Feasibility estimation of new mitigation system through causal inference analysis with functional model. (March 2020)

• Record Type: Journal Article
• Authors: Jeon, In Seop; Yoon, Ho Joon; Kang, Hyun Gook
• Is Part Of: Annals of nuclear energy. Volume 137(2020)
• Publication Date: 2020-03
• Subjects: APR 1400 advanced power reactor 1400MWe -- ADV atmospheric dump valve -- CSP containment spray pump -- DVI direct vessel injection -- F&B feed and bleed -- HSIT hybrid safety injection tank -- HPSI high-pressure injection -- LOCA loss of coolant accident -- LPSI low-pressure safety injection -- MFM multi-level flow modeling -- MSSV main steam safety valve -- NPP nuclear power plant -- P&ID piping and instrumentation diagram -- POSRV pilot operated safety relief valve -- PSF passive safety feature -- PWR pressurized water reactor -- RCGVV reactor coolant gas venting valve -- RCS reactor coolant system -- RPV reactor pressure vessel -- SBO station blackout -- SCP shutdown cooling pump -- SG steam generator -- SGTR steam generator tube rupture -- SIP safety injection pump -- SIS safety injection system -- TH thermal hydraulic; Multilevel flow modeling -- Causal inference analysis -- Accident scenario -- Mitigation procedure; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; 621.4805
• DOI: 10.1016/j.anucene.2019.107087
• Languages: English
• ISSNs: 0306-4549

Abstract

Highlights: Functional model is developed based on the design configuration of PWR. Cause analysis with the functional model identifies all possible accident scenarios. Mitigation feasibility of the new mitigation system is evaluated by consequence analysis. The proper mitigation procedures with the Hybrid-SIT system are suggested. Abstract: After the Fukushima accident, passive safety features have been highlighted to prevent severe accidents. Since passive safety features are newly adopted in a nuclear power plant, mitigation feasibilities of those features need to be evaluated. Feasibility estimation is a challenging process in that plant safety depends on complex combinations of diverse safety functions. In this paper, a novel methodology that evaluates the mitigation feasibility of the newly applied system and generates possible mitigation procedures is developed. In the proposed methodology, accident scenarios are identified by causal inference analysis with a functional model. An improved reasoning method and conversion process are proposed for this analysis. The number of scenarios that can be mitigated by the application of the new system is determined as an indicator of mitigation feasibility. This method allows the feasibility estimation of the new mitigation system with high speed and fidelity, and the development of mitigation procedures.