A covering element for a reactor core of a nuclear installation provides a secure and tight closure of the reactor core in an operating state and at the same time being simple and cost effective to produce. The covering element is easily disassemblable during maintenance or loading processes and provides good possibilities for intervention in the reactor core. For this purpose, the covering element has a closure head and a separate support ring. The support ring is joined form-lockingly and/or force-lockingly to the closure head.