Patent Number: 046408126
Section: summary

This document includes two Microfiche Appendices: Appendix A, consisting of 5 fiche having 315 frames, lists an exemplary computer program for use in the preferred embodiment of the invention; and Appendix B, consisting of two fiche having 75 frames, provides a set of schematic diagrams of a preferred embodiment of the invention. This invention relates generally to nuclear reactors, and more specifically to a simulation, analysis and test apparatus and process for automated checkout of the nuclear control rod drive system. BACKGROUND OF THE INVENTION Reactivity and the resulting power level of a nuclear boiling water reactor (BWR) is adjusted by moving control rods in the nuclear core. A large reactor uses about 185 such rods. Each rod is driven in or out of the core in discrete steps by a hydraulic drive mechanism, which, in a typical installation, is controlled by four solenoid valves in a hydraulic control unit. A rod drive control system allows an operator to control these solenoid valves and, through them, the positioning of all the rods in the core. The basic function of the rod drive control system involves the operator's choice of a particular rod and the timed control of the solenoid valves to drive the rod in or out. The system returns status information from each hydraulic control unit. Due to the nature and sophistication of nuclear reactor systems and their associated electronics, comprehensive testing equipment has been developed. Typically, such testing equipment is built into the system, and requires considerable space and complexity. Numerous tests are performed by this equipment, including the status of control rod drive and instrumentation systems. These tests are impeded by several factors: first, the control rods may not normally be moved during shutdown plant conditions; second, the operator must monitor the tests at his or her control panel located some 200 to 500 feet from the valves and rods themselves; third, the response of the rods to control commands are complex signals which require sophisticated and highly expert knowledge to decipher. SUMMARY OF THE INVENTION What is provided as invention is a portable, microprocessor-based test instrument for the calibration, testing, and checkout of nuclear power reactor systems under simulated operating conditions. Included in the invention is a process using the instrument to check out reactor control instrumentation by simulating inputs, outputs and closed loop responses in real time, and to deliberately inject faulted signals to the system. The instrument is expandable to perform a variety of applications through the use of a master microprocessor bus with direct communication to interchangeable plug-in printed circuit board modules. Such applications include rod control simulation and analysis, neutron monitoring system analysis, and rod block monitoring system simulation and analysis. The portable test instrument of the instant invention is designed to electrically interconnect at any of a plurality of points within the control and monitoring systems of the reactor. The electrical network from the point of interconnection to the control rods is thereupon disabled and the test instrument, located at close proximity to the point of interconnection, receives serial control command signals just as would the disabled portion of the network, and generates appropriate acknowledgements and response signals just as would the disabled portion as if it were performing properly the command. Alternatively, the instrument can generate faulty response signals simulating improper responses to the command. The instrument is provided with a cathode ray tube (CRT) display which permits the operator to monitor the simulated control rod movements in a readily comprehensible fashion.