During the test, core material was heated to over 2000oC. Steel was introduced after melting of the material, and the test was continued for another half hour before reaching a steady state. All measuring and engineering systems functioned normally during the experiment. The post-test examination will consist of sectioning the solidified material and performing metallographic examination.
In addition, Argonne National Laboratory in the USA has carried out two tests to study the emergency cooling of the debris of a molten reactor core following a severe accident. These tests were intended to assess the extent to which water ingress through cracks and pores in the crust of molten debris will enhance the cooling of the melt. The two tests were performed with two different melt compositions, but otherwise under identical test conditions. Preliminary data from the experiments indicate that enhanced cooling was achieved in both tests, confirming that water ingress can be a viable cooling mechanism.
In a core melt accident, if the molten core is not retained inside the vessel despite severe accident mitigation actions, the core debris will relocate to the reactor cavity region and interact with the structural concrete, potentially resulting in failure of structures through erosion or over-pressurisation.