POWER November 2010 - 41

PLANT DESIGN
in Japan, two plants are under construction
in Japan, and two plants are under construction
in Taiwan that are identical to the
Kashiwazaki-Kariwa design. According to
GEH, nine more units are planned in Japan
and seven units are under active consideration
in the U.S. (Table 3).
Other interesting technology enhancements
over the earlier Generation II BWRs
include these:
■ Reactor internal pumps added to the bottom
of the reactor pressure vessel improved
safety and performance by eliminating external
recirculation systems.
■ An integrated containment and reactor
building improved seismic response
and is more compact, thus reducing the
amount of construction materials required
and the time required to construct
the building.
■ A digital reactor protection system included
multiple digital and manual backup
systems with fully automated start-up and
shutdown capability.
■ The plant design is modularized to reduce
construction time and cost.
■ Fiber optic data channels replaced miles
of copper wires.
■ High-integrity fuel, improved water chem2.
Made in Japan. The Kashiwazaki-Kariwa Nuclear Power Station began operation in September
1985. By 1997, seven units were in commercial operation with a total capacity of 8,212
MW, making it the largest nuclear power station by capacity in the world. The plant is located in
Niigata Prefecture, approximately 130 miles northwest of Tokyo, along the coast of the Sea of
Japan. Courtesy: Tokyo Electric Power Co.
istry, and eliminating radiation sources reduced
radwaste and occupational radiation
exposure.
The ESBWR
The ESBWR is a Generation III+ 4,500MWt/1,590-
to 1,690-MWe natural circulation
BWR but with a further simplified,
inherently safe reactor design (Figure 3).
GEH believes this simpler, standardized
design will further reduce capital cost and
construction time in addition to lowering
operating and maintenance costs compared
with the ABWR design. The greatest departure
from earlier reactor designs is the
incorporation of " passive " safety features,
which rely on natural forces such as gravity,
evaporation, and condensation rather
than " active " systems, which rely on large
numbers of powered pumps and motoroperated
valves in the event of a reactor
malfunction.
Table 3. Current ABWRs in operation or under construction. Source: GE Hitachi
Company
Plant
Tokyo Electric Power Co.
Tokyo Electric Power Co.
Chubu Electric Power Co.
Status
Kashiwazaki Kariwa-6 Commercial Nov. 1996
Kashiwazaki Kariwa-7 Commercial July 1997
Hamaoka 5
Hokuriku Electric Power Co. Shika 2
Taiwan Power Co.
Taiwan Power Co.
Lungmen 1
Lungmen 2
Chugoku Electric Power Co. Shimane 3
Electric Power Development Co. Ohma 1
40
Commercial Jan. 2005
Commercial Mar. 2006
Rating (MWe)
1,356
1,356
1,380
1,358
Under construction, commercial Dec. 2011 1,371
Under construction, commercial Dec. 2012 1,371
Under construction, commercial Dec. 2011 1,373
Under construction, commercial Nov. 2014 1,383
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The ESBWR program started in the
early 1990s with GE's Simplified Boiling
Water Reactor (SBWR) design rated
at 670 MWe, augmented with features
taken from the NRC-certified ABWR. GE
submitted the SBWR application for final
design approval and design certification
to the NRC in August 1992. The NRC, in
May 1993, determined that it was acceptable
for review. In response to some NRC
concerns, GE sponsored testing of passive
safety equipment that continued into 1996.
However, GE announced its withdrawal
of the design certification application in
March 1996 because the power output of
the SBWR was too small to produce acceptable
economics for a new-build project.
Instead, it shifted its focus from the
SBWR program to plants of 1,000 MWe
or larger, such as the ABWR and ESBWR.
At GE's request, the NRC closed out its
SBWR review activities in early 1997.
Since that time, GEH has been diligently
developing sources for key nuclear components
(see sidebar " Building the Nuclear
Supply Chain " ).
Notably, the key passive safety technology
enhancements developed as part of
the SBWR program were merged into the
new ESBWR program. The ESBWR core
was also increased in size by adding fuel
assemblies to increase power level. Fuel
height was decreased to 3.0 meters in order
to achieve the appropriate pressure
drop, while the power density was set to 54
kW/liter. The core increased from the 732
fuel assemblies in the SBWR to 1,132 fuel
assemblies in the ESBWR, resulting in a
thermal power rating of 4,500 MWt. Table
4 summarizes additional ESBWR design
features compared with the ABWR design.
POWER| November 2010

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POWER November 2010

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