Concrete pressure vessel for pressurized or boiling-water nuclear reactors

Claim 1

Concrete pressure vessel for a pressurized water nuclear reactor comprising a cool sealing wall engaging an inner surface of the concrete pressure vessel, a hot inner wall surrounding the reactor and spaced from said cool sealing wall, and at least one intermediate wall disposed between said cool sealing wall and said hot inner wall substantially parallel and in spaced relationship thereto, said intermediate wall being formed with a limited number of passage openings therethrough for conducting coolant medium from the space between said intermediate wall and said cool sealing wall to the space between said intermediate wall and said hot inner wall, said cooling medium comprising water from a primary circulatory loop of the reactor flowing radially inwardly in sections, heat absorbable by said cooling medium in a cooling process being transferable to feedwater of a steam power generating system associated with the nuclear reactor, said primary circulatory looP including a circulatory pump and a heat exchanger therein for heating the feedwater flowing therethrough.