POWER August 2011 - 31

PLANT OF THE YEAR
trains. Also added was a second delivery conveyor
to Iatan 1 to match the redundant conveyors
installed on Iatan 2. When operating
at full load, each unit consumes about 10,000
tons a day, the equivalent of about one and
one-half unit trains each day. The conveyors
are fully enclosed and have a considerable
number of dust collection stations, including
the transfer towers (Figure 3). Automatic
Systems Inc. supplied the fuel- and materialhandling
equipment and was responsible for
its installation.
The coal pile, sized to about 50 days' storage
(about 1,000,000 tons) is managed using
rubber-tired vehicles. The size of the stockpile
at any time is usually determined by
external factors, such as the projected conditions
of the rail after flooding in the Missouri
River basin.
Iatan 2's dry ash system, part of KCP&L's
commitment to eliminate ash ponds and wet
ash sluicing at Iatan, required construction
of a new dry ash landfill with the requisite
liners and leachate collection and monitoring
systems to ensure that any water collected
does not seep into the ground, particularly
from rainfall and drainage. Iatan 1 was also
retrofitted from wet sluice bottom and fly ash
to dry ash.
Portions of the bottom dry ash are sold for
construction materials, particularly as an additive
in cement products, although the rate
of sale closely follows construction demand.
Gypsum from the wet FGD system is transferred
by truck to the dry ash landfill, located
only about 2 miles from the plant. Unsold fly
ash is also transferred by trucks from each
unit's ash silos to the landfill. Unlike other
plants with mercury control, ACI carryover
into the dry ash has been minute and has not
affected ash sales.
Water and Wastewater Systems. One
of the design challenges facing KCP&L was
treatment of the large amounts of wastewater
produced by the two wet FGD systems. This
additional wastewater, about 60 gpm, would
have required the water discharge permits
to be modified, causing a potential delay in
the plant's permitting schedule. Adding to
the water discharge challenge was the large
amount of cooling tower blowdown from
Iatan 2's 12-cell evaporative cooling tower
that must also be treated and disposed. (Iatan
1 is a once-through cooling plant and does
not have evaporative cooling towers.)
As part of the permitting process, KCP&L
committed to regulators that Iatan would become
a zero-liquid discharge (ZLD) plant.
KCP&L assigned the task to engineer and
construct the ZLD system to Burns & McDonnell.
The conceptual approach was to
minimize wastewater production by using
evaporation followed by spreading the reAugust
2011 | POWER
IATAN.indd 2
maining concentrate on the fly ash, a much
less expensive and much more reliable approach
than using a conventional crystallizer
and solids disposal. Essentially, the ZLD
system takes all concentrated waste streams
from plant processes and either reprocesses
the water for plant reuse, or the surplus brine
produced is used for ash dust control. The
Burns & McDonnell system is simple yet
very effective.
Water supply to the plant is much more
complicated than merely drilling a well and
dropping in a pump. Instead, another simple,
yet inspired approach was taken. A vertical
caisson collector well was placed into the
sandy ground and sunk about 100 feet deep
near the Missouri River. Operating opposite
of the common septic leech field, a drain
field was installed below the river water level.
The effect is that river water is collected
in the underground collector well through
the equivalent of a massive sand filter. Clean
IATAN 2
2011 Plant of the Year
Congratulations to KCP&L
as Power Magazine's Power Plant
of the Year Award winner.
Alstom is proud to have supplied and erected
the advanced high-efficiency boiler (Unit 2) and
air quality control systems for Iatan 1 & 2.
As an efficient and environmentally-conscious
generating plant using domestic coal resources,
Iatan makes clean power a reality for today.
CLEAN POWER TODAY!®
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POWER August 2011

Table of Contents for the Digital Edition of POWER August 2011
