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[en] This project mainly focused on technical development on remote monitoring. It covers optical fiber scintillator to be used as NDA sensor to targets to be applied. Optical fiber scintillator was tested at the high radioactive environment. It is the first try in its kind for spent fuel measurement. It is confirmed that optical fiber sensor can be used for safeguards verification. Its feasibility for spent fuel storage silo at Wolsong reactor was studied. And to optimize remote transmission cost which can be regarded as a major barrier, virtual private network was studied for possible application for safeguards purpose. It can drastically reduce transmission cost and upgrade information surety. As target for remote monitoring, light water reactor and heavy water reactor were feasibly studied. Especially heavy water reactor has much potential for reduction of inspection efforts if remote monitoring is introduced. In overall remote monitoring can play a pivotal role to streamline safeguards inspection
[en] It was decided in the IAEA Board of Governors Meeting held in Sept. 1999 that Neptunium and Americium could be diverted for manufacturing nuclear weapon or explosives, so that appropriate measures should be taken for the prevention of proliferation of these materials. It is expected to take relatively long time for settling down the aligned system dealing with the above materials because the present regulatory statement was prepared on the basis of voluntary offers from the States concerned. The necessity of preventive measures is being convinced among Member States, but it would not be easy to take voluntary participation in detail because of their respective interests. It is expected that this paper could contribute to the effective response as to the international commitments as well as for protecting the domestic nuclear industry and R and D area through analysis on the IAEA's approach on Neptunium and Americium
[en] Thermal neutron detection using optical fiber scintillator (enriched in 6Li) was described. The shapes of the fiber are 0.5mm and 1mm diameters by 5cm length, respectively. For remote measurement, the fiber scintillating assembly was connected with an optic cable for the fluorescence light transmission between the fiber and PMT. This detection was used to pulse-height spectrum due to interaction with radioactive material. The result showed the neutron could be detected in spectrum. Also, the fiber was carried out reliability for high radiation dose at spent fuel
[en] This paper proposes with the conceptual design of the Central Monitoring Station (CMS). The Central Monitoring Station collects and review the information of safeguard from the remote monitoring system at Nuclear Power Plants. For the design of the station, the concept on CMS was designed according to the new developed unattended monitoring system design methodology
[en] OFS assembly was constructed for experimental of radiation characteristics. the OFS assembly was used to OFS as a radiation detection material and optic cable for the light transmission from PFS. Neutron separation measurement for mixed source of gamma ray and neutron and damage characteristic for high radiation intensity were carried out. The result showed that the OFS assembly was possible to separation of neutron by pulse-height spectrum method and the OFS and optical fiber cable were verified without any damage is irradiated up to 10 Mrad with radiation intensity 5,000rad/h. And 10 OFSs were constructed and the measured count rate for each OFS was comparatively constant, the calculated percent relative average deviation was maximum 2.12
[en] The fatigue lifetime of principal components in nuclear power plant is evaluated by using the design fatigue curves in ASME B and PV code during design process. However, it is inadequate to evaluate fatigue lifetime considering the LWR environmental effect by these design fatigue curves because these are presented only under atmosphere environment. Therefore, many studies are recently performed for the design fatigue curves considering LWR environmental effect and are presented that the design fatigue curves in ASME B and PV code can be non-conservative. In present paper, the limits and differences of the design fatigue curves considering environmental effect are presented. To investigate the change of fatigue lifetime according to each design fatigue curve, the CUFs for the pressurizer spray nozzle partly composed of austenitic stainless steel are calculated according to each one. Finally, if the evaluation result can not be satisfied with fatigue design requirement, the alternatives to reduce design cumulative usage factor are discussed. (author)
[en] Technical part Li ion battery market is explosively growing in the world. And then, the acquisition of technologies and patents for Li ion batteries is considered as one of the important issues in the world. Economical/Industrial parts Li ion batteries have been considered as the best candidate of energy storage system for large scale application such as electric vehicles as well as small devices such as cellular phones. It is expected that Li ion battery market size grows dramatically each year. Ⅲ. Scope and Contents of Project 1. Research scope The structural information of electrode materials for ion batteries is calculated using Rietveld refinement with neutron/X-ray diffraction. Their thermal stability is measured using in situ high temperature X-ray diffraction. Ⅳ. Result of Project 1. Research results Using Rietveld refinement with neutron diffraction, we calculated Li-Ni site mixing in NCM 811 which is well known as one of the best cathode materials for Li ion batteries. Maximum entropy method (MEM) showed us the possibility of fast Li diffusion in NCM 811. And, we developed a novel cathode material Na7V3(P2O7)4 with high operation potential and excellent cyclability for the first time using Rietveld refinement with neutron/X-ray diffraction and first principle calculation.
[en] This report describes the local burnup properties of high burnup nuclear fuels, which was carried out from 2007 to 2011 under national nuclear R and D program 'Nuclear Technology Development Project'. The goal of this work is the production of experimental database of burnup dependant chemical properties to support the evaluation of fuel integrity, a safety analysis and to verify the fuel performance code. This report is divided by four tasks as 'characterization of local burnup properties', 'distribution of retained fission gas in an spent fuel', 'fuel/cladding chemical interaction' and 'source terms of actinides'. In addition, the state-of-the arts on the leaching behavior of spent fuel was added. The data can contribute for the practical use of the high/ultra-high burnup fuel. In addition, the source term data can be used for a burnup credit related with long term management of spent nuclear fuel and fuel transportation
[en] The development of the ripple pattern during the ion beam sputtering (IBS) is expounded via the evolution of its constituent ripples. For that purpose, we perform numerical simulation of the ripple evolution that is based on Bradley–Harper model and its non-linear extension. The ripples are found to evolve via various well-defined processes such as ripening, averaging, bifurcation and their combinations, depending on their neighboring ripples. Those information on the growth kinetics of each ripple allow the detailed description of the pattern development in real space that the instability argument and the diffraction study both made in k-space cannot provide.
[en] This first stage report describes “Research on the solid chemical characteristics and behavior of irradiated fuels”(2017. 03 ~ 2018. 12) under national “Nuclear R&D program “Nuclear Technology Development Project”. The purpose of this study is to secure the nuclide distribution measurement technology that is essential for the long-term safety assessment of the spent nuclear fuel management, and to study the chemical behavior of major nuclides in the spent fuel and the changes in physicochemical characteristics of the nuclear fuels. This work can be divided by three tasks as establishment and optimization of precision measurement system for local nuclide distribution, establishment of high temperature analysis system and development of analytical measurement and interpretation techniques for chemical behaviors of metallic fuels, and chemical behaviors of the fuel interface depending on the concentration of solid solution elements. The results of this study are high-radioactive handling technologies required for fuel research, which are the core technologies for the fuel cycle. These technologies are expected to be used in the nuclear industry in the future. In the next step, we will acquire local nuclide distribution characteristics data, high-temperature behavior, and interface behavior of the fuels to cope with the data requirements for permits related to recycling, transportation, intermediate storage, and disposal of the spent nuclear fuel. By evaluating the reliability of the developed analytical method, it is expected to secure standardized analytical technology and to provide related technology in response to the chemical measurement needs of the entire nuclear industry.