26
NuclearPlantJournal.com Nuclear Plant Journal, July-August 2015
Today’s handheld UT probes are
widely used to provide immediate
but mostly qualitative insights into
component integrity and detected defects.
While offering relatively low cost and
the ability to interrogate locations not
accessible to existing robotic scanners, the
necessarily conservative interpretations
associated with manual scanning results
can lead to premature or unnecessary
repairs. Automated UT systems typically
collect computer-encoded 3-D images
that support both immediate inspection
and later quantitative NDE. However,
significantly higher costs, along with
accessibility limitations, sometimes
constrain their use to specific applications.
The acoustic mouse will deliver
high-quality, computer-encoded imaging
at reduced cost and with handheld
convenience. Through a multifaceted
appliedR&Dprogram,EPRIhasadvanced
data processing, image reconstruction,
ultrasonic phased array, and position
tracking technologies in an integrated
design. In 2014, a prototype acoustic
mouse system was applied to perform
manual UT scans, with sensor liftoffs,
on both flat and curved surfaces. The
prototype proved capable of generating
real-time,
high-quality,
computer-
encoded images of simulated defects
and internal features in reference blocks
and component mockups. (Program on
Technology Innovation: Acoustic Mouse
Technology, 3002004437)
Ongoinglaboratorytestsfocusonsub-
system and system-level optimization.
Over the next few years, the goal will
be for NDE equipment manufacturers
to begin incorporating EPRI-developed
innovations into commercial products
for field demonstration and qualification
testing. Sparse array and other advances
will support a substantial reduction in
hardware and software requirements
for state-of-the-art manual UT systems,
producing cost savings that will facilitate
widespread applications of computer-
encoded NDE for volumetric inspection.
Contact: Mark Dennis, EPRI,
telephone: (704) 595-2648, email:
.
ABOVE:
Workers prepare to use a HEPA
ventilation unit as an engineered control
Engineering Controls for Hazardous Environments
Portable HEPA filtration systems are a cost
-
effective means to reduce
exposure levels to as low as reasonably achievable (ALARA).
By Haley Stout
Radiation Protection Systems, Inc.
What are Engineering Controls
?
According to OSHA, “the first and best
strategy is to control the hazard at its
source. Engineering controls do this,
unlike other controls that generally focus
on the employee exposed to the hazard.
The basic concept behind engineering
controls is that, to the extent feasible, the
work environment and the job itself
should be designed to eliminate hazards
or reduce exposure to hazards.”
Engineered Controls are designed to integrate or
compliment a work process or operation, such
that the controls function without inhibiting the
work and will enhance the process when
compared to using personal protective equipment
(PPE) only.
One important engineering control is the
application of portable High Efficiency
Particulate Air (HEPA) filtration and carbon
adsorption ventilation systems when airborne
hazards are expected. When used properly, these
systems effectively control contamination at its
source, minimize the spread of contaminants,
and reduce exposure of personnel while
increasing safety and efficiency.
When to Consider Engineering
Controls?
Ventilation should not be an afterthought. It
should be considered at the beginning of work
planning and integrated into the process.
Why Consider Engineering
Controls?
The burden of control is removed from the
worker (eliminating heat stress, for example),
allowing him/her to perform more work of
higher quality in a shorter time.
Controlling contamination at its source
reduces cleanup and the associated radiation
exposure.
Use of respiratory protection devices is
minimized substantially, reducing cost for
operation of an extensive respiratory
program.
The primary goal of a radiological engineering
program is to provide controls which minimize
radiation exposure of personnel without
incurring high costs. A number of factors must
be considered when evaluating different
methods. Factors include initial cost of
equipment, cost to repair and service the
equipment, the number of personnel and time
required to use the method, effectiveness of
controlling radioactive contamination, and
effectiveness in reducing radiation exposure to
personnel.
Personnel working where there are airborne
radioactive particulates must be protected from
inhaling the contaminants. Protection may be
provided by respiratory protection devices or by
controlling contamination at its source using
engineering controls, such as HEPA filtration. Of
the two approaches, engineering controls are
more advantageous, offering cost benefits by
reducing: the spread of contamination, laundry,
respirator cleaning, cleanup time, outage time,
and radiation exposure.
To learn more about how
Engineering Controls can benefit you,
visit Radiation Protection Systems on
the web at
or call 888.637.7779
Research &
Development...
UT transducer on a reference block
during testing and development of
the acoustic mouse.
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