Analysis of loss of full reactor coolant flow accident for ASMR 2741-2746 W. Sun, C-M. Zhang, X-D. Qiao3,J-P.Jing

Energy Education Science and Technology Part A: Energy Science and Research

2014 Volume (issues) 32(4): 2741-2746


Analysis of loss of full reactor

coolant flow accident for ASMR

Wei Sun1, Chun-mingZhang2 , Xue-dong Qiao3Jian-ping Jing4,*


1,2,3,4Nuclear and Radiation Safety Center, MEP, Beijing 100082, China



Received: 01 March 2014; accepted: 05 May 2014



Advanced Small Modular Reactor (ASMR) is a multipurpose and modularized reactor designed by China. It uses passive safety system and integrated design technology for reactor, in which the once-through steam generator is installed inside the pressure vessel. The safe and economic factor for ASMR have reached a level of Generation III nuclear system. Now the ASMR is in the phase of preliminary design, so the safety analysis for transient condition is important and necessary in preliminary design. Based on the characteristic of ASMR, the Loss of Full Reactor Coolant Flow Accident (LOFA) is calculated and analyzed by RELAP5/MOD3.3. In this condition, all primary pumps stop operating because of the loss of power, which leads to the loss of coolant flux and reactor scramming. The initial phase is the most dangerous in this condition, in which the temperature of the coolant increases rapidly and the DNBR decreases as a result of the loss of flow. The calculated result shows that the reactor trip system could keep the reactor subcritical activated by the signal in the accident and the coolant could carry out the residual heat of the core because of the idle of pumps. The DNBR and temperature of the fuel rods could meet the safety criterion. So, the ASMR is safe in the accident of LOFA.


Keywords: ASMR; RELAP5/MOD3.3; LOFA