[en] The framework of proliferation resistance evaluation methodology, based on attribute analysis and scenario analysis, for nuclear energy system is suggested in order to allow for the comprehensive assessment of proliferation resistance by addressing the intrinsic and extrinsic features of nuclear energy system. Proliferation resistance is viewed within the context of the success tree model of proliferator's diversion attempt and expressed by the value of top event probability of the success tree model. This study focused on the method that the value of top event is estimated. The methodology uses two different methods to quantify the likelihood of basic events constituting the top event. The likelihood of basic event success affected by intrinsic feature of nuclear energy system was assessed by using multi-attribute utility theory and likelihood of basic event related to the diversion detection measures was assessed by direct expert elicitation. The value of top event was calculated based on the intersection of probabilities of basic event success. Feasibility of the methodology was explored by applying it to selected reference nuclear energy systems. System-Integrated Modular Advanced Reactor (SMART) system and Light Water Reactor (LWR) were chosen as reference systems and the value proliferation resistance of SMART and LWR were evaluated. Characteristics of inherent features and hypothesized safeguards measures of both systems were identified and used as input data to evaluate proliferation resistance. The results and conclusions are applicable only within the context of subjectivity of this methodology

[en] Graphical abstract: - Highlights: • Anodization of near-equiatomicTi-Ni alloys with different Ni contents was examined in an ethylene glycol electrolyte containing ammonium fluoride and water. • The morphology of oxide layers was not affected by the crystal structure of Ti-Ni alloy substrate, but by the chemical composition. • The morphological transition of oxide layers from tubular to irregular-shaped porous structure proceeded with time on the Ti-Ni alloys. - Abstract: Anodization of near-equiatomic Ti-Ni alloys was performed in an ethylene glycol based electrolyte under various conditions in order to investigate the effects of crystal structure and chemical composition of the Ti-Ni alloy on the morphology of the resulting oxide layers. X-ray diffraction patterns revealed that Ti-Ni substrates with Ni content lower than 50.0 at.% were in the martensitic phase, while substrates with Ni content higher than 50.0 at.% were in the austenitic phase. Oxide layers formed at 20 or 35 V for 5 min exhibited no distinct nanotubular structures; however, at 50 V, nanotubular oxide layers were formed. After anodization at 50 V for 20 min, the growth of an irregular-shaped porous layer underneath the nanotubular oxide layer was observed for Ti-Ni alloys with Ni content lower than 52.2 at.%, whereas the oxide layer consisted of only irregular-shaped porous structures for the Ti-52.5 at.% Ni alloy. Further anodization resulted in the formation of irregular-shaped porous oxide layers on all Ti-Ni alloys examined. Energy-dispersive X-ray analysis indicated that this morphological transition is related to Ni accumulation in the vicinity of the interface between the bottoms of the oxide layers and the surfaces of the substrate alloys. Therefore, nanotubular oxide layers cannot be grown, and instead irregular-shaped porous oxide layers are formed underneath the nanotubular layers. These results indicate that the morphology of anodic oxide layers formed on the near-equiatomic Ti-Ni alloys is not affected by their crystal structure, but by Ni content and anodization time.

[en] According to the decision of the Atomic Energy Commission of Korea government, Transuranic (TRU) fuel manufacturing facility (TFMF) capable of 1.8 t-HM/yr will be constructed by 2025 together with technology development of nuclear fuel using TRU material recovered from pyro-processing of spent fuel. In this paper, to facilitate the development of safeguards approach for TFMF, safeguards design information of TFMF is analyzed and material balance area (MBA) and key measurement points (KMP) are suggested

[en] TRU material including higher contents of minor actinide has never been addressed in IAEA safeguards criteria. Therefore, safeguards approach for TRU metal fuel fabrication facility need to be developed. Development of safeguards approach and measures applicable to TRU metal fuel fabrication facility begins with how to define TRU material in terms of safeguards since safeguards requirements depend upon the nuclear material category of the nuclear material. In this paper, material category of TRU bearing material at SFR fuel fabrication facility has been reviewed in terms of safeguards as a starting point in facilitating development of safeguards approach for TRU bearing SFR fuel fabrication facility. TRU material is classified into category I by material attractiveness. Overall TRU bearing material at SFR fuel fabrication facility is defined as unirradiated direct use material in safeguards point of view. Therefore, safeguards approach for SFR fuel fabrication facility using TRU material should be developed based on the material category of TRU as unirradiated direct use material.

[en] State Systems of Accounting for and Control of Nuclear Material (SSACs) are fundamental to effective and efficient safeguards implementation. In that regard, legislative and regulatory systems to implement the pertinent accounting and control are required. SSACs also need the technical and analytical ability to perform essential safeguards-related measurements and to operate administrative systems to meet their safeguards reporting obligations. The IAEA prepared so called ISSAS(International SSAC Advisory Service) to provide member states with advice and recommendation for the effectiveness and efficiency of SSACs. The ROK government officially requested the ISSAS mission on Jan. 28, 2005 for the purpose of enhancing nuclear transparency as a countermeasure to solve the nuclear experiment crisis in 2004. The main mission was performed in July and the initial findings with recommendations were presented, and the final draft report with some recommendations will be issued by IAEA in the near future. In this stage, it is important to review the ISSAS procedures and mission activities for the safeguards implementation in the future according to the results and action plans of the final report

[en] This article is aiming at clarifying two objectives concerning the activities of the Permanent Coordinating Group(PCG) of the Ministry of Science and Technology(MOST) of the Republic of Korea(ROK) and the Department of Energy(DOE) of the United States of America(USA). The MOST-DOE PCG and a series of its meetings have been based on the Arrangement between MOST and DOE concerning research and development in nuclear material control, accountancy, verification, physical protection, and advanced containment and surveillance technologies for international safeguards applications. The Arrangement was made on September 19, 1994, and was prolonged on September 17, 2001 for 5 years. The first objective of this article is to analyze meanings and roles of the MOST-DOE PCG and its meetings compared to the actual nuclear policies of Korea Government. The second objective is to make a suggest how to apply them for the formation of nuclear policy

[en] The Korea government has a plan to introduce a IAEA's Integrated Safeguards system through IAEA's broader conclusion in order to enhance transparency of nuclear activity in the ROK. In addition, government is organizing independent nuclear control institute to make national nuclear control system be more strong and systematic. According to these changes in external/internal circumstance, necessity to change the roles and measure of national safeguards inspection is arising. Therefore, this paper considered need to change and basic principles for national safeguards inspection and proposed direction of shift in national safeguards inspection that is the most suitable to the integrated safeguards system

[en] ZnO thin films on molecular beam epitaxy (MBE) seed layers/Si (111) substrates were prepared by using the sol-gel method. The seed layers were grown at various growth temperatures ranging from 300 to 900 .deg. C. Atomic force microscopy (AFM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) measurements were carried out to investigate the effects of the seed layers' growth temperature on the properties of the ZnO thin films. The grains of the seed layers become larger and rougher as the growth temperature is increased. The surface morphologies of the ZnO thin films are changed from elliptical to spherical and the particle size of the ZnO thin films surface is decreased as the growth temperature is increased. The (002) diffraction peaks for ZnO thin films with seed layers are observed to be higher and narrower compared to those of the ZnO thin films without a seed layer. Especially, the ZnO thin films on seed layers grown at a low growth temperature (300 .deg. C) exhibit the largest enhancement among the ZnO thin films with seed layers. In contrast to the XRD results, the PL intensity ratio of the ZnO thin films gradually increases as the growth temperature is increased due to an increase in the quantum efficiency attributed to the change in the surface morphologies of the ZnO thin films.

[en] ZnO thin films with ZnO buffer layers were grown on Si substrates by using plasma-assisted molecular beam epitaxy (PA-MBE). The ZnO buffer layers were grown with the growth interruption technique. The structural and the optical properties of the ZnO thin films were investigated by using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and photoluminescence (PL). The surface morphology of the ZnO thin films was changed from an island to a net-like shape. An evident net-like shape was observed, and the optical properties were enhanced with increasing number of growth interruptions.

[en] ZnO epilayers were grown on pretreated Si (100) substrates by using a N₂ plasma and plasma-assisted molecular beam epitaxy (PA-MBE). The pretreatment for the surfaces of the Si substrates was conducted at different temperature in the range from 100 to 700 .deg. C before the growth. High resolution X-ray diffraction (HR-XRD), atomic force microscopy (AFM), and photoluminescence (PL) measurements were carried out to investigate the effects of the pretreatment on the properties of the ZnO epilayers. All samples show the typical XRD patterns, AFM images, and PL emission peaks for ZnO. A higher intensity and a narrower full width at half maximum (FWHM) of the XRD (002) diffraction peak are observed from the ZnO epilayers grown on the pretreated substrates. The residual stress of the ZnO epilayers is relaxed, and the average grain size is gradually increased as the pretreatment temperature is increased to 300 .deg. C. The luminescent properties of the ZnO epilayers grown on the Si pretreated at a pretreatment temperature of 100 .deg. C are enhanced. However, the ZnO epilayers grown on the Si pretreated at the temperature of 300 .deg. C show anomalous PL behaviors. With further increases in the pretreatment temperature up to 700 .deg. C, the nitrogen passivation efficiency of the substrate surface is degraded. Therefore, a pretreatment temperature below 300 .deg. C during the pretreatment process is the most suitable for obtaining high-quality ZnO epilayers with good luminescence performance.