Abstract: This governing valve drive mechanism is a governing valve drive mechanism (15) that opens/closes a steam flow path (12) with a valve body (13) in order to regulate the flow rate of steam in a steam turbine (10), and is equipped with: a valve body advancing/retreating mechanism (14) for advancing and retreating the valve body (13) toward and from the steam flow path (12); multiple sets of electric actuators (23A, 23B) each having a rotational drive source (26) and a conversion section (30) for converting rotation of the rotational drive source (26) into a linear motion; connection switching sections (38) by which the electric actuators (23A, 23B) can be individually connected to the valve body advancing/retreating mechanism (14); and a control unit (17) for controlling operations of the rotational drive sources (26) and connection switching sections (38).

Abstract: The operator of a nuclear steam supply system manually selects a lineup of either one, two, or three main feedwater pumps for normal reactor operation to generate power. This selection sets or resets a status latch for each pump, representative of intended pump operation.

Abstract: A method and apparatus for reducing thermal stress in steam turbines having steam chests with a plurality of linearly-arranged valves controlling respective nozzle chambers. By crosstying selected pairs of the valves, and selectively admitting steam through the crosstie, transfers of the turbine from a full-arc admission mode to a partial-arc admission mode, and vice versa, can be made with a minimum temperature differential.

Abstract: This invention relates to a control system for heat supply as hot water from nuclear power plants equipped with condensation units. This leads to the increased efficiency of the nuclear power plant on the basis of heat extraction from the turbine and its utilization for district heating with hot water as agent. The system requires a turbine nonadjustable bleeding through which a steam flow is extracted. A flow nozzle for steam flow measurement is provided on the steam transport line, a pressure transducer which sends a signal to a comparing and control unit which receives also a signal from another pressure transducer located on the turbine first stage. The comparing and control unit actuates the motorized steam and condensate valves, performing the turbine protection in case that the steam flow extracted at the nonadjustable bleeding exceeds the allowed limit.

Abstract: A method for regulating the power supplied to a steam turbine by a pressurized water nuclear reactor driving an electric current generator supplying a network by utilizing the movement of control rods in the reactor and the by-passing of a fraction of the steam produced by the reactor out from the turbine circuit. In the case of electrical uncoupling between the generator and the network or load rejection, the parameter determining the position of the control rods is selected as the greater of two values of a reference temperature. The by-passing of the steam is kept in operation and the operation of the reactor remains automatic. The opening signal for the by-pass valves is modified by a gain signal determined from a signal representing the power level. The invention is particularly applicable to the regulation of the power of pressurized water nuclear power stations.