Analysis of RPV Downcomer for the SBLOCA in ACME Integral Test Facility

The Advanced Core cooling Mechanism Experiment (ACME) facility is a 1/3 height scale, high pressure, 1/54.3 power scale and 1/94 volume scale simulation of CAP1400 PWR. A series of twenty-one small break loss of coolant accident (SBLOCA) tests were performed at ACME to collect thermal-hydraulic data for computer code assessment and to support the license of CAP1400. The tests included a range of hot-leg or cold-leg break, double ended direct vessel injection (DEDVI) line break, inadvertent ADS actuation and double ended pressure balance line (PBL) break accidents. The purpose of this paper is to describe the test data of the typical SBLOCA, and to analyze the mixing of liquid in Reactor Pressure Vessel (RPV) downcomer. Furthermore, the trend of RPV downcomer temperature and the temperature distribution in RPV downcomer are investigated.