Abstract: The device includes a corium collector arranged below the vessel of the reactor, with circulation channels for cooling the collector and the corium. These channels are connected to a water feed and cooling-fluid removal circuit including a water storage tank, a tank for collecting fluid removed from the channels and a steam ejector which receives steam from the cooling fluid originating from the collection tank and sucks water from the storage tank and injects the water into the channels.

Abstract: Sealing device for the drive shaft (27) of a high pressure fluid pump comprising a system of seals (33, 34, 35) at least one of which (33) is a hydrostatic seal. Between this hydrostatic seal (33) and the interior of the volute (21) is disposed an auxiliary seal (45) of the mechanical type. The auxiliary seal (45) separates two chambers (46a) and (46b) which can be brought into communication or isolated by a system of pipes (47) on which a valve (48) is disposed. The invention is particularly applicable to the primary pumps of a pressurized water nuclear reactor.