Experimental Study of Departure from Nucleate Boiling on the Surface of a Molten Core Catcher Under Conditions of Boiling Borated Water with Debris

The results of an experimental study associated with the departure from nucleate boiling flux on the surface of a flat plate in the absence of a directional movement of borated water burdened with debris are presented. The experiments model the external surface cooling of a water-water energy reactor molten core catcher in the case of a severe accident involving the destruction of the reactor vessel. The obtained data showed that critical heat flux can be approximately a quarter lower for debris-burdened water than for pure process water under the same conditions. At elevated temperatures, debris components containing epoxy resin particles adhere to surfaces to impair heat transfer.