Self-test subsystem for nuclear reactor protection system

In a nuclear reactor protection system (RPS), a protection function circuit card for a self-test subsystem, comprising:

• a first register for receiving RPS test vectors;
• a second register for storing actual RPS test results;
• means for isolating a self-test circuitry component of said protection function circuit card from an RPS essential circuitry component of said protection function circuit card while maintaining communication therebetween;
• means adapted to inject said RPS test vectors into the RPS via said protection function circuit card essential circuitry along the actual RPS operating path during a short duration test pulse period so that said test vector will not cause an RPS response, said data simulating a selected actual RPS condition;
• means for providing said second register with said actual RPS test results;
• means for interfacing said protection function circuit card with a self-test subsystem bus;
• first means for acknowledging receipt at said protection function circuit card via said bus of a protection function circuit card select command from said self-test subsystem;
• and
• second means for acknowledging receipt at said protection function circuit via said bus of an RPS test pulse command from said self-test subsystem.

In a nuclear reactor protection system (RPS), a self-test subsystem, comprising:

• a self-test system controller including:
• (a) a central processing unit including a self-test operating program;
• (b) memory means for storing said operating program;
• (c) random access memory means for storing RPS test patterns and test vectors;
• (d) a self-test subsystem bus for communicating system control information, test data, and system address information to and from said central processing unit;
• (e) a first input/output port for interfacing said central processing unit to a plurality of RPS self-test elements via said self-test subsystem bus;
• and
• (f) a second input/output port adapted to communicate between said self-test subsystem, additional self-test subsystems, and RPS diagnostic systems;
• and
• a protection function circuit card including:
• (a) a first register for receiving said RPS test vectors;
• (b) a second register for storing actual RPS test results;
• (c) means for isolating a self-test circuitry component of said protection function circuit card from an RPS essential circuitry component of said protection function circuit card while maintaining necessary communication therebetween;
• (d) means adapted to inject said RPS test vectors into the RPS via said protection function circuit card essential circuitry along the actual RPS operating path during a short duration test pulse period so that said test vectors will not cause an RPS response, said data simulating a selected actual RPS input condition;
• (e) means for providing said second register with said actual RPS test results;
• (f) means for interfacing said protection function circuitry card with said self-test subsystem bus;
• (g) first means for acknowledging receipt at said protection function circuit card via said bus of a protection function circuit card test pattern command from said self-test system controller;
• and
• (h) second means for acknowledging receipt at said protection function circuit card via said bus of a RPS test pulse command from said self-test controller.

A protection function card for insertion in the actuating circuitry of a nuclear reactor protection system (RPS) including a control input for actuating and controlling an actual operating path along said card and for transporting an RPS actuating signal to an RPS output signal from said RPS in combination with said card, comprising:

• first registers for receiving card inputs for actuating the actual operating path along said car responsive to a test signal;
• input means for said register to receive a first strobe signal to cause the release of test signal data loaded in said first registers on a simultaneous basis through the actual operating paths of said card during a short duration test pulse period transparent to RPS operation;
• output registers responsive to a compare signal for monitoring the state of said cards and latching the operative state of said cards at said operating paths;
• and
• means for releasing card state data from said output registers to output the status of said cards responsive to a second strobe signal.

A self-test system for a nuclear reactor protection system (RPS), the RPS being located intermediately between a sensor and a sensor annunciator, the RPS responding to said sensor and actuating said annunciator, the RPS including a communicating path between said sensor and said sensor annunciator, said path including a plurality of discrete cards having a portion of the path thereon, said self-test system comprising:

• input registers on said cards for receiving, at preselected points along said path, data for strobing said path;
• timing means for timing data strobes on said path from said registers, said timing means having a time domain less than the actuating intervals of said path;
• means for causing said timing means to release a strobe from at least one of said cards;
• output register means operatively connected to the system communicating path portion of said cards for reading the state of said cards;
• register strobe means operatively connected to said timing means for reading said cards upon a reading strobe;
• a system controller;
• means for unloading said output register means to said system controller;
• and
• comparison means in said system controller for comparing the actual status of said output register means to an expected memory status to determine operability of said actuating path.

In a nuclear reactor protection system (RPS) wherein sensors communicate electrically to sensor annunciators along an real actuating electrical path, said path including discrete components isolated to discrete electronic units, a process for testing the RPS comprising the steps of:

• (a) providing registers at the discrete components of said system path for receiving strobe commands and RPS test data;
• (b) loading said registers with said test data in response to said strobe commands;
• (c) releasing said strobe data along said real actuating path during a time domain based at intervals transparent to the command domain of said RPS;
• (d) providing RPS status registers;
• (e) reading said RPS status registers at predetermined intervals after said strobe to determine the state of said RPS;
• and
• (f) comparing said RPS status registers with expected data, indicating the operability of the tested portion of said RPS real actuating path.

In a nuclear reactor protection system (RPS), a self-test subsystem process for interpreting communications sent from a self-test system controller to a protection function circuit card comprising:

• providing a first register for receiving RPS test vectors;
• providing a second register for storing actual RPS test results;
• isolating a self-test circuitry component of said protection function circuit card from an RPS essential circuitry component of said functional circuit card while maintaining communication therebetween;
• injecting said RPS test vectors into the RPS via said protection function circuitry card essential circuitry along the actual RPS operating path during a short duration test pulse period so that said test vectors will not cause an RPS response, said test vectors simulating a selected actual RPS condition;
• providing said second register with said actual RPS test results;
• interfacing said protection function circuit card with a self-test subsystem bus;
• acknowledging receipt at said protection function circuit card via said bus of a protection function circuit card select command from said self-test subsystem;
• and
• acknowledging receipt at said protection function circuit card via said bus of an RPS test pulse command from said self-test subsystem.