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NuclearPlantJournal.com Nuclear Plant Journal, March-April 2016
Research &
Development
NIST Workshop
Challenges and
Opportunities
The development and use of
robotics and remote systems has become
widespread and relatively common in
many industries including aerospace,
defense, oil & gas and automotive. The
move towards the use of these types of
systems has been driven by the need to
reduce cost, improve operations and
safety and to facilitate work in repetitive
or challenging environments.
Although there aremany opportunities
for the use of such systems in the nuclear
industry (operations, outages, D&D),
there is an inherent conservatism to
their implementation. However, the
critical need to use remote systems at the
Fukushima Daiichi Nuclear Power Station
in Japan has caused a paradigm shift in
thinking about the use of remote systems.
Indeed, there are many technical
challenges at nuclear facilities that
require some form of remote handling
expertise and equipment. In addition
to the significant R&D efforts being
undertaken worldwide, there are also
numerous remote systems in use in
multiple applications in both nuclear and
non-nuclear industries. In many cases,
the systems developed are customized
for their given application but there are
also multiple systems in use which could
be applied to nuclear challenges either
directly or with some minor adaptation.
In 2014, the U.S. Department of
Energy’s Office of D&D and Facility
Engineering supported Cogentus and
NuVision Engineering to conduct a review
and assessment of the current state-of-the-
art of robotics and remote technologies in
order to generate a baseline of what is
available, what has been used where and
for what applications as well as what has
been successful and what hasn’t.
In all, more than 1100 remote
systems were identified and have
been cataloged as a searchable, web-
based database. Having assembled and
assimilated the data, it was considered
that, while many of these individual
systems were customized to a single
application, linking and integrating two
or more systems together could address
a completely different need or challenge.
Such integration has never been possible
in the past as there has been no such
comprehensive database which contains
so much information on available
systems.
The above is a presentation by
Laurie Judd, Longenecker & Associates
and Andrew Szilagyi, DOE at the
International Workshop on the Use
of Robotic Technologies at Nuclear
Facilities at the National Institute
of Standards Technology (NIST), in
Gaithersburg, Maryland on February
2-4, 2016.
Contact: Andrew Szilagyi, DOE,
email:
.
EPRI R&D
Equipment Malfunction
Monitoring
Electrical
and
mechanical
components in power plants emit an
“aura” of acoustic and electromagnetic
signals that vary during malfunctions.
An EPRI feasibility study points to the
potential for using ambient sensors to
measure these signals for comprehensive
plant health monitoring at significantly
lower cost than current inspection
methods.
Traditional plant monitoring relies
on sensors embedded in equipment,
which can be costly and impractical to
implement comprehensively.
EPRI evaluated the concept of
an integrated system of low-cost,
commercially available ambient sensors
to monitor acoustic and electromagnetic
emissions in large plant spaces for
indications of equipment degradation
or failure. Software would enable real-
time analysis and alert technicians to
investigate potential problems.
In the laboratory, researchers
positioned microphones and antennae at
a distance from electric motors of various
sizes during normal and faulty operation.
They demonstrated that changes can be
detected for a range of failures, such as a
broken rotor bar, a bowed armature shaft,
and overvoltage.
In 2016, EPRI will further develop
the system’s hardware requirements and
collect and analyze data from additional
power plant equipment, such as pumps
and generators.
Robotic Car for NDE
It resembles a toy car with outsize
metal wheels. It measures 6 inches by 6
inches by 2 inches. Its headlights blink on
and, with a little whizzing noise, it moves
forward to the edge of a metal ledge. Then
it slowly drives over the edge and straight
down the wall, its magnetic wheels never
losing their grip.
EPRI is testing the ability of this
robotic car to wriggle its way through
the narrow spaces between spent nuclear
fuel storage canisters and their concrete
overpacks,
carrying
nondestructive
evaluation probes into places no human
can reach. EPRI is also testing a robot that
uses suction to stick to surfaces. EPRI is
working with vendors to design and build
both the robots and the tiny cameras and
inspection probes they will transport.
In September 2015 at the Palo
Verde Nuclear Generating Station in
Arizona, EPRI tested the robots with
an eddy current array probe and an
electromagnetic-acoustic
transducer
probe that generated guided waves. The
eddy current array probe provides more
detail of the metal surface, while the
guided wave probe can “see” farther
and detect indications of degradation in
crevices and other inaccessible areas that
the probe can’t contact directly.According
to EPRI Senior Technical Leader Jeremy
Renshaw, EPRI research on canister and
fuel aging will help determine where each
probe could be most useful in detecting
any degradation indications for future
canister inspections.
Using full-scale mockups of two cask
designs, the EPRI team demonstrated
that either robot could navigate entry
into the casks through available vents
and maneuver in the constricted spaces
inside. Both probes maintained contact
with metal surfaces and recorded good
data on the mockups’ surface conditions.
Although the demonstration went
well, the EPRI team identified some
areas for improvement. For instance,
the electromagnetic-acoustic transducer
probe encountered challenges entering
and exiting the cask outlet vent. “This is
a minor issue that we need to address,”
said Renshaw. “It illustrates how on-site
demonstrations are valuable in working
out the kinks in prototypes to prepare for
actual field inspections.”
The storage casks now in use were
designed by multiple vendors and vary
