PSAM 16 Conference Paper Overview
Welcome to the PSAM 16 Conference paper and speaker overview page.
Lead Author: Woo Sik Jung Co-author(s): Seong Kyu Park (sparkpsa@ness.re.kr)
| Balanced Fault Tree Modeling of Alternating Operating Systems in Probabilistic Safety Assessment |
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| Nuclear power plants (NPPs) have alternating operation systems, such as the component cooling water system (CCWS), essential service water system (ESWS), essential chilled water system (ECWS), and chemical and volume control system (CVCS). Single-unit Probabilistic safety assessment (SUPSA) models for nuclear power plants (NPPs) have many failures of alternating systems. Furthermore, since NPPs undergo alternating operations between full power and low power and shutdown (LPSD), multi-unit PSA (MUPSA) models have failures of NPPs that undergo alternating operations between full power and LPSD. Their failures for alternating operations are modeled using fraction or partitioning events in seismic SUPSA and MUPSA fault trees. Since partitioning events for one system are mutually exclusive, their combinations should be excluded in exact solutions. However, it is difficult to eliminate the combinations of mutually exclusive events without modifying PSA tools for generating MCSs from a fault tree. If the combinations of mutually exclusive events are not deleted, core damage frequency (CDF) is underestimated. To avoid CDF underestimation in SUPSAs and MUPSAs, this paper introduces a process of converting partitioning events into conditional events, and conditional events are then inserted explicitly inside a fault tree. With this conversion, accurate CDF can be calculated without modifying PSA tools. It is strongly recommended that the method in this paper be employed for avoiding CDF underestimation in seismic SUPSAs and MUPSAs. |
Paper WO177 Preview
Author and Presentation Info
Lead Author Name: Woo Sik Jung (woosjung@sejong.ac.kr)
Bio: (1) Master and Doctoral Degrees for PSA at Korea Advanced Institute of Science and Technology, (2) Worked for KEPCO E&C, KAERI, and US EPRI, (3) Teaching Nuclear Engineering at Sejong University, (4) Developed fault tree solvers FORTE and FTREX that are interfaced with many PSA tools such as US EPRI tools (CAFTA, EOOS, FRANX, PHOENIX), SAPHIRE, SAREX, and AIMS-PSA
Country: South Korea
Company: Sejong University
Job Title: Professor
Bio: (1) Master and Doctoral Degrees for PSA at Korea Advanced Institute of Science and Technology, (2) Worked for KEPCO E&C, KAERI, and US EPRI, (3) Teaching Nuclear Engineering at Sejong University, (4) Developed fault tree solvers FORTE and FTREX that are interfaced with many PSA tools such as US EPRI tools (CAFTA, EOOS, FRANX, PHOENIX), SAPHIRE, SAREX, and AIMS-PSA
Country: South Korea
Company: Sejong University
Job Title: Professor