POWER April 2016 - 70

RESILIENCY
Maximizing Coastal Power Plant
Resiliency
Hurricanes, tsunamis, and climate change-operating a power plant on the
seacoast carries with it an array of unique challenges. Here's what some
generators are doing to ensure the lights stay on when Mother Nature
comes calling.
Thomas W. Overton, JD
L
ike experienced sailors, power plants
located along a coastline have always
looked at the sea as both a friend and a
potential enemy. Ocean waters provide vital
plant cooling, but the ocean can also bring
floods, storms, and heavy surf that can wreak
havoc with plant operations. That means that
designing, building, and operating a plant
along a coast requires a healthy respect for
the sea's unpredictability.
That's always been the case, but coastal
resiliency issues have taken on new
prominence in recent years as a result of
major natural disasters such as Hurricanes
Katrina and Sandy, and more insidious
threats such as climate change-induced
sea-level rise.
The scope of the threat depends on whom
you ask, but there's little dispute that it's
growing. Even adjusting for inflation, the
incidence of disasters causing more than a
billion dollars of damage has been increasing,
in part because coastal infrastructure has
been expanding over the past decades: There
is simply a lot more coastal property vulnerable
to damage, including power plants. Even
though once-through cooling (OTC) is being
replaced by more environmentally friendly
methods, in many cases, new power plants
relying on air cooling are replacing plants
that relied on OTC on the same sites.
According to data from the U.S. Energy Information
Administration, reported weatherrelated
outages have increased substantially
in frequency over the past two decades even
as outages from other causes have remained
flat. While much attention has been devoted
to transmission infrastructure-such as hardening
grids through various means such as
burying power lines, better protecting transformers
and substations from severe weather,
and leveraging microgrid and other advanced
transmission technology such as fiber optics
(see sidebar)-power plants remain key
anchors, because electricity can't be turned
back on after a disaster if area power plants
are offline as a result of damage.
70
Flood Tide
Perhaps the largest threat to coastal power
plants is storm-related flooding, whether as a
result of a hurricane storm surge, heavy rains,
or some other threat. During Hurricane Sandy,
Exelon's Oyster Creek nuclear plant and
Unit 1 at Salem Generating Station (jointly
owned by PSEG and Exelon, Figure 2), both
in New Jersey, experienced abnormally high
intake water levels. Salem was forced to shut
down, while Oyster Creek-offline for refueling-had
to declare an alert.
PSEG's New Jersey fleet took a body
blow from Sandy, which landed a direct
hit on the Jersey Shore south of New York
City. The company saw nearly 4 GW of caGulf
of Mexico, has been designed so that all
of its key equipment is elevated well above
mean sea level (Figure 3). Duke had originally
designed the site to ride out a generic
100-year flood, but planners ultimately decided
that planning for possible storm surges
was more prudent.
" We designed for a Cat 3 storm surge,
which is about 21 feet above mean sea level,
so our super-critical equipment will be 24
feet in the air, and our critical equipment is
designed for a Cat 2 storm surge, which is
about 16 feet above sea level. "
Duke's experience with multiple hurricanes
over the past decade or so caused it
to reassess its severe storm planning. Toms,
Duke's experience with multiple hurricanes
over the past decade or so caused it to reassess
its severe storm planning.
pacity knocked offline by the storm. At one
plant, the 452-MW natural gas-fired Kearny
Generating Station, the company had dedicated
six new peaker units totaling 270 MW
scarcely a week before Sandy hit. Nearly all
of PSEG's customers experienced some sort
of outage. As a result, PSEG is in the middle
of a multi-billion-dollar initiative to harden
its fleet against future storms.
But severe storm planning is an ongoing
process.
Awareness of potential risks from storm
surges has grown since Sandy. Duke Energy,
with numerous plants along the Atlantic and
Gulf coasts, has made protection from storm
surge much more of a priority for its future
plants. Wayne Toms, manager of Duke's
1,113-MW Bartow Station in St. Petersburg,
Fla., explained to POWER in an interview
how the company's Citrus County Combined
Cycle plant, which broke ground north of
Tampa in March about 2.5 miles from the
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who was operations manager of the Crystal
River plant during some of those storms,
said that because of the flooding they experienced,
they realized previous approaches
weren't enough. " We went back and re-wrote
our procedures for these kinds of events to
increase the number sandbags and other
equipment we needed to keep the water out. "
Fuel and Staff Planning
Planning for fuel supply is also an element
of storm preparedness for coal-fired plants,
Toms noted. " The hurricane season starts
June 1, and at Crystal River, we tried to have
at least 60 days of coal on the ground. " Some
of the coal for Crystal River comes across the
Gulf of Mexico on barges from the Mississippi,
and in bad weather, the barge deliveries
can get curtailed.
Storm planning also includes preparation
for plant staff. Toms said that when a hurricane
is approaching, they will send half the
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POWER April 2016

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