IEEE Spectrum May, 2010 - 15

this year, scientists expect to
shine the combined beams
on test capsules containing
deuterium and tritium,
in the hope of igniting
thermonuclear fusion.
Project director Ed Moses
expects to reach scientific
breakeven-when more
energy comes out of the
system than what goes in-
within a couple of years.

hIghESt powEr
The laser with the highest
peak power in the world-
1.1 petawatts, about 2200 times
the power output of the entire
U.S. electrical grid-is run
by the University of Texas at
Austin. The laser starts with a
short, low-energy laser pulse
and stretches it to 10 000 times
its length, amplifies it to
186 joules, then recompresses
it to 167 femtoseconds. The
laser provides scientists
with enough power to
study thermonuclear fusion
as well as to examine the
nature of plasmas and the
properties of dense matter
in brown dwarf stars.
SmaLLESt LaSEr
A particle of gold in a silica
shell only 44 nm across is the
smallest laser yet devised.
Scientists from Cornell,
Norfolk State, and Purdue
universities designed the
laser, which exploits surface
plasmons-oscillations of
electrons that occur where a
metal touches an insulator. The
laser emitted light in the green
spectrum at a wavelength
of 530 nm, far larger than
the laser itself, which is tiny
enough to place on a computer
chip or attach to a cancer cell. ❏
14

Na * IEEE SpEctrum * may 2010

Downsizing
Nuclear
Power Plants
modular designs rely on
"economies of multiples" to
make small reactors pay off big

A

standard nuclear power plant
generates a gigawatt or more of
low-carbon power, a boon in this
age of anxiety over climate change. The
problem is getting the thing built in the
first place: At US $7 billion to $10 billion
apiece, nuclear plants are tough for even
the largest utilities to finance.
President Obama proposes to handle
the problem by tripling federal loan
guarantees to such plants, to $54 billion.
But now a more economical solution
is coming under scrutiny: downsizing
nuclear plants from gigawatt scale to more
affordable units that can be built by the
dozen. "Size matters. In this case, small
size," says Andrew Kadak, a professor of
nuclear science and engineering at MIT.
Small modular reactors, or SMRs, of
70 to 210 megawatts are under construction
in China and Russia, and a mix of start-ups
and established nuclear technology
firms, such as Westinghouse Electric
Co., General Atomics, and the Babcock
& Wilcox Co., are shopping similarly
modest designs in the United States.
This strategy overturns the drive toward
economies of scale that has pushed nuclear
designers toward ever-larger reactors since
the industry's inception. Now the designers
may instead rely on the "economies of
multiples" that accrue to the mass production of everything from cars to iPhones.
"We want to manufacture in a plant with
supply-chain management. This enables
you to drive down cost and control the
schedule," says John Parmentola, senior vice
president for energy and electromagnetic
systems at General Atomics. That means
building modules, including reactors, that

muLtiPLe meGawatts: Engineering
ﬁrms are hoping that many smaller
reactors will be easier for utilities to
ﬁnance than a few large ones.
ILLUSTRATIONS: CHINERGY CO.

are small enough to be shipped on a truck
or railcar and designed so that they can
be snapped together on-site. "It's almost
Lego-style assembly," says Kadak.
These innovators hope to avoid the
sprawling construction sites required to
build today's gigawatt-plus reactors, which
are prone to quality problems and delays.
For example, in 2005 France's Areva
boasted that its flagship 1.65-gigawatt
pressurized water reactor, the EPR, would
be completed by 2009. Now the company
is admitting that faulty materials and
planning snafus have set the completion
target back to 2012 and raised the
project's estimated cost by 66 percent, to
a budget of €5.3 billion ($7.2 billion).
Proponents of SMRs admit that their
installation costs may turn out to be as
much as or even more than that of today's
behemoths, but they argue that the lower
risk involved should make SMRs the better
deal anyway. Christofer Mowry, CEO
of Babcock & Wilcox's Modular Nuclear
Energy subsidiary, leads the development
of a 125-MW SMR called mPower that
he estimates will cost about $600 million
in parts and labor. That's comparable to
Areva's Olkiluoto plant on a per-megawatt
spectrum.ieee.org
http://spectrum.ieee.org
Table of Contents for the Digital Edition of IEEE Spectrum May, 2010
