Commissioning of TRATEL thermal-hydraulics experimental equipment

This paper aims to present the installation, operation and the operating experience of the TRATEL (TRAnsparent thermal-hydraulics TEst Loop) facility that is located at BUTE, Institute of Nuclear Techniques. Since the beginning of 2009 TRATEL has been owned by the Institute. The test loop is modeling the primary loop of a VVER-440 pressurized water reactor of the Paks Nuclear Power Plant in Hungary. The model is made of glass, allowing insight into the primary loop: the two-phase flow during a Loss of Coolant Accident (LOCA) can be observed directly in TRATEL. The paper describes the renovation and installation of the experimental equipment. The structure of the system and the operation of the test loop are presented. The thermal-hydraulics processes of LOCAs with different break size and location are demonstrated. The loop is equipped with valves to simulate both hotand cold leg breaks and different break simulators can be used to change the break size. In the course of the experiments the two-phase flow and the depletion of the primary loop can be observed in the pressurizer, primary pipes, the core and the steam generator. This paper describes the equipment installation process, and presents some experiments with the most important one- and two phase thermal-hydraulics phenomena that can be demonstrated by TRATEL.