Abstract: Each parameter of the processes of the nuclear reactor and of the components of a power supply which convert the thermal energy generated by the reactor into electrical power is monitored by a set of four like sensors. One each of the unlike sensors which monitor the different parameters is contained in a reactor-trip logic channel. Each such unlike sensor is referred to here as a "local sensor". Each channel is interlocked with the other three channels and receives the signals sensed by the other three sensors, herein called "remote sensors". Each channel also includes means for processing the signals from the local and remote sensors. The apparatus also includes means for tripping the reactor to deenergize or trip the control rod drive and insert the control rods fully into the core so that the reactor stops supplying power. The apparatus normally operates on a "two out of four" configuration. This assumes that all sensors are in normal operating condition.

Abstract: A method of operating a pressurized water nuclear reactor comprising determining the present core power and reactivity levels and predicting the change in such levels due to displacer rod movements. Groups or single clusters of displacer rods can be inserted or withdrawn based on the predicted core power and reactivity levels to change the core power level and power distribution thereby providing load follow capability, without changing control rod positions or coolant boron concentrations.

Abstract: A protection and control system for a nuclear reactor which monitors a variable operating parameter indicative of the state of reactor operation and identifies an abnormal rate of change in reactor operating conditions. The operating parameter monitored at a given time after the abnormal change in operating conditions is identified and is employed as a base for a variable setpoint defining a design limit within which the reactor can continue to operate. At a preselected time following the identification of the abnormal rate of change of the reactor operating conditions, control of the reactor is automatically modified to establish a reactor working environment in which the reactor can continue to operate. Should the established setpoint be exceeded, the reactor will automatically be tripped.In one embodiment the negative rate of change of neutron flux of the nuclear core is monitored and compared to a preselected reference.

Abstract: A monitor circuit for a control rod drive mechanism (CRDM) that is adapted to detect erroneous stator phase sequences and generate a visible and audible alarm. The monitor circuit has particular application for use in connection with the control element assembly of a nuclear reactor. The monitor circuit includes an interface circuit for each stator phase winding of the drive motor, a plurality of logic gates to detect the predetermined erroneous phase sequences, a plurality of flip-flops to maintain the fault condition signal, visible and audible alarm circuits, and circuitry for resetting the monitor circuit after a fault condition. The monitor circuit also includes a ratchet trip circuit for disengaging the clutch mechanism from the control rods when the rods are in motion in the time a fault condition is detected.

Abstract: Disclosed is a control system and process for operating same for nuclear reactors, particularly gas cooled nuclear reactors, comprising in the control system a means for measuring the output produced in the reactor core and the output removed by a primary circuit or a secondary circuit, a means for integrating the integral of the core produced output over the output level, during the same time, of the primary or secondary circuit of the reactor and a means for forming a control signal from the value of the integral.

Abstract: A temperature control system for liquid plant is comprised of liquid metal, plant members, heaters for heating these liquid metal and the plant members at respective control points, a temperature control unit and a control unit. The plant members include a vessel containing liquid metal, pipe lines through which the liquid metal circulates, and valves. Further, temperature sensors, a level detector for detecting the level of the liquid metal, and a meter for detecting the flow rate of the liquid metal, are mounted to the plant members. Temperature sensors produce output signals relating to the condition parameter of the plant which data is delivered via an interface to the temperature control system and the control unit, as the information at each control point. The control unit previously stores the operating schedule of the plant members and transfers, the input signal relating to the plant condition to the temperature control system, with reference to the temperature control schedule.