• Eliminates most manual data logging.
• Provides automatic or manual reactor operation modes.
• Provides complete real-time operator display.
• Replays historical operating data on monitor or printer.
• Eliminates spare parts replacement problems.
• Meets all applicable NRC and lEE specifications

The complete system consists of three major subsystems-the Control Rod Drive and Detector System, the Data Acquisition and Signal Processing System, and the Control Console System. The Data Acquisition and Signal Processing System and Control Console System each have independent computers (DAC and CSC) for monitoring and control purposes. The Data Acquisition and Signal Processing System includes the NLW-1000 and NMP-1000 nuclear channels as well as the related reactor safety scram and shutdown circuits. All these systems are mounted in an auxiliary instrumentation cabinet, which is located in the reactor hall usually near the reactor. Thus, even if the Control Console System is disconnected, the Data Acquisition and Signal Processing System can control or shutdown the reactor in a safe manner.

Information on all aspects of reactor operation is displayed on the Control Console System. The two color graphics monitors can display real-time operations data in concise, accurate, and easily understood formats. Bar graph indicators and visual and audible annunciators are also provided. Information displayed on the two monitors can be recorded on hard copy using the graphics printer in the Control Console System. The DAC collects data during reactor operations and stores it in a historical database. Reactor operations can then be replayed in real-time or slow motion. This record is a powerful tool that can be used for operations review and maintenance troubleshooting.

Reactor control rod position commands are transmitted via a high-speed Ethernet link from the Control Console System to the Data Acquisition and Signal Processing System and in turn to the rod drive mechanisms. This reduces the complexity, vulnerability, and cost of data transfer. The Data Acquisition and Signal Processing System computer controls rod positions using integral software during automatic mode operation.

(a) Photo of typical cabinet which contains the Data Acquisition and Processing System which includes the DAC, the NLW-1000, the NMP-1000 and NP-1000 channels. Closeup views are shown in the photos of (b) the NP-1000 channel, (c) the NMP-1000 microprocessor, and (d) the NLW-1000 amplifier.

The NLW-1000, NMP-1000 and NP-1000 channels provide power indication. The NLW-1000 can replace existing source and intermediate range channels and provide wide range log power and period. The NMP-1000 provides multi-range linear power. The NP-1000 analog channel was developed specifically as a research reactor safety channel. It monitors percent power. For pulsing reactors, the NP-1000 is also wired to output nv and nvt data, which can be graphically displayed or recorded on hard copy.

Safety Features

The two independent, redundant percent power safety channels are provided to ensure safe operation of the reactor (the NMP-1000 and NP-1000). Both channels are designed to meet all applicable specifications and both channels also have automatic pre-startup on-line self-diagnostic/testing and calibration verification with data display and documentation printout. Both channels also have isolated outputs for display and safety scram circuit inputs. Redundancy and diverse designs ensure against reactor instrumentation and control system common mode failure. Backup bar graph displays and safety/scram circuits are also hardwired to NMP-1000 and NP-1000 outputs.

NP-1000 Analog Safety Channel

The NP-1000 is an advanced design analog neutron monitoring safety channel. The design is very versatile and diverse applications are easily accommodated. This has led to the sale of additional NP-1000 units to expand the capability of standard Research Reactor Instrumentation and Control Systems. One interesting application employs twelve NP-1000 units organized for safety monitoring of four reactor parameters using two-out-of-three logic circuitry. The system meets IEEE 269 physical separation requirements in a 19-inch, rack-mounted array using new plug-in physical separation connectors. NP-1000 channels feature current mode analog circuitry for percent power and pulse-power monitoring using signals generated by a self-powered, in-core detector or an ionization chamber. They include a built-in pulse integrator circuit and circuits for pre-operational testing and calibration. NP-1000 channels may also be used to monitor temperature and other parameters using appropriate transducer signals. Safety trip circuits connect to computer analysis systems and/or hard-wired scram systems. The integrity of NP signals is assured by use of isolation devices. Input signals from as low as 10-9 to 10-3 Amp are accommodated. Gain adjustments are manual and range selection either manual or computer controlled. The unit can be configured in a compact NEMA-12 enclosure that can be mounted horizontally or vertically.

Data Display and Storage

Two color monitors provide real-time information one shows reactor operations graphics and the other displays important operating parameters. Hard copies of the two displays can be made using the graphics printer.