Thermal Hydraulic Analysis of Double Ended Hot Leg Pipeline Break Accident in AP1000 Reactor

Abstract

In the present research, the Loss of Coolant Accident (LOCA), as a postulated accident in nuclear reactors, in its worst condition called large LOCA has been modeled. A specific type of large LOCA in which a totally guillotine break occurs in the hot leg pipe is the Double Ended Hot Leg (DEHL). Once the ‘LOCA’ occurs, the pipe is break and the coolant is lost and as a result, the danger of core melting is expected. In this paper, the single volume method was used to perform the numerical modeling on AP1000 reactor, a pressurized water reactor, which is among the most complex safe reactors that have been made so far. A wide range of safety margins are provided by its safety systems. The passivity is one of the most important safety features of AP1000 by which several simplifications can be made so that safety, reliability, construction, operation, maintenance, investment, protection and plant costs can be enhanced. Analyzing the most dangerous accident in one of the most secure reactors can be considered a valuable and logical work. The MATLAB software was used to perform the numerical analysis. Finally, the results obtained from the analysis were compared with the reports on the safety, security and environmental of AP1000 reactor.