Neil Sheehan
Public Affairs Officer
Region I
When
the temperatures plunge into Arctic territory, there are few parts of
the infrastructure not impacted in one way or another. Pipes can freeze,
roads and bridges can quickly ice over and car batteries can go
dormant.
Now,
with what meteorologists are calling a “polar vortex” flooding much of
the country with a blast of frigid air, precautions are being taken to
guard against potential effects. Count U.S. nuclear power plants among
those facilities gearing up for the
2014 version of the Big Chill.
As of Monday
afternoon, no plants were reporting any problems of note related to the
frigid extremes, but ongoing checks will be in order to ensure that
remains the case.
The
NRC’s regional offices in the Midwest and Northeast are keeping an eye
on plant owners’ responses to the unusually low temperatures. Plants in
the affected areas have entered off-normal procedures that entail
minimizing regular surveillance activities and increasing the frequency
of checks and walkdowns (visual evaluations) of equipment that could be
impacted by the temperatures.
NRC Resident Inspectors, who are assigned to specific sites, will continue to monitor the situation. The inspectors use an
“Adverse Weather Protection” inspection procedure to
guide their assessments of whether plants are ready for extreme
temperatures, including the bitter cold. Those reviews are typically
done at the start of the season.
“As
applicable, verify cold weather protection features, such as heat
tracing, space heaters, and weatherized enclosures are monitored
sufficiently to ensure they support operability of the system, structure
or component (SSC) they protect,” the procedure states in part.
It also instructs inspectors to perform walkdowns to verify the physical condition of weather-protection features.
The
NRC has long recognized the need for nuclear plant owners to be on
guard for extreme cold-related issues. Along those lines, the agency in
January 1998 issued an
Information Notice on
“Nuclear Power Plant Cold Weather Problems and Protective Measures.”
Although such notices do not require a specific action or written
response, they do serve to make plant owners aware of possible concerns.
For
example, the Information Notice discussed an ice plug that formed on
Jan. 8, 1996, at the Millstone Unit 2 nuclear power plant in a service
water strainer backwash drain line. Service water refers to water taken
from a nearby source of water -- be it the ocean, a lake or river --
used for cooling purposes in the plant and then returned.
To
prevent a recurrence of the problem, the plant owner changed an
operating procedure to ensure closer monitoring when service water
intake structure temperatures drop below 40 degrees Fahrenheit and to
make use of portable heaters or go to manual operation of the strainers.
Nuclear
power plants are designed to withstand weather extremes. Nevertheless,
NRC inspectors will be on hand to keep a close watch on plant conditions
during the “vortex” and beyond.
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