A core -catcher or core catcher is a device to collect melting core material ( dermis ) at a core melt in a nuclear reactor, in particular in order to prevent the melt-through of the core material through the containment. It consists of a special concrete ceramic mixture and a special structure for cooling the core material.

Are used core catcher among others at the reactors of the European pressurized reactor ( EPR), sodium -cooled fast reactor 300 (SNR - 300) and the water-water power reactor 1000/428 ( WWER-1000/428 ). Furthermore, it is in the boiling water reactor KERENA (formerly SWR -1000) and the pressurized water reactor used ATMEA1. The core catcher of the EPR example, has a spreading area of 170 square meters and a weight of 500 t.

In nuclear power plants of the type AES -91 of Atomstroiexport, with reactors of the type WWER-1000/428, core catcher are used for the first time by default. Thus the two reactors of the Chinese nuclear power plant Tianwan are the beginning of 2011 the world's only active reactors with such a device.