Success Stor y
EPRI Guidelines Reduce Unnecessary
Alarms at TVA Plants
EPRI alarm management guidelines provided a step-by-step approach to analyzing
and improving the alarm systems at a number of plants in the Tennessee Valley Authority (TVA) fleet. Application of the guidelines reduced the number of nuisance and
unnecessary alarms that can cause operator distractions.
Poorly Performing Alarm Systems
In some U.S. power plants, the alarm systems that were designed to warn plant operators of
“At TVA, our efforts to
off-normal operating conditions are plagued with unnecessary and redundant alarms. These
improve alarm manage-
systems generate far more alarm events than can be individually understood and acted upon
by the operator. As a result, in some installations, the alarms are considered a nuisance and are
ignored. During an upset, the number and speed of alarm occurrences may suddenly increase
by an order of magnitude, rendering the alarm system not only useless, but creating an active
ment focused on significantly reducing the
number of ‘bad actor’
hindrance to the operator’s ability to deal with the situation.
and nuisance alarms. We
In addition, upgrades and changes to alarm systems have been implemented, along with new
management philosophy
distributed control systems and added equipment, without a well-documented design philosophy. This evolution has resulted in inconsistent use of alarm systems, alarms that do not warrant
operator attention, and redundant alarms. Inadequate oversight of alarms by plants causes
operators to have too many existing alarm conditions to effectively oversee and correct. Often
implemented an alarm
that assigns no more
than three annunciated
alarm priorities based on
equipment maintenance and alarm set-points are not kept in proper condition.
the severity of the event,
Analysis of plant alarm systems has shown that a relatively few “bad-actor” alarms usually cre-
response time,
ate a disproportionate load on the system. Common bad-actor alarms include chattering
alarms, which actuate and clear at least three times in one minute; fleeting alarms, which are
short-duration alarm events; stale alarms, which remain continuously in effect for 24 hours or
more; and duplicate alarms, which result when a process condition produces simultaneous,
different alarms signifying the same thing.
EPRI Alarm Management Guidelines
Several years ago, to address the issue of poorly performing alarms, EPRI set out to develop a
number of best practices and suggested methodologies that power plants could use to improve
their alarm management strategies. With the assistance of third-party expertise provided by Bill
Hollifield and Eddie Habibi, the authors of The Alarm Management Handbook, the project
team conducted literature searches of past publications, solicited input from the industry through
a formal survey, and conducted site visits where practical. The result was the EPRI Alarm Management and Annunciator Application Guidelines, which provides a comprehensive review
and analysis of existing alarm management practices and annunciator applications in the
power industry.
combined with operator
to prevent undesired
consequences.”
~ Bill Morrison, Vice President,
Generation Engineering,
Tennessee Valley Authority
At the heart of the Guidelines is a proven, best-practice, seven-step
and taking more timely corrective action. Overall, such enhancements
methodology for improving an alarm system. The methodology is based
increase plant equipment reliability and reduce damage to equipment.
on hundreds of successful, real-world alarm improvement projects. The
Equipment reliability is the key driver in achieving high levels of environ-
seven steps include developing an alarm philosophy, which provides an
mental compliance, low cost operation, and reliable power supply.
optimum basis for alarm selection and priority setting; collecting data
and benchmarking the system; resolving bad-actor alarms; and performing alarm documentation and rationalization, which is a thorough reexamination of every existing and possible alarm on a system to ensure
that they all meet the requirements for proper alarming.
New Alarm Management Philosophy in the TVA Fleet
Related EPRI Work
EPRI Alarm Management and Annunciator Application Guidelines.
EPRI, Palo Alto, CA: March 2008. 1014316.
Wayne Crawford and Bill Hollifield. “Better Management of Plant
Alarms.” Energy-Tech Magazine, May 2010.
“At TVA, our efforts to improve alarm management focused on significantly reducing the number of ‘bad actor’ and nuisance alarms,” said Bill
Morrison, Vice President, Generation Engineering. “We implemented an
alarm management philosophy that assigns no more than three annunci-
For more information, contact the EPRI Customer
Assistance Center at 800.313.3774 ([email protected])
ated alarm priorities based on the severity of the event, combined with
operator response time, to prevent undesired consequences.”
The work has been completed to various degrees at the following
plants in the TVA fleet: Bull Run, Widows Creek, Magnolia, Southaven,
Gallatin, and Lagoon Creek. Implementation of this guidance has
resulted in enhanced operator situational awareness by decreasing
C O N TA C T S
Wayne Crawford, Program Manager,
Operations Management and Technology Program,
704.595.2233, [email protected]
unnecessary alarms, allowing operators to focus on important alarms
300200042
February 2013
Electric Power Research Institute
3420 Hillview Avenue, Palo Alto, California 94304-1338 • PO Box 10412, Palo Alto, California 94303-0813 USA
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