Tiny particles have big potential in debate
over nuclear proliferation
1 September 2014, by Elle Calderone, Medill New Service
The solution to the big issue of nuclear
nonproliferation might be smaller than you think so small it's virtually invisible and massless.
Physicists at Virginia Tech have found a way to
use these teeny subatomic particles, called
neutrinos, to detect what's going on at nuclear
reactors, such as the Arak reactor in Iran.
Neutrinos are ghostlike particles that move close to
the speed of light and travel to Earth by the billions
from space every day. They barely interact and
can travel through planets; even through you.
Here on Earth, nuclear reactors produce large
amounts of antineutrinos, the counterpart of
neutrinos, which is handy for monitoring reactor
use.
"You can't shield neutrinos or antineutrinos. It's
impossible to shield. You can't hide them," said
Bob Svoboda, a co-leader of the WATCHMAN
Collaboration, a group of universities and
laboratories that are experimenting with nuclear
detection methods.
The researchers from Virginia Tech found a way
to monitor plutonium or uranium use outside a
reactor by using antineutrino detectors with
surprising accuracy. This might provide information
on whether Iran is honoring its commitment under
the Treaty on the Non-Proliferation of Nuclear
Weapons not to develop a nuclear weapons
program.
"If Iran cheats, antineutrino monitoring could
provide an early warning to the international
community, prompting further investigations,
diplomatic interventions or potentially military
action," said Thomas Shea, a nuclear scientist
from TomSheaNuclear Consulting Services. Shea
spent more than two decades with the International
Atomic Energy Agency.
Essentially, scientists are inferring what's going
on inside a nuclear reactor from neutrino emissions
without having to actually go in and check. If the
amount of uranium or plutonium goes up - and you
need a lot of the former to produce the latter scientists can tell that the uranium likely isn't being
used for energy purposes.
"If you can carefully measure the energy of the
outcome in the neutrinos, which is actually fairly
simple, then you can sort of distinguish whether
they're making plutonium or uranium," said Patrick
Huber, an associate professor of physics at Virginia
Tech and author of the neutrino research.
Physicists can detect the frequency of use and
whether anyone is removing plutonium, and they
can do it all by setting up detectors in the range of
10 kilometers - about 6.25 miles - from an
installation.
Without this technology, "If they kick you out the
day before they open the reactor, you have no idea
what's really in the reactor," Huber said in a
telephone interview. "And you also have no idea, if
they let you back in two weeks later, what they did."
Neutrinos, which get their name from an Italian
diminutive meaning "little neutral one," were
discovered in the 1930s by a German physicist,
Wolfgang Pauli. Despite physicists studying
neutrinos for nearly a century, they still hold many
mysteries and might help unlock the history of the
universe.
"There's not much in terms of practical application
for neutrinos. So these detectors outside these
nuclear reactors is sort of a concrete application of
neutrino physics that hopefully leads to the benefit
of society," said David Latimer, an assistant
professor of physics at the University of Puget
Sound in Washington state.
In August, Iranian President Hassan Rouhani told
the International Atomic Energy Agency he'd reject
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restraints imposed outside the framework of the
the Lawrence Livermore National Laboratory.
nuclear treaty. However, there may be a benefit for
Iran to allowing a detector to be set up outside the
So what's the bad news? Getting one of these
Arak, or IR-40, reactor.
antineutrino detectors set up and operating isn't
something that is happening tomorrow - or maybe
It could offer a way for Iran to show it's not
even a year from now. Technical feasibility isn't
cheating on the agreement, while satisfying the
ready yet. "In terms of politics, now, that's
needs of some who may think negotiations can't be everybody's guess," Huber said.
trusted, said Stephen Zunes, a professor of politics
at the University of San Francisco.
Shea said the next steps would be to create a
group of antineutrino experts, such as the ones at
"I think this kind of helps the more moderate of
Virginia Tech and WATCHMAN, to build, design
voices, the voices that are interested in a diplomatic and install a detector adjacent to the IR-40 reactor
solution," he said.
in Iran in order to experiment and analyze data.
Huber and Shea think this could open the doors
for scientific collaboration with neutrino experts in
Iran, allowing for participation in research and
development.
Science can build bridges, Huber said, because
scientists tend to be less focused on politics and
"more on getting things done."
"After a suitable period of time, the IAEA could
then take over these functions, as the
circumstances warrant," he said.
©2014 Medill News Service
Distributed by MCT Information Services
The research conducted at the European
Organization for Nuclear Research, known as
CERN, was one of the first things European
countries did together after fighting two world wars.
Internationally, scientists such as the researchers
at Virginia Tech are making strides in neutrino and
antineutrino studies.
"The good news is that early this year, a Japanese
group demonstrated detection of neutrinos actually
out of the back of a van," Huber said. That is, the
scientists were mobile and using a detector
aboveground. "That's a huge breakthrough."
The other good news is that the WATCHMAN
group, which is planning experiments in Cleveland,
will be making its own headway. The researchers
are hoping to try a different form of detection using
water instead of scintillator, a liquid that can be
costly and isn't great for the environment, Svoboda
said.
"The hope is we can find a hidden reactor
somewhere in the world. Is there a reactor around
or is there not?" said Adam Bernstein, leader of the
rare event detection group in the physics division of
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APA citation: Tiny particles have big potential in debate over nuclear proliferation (2014, September 1)
retrieved 18 June 2017 from https://phys.org/news/2014-09-tiny-particles-big-potential-debate.html
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