Underground Construction - July 2018 - 32

REHABTECHNOLOGY

Jeﬀ Griﬃn | Senior Editor

Nuclear CIPP
Patience, Safety, Security Paramount
For Critical Plant Rehab Jobs

Most people are perfectly
happy to stay away from any
activity that could expose them
to anything radioactive. We've
driven past nuclear power
plants, but few have ever entered their grounds or had the
desire to do so.
However, Elite Pipeline Services has made pipeline inspections, rehabilitation and repair
in nuclear power facilities an
important part of its workload,
and is recognized as an industry
leader in this specialized field.
Elite has been serving the
nuclear industry for more than
12 years, said General Manager
Terry Bell.

Extensive underground
piping
Bell explained that nuclear
plants have extensive underground piping infrastructure
that is critical to power generation and that all systems,
regardless of purpose, are typically well-maintained and commonly evaluated.
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JULY 2018 | UConOnline.com

The Nuclear Regulatory Commission (NRC) describes buried
pipe as piping that is in contact
with soil. Quoting the NRC,
"At nuclear power plants, the
buried piping systems are comparable to those used in other
industries transporting a public
water supply, and for oil and
gas transmission."
"Cooling water is the most
common material transported in buried pipes," Bell
explained. Cooling water is
generally taken from a lake or
river and, except for a slight
increase in temperature, is returned unchanged to the same
body of water. Generally, this
water contains only naturally
occurring, background levels
of radioactive materials. Some
buried piping also transports
smaller amounts of water that
may contain slightly elevated
levels of radioactive isotopes,
usually tritium. Diesel fuel is
the other commonly transported material.
"The NRC distinguishes

between buried piping and
other components beneath
the surface because they are
exposed to different environments; they corrode by different mechanisms, and they
are protected from corrosion
differently."

Risks to buried piping

Bell said preventive measures
for corrosion and degradation
are always front and center, and
depending on the system, have
NRC-mandated procedures.
"While buried piping is highly
reliable," he continued, "damage
and corrosion can lead to leaks,
which are often addressed with
systems oﬄine, unless the issue
causes significant problems.
"In 2005, nuclear power facilities focused on a Buried Pipe
Initiative (NEI 09-14) that took
several years to investigate. Systems were found to be in much
better shape than expected
and, in fact, provided comfort
that CP systems and program
maintenance were working.

When leaks do occur, they are
often contained to ensure they
do not create safety concerns
for the plant or public . While
some leaks do introduce slightly
elevated levels of radiation into
the ground water, they do not
exceed regulatory limits."
In selecting methods to address piping issues at nuclear
facilities, Bell said engineers
and decision makers always
evaluate product data, history,
performance, testing and
references.
"Nuclear facilities are not
testing grounds for new technologies," Bell emphasized.
"They value the input of industry providers and perform extensive research before allowing
products in their systems. By
the time a project is ready to
be performed, plant engineers
and program owners have performed their due diligence."
As in other markets such
municipal rehabilitation, using
proven trenchless methods are
commonplace. However, there

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Underground Construction - July 2018

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