The following is excerpted from a report submitted by
MPR Associates, INC.:
The basic component that contains a defect is an MPR Model 0380-1103 Timing Module. Six modules are in use for the three Emergency Diesel Generators (EDGs) at Plant Hatch Unit 2. Eight modules are at Plant Hatch as spares. The modules use a field programmable gate array (FPGA) to implement a specific pre-programmed load shedding and load sequencing logic associated with the standby power source safety function of the Hatch Unit 2 EDGs.
MPR Timing Module Part Number 0380-1103, Serial Number 16 failed after operating successfully, along with five other installed modules, for more than eight months. The module failure resulted from a capacitor short in the input power circuit. When the capacitor shorted, the module ceased to function and annunciated its failure in the Main Control Room. The other five installed modules have given no indication of failure to date.
MPR identified a replacement capacitor model that is suitable for the application and the application is within the manufacturer's recommendations. MPR is working with Plant Hatch to develop a schedule for rework to restore the expected design life of the timing modules.
Contact the following for additional information:
Paul Damerell, Principal Officer
MPR Associates, Inc.
320 King Street
Alexandria, VA 22314
Ph: 703-519-0269