POWER January 2015 - 31

NUCLEAR
South Korea's SMART Approach to Small Modular
Reactors
South Korea began the conceptual design
for its System-Integrated Modular Advanced
Reactor, or SMART, in 1997, with
the basic design completed in 2001 (Figure
2). The design firmed up and was developed
and components tested over the
next decade, with the Korea Atomic Energy
Research Institute (KAERI) spending some
$300 million and 1,500 person-years on
the project, which won approval from the
Korea Institute of Nuclear Safety, the government's
nuclear regulator, in mid-2012.
The approved design is for a 300-MWt
Control rod drive
mechanism
In-core instrument
nozzles
Reactor closure
head
Reactor coolant
piping
Steam
nozzle
Feedwater
nozzle
reactor, with up to 100 MW in electrical
output. It is also suited for thermal applications
such as desalination.
According to the World Nuclear Organization,
SMART's design life is 60 years, fuel
enrichment is 4.8%, and the design features
a three-year refueling cycle. As in many
SMRs, the residual heat removal is passive.
According to KAERI, the passive heat recovalong
with 40,000 cubic meters/day of freshwater.
The design has won standardized approval
from Korea's nuclear regulator, which
Korea Electric Power Co. touts as a selling
point in its literature (see sidebar). WNO
commented, " While the design is complete,
the absence of any order for an initial reference
unit has stalled development. " KAERI
has said it wants to build a demonstration
plant to operate in 2017.
Long History
Small reactors are familiar to the nuclear industry,
which began with small machines that
bulked up over the years to take advantage of
economies of scale. The legendary Shippingport
nuclear plant in western Pennsylvania,
the first fully commercial pressurized-water
nuclear plant, entered service in 1957 and
was rated at 60 MW. The U.S. military and
the Soviet Union spent considerable sums in
the 1950s and 1960s on designs for small,
transportable, remote reactors and for reactors
to be used in ship propulsion.
Many of today's SMR plans have their
roots in naval reactor technology, as did
Shippingport. Its technology was based on
Westinghouse reactors that powered the
first U.S. nuclear submarines. Argentina's
CAREM 25 reactor design came from the
Argentine navy. The country unveiled the
design at a 1984 IAEA conference. The project
then got shelved, but was revived in 2006
January 2015 | POWER
Reactor vessel
support structure
ery design gives the plant a " 20 days grace
period against Fukushima-type accidents. "
In the design, all fuel is submerged in
water and the containment building can
withstand a crash from a Boeing 767. The
containment also includes a passive hydrogen
removal system to prevent hydrogen
explosions.
as Argentina moved to revitalize its nuclear
power program in the face of limited supplies
and high prices for imported natural gas. Argentina
has few easily accessible indigenous
energy resources.
Russia's floating nukes also rely on maritime
technology, reactors developed for its
successful fleet of nuclear icebreakers, dating
back well into the days of the Soviet
Union. The nation's first nuclear icebreaker,
the NS Lenin, was launched in 1957, the
same year that Shippingport went into commercial
service.
In the U.S., two of the major SMR industrial
developers, Babcock & Wilcox and
Westinghouse, both have extensive experience
with naval reactors. But that technology
advantage has not provided commercial
leverage, as both companies have scaled
back their SMR programs in the face of a
lack of demand for their product (see " What
Went Wrong with SMRs? " in the September
2014 issue).
Short on Results
What accounts for the inability of the U.S.
(and European, for that matter) market to embrace
SMR technology, when less-developed
and less-financially muscular countries and
utilities are moving ahead?
Giorgio Locatelli of the UK's University
of Lincoln, who published a recent paper
on the economics of SMRs, " Small Moduwww.powermag.com
2.
SMART design. South Korea's
300-MWt SMR design could be up and
running by 2017. Courtesy: Korea Atomic
Energy Research Institute
lar Reactors: A Comprehensive Overview
of Their Economics and Strategic Aspects, "
argues that the smaller reactors make sense
in developing countries, where " it can be
very tricky to get equity to make the investments.
But with a small modular reactor,
you build the first one, which comes
cheaper, and then when you've raised more
money you create the second, and then you
start to sell electricity with the first and the
second, and by selling electricity you can
finance the construction of the third and
then the fourth. "
He contrasts that with the mammoth £16
billion ($25 billion) Hinkley Point nuclear
project in the UK. " If you are building a nuclear
reactor with £16 billion investment and
then you decide not to go ahead with the infrastructure
and stop it, you have £16 billion
in funds that you are not able to recover. If
you have a small modular reactor, the financial
risk is reduced. "
So why have the U.S. and the Europeans
not been successful with SMRs? Locatelli
pointed to natural gas, noting the
low cost. " The point is, " he said in an interview
with power-technology.com, " that
if you build a combined cycle gas power
plant, it is very easy and cheaper to build
and if the gas is cheap it is also cheaper
to operate. "
Veteran nuclear power observer Chris
Paine of the Natural Resources Defense
Council, after attending an SMR conference
in Washington last year, noted another
problem with the economics of SMR projects,
regardless of where they are located.
" Nuclear reactors, " he wrote, " historically
have evolved to very large single-unit sizes
in order to distribute the very large initial
fixed capital costs of nuclear power over a
larger base of electricity sales, or put another
way, to reduce the fixed capital cost requirement
per megawatt-hour of electricity
produced. But a multi-unit SMR inverts this
economic logic, producing fewer kilowatt
hours from a larger physical capital investment
per unit of capacity. "
Outside the developed world, the economics
are often different, or even irrelevant, with
state-supported projects, state-monopoly
companies, and generally streamlined regulatory
regimes dominating the economic and
political environment for nuclear power. In
countries such as Argentina, China, Russia,
and South Korea, the seller of the technology
and the buyer are essentially the same, just
wearing different hats.
Murky Future
University of Lincoln's Locatelli noted that
it will take a " first mover " to get the SMR
market off the ground, and that's likely to
31
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POWER January 2015

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