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Title: Fault-tolerant reactor protection system

A reactor protection system is disclosed having four divisions, with quad redundant sensors for each scram parameter providing input to four independent microprocessor-based electronic chassis. Each electronic chassis acquires the scram parameter data from its own sensor, digitizes the information, and then transmits the sensor reading to the other three electronic chassis via optical fibers. To increase system availability and reduce false scrams, the reactor protection system employs two levels of voting on a need for reactor scram. The electronic chassis perform software divisional data processing, vote 2/3 with spare based upon information from all four sensors, and send the divisional scram signals to the hardware logic panel, which performs a 2/4 division vote on whether or not to initiate a reactor scram. Each chassis makes a divisional scram decision based on data from all sensors. Each division performs independently of the others (asynchronous operation). All communications between the divisions are asynchronous. Each chassis substitutes its own spare sensor reading in the 2/3 vote if a sensor reading from one of the other chassis is faulty or missing. Therefore the presence of at least two valid sensor readings in excess of a set point is required before terminating the outputmore » to the hardware logic of a scram inhibition signal even when one of the four sensors is faulty or when one of the divisions is out of service. 16 figs.« less
Authors:
Publication Date:
OSTI Identifier:
462856
Report Number(s):
US 5,621,776/A/
PAN: US patent application 8-502,411; TRN: 97:007359
DOE Contract Number:
AC03-89SF17445
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 15 Apr 1997
Research Org:
General Electric Co
Country of Publication:
United States
Language:
English
Subject:
22 NUCLEAR REACTOR TECHNOLOGY; REACTOR PROTECTION SYSTEMS; DESIGN; REACTOR INSTRUMENTATION; DATA TRANSMISSION SYSTEMS; DATA ACQUISITION SYSTEMS; MICROPROCESSORS; COMPUTERIZED CONTROL SYSTEMS