Page 28 - Nuclear Plant Journal - March April 2013
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Passively
Safe Plant
By William (Ed) Cummins, Westinghouse
Electric Company.
William Cummins
Ed Cummins has spent his 36-year
Westinghouse career in a variety of
assignments in project management,
engineering management and new
plant design.
Prior to joining
Westinghouse in
1976, Ed served
seven years in the
U.S. Navy with
assignments in
engineering and
operations on two
nuclear powered
submarines.
In March of 2000,
Westinghouse
initiated
development of
the AP1000 plant
designed to be competitive with natural
gas fired combined cycle plants. He
is currently Vice President & Chief
Technologist of New Plant Technologies,
responsible for passive plant technology.
He is also coordinating the design
activities for the Westinghouse Small
Modular Reactor.
Mr. Cummins holds a Bachelor of
Science Degree from the U.S. Naval
Academy, a Master of Science Degree
in Engineering Applied Science from
the University of California, Davis,
Livermore and a Master of Business
Administration from Duquesne
University.
Response to questions by Newal
Agnihotri, Editor of Nuclear Plant
Journal.
1.
What is the current licensed life of
the AP1000
®
nuclear power plant in the
United States and in China?
The licensed lifetime of the AP1000
plant in the U.S. is 40 years. It is expected
that China will follow the same licensing
model as in the U.S., with the planned
40-year life and a dedicated review for
license extension at that time.
2.
What is the design life of the AP1000
nuclear power plant?
The design life of the AP1000 plant
is 60 years.
Both EPRI and the Nuclear Regula-
tory Commission (NRC) are studying the
aging mechanisms for plant components
in order to achieve
an 80 year life.
Conclusions have
not yet been made
regarding what is
necessary. Some of
the potential con-
cerns include the
aging of electric
cables and structural
concrete. Plants
with digital instru-
mentation and con-
trol (I&C) systems
such as the AP1000
plant use dramati-
cally less cable and
do not have cable spreading rooms for the
main control room. These features should
enable replacement of cable in a much
less complicated manner than for tradi-
tional plants. Also some of our steel and
concrete composite modules may limit
the aging of concrete and improve the in-
spectability of the reinforcing steel.
There is much yet to learn regarding
the justification of an 80 year life.
3.
What modifications in design,
structures, systems, equipment, and
instruments have been made to support a
plant life higher than 40 years?
The modifications for greater than
a 40-year life are primarily in analysis
of stress/fatigue cycles which have been
analyzed for 60 years of operation instead
of 40 years of operation.
4.
Are there any plans, built into the
AP1000 plant’s design to enable its 80-
year life?
Westinghouse’s goal was to achieve
a 60-year life for theAP1000 plant. While
we did not specifically target an 80-year
life, it is quite possible that the design
will support operation for that period
of time. However as previously stated,
there is much yet to learn regarding the
justification of an 80-year life.
5.
What monitoring systems have been
provided in the AP1000 plant to monitor
and detect degradation of a structures,
systems, equipment, and instruments to
ensure an early warning of an incipient
failure?
Monitoringsystems includevibration
monitoring for large rotating equipment
such as reactor coolant pumps and
feedwater pumps, temperaturemonitoring
of motor windings, and temperature
monitoring of pipe segments that might
experience temperature stratification.
6.
What are the features of the AP1000
plant control room to make it user friendly
to the younger generation who are more
IT and Internet savvy?
The AP1000 plant control room
is completely digital, and the plant
is controlled by the operation of a
computer mouse. The AP1000 plant is
the first nuclear plant in the U.S. with a
completely digital control room. There
are also interesting enhancements such
as computerized procedures where the
status being questioned is presented as
part of the procedure step. Advancements
have been made in alarm management
and other human factors areas. These
features can be seen in our AP1000 plant
simulator in Cranberry.
7.
What margins are built in the
design of the turbine, condensate pumps,
motors, generators and transformers to
accommodate extended power uprate
or other type of power uprates in the
future?
No margins were added to AP1000
plant components specifically for the
purpose of extending the power rating
of the AP1000 plant. However based on
sound engineering practices, margins
inherently exist in many components
that possibly could be used for power
uprating.
28
Nuclear Plant Journal, March-April 2013
