The effect of sensitive and non-sensitive parameters on DCGL in probability analysis for decommissioning of nuclear facilities

서형우,김혜인 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.10

In the decommissioning of nuclear facilities, Derived Concentration Guideline Level (DCGL) derivation is necessary for the release of the facility after the site remediation, which also needs to be implemented in the stage of establishing a decommissioning planning. In order to derive DCGL, the dose assessment for the receptors can be conducted from residual radioactivity by using RESRAD code. When performing sensitivity analysis on probabilistic parameters, secondary evaluation is performed by assigning a single value for parameters classified as sensitive. However, several options may arise in the handling of nonsensitive parameters. Therefore, we compared the results of the first execution of RESRAD applying probabilistic parameters for each scenario with the results of the second execution applying a single value to sensitive parameters among the probabilistic parameters. In addition, we analyzed the effect of setting options for non-sensitive parameters. As a result, the effect on DCGL were different depending on the application scenario, the target radionuclides, and the input parameter selections. In terms of the overall evaluation period, the DCGL graph of the default option was generally shown as the most conservative except for some radionuclides. However, it will not necessarily be given priority in the aspect of the need to reflect site characteristics. The reason for selecting a probabilistic parameter is the availability of the parameter and the uncertainty of applying a single value. Therefore, as an alternative, it can be consistently applied to distribution as an option for non-sensitive parameters after sensitivity analysis.

Preliminary ALARA residual radioactivity levels for Kori-1 decommissioning and analysis of results and effects of remediation area

서형우,유지환,김기림,손진원 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.3

The effects of nearby residents and the public by the residual contamination from the decommissioningof nuclear facilities should comply with the dose criteria, and whether additional remediation action isnecessary from the ALARA perspective must be determined. Therefore, we analyzed the requirements ofALARA action levels and performed preliminary ALARA evaluation. The ratio of residual contaminationconcentration to DCGL was calculated for the basement fill and the building occupancy mode. The resultsshowed that the additional remediation actions below DCGL are not justified. In addition, we analyzedthe effect of remediation area. It was noted that the increase of the remediation area showed a positivecorrelation with the Conc/DCGL value in the basement fill mode. On the other hand, in the buildingoccupancy mode, since the floor area of the building is the target of remediation and has the effect ofincreasing the same as the evaluation area of the building occupants, but due to the difference in theamount of increase, the Conc/DCGL showed a negative correlation. We expect the approach and methodof ALARA evaluation can be utilized for concrete cost-benefit calculation during the decommissioning orat the time of remediation

천연 Cellulose를 재구성한 생분해성 복합체 제조

서형우,유창하,이원준 한국섬유공학회 2020 한국섬유공학회지 Vol.57 No.5

Environmental issues have led to a growing demand for eco-friendly functional materials and their biodegradable ability. One of the best way to design eco-friendly materials is to utilize bio-mimetic process to mimic their physical structures and chemical characteristics of naturally abundant materials. Here we develop lignocellulose-based composites for sustainable biodegradable materials, which mimic natural cellulose structures. Briefly, biodegradable PCL and stiff CNC crystals replace amorphous hemicellulose and cellulose fibroin, respectively, with enhanced mechanical strength and their facile fabrication. Indeed, electro-spinning with various applied voltage aided to manufacture nano-web structure to obtain definitely increased surface area. Importantly, the control of voltage affected the formation of agglomerates with different taylor cone structure, which could be attributed to the balance between spinning rate and charged constituents. The CNC reinforcement increased the mechanical strength (up to 3 MPa), and PCL increased the degradablity (up to 20% after 24 hrs), which confirms their aforementioned advantages.

국내외 해체원전 주관기관 및 산업 환경 비교 검토

서형우,이상현,유지환,김기림,김혜인 한국에너지학회 2022 한국에너지공학회 학술발표회 Vol.2022 No.4

Calculation of Preliminary Site-Specific DCGLs for Nuclear Power Plant Decommissioning Using Hybrid Scenarios

서형우,손욱 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.4

Korea's first commercial nuclear power plant at Kori site was permanently shut down in 2017 and iscurrently in transition stage. Preparatory activities for decommissioning such as historical site assessment,characterization, and dismantling design are being actively carried out for successful D&D(Dismantling and Decontamination) at Kori site. The ultimate goal of decommissioning will be to ensurethe safety of workers and residents that may arise during the decommissioning of nuclear facilities and,thereby finally returning the site to its original status in accordance with the release criteria. Uponcompletion of decommissioning, the resident's safety at a site released will be assessed from the evaluationof dose caused by radionuclides expected to be present or detected at the site. Although the U.S. commercial nuclear power plants with decommissioning experience use different site release criteria,most of them are 0.25 mSv/y. In Korea, both the unrestricted and restricted release criteria have been setto 0.1 mSv/y by the Nuclear Safety and Security Commission. However, since the dose is difficult tomeasure, measurable concentration guideline levels for residual radionuclides that result in doseequivalent to the site release criteria should be derived. For this derivation, site reuse scenario, selectionof potential radionuclides, and systematic methodology should be developed in planning stage of Korisite decommissioning. In this paper, for calculation of a preliminary site-specific Derived Concentration Guideline Levels(DCGLs) for the Nuclear Power Plant site, a novel approach has been developed which can fully reflectpractical reuse plans of the Kori site by taking into account multiple site reuse scenarios sequentially,thereby striking a remarkable distinction with conventional approaches which considers only a singlesite scenario.

국내 자동차 연비 관리제도

서형우 한국자동차공학회 2017 한국자동차공학회 Workshop Vol.2017 No.9

法人稅率의 變更과 企業의 投資決定

徐衡祐 한국기업경영학회 1994 기업경영연구 Vol.1 No.1

The purpose of this study is to examine how the decreased taxation effect and the increased taxation effect have influenced the investment by changing the corporation Tax rate. The analysis based upon the investment theory model is made by the expense control of Abel, Lucus, Gould, Tread, Way. It was to survey how the required and temporary change have influenced to the investment followed by the funds raising ways. As a result of bilateral analysis for the effects of the required rate change and the temporary rate change, it is found that the both part`s difference is that the equity capital has influenced a lot to the cost of depreciation. Also, in some extreme case, the investment effect by the rate change turned out differently when the full amount of investmeat capital was raised by the equity Capital and the deficit. In the end, our problem on tax law is that the dividend on the capital is not regarded as a expense, therefore, the deficit raise which can be allowed with the expense as the debt interest will be surely beneficial this is the systemic problem.

相續稅法上 遺産課稅制度에 관한 硏究

徐衡祐 한국기업경영학회 1995 기업경영연구 Vol.2 No.2

The human beings acquires property or service in order to carry out his social life and manages this and guarantees this institutionally is the recognition of private ownership system, and the transfer of property of economic value between economic subject without any price cost relation with the eternal guarantee of this system is the inheritance system. The inheritance tax has its major object to realize rather than the object of financial demand but to repress the concentration of wealth and to redistribute the income and property. However, the inheritance tax imposed to transfer of wealth without charge to the inheritance has mich difference in burden of taxation to the tax payers depending on taxation based on what kind of basis. Since the distributing problem of income has become influential as the import policy issue no the facet of social justice in modern country today, it seems that the inheritance tax system of taxation methods of the inheritance tax has persuasive power, but taking standpoint of what kind of method is the issue of the most important legislation policy decision. The inheritance taxation law in our country shall be taxed by income earner, but since it is the administrative opportunism taxation system to tax collectively, the burden amount of the inheritance tax in the same amount whether the successor is one or several persons, so the taxation method of taxation model for the legacy which gas the weakness that it concentrates the wealth or accelerate preponderance of the wealth shall be improved. Also, in case of our country, the taxation type for legacy is applied, but when the actual record of taxation for the inheritance tax of major foreign countries such as Japan which is taking legacy acquiring taxation type is analyzed, the actual standing of tax income is very little. Therefore, the taxation system to the whole inherited property is against the objectives and consistency of the whole taxation system on the taxation law such as income tax in our country of taxation system by individual, and the legacy income taxation system is rational in the theoretical aspect or policy aspect and can be said to accord with principle of burden in accordance with ability. Also, the burden in accordance with ability can be burdened to the property obtainer, and the chance of dispersion of inherited property rationally is prepared naturally to the successor who is the obtainer of the inherited property, so the promoting function of distribution of wealth is displayed and at the same time, the effect of relative decrease of burden of inheritance tax can be obtained.

전기자극 조건에 따른 근육 세포에 미치는 영향과 반응

서형우,신현영,이현주,태기식,김민석 대한의용생체공학회 2017 의공학회지 Vol.38 No.6

Skeletal muscle function plays a very important role in quality of life. However, skeletal muscle causes functional decline under aging or some diseases. Exercise and muscle training are good solutions to delay sarcopenia, but there are limitations to those who are uncomfortable in exercise. For this reason, alternative interventions for muscle sarcopenia are required, and many studies proved the increase of skeletal muscle mass by electrical stimulation. In conventional studies, however, mouse skeletal muscle cells have been mostly used in experiments to identify electrical stimulation conditions while human derived cells have not been frequently utilized in these studies. Stimulation used for rehabilitation has been uniformly treated without the consideration of aging. In addition, many studies have been used with conventional petri dish usually requiring many numbers of cells, which is not appropriate for rare. Moreover, they are not usually condition uniformity of electrical field. In this study, we have developed an electrical stimulation device which consumes a small amount of cells and can form a uniform electrical field. With the system, we analyzed the skeletal muscle differentiation and Myotube thickness depending on the electrical stimulation condition.

민자철도사업 현황과 최근 정책동향

서형우 한국철도학회 2022 철도저널 Vol.25 No.1