Reactor control system verification

In a nuclear reactor power plant including a protection system having transducer means for sensing an operating parameter of said power plant represented by a time dependent state variable signal for generating a shutdown signal in terminating operation of said power plant when the magnitude or rate of change of said time dependent state variable signal exceeds predetermined limits and for further generating a reset signal when said time dependent state variable signal no longer exceeds said predetermined limits whereupon operation of said power plant is re-initiated, wherein said transducer means has a characteristic response time, means for verifying operation of said protection system comprising:

• input means responsive to user inputs for generating first control signals;
• programmable control means coupled to said input means and responsive to said first control signals for generating second control signals;
• ramp signal generating means coupled to said protection system and to said programmable control means and responsive to said second control signals for providing a time varying signal representing the time dependent state variable to the transducer means, wherein the characteristic response time of said transducer means is not compensated for by said time varying signal;
• and
• detection/display means coupled to the protection system for measuring and displaying the response of the protection system to the time varying signal provided thereto and for detecting said shutdown signal when the magnitude or rate of change of said time dependent state variable signal exceeds said predetermined limits and said reset signal when said time dependent state variable signal no longer exceeds said predetermined limits.

In a nuclear reactor power plant having a protection and control system for monitoring various state variable of said power plant and controlling power plant operation, wherein said protection and control system has a characteristic time constant and includes an input end to which a time dependent state variable signal representing a power plant operating parameter is provided and an output end from which a shutdown signal is provided when said time dependent state variable signal exceeds a predetermined threshold for terminating operation of the power plant and from which a reset signal is provided when said time dependent state variable signal no longer exceeds said predetermined threshold for re-initiating operation of the power plant, a verification system for verifying in-place operation of said protection and control system comprising:

• user responsive input means for generating a first control signal representing a selected power plant process and a first input signal representing a state variable associated with said power plant process;
• controller means coupled to said input means and responsive to said first control and input signals for outputting a second control signal;
• logic/interface circuitry coupled to said protection and control system and to said signal for providing a first process designation signal to said protection and control system and for generating a state variable designating signal;
• simulation signal generating means coupled to the input end of said protection and control system and further coupled to said logic/interface circuitry and responsive to said state variable designating signal for generating and providing a dynamic signal simulating a state variable of said power plant to the input end of said protection and control system which, in turn, outputs the shutdown signal to said logic/interface circuitry when said dynamic signal exceeds the predetermined threshold and outputs the reset signal when said dynamic signal no longer exceeds the predetermined threshold, wherein the characteristic response time of the protection and control system is not compensated for by said dynamic signal;
• and
• measurement/display means coupled to said logic/interface circuitry for measuring and displaying the shutdown and reset signals in verifying in-place operation of said protection and control system.

A method for the in-place monitoring and verification of the transient signal response of a protection/control arrangement having a characteristic response time and at least one protection channel coupled to an operating system and responsive to a state variable signal representing a first operating parameter of said operating system, said method comprising:

• providing a selection signal in response to an operator input, said selection signal representing said state variable signal and a selected variation of said state variable signal;
• providing a simulated state variable signal in response to said selection signal to said protection channel, wherein said said simulated state variable signal corresponds to said first operating parameter and a selected variation thereof and does not compensate for the characteristic response time of the protection/control arrangement;
• measuring the response of said protection channel to said simulated state variable signal in detecting a shutdown signal from said protection channel when the response of said protection channel is not within predetermined limits and detecting a reset signal from said protection channel when the response of said protection channel is again within said predetermined limits, wherein said shutdown signal terminates operation of the operating system and said reset signal re-initiates operation of the system;
• and
• monitoring said simulated state variable signal and said shutdown and reset signals in verifying the in-place transient signal response of said protection/control arrangement.

A programmable ramp/step generator comprising:

• user responsive input means for receiving user-initiated inputs and providing first and second control signals in response thereto;
• programmable memory means coupled to said input means for storing data representing operating parameters of the ramp/step generator, wherein data is read from said programmable memory means in response to receipt by said programmable memory means of said first control signals from said user responsive input means;
• logic means coupled to said input means and to said programmable memory means and responsive to said second control signals and said data representing ramp/step generator operating parameters respectively output therefrom for providing third control signals;
• and
• ramp/step control means coupled to said logic means and to said programmable memory means and responsive to said third control signals and said data representing operating parameters of the ramp/step generator respectively output therefrom for providing a ramp/step output signal varying in either voltage or current.