Abstract: A nuclear reactor plant protection system printed circuit card comprises a first logic device having a number of basic logic circuits, and a second logic device operatively connected with the first logic device for testing the number of basic logic circuits without taking the printed circuit card out of service. A nuclear reactor plant protection system printed circuit card comprises a first logic device producing a first output signal in response to a test signal, a second logic device producing a second output signal in response to the test signal, and a comparator for comparing the first output signal and the second output signal, wherein the test signal has a pulse duration that is less than a latching period associated with the printed circuit card. A method of testing and a nuclear reactor control system incorporating the nuclear reactor plant protection system printed circuit card is also provided.

Abstract: A test tool for a reactor vessel level instrumentation system which simulates and verifies the values of input signals applied to the instrumentation system. The test tool includes potentiometers for simulating the signals produced by resistance temperature detectors, switches for simulating pump status and isolator overrange limit signals, a power supply, resistors and potentiometers for simulating temperature hot sensors and a pressure wide range sensor, and potentiometers and resistors for simulating differential pressure cell signals. The invention also includes a switchable meter for verifying the values of the various input signals simulated.