Page 77 - July-August 2012
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Nuclear Plant Journal, July-August 2012
77
A Pioneer
Plant
Oconee Nuclear Station is located
on Lake Keowee in Oconee County, S.C.,
eight miles north of Seneca, S.C. Unit 1
began commercial operation in 1973,
followed by units 2 and 3 in 1974.
Since it began operating, Oconee has
safely and reliably generated more than
500 million megawatt-hours of electricity
— the first nuclear power station in the
United States to achieve this milestone.
Oconee is one of the nation’s largest
nuclear plants with a generating capacity
of approximately 2.6 million kilowatts.
This is enough electricity to power 1.9
million homes.
Oconee earned the further distinction
of being the second nuclear station in the
country to have its licenses renewed by
the Nuclear Regulatory Commission
(NRC) for an additional 20 years. All
U.S. reactors are initially licensed by the
NRC for 40 years.
Duke Energy nuclear power plants
operate at a very high level of security
every day. Oconee was designed and
built with redundant safety systems and
multiple barriers to protect the public,
plant workers and the environment.
World of Energy
Located at Oconee Nuclear Station,
Duke Energy’s World of Energy offers
educational activities and interactive
exhibits for visitors interested in learning
more about electricity generation, Duke
Energy and Lake Keowee. This energy
education center also regularly hosts free,
family-friendly events.
Digital Upgrade
When it came on line in the summer
of 1973, Oconee Nuclear Station, in
Seneca, South Carolina, was one of
the nation’s first nuclear power plants
to begin commercial operation. Years
later, it became the nation’s first nuclear
station to generate more than 500 million
megawatt-hours of electricity. In 2011,
Oconee completed two more firsts.
Thestationperformedmajorupgrades
to its reactor protection system (RPS) and
engineered safeguards protection system
(ESPS), a first for a U.S. pressurized
water reactor design.
The RPS/ESPS upgrades were
implemented on unit 1 during the plant’s
spring 2011 refueling outage, making
Oconee the first plant in the nation tomove
the systems from analog to digital. Units
2 and 3 will receive the upgrades during
2012 and 2013. While the operators’
interaction with the new system isn’t
drastically different, the modifications
further enhance the safety and reliability
of an already safe plant.
With the exception of a few extra
indicator lights and digital read-outs,
the system looks and feels the same as
the old one. Behind the scenes though,
in cabinets full of computer equipment
and large mazes of strategically placed
wiring, the system provides real-time
assessments and calculations on a number
of important parameters.
On a continuous basis, the reactor
protection system monitors inputs like
reactor coolant system temperature and
pressure, while the engineered safeguards
system monitors pressure changes in
the reactor coolant system and reactor
building. If any limits are approached,
the RPS/ESPS systems can automatically
trip the reactor or activate key systems
that would mitigate the situation.
On theflip side, the systemalsoknows
when to exclude inaccurate information.
In other words, if one of the plant’s many
back-up sensors fails, the new system
will automatically exclude the bad sensor
and won’t use it to make decisions for
the plant. This prevents reactor trips and
further improves plant reliability.
The upgrade was a large undertaking
for Oconee, which planned an extended
unit 1 refueling outage to accommodate
the work.
“As the first plant in the nation
to add this new equipment, Oconee
is demonstrating its commitment to
continuous improvement as new systems
and technologies become available,”
said Oconee Site Vice President Preston
Gillespie. “It’s enhancements like these
that have us well-positioned to operate a
safe, reliable, efficient plant through the
duration of our license.”
With more units to upgrade, the
project work isn’t complete, and the site
knows the industry is watching.
“Our plans went through an extensive
approval process with the Nuclear
Regulatory Commission, and we want to
be an industry leader for this important
work,” Gillespie added. “The system
has worked extremely well and we look
forward to completing the upgrades on
the other two units.
“Oconee has more than two decades
of operation remaining on its current
license, which was renewed in 2000,”
Gillespie added. “We’re making the
necessary investments in this plant, and
we’re implementing new systems and
guidelines that position Oconee Nuclear
Station as a leader in the industry.”
A more detailed article on Oconee’s
digital upgrade, “Digital Has Served
Us Well.” (Questions and Answers by
Michael Bailey, Nuclear Engineering
Section Manager for I &C Systems at
Duke Energy’s Oconee Nuclear Station)
may be reviewed in Nuclear Plant
Journal, September October 2011 issue,
Volume 29 No. 5, starting on page 32.
Contact: SandraMagee, Duke Energy;
RPS Work.
