Browse > Article
http://dx.doi.org/10.14346/JKOSOS.2020.35.5.121

Thermal-hydraulic Analysis of Operator Action Time on Coping Strategy of LUHS Event for OPR1000  

Song, Jun Kyu (Korea Hydro & Nuclear Power)
Publication Information
Journal of the Korean Society of Safety / v.35, no.5, 2020 , pp. 121-127 More about this Journal
Abstract
Since the Fukushima nuclear accident in 2011, the public were concerned about the safety of Nuclear Power Plants (NPPs) in extreme natural disaster situations, such as earthquakes, flooding, heavy rain and tsunami, have been increasing around the world. Accordingly, the Stress Test was conducted in Europe, Japan, Russia, and other countries by reassessing the safety and response capabilities of NPPs in extreme natural disaster situations that exceed the design basis. The extreme natural disaster can put the NPPs in beyond-design-basis conditions such as the loss of the power system and the ultimate heat sink. The behaviors and capabilities of NPPs with losing their essential safety functions should be measured to find and supplement weak areas in hardware, procedures and coping strategies. The Loss of Ultimate Heat Sink (LUHS) accident assumes impairment of the essential service water system accompanying the failure of the component cooling water system. In such conditions, residual heat removal and cooling of safety-relevant components are not possible for a long period of time. It is therefore very important to establish coping strategies considering all available equipment to mitigate the consequence of the LUHS accident and keep the NPPs safe. In this study, thermal hydraulic behavior of the LUHS event was analyzed using RELAP5/Mod3.3 code. We also performed the sensitivity analysis to identify the effects of the operator recovery actions and operation strategy for charging pumps on the results of the LUHS accident.
Keywords
stress test; loss of ultimate heat sink; nuclear power plant; natural disaster; operation strategy; operator action;
Citations & Related Records
연도 인용수 순위
  • Reference
1 OCED/NEA No.7284, "Five Years after the Fukushima Daiichi Accident, Nuclear Safety Improvements and Lessons Learnt", Nuclear Energy Angency, 2016.
2 Korea Hydro and Nuclear Power Co. Ltd., "Stress Test Report for Hanul Unit 3&4 (an open copy)", 2018.
3 Nuclear Safety and Security Commission, "Stress Test Implementation Guide", 2016.
4 D. H. Kim et.al, "Development of Mitigation Strategy for Beyond Design Basis External Events for NRC Design Certification", Transactions of the Korean Nuclear Society Autumn Meeting, 2013.
5 Information Systems Laboratories, Inc., "RELAP5/MOD3.3 Code Manual", 2016.