Hwang Bae

Experimental Study of SBLOCA Simulation of Safety-Injection Line Break with Single Train Passive Safety System of SMART-ITL

An experimental study of the thermal-hydraulic characteristics of passive safety systems (PSSs) was conducted using a system-integrated modular advanced reactor-integral test loop (SMART-ITL). The present passive safety injection system for the SMART-ITL consists of one train with the core makeup tank (CMT), the safety injection tank, and the automatic depressurization system. The objective of this study is to investigate the injection effect of the PSS on the small-break loss-of-coolant accident (SBLOCA) scenario for a 0.4 inch line break in the safety-injection system (SIS). The steady-state condition was maintained for 746 seconds before the break. When the major parameters of the target value and test results were compared, most of the thermal-hydraulic parameters agreed closely with each other. The water level of the reactor pressure vessel (RPV) was maintained higher than that of the fuel assembly plate during the transient, for the present CMT and safety injection tank (SIT) flow rate conditions. It can be seen that the capability of an emergency core cooling system is sufficient during the transient with SMART passive SISs. §이 논문은 대한기계학회 2015 년도 에너지 및 동력 부문 춘계학술대회 발표논문임. † Corresponding Author, rsu@kaeri.re.kr C 2016 The Korean Society of Mechanical Engineers 류성욱 · 배황 · 유효봉 · 변선준 · 김우식 · 신용철 · 이성재 · 박현식 166 형 피동로) CLOF : Complete Loss of RCS Flowrate (원자로냉각재유량완전상실사고) CMT : Core Makeup Tank (노심보충탱크) JAEA : Japan Atomic Energy Agency (일본원자력 연구개발기구, JNC 와 JAERI 가 통합된 기관) LSTF : Large Scale Test Facility (일본 대형 비정상시험장치) NPIC : Nuclear Power Institute of China (중국원자력연구소 = 중국 핵동력연구 설계원) PRHRS : Passive Residual Heat Removal System (피동잔열제거시스템) PSS : Passive Safety System (피동안전계통) ROSA : Rig of Safety Assessment (일본 경수로 냉 각재상실사고 모의실험장치) SBLOCA : Small Break Loss-of-Coolant Accident (소형냉각재상실사고) SMART : System Integrated Modular Advanced ReacTor (중소형일체형 원자로) SIT : Safety Injection Tank (안전주입탱크)

Code validation on a passive safety system test with the SMART-ITL facility

ABSTRACT A thermal-hydraulic integral effect test facility, SMART-ITL, was constructed to examine the system performance of SMART, a 330 MWt integral type reactor, and to provide data for validation of related thermal-hydraulic models in the system analysis codes. SMART is equipped with various passive systems such as a passive residual heat removal system (PRHRS), a passive safety injection system (PSIS), and an automatic depressurization system (ADS). The PSIS of SMART is made up of four core makeup tanks (CMTs), four safety injection tanks (SITs), and related piping. Over 10 tests have been performed to investigate the behavior of a single train of a PSIS (a CMT and a SIT) in connection with PRHRSs and an ADS. Using a system analysis code, MARS-KS, we validated the experimental results for a representative test. All geometrical and thermal-hydraulic conditions of SMART-ITL were reflected in the code input construction. Through the validation process, several models, including a break flow model, heat transfer models, and pressure drop models, were examined. Overall, the major system parameters were well reproduced.

An integral effect test of a complete loss of reactor coolant system flow rate for the SMART design using the VISTA-ITL facility and its simulation with the MARS-KS code

ABSTRACT An integral effect test was successfully performed to provide data to assess the capability of the system analysis code to simulate a complete loss of reactor coolant system (RCS) flow rate (CLOF) scenario for the SMART (System-integrated Modular Advanced ReacTor) design. The steady-state conditions were achieved to satisfy initial test conditions presented in the test requirement, its boundary conditions were accurately simulated, and the CLOF scenario in the SMART design was reproduced properly using the VISTA-ITL facility. The natural circulation flow rate in the RCS was about 12.0% of the rated RCS flow rate and the flow rate in the passive residual heat removal system (PRHRS) loop was about 10.6% of its rated value in the early stage of the PRHRS operation. In this paper, the major experimental results of the CLOF test are discussed. The test results were analyzed using the best-estimate system analysis code, MARS-KS, to assess its capability to simulate a CLOF scenario for the SMART design.