DIspersion of Simulated COrium-Hot

Ms. Dr. Xiaoyang Gaus-Liu

Programme: Nuclear Waste Management, Safety and Radiation Research (NUSAFE)

Research on Severe Accidents in Light Water Reactors (LWR). Investigation of the fluiddynamic, thermal and chemical processes during melt ejection out of a breach in the lower head of a LWR pressure vessel, at pressures below 2 MPa and various failure modes with an iron-alumina melt and steam.

Experiments are performed in a scaled annular cavity design, to investigate melt dispersal from the reactor pit when the reactor pressure vessel lower head fails at low system pressure of less than 2 MPa. The test facility models the reactor pressure vessel the reactor cavity, compartments and the containment. The mechanisms of efficient melt-to-gas heat transfer, exothermic metal/oxygen reactions, and hydrogen combustion produce a rapid increase in pressure and temperature in the cavity, compartments and containment. In the frame of these Direct Containment Heating (DCH) phenomena the following issues are addressed:

1. final location of the melt
2. loads on the containment in respect to pressure and temperature
3. amount of hydrogen produced and burnt
4. loads on reactor pit and support structures
5. impact on safety components

Knowledge of these point can lead to realize additional safety margins for existing or new plants and help to identify appropriate accident management measures.

• Description of the test facility (TestFacilityDISCO-H.pdf (1511kB))