Page 38 - Nuclear Plant Journal - March April 2013
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Robotic Pipe
Inspection to
Meet License
Renewal
Commitments
By David Bremer, Cooper Nuclear
Station.
David Bremer
David Bremer has been with Cooper
Nuclear Station for more than 30 years.
Since the project’s
inception in 2005,
he has served as
the license renewal
project manager,
with the previous
25 years spent in
Operations.
Dave began his
nuclear career
in the US Navy
and has a BS in
Nuclear Technology
from Peru State College. He is an
active member in the NEI-sponsored
License Renewal Taskforce and the
Implementation Working Group.
US nuclear power plants contain ex-
tensive piping systems, many of which
are buried underground, in constant con-
tact with soil. These plant piping sys-
tems often contain potentially-hazardous
substances such as diesel oil, or coolant
water containing small levels of tritium.
Because these buried pipes are vulnerable
to degradation from internal and external
corrosion, nuclear plant operators are ob-
ligated to maintain buried pipe programs
that identify, rank, monitor, and inspect
these piping systems. These activities are
driven by industry mandates such as NEI
09-14 (Guideline for the Management
of Underground Piping and Tank Integ-
rity), NEI 07-07 (Industry Ground Wa-
ter Protection Initiative- Final Guidance
Document) groundwater protection, or
required relicensing
commitments.
Cooper Nuclear
Station (CNS) is an
830 MWe BWR-4
located in Browns-
ville,
Nebraska,
which began com-
mercial operation in
1974. CNS main-
tains a buried pipe
inspection and mon-
itoring program that
began in the Spring
of 2011, consisting of 21 plant systems
that account for a total piping length of
60,406 feet. Since CNS’ buried pipe pro-
gram inception, we have completed 4 to-
tal pipe inspections: 2 excavations, 1Area
Potential-Earth Current (APEC) survey,
Soil Analysis, and 1 in-line inspection
(ILI). The in-line inspection was the first
of its kind in the US nuclear power indus-
try, and is the subject of this article.
License Renewal
Inspection
As part of Cooper Nuclear Station’s
2010 license renewal, a commitment was
made that 6 piping systems be inspected
prior to the start of the extended operation
period. One of these systems was our
High Pressure Coolant Injection (HPCI)
line. This safety-related piping system
transports demineralized water from the
Emergency Condensate Storage Tank
(ECST) room in the Control Building
(where the control room is located)
basement to the safety injection systems
in the Reactor Building. Since the
inspection needed to be conducted while
the plant was offline, CNS scheduled the
inspection to coincide with our Fall 2012
refueling outage.
The line to be inspected was a 30 foot
section of 18-inch Schedule XS (0.500")
carbon steel pipe with two welded vertical
45° elbow fittings. The only access to the
system was via an opening in the ECST
room, so it was decided that a robotic in-
line inspection was the most practical,
comprehensive, and cost-effective means
of completing the inspection.
CNS’ Senior Nuclear Safety
Assurance Group Analyst, David Bremer,
contracted the team of Diakont and
Structural Integrity Associates, Inc. (SI)
to perform the robotic inspection and flaw
evaluation of the HPCI system piping.
TheDiakont/SI teamwas selected because
it offered a “turnkey” approach to the
complete project, including inspection,
analysis, and datamanagement. Diakont’s
HPCI Piping Requiring Inspection for Extended Operation.
38
Nuclear Plant Journal, March-April 2013
