Fault-tolerant reactor protection system

Patent · Wed Jan 01 00:00:00 EST 1997

OSTI ID:870905

Gaubatz, Donald C ^[1]

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1. Cupertino, CA

A reactor protection system 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 output 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.

• Research Organization: General Electric Co., Boston, MA (United States)
• DOE Contract Number: AC03-89SF17445
• Assignee: General Electric Company (San Jose, CA)
• Patent Number(s): US 5621776
• Application Number: 08/502411
• OSTI ID: 870905
• Country of Publication: United States
• Language: English

Related Subjects

fault-tolerant
reactor
protection
divisions
quad
redundant
sensors
scram
parameter
providing
input
independent
microprocessor-based
electronic
chassis
acquires
data
sensor
digitizes
information
transmits
reading
via
optical
fibers
increase
availability
reduce
false
scrams
employs
levels
voting
perform
software
divisional
processing
vote
spare
based
send
signals
hardware
logic
panel
performs
division
initiate
makes
decision
independently
asynchronous
operation
communications
substitutes
faulty
missing
presence
valid
readings
excess
set
required
terminating
output
inhibition
signal
service
reactor scram
reactor protection
parameter data
scram signal
data processing
optical fibers
optical fiber
electronic chassis
reduce false
microprocessor-based electronic
scram parameter
providing input
quad redundant
redundant sensors
chassis acquires
parameter providing
independent microprocessor-based
via optic
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