POWER August 2011 - 30

PLANT OF THE YEAR
Table 3. Key Iatan 2 performance parameters. Iatan 2 uses a supercritical steam
generator and a system of air quality control devices to keep air emissions low. Source: KCP&L
Parameter
Net unit output
Net plant heat rate
Turbine throttle conditions
Fuel
Emissions
NOx
SO2
CO
PM10 (filterable)
Hg
Boiler
Type
Steam pressure
850 MW
9,000 Btu/kWh
3,700 psig/1,080F main steam; 686 psig/1,080F reheat steam
Powder River Basin subituminous 8,200 to 8,800 Btu/lb range
0.070 lb/MMBtu
0.060 lb/MMBtu
0.14 lb/MMBtu
0.014 lb/MMBtu
Activated carbon injection, Hg limited to 39x10-6 lb/gross MWH +
210 lb/yr total for the station
Supercritical
3,700 psig
Steam temperature 1,080F/1,080F
Maximum continuous
rating
Turbine
Rating
Type
938 MWh
Single-flow high-pressure turbine, double-flow intermediatepressure
(reheat) turbine, four flow low-pressure condensing
turbines
Generator
Rotational speed 3,600 rpm
Condenser vacuum 3 inches HgA
Feedwater heaters Eight stages of feedwater heating, including deaerator
Voltage
Capacity
24 kV
1,000 MVA @ 0.9 PF
Boiler feed pump configuration
Water pretreatment system
Zero-liquid discharge
Two 60%-sized pumps, steam turbine-driven
Well water for service water and plant feedwater makeup
Iatan 2 is a zero-liquid discharge facility
3. Carrying coal. Coal is delivered to each of the two units via a common, redundant conveyor
system. The conveyor is enclosed with dust collectors, ensuring no fugitive emissions
occur. Courtesy: KCP&L
6,246,000 lb/hr
Iatan 2
ments in initiatives with the goal of improving
the operating efficiency of its coal fleet
3% by 2013.
Iatan 2's sliding pressure boiler mode of
operation also helps the plant meet the design
goal of being capable of performing daily
load swings from 40% to 100%. Of particular
interest in the project technical specifications
(Table 3) are the main and reheat steam
temperatures, which are both 1,080F-more
aggressive than the typical 1,050F of similar
supercritical plants. Recent reports from the
plant confirm that plant operation has been
very stable with these near-state-of-the-art
steam temperatures.
Unique Contracting Approach
Once the long-lead equipment purchases
were completed (over $1 billion by August
2006), KCP&L made inquiries with experienced
power industry contractors to assume
the project lead but found little interest in
constructing the plant on a turnkey basis. The
challenge for contractors at the time was the
rapidly increasing cost of commodities such
as copper and steel plus nationwide high demand
for limited journeyman construction
talent for constructing new coal plants and
retrofit AQCS systems. KCP&L decided to
proceed with the project using a multi-prime
approach combined with aggressive purchasing
processes to limit the risk of future price
increases. In essence, KCP&L would assume
the responsibility and risk of the general
contractor by using seven or eight smaller
contractors to complete the balance-of-plant
work on Iatan 2.
Alstom mobilized onsite to begin its work
on boiler erection shortly after signing of the
Collaboration Agreement. Fortuitously, the
cancellation of another large project opened
up the work schedule of Kiewit Power, a very
experienced prime contractor in the power
industry. Kiewit Power was subsequently
selected as the contractor responsible for all
balance-of-plant construction, construction
interface with the boiler island, and assembly
of the steam turbine generator.
Plant Systems' Design
The design of several plant systems deserves
particular note given their unique approach
for solving sticky problems, often with a
simple solution.
Coal- and Ash-Handling Systems. Coal
is delivered to the plant by BNSF railroad by
one or two unit trains each day. The coal is
dumped through a single rotary car dumper
and delivered by a stacker reclaimer, a system
that has proven its reliability since Iatan
1 was put into service. The design of Iatan 2
added a parallel stackout pile with the capacity
to handle the coal delivered by two unit
30
www.powermag.com
POWER | August 2011

http://www.powermag.com

POWER August 2011

Table of Contents for the Digital Edition of POWER August 2011