Quick-look report of the ROCOM Tests 1.3, 2.1 and 2.2 conducted within the OECD PKL2 Project

In the frame of the OECD PKL 2 Project the Test G3.1 was conducted at the PKL test facility. This test was dedicated to the investigation of a fast cool down transient. The transient was initiated by a main steam line break. One of the objectives of this test was to create experimental data for the the qualification of thermal hydraulic codes against Pressurized Thermal Shock (PTS) and re-criticality aspects. To investigate in more detail the thermal hydraulic behavior inside the reactor pressure vessel (RPV) complementary tests on the coolant mixing were conducted at the ROCOM (Rossendorf Coolant Mixing) test facility. Experimental results at the RPV inlet derived from the Test G3.1 were used as boundary conditions for the ROCOM tests. In the ROCOM Test 1.3 a specific aspect of the behavior of an ECC water stripe was investigated. The goal of the Tests 2.1 and 2.2 was the re-criticality issue, more specific, the investigation of the possibility of the formation of a sector with overcooled water at the core inlet.