Jae Seong Je

The systematic management of plant risk is crucial for enhancing the safety of nuclearpower plants and for designing new nuclear power plants. Accident sequence precursor(ASP) analysis may be able to provide risk significance of operational experience by usingprobabilistic risk assessment to evaluate an operational event quantitatively in terms of itsimpact on core damage. In this study, an ASP methodology for two operation mode, fullpower and low power/shutdown operation, has been developed and

본 연구에서는 국내 전력공급을 양분하는 원자력발전시스템과 화력발전시스템사이에 대하여 LCA를 수행하여 환경영향을 비교 평가하였다. 연구범위로서 두 발전시스템의 건설, 운영, 해체 및 폐기처분단계를 포함하였으며, 환경영향은 Life Cycle Impact Assessment(LCIA) 방법론을 이용하여 단일 환경영향으로 CO2 배출량을 평가하고, 영향 범주를 확대하여 8대 지구 환경영향 및 방사능 영향을 포함한 환경영향에 대하여 평가를 수행하였다. 평가 결과, 원자력발전시스템이 화력발전시스템보다 CO2 배출량 평가에서는 10,000배, 8대 환경영향범주에 대한 평가에서는 90배, 방사능을 고려한 환경영향 평가결과에서는 40배의 환경적 우위를 나타내어 환경영향범주 확대와 방사능 포함여부에 따라 원자력발전의 친환경성이 크게 달라짐을 알 수 있었다.

Evacuation Time Estimate (ETE) can provide decision-makers with a likelihood to implement evacuationof a population with radiation exposure risk by a nuclear power plant. Thus, the ETE is essential fordeveloping an emergency response preparedness. However, studies on ETE have not been conductedadequately in Korea to date. In this study, different cohorts were selected based on assumptions. Existinglocal data were collected to construct a multi-model network by TSIS-CORSIM code. Furthermore, seve

This study developed a Safety Culture Impact Assessment Model (SCIAM) which consists of a safety culture assessment methodology and a safety culture impact quantification methodology. The SCIAM uses safety culture impact index (SCII) to monitor the status of safety culture of the NPPs periodically and it uses relative core damage frequency (RCDF) to present the impact of safety culture on the safety of the NPPs. As a result of applying SCIAM to the reference plant (Kori 3), the standard for the

In order to reduce risks from the Steam Generator Tube Rupture (SGTR) accident and to meet safetytargets, various measures have been analyzed to minimize the amount of fission product (FP) release. Inthis paper, we propose an introduction of a Containment Filtered Venting System (CFVS) connected tothe steam generator secondary side, which can reduce the amount of FP release while minimizingadverse effects identified in the previous studies. In order to compare the effect of new equipment withthe

One of the important issues raised from the Fukushima-Daiichi accident is the safety of multi-unit siteswhen simultaneous accidents occur at the site and recently a multi-unit PSA methodology is beingdeveloped worldwide. Since all operation modes of the plant should be considered in the multi-unit PSA,the accident analysis needs to be performed for shutdown operation modes, too. In this study, a stationblackout during the mid-loop operation is selected as a reference scenario. The overall accide

As the amount of fission product released from ISLOCA was overestimated because of conservative assumptionsin the past, several studies have been recently conducted to evaluate the actual releaseamount. Among several pathways for the ISLOCA, most studies were focused on the pathway with thehighest possibility. However, different ISLOCA pathways may have different fission product releasecharacteristics. In this study, fission product behavior was analyzed for various pathways at the Westinghouset

Hydrogen production facility using very high temperature gas cooled reactor lies in situation of high temperature and corrosion which makes hydrogen release easily. In that case of hydrogen release, there lies a danger of explosion. However, from the point of thermal-hydraulics view, the long distance of them makes lower efficiency result. In this study, therefore, outlines of hydrogen production using nuclear energy are researched. Several methods for analyzing the effects of hydrogen explosion

The correlations between Large Early Release Frequency (LERF) and Early Fatality need to be investigated for riskinformed application and regulation. In Regulatory Guide (RG) -1.174, while there are decision-making criteria using the measures of Core Damage Frequency (CDF) and LERF, there are no specific criteria on LERF. Since there are both huge uncertainties and large costs needed in off-site consequence calculation, a LERF assessment methodology needs to be developed, and its correlation fac

Limiting conditions for operations (LCOs) are evaluated dynamically using the tool of system dynamics. The LCOs define the allowed outage times (AOTs) and the actions to be taken if the repair cannot be completed within the AOT. Syste-m dynamics has been developed to analyze the dynamic reliability of a complicated system. System dynamics using Vensim software have been applied to LCOs assessment for an example system, the auxiliary feed water system of a reference nuclear power plant. Analysis

The feature of the COntainment Failure probability and Uncertainty aNalysis program (COFUN) is the quantification of the containment state. The probability factors used in probabilistic safety assessment (PSA) and the resulting outputs contain probability bands, so it is necessary to present the uncertainty bands as results. The uncertainty analysis process of the level 2 PSA is that a level 1 PSA uncertainty propagates to a level 2 PSA uncertainty. The basic event data including probability dis

Background: In terms of the Level 3 probabilistic safety assessment (Level 3 PSA), ingestion of food that had been exposed to radioactive materials is important to assess the intermediate- and long-term radiological dose. Because the ingestion dose is considerably dependent upon the agricultural and dietary characteristics of each country, the reliability of the assessment results may become diminished if the characteristics of a foreign country are considered. Thus, this study intends to evalua