt Reactors (MSRs), where structural materials are exposed to high temperatures and fast-neutron damage for long periods of time. In this study, we collected a broad set of cold-worked SS316 swelling data from the open literature, and developed two types of empirical models: a power-law model and an incubation-saturation model. For the benchmark Garner dataset, the incubation-saturation model reproduced the typical incubation period and saturation behavior of SS316 and showed better fitting accuracy than the power-law model. When the two models were applied to a larger pooled dataset that combined results from multiple literature sources, both models were able to describe the general swelling trends across a wide range of temperatures and doses, showing that they can be applied to MSR related conditions. The models presented in this work provide a useful empirical basis for early stage MSR design and for interpreting the irradiation behavior of cold-worked SS316. Future work, including statistical methods that can consider differences among studies, will help improve the generality and prediction capability of the proposed approach.},
	language = {ko},
	number = {2},
	urldate = {2026-04-15},
	journal = {Transactions of the Korean Society of Pressure Vessels and Piping},
	publisher = {한국압력기기공학회},
	author = {Lee, Gyeong-Geun and Kwon, Junhyun and Hong, Min-Sung and Ahn, Dong-Hyun},
	month = dec,
	year = {2025},
	pages = {171--180},
	file = {PDF:files/5344/Lee et al. - 2025 - Empirical Modeling of Swelling in Cold-Worked SS316 Stainless Steel under Molten Salt Reactor Condit.pdf:application/pdf},
}