POWER October 2013 - 76

Nuclear Power
NuScale Puts Single-Minded
Focus on Small Modular Reactor
The western U.S. could host the first NuScale small modular reactor, which traces
its roots to Oregon State University. Financial backing from Fluor Corp. could
make the design more than an academic exercise and provide a scalable, carbon-free
electric power source by the mid-2020s.
David Wagman
T
he global nuclear industry has endured
a rough patch since March 2011, when
an earthquake and tsunami crippled
the Fukushima Daiichi nuclear station in Japan.
Attention in the U.S. after the accident
focused on the ability of nuclear reactors to
safely shut down in the event of a loss of
power to water circulating pumps critical in
keeping the reactor core cool. The Nuclear
Regulatory Commission (NRC) adopted a
number of recommendations for operators
to follow, including enhancing the capability
of operators to maintain plant safety during a
prolonged loss of electrical power.
Then in January 2012, excessive wear in
the tubes of replacement steam generators
at a unit of the San Onofre Nuclear Generating
Station (SONGS) in California focused a
spotlight on materials that could lead to accelerated
tube corrosion.
This past July, French nuclear operator
EDF said it would exit the U.S. nuclear
market, and Entergy said it would consider
" all options " regarding its non-utility nuclear
generating assets. Both companies cited low
U.S. wholesale electric prices-the result of
recent historically low natural gas prices-as
among the reasons for their decision.
These concerns and market challenges
aren't lost on proponents of small modular
reactors (SMRs), the genre of nuclear power
plant that aims to combine modular, factorybuilt
reactors with secure, reliable, and safe
operations. POWER has already profiled the
Babcock & Wilcox mPower and GE PRISM
SMRs and has written about the Holtec and
Westinghouse SMRs. Here we look at the
NuScale SMR design, backed financially
since 2011 by Fluor Corp.
Considering safety, Dr. Jose N. Reyes,
chief technology officer for NuScale, told
POWER in an interview that his company's
SMR relies on the laws of physics rather than
mechanical equipment to provide an " infinite
period of cooling " to the reactor core in the
event of a Fukushima-type loss of power.
" It became apparent after Fukushima that
76
our design had fundamental differences " with
large-scale nuclear reactors, particularly in
its ability to safely shut down and cool itself
without electric power, Reyes said. In particular,
the design relies on gravity and natural
circulation to safely and passively cool the reactor.
What's more, at 45 MW, each module
contains a relatively small amount of nuclear
fuel. Reyes said this reduces considerably the
environmental risk any one module would
present in the event of a crippling accident.
Considering corrosion, NuScale has two
large-scale test facilities in Italy that are conducting
flow-induced vibration tests on fulllength
steam generator tube bundles. The aim
is to learn if vulnerabilities exist similar to
those found at SONGS. Test results are expected
at the end of the year, Reyes said.
Considering economics, the company
estimates that it can install a 12-pack of its
45-MW NuScale Power Modules (540 MW
total plant output) for less than $5,000/kW.
By comparison, the Energy Information Administration
estimated earlier this year that
advanced baseload nuclear generating capacity
would carry an overnight cost of $4,700/
kW (in 2011 dollars), a new scrubbed coal
facility would be $2,694/kW, and a gas-fired
combined cycle plant would run $931/kW.
Adding carbon sequestration to the coal plant
would lift its overnight cost to more than
$4,600/kW. The overnight cost for a combined
cycle plant would exceed $1,800/kW
with carbon sequestration.
Even so, the economics of SMR might
work for an entity that wants a scalable, zeroemissions
source of electricity, and where
transmission constraints make it difficult to
site a much larger central generating station.
That makes the western U.S. an attractive location
for one of the first SMRs. This past June,
NuScale Power announced the launch of the
Western Initiative for Nuclear (WIN)-a multiwestern
state collaboration-to study the demonstration
and deployment of a multi-module
NuScale SMR. A NuScale SMR built as part of
WIN is projected to be operational by 2024.
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If built, WIN would serve as the initial
commercialization project for a potential
series of projects that may be developed in
other states. The first NuScale plant will
most likely be developed, built and owned by
a consortium of regional utilities, and operated
by one of those utilities. The preferred
location at this point lies within the Idaho
National Laboratory site. The laboratory has
a history of supporting nuclear power deployment,
and the state's governor has expressed
support for an SMR deployment.
Oregon Roots
The NuScale SMR traces its origins to 2000,
when the Department of Energy (DOE) funded
research for the development of a small
nuclear power plant for use in multiple applications.
Idaho National Environment &
Engineering Laboratory led the project with
support from Oregon State University (OSU).
At the same time, OSU was gaining notice
for developing passive safety systems using
natural circulation to cool nuclear plants.
OSU built and operated 1,000-MW and 600MW
nuclear steam supply system scale models
to help win NRC design certification for
those technologies.
When the DOE research project ended in
2003, OSU scientists continued to pursue design
of a small-scale nuclear plant that used
natural circulation. Ultimately, the team built
a one-third-scale electrically heated version
of a plant. OSU granted NuScale Power LLC
exclusive rights to the design, plus continued
use of a test facility, through a 2007 technology
transfer agreement.
In February 2008, NuScale began the process
of seeking NRC design certification for
its technology. The company currently is in
the pre-application review phase.
In 2011, Fluor Corp. became NuScale's
primary investor with the intent of leveraging
its engineering, fabrication, procurement,
and construction capabilities, along with its
global supply chain, to support commercialization.
This past August, Rolls-Royce said it
POWER | October 2013
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