Abstract: A secondary-side residual-heat removal system for a pressurized-water reactor removes residual heat through a secondary side of a steam generator in certain modes of operation and malfunction. For this purpose, the respective steam generator has a connection on a live-steam and feed-water side to a secondary side of a safety condenser. The connection on the feed-water side is led to a supply connection of a swirl or vortex chamber valve having a control connection which is connected to a feed-water line part on the pressure side, with a downgradient from a main feed-water pump, and the swirl or vortex chamber valve has an outlet which opens out into a feed-water inflow space of the steam generator. A tertiary side of the safety condenser is fed from a water reservoir disposed at a geodetically higher level. The steam being generated is discharged into the atmosphere through a blowing-off line, with a separating device if appropriate.

Abstract: A hydraulic control rod drive for a nuclear reactor, with a a reactor plenum enclosing the drive, comprises first and second hollow bodies together forming a cylinder and a hollow piston. Working fluid is supplied through one of the hollow bodies. The first hollow body is stationary and the second hollow body is disposed coaxially around the first hollow body. The two hollow bodies define an annular gap therebetween so as to allow axial reciprocating movement of the second hollow body, which forms a carrier body for control elements of the control rod. The second hollow body can be lifted, lowered or suspended by feeding working fluid. A portion of the fluid is removed from the inner space via a throttle passage. A positional measurement system determines the relative displacement of the second hollow body by measuring an ultrasonic measurement path. The system includes an ultrasound reflector and an ultrasonic transducer rigidly mounted remote from the ultrasound reflector.

Abstract: A hydraulic control rod drive for a water-cooled nuclear reactor includes a control valve assembly outside the reactor pressure vessel for influencing the fluid quantity on the pressure side of a fluid pump assembly for adjusting control rods in raising and lowering directions and to maintain a control rod position.

Abstract: Liquid-cooled nuclear reactor having a reactor pressure vessel and a reactor core of fuel assemblies received therein, the fuel assemblies being grouped into core cells each having a control rod containing absorber material and connected to a drive mechanism, including a sheetmetal shaft associated with the core cells, respectively, and extending beyond the length of the reactor core by a length at least equal to that of the respective control rod and having a cross section substantially equal to that of the respective core cell, the sheetmetal shaft being formed with longitudinal channels through which the fuel assemblies are loadable and unloadable.