Teamwork
&Timing
By Mark Stanislawski, Konecranes
Nuclear Equipment and Services, LLC.
Mark Stanislawski
Mark Stanislawski is the Vice President
and General Manager of Konecranes
Nuclear Equipment
and Services, LLC
where he has overseen
Sales and nuclear
equipment installations
for over five years. He
received his Bachelor
of Science in Industrial
Management from
the University of
Wisconsin. Mark
has been in the
Material Handling
Manufacturing industry
for 20 years with an
extensive background
in Engineering and Production
Management.
When FirstEnergy Corporation’s
Davis-Besse Nuclear Power Station
decided to replace its degrading polar
crane conductor bar insulation, they
embarked on an ambitious planning
process. This was not a simple task,
considering the polar crane operates in
the containment building, which meant
problems of access, contamination, and
heat.
To complicate matters, operators
wanted to imple-
ment the project
while simultane-
ously
modifying
the crane to add
lift capacity for a
planned steam gen-
erator replacement.
Because the con-
ductor bar is 90 feet
above normal ac-
cess, the operation
required good plan-
ning. Davis-Besse
engineers,
along
with Konecranes,
planned and executed this mission flaw-
lessly, completing both projects in less
than four days.
Degraded insulation
spurs replacement
Davis-Besse Nuclear Power Station,
a pressurized water reactor in Oak Har-
bor, Ohio, uses a polar crane to lift the
reactor head to start the refueling pro-
cess, approximately every 18 months.
The crane’s conductor bar powers all of
its functions and consists of three phases,
each with two pick-up shoes. Conductor
bar insulation provides protection from
phase-to-phase contact and helps main-
tain shoe alignment and containment
within the track.
FirstEnergy decided that replacement
was needed after condition reports
recorded degraded insulation. Over 30
years, heat had cracked the insulation,
causing it to become brittle and separate
from the bar in places. The concern
was that degradation could cause pick-
up shoes to jump the track. If this were
to happen, the shoes might contact an
adjacent conductor, which could lead to
crane component failure – and extensive
downtime. Operators noted that they had
to tag out the crane and remove hanging
insulation six times during the previous
outage, with several hours of downtime
per event.
Mike Zawacki, a senior nuclear
engineer for FirstEnergy and crane
engineer for the project, explains that
they were not originally planning an
insulation change out. However, due to
reliability concerns, they decided to take
advantage of the fact that the crane was
down anyway. “The condition had to be
fixed, and it worked out well that we could
complete the project at the same time we
were doing the crane modification.”
Zawacki explains that planning a job
in a containment building that has limited
access is challenging. The team began
with discussions on the best way to fix
the issue, asking themselves if it would
be better to replace or upgrade the entire
system, or only the problem areas. After
talking with vendors, they decided to stay
with the original system and replace the
old conductor bar covers. This included
removing the old insulation, installing
new insulation, and replacing support
clips.
“The project was filled with technical
challenges, mainly because it is such a
difficult location in which to work,” said
Zawacki. He cites a variety of problems,
including unknown stay times and lack
of cool tent options with a constantly
moving work location. A very large job
had to be done within a four-day window,
and everything would have to be set up at
the job site prior to tag out. Special tools
and skills were required at insulation
splices and joints, and to top it off, the
project was being done under foreign
material exclusion (FME) procedures.
Zawacki began by discussing
logistics with Konecranes, which had
been Davis-Besse’s crane supplier since
2001 and knew the facility well, having
worked on about 10 other projects at
Davis-Besse.
34
NuclearPlantJournal.com Nuclear Plant Journal, March-April 2014
