“Unplanned”
shut-down and an NRC special inspection
By
Will Collette
Only
20 miles to the west of Charlestown, well within the danger zone in the event
of a major accident, sits the Millstone nuclear power plant owned by
Virginia-based Dominion Energy.
On
January 31, Unit
2 had to be manually shut down after an electrical short in the power supply
for the heaters for its water pressurization system. The emergency diesel
back-up was out of service at the time.
Unit 2 is the older of the two
operating reactors at Millstone. It was built in 1975 and has been the source
of many of the safety issues I have reported to you.
More
troubling is the decision by the Region 1 office of the Nuclear
Regulatory Commission to conduct a special inspection at Millstone to
examine the operations of Millstone’s back-up pumping system for Unit 3, the
newer of the two reactors.
This
system is vital to prevent a reactor disaster like the one that led to the
Fukushima disaster after Japan’s earthquake and tsunami. Reactors on the US
east coast are also vulnerable to natural disasters caused by hurricanes and
tsunamis (yes, these have occurred in the Atlantic and will certainly occur again).
In
the NRC’s news
release, the NRC’s regional administrator Bill Dean said “We have witnessed problems involving this
safety-related component stretching back to last May. The fact that these
issues occurred on multiple occasions despite repeated efforts to repair this
component has prompted us to take a closer look at the situation.”
The
NRC issued a notice of violation to Millstone last November because of problems
with this pumping system.
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| From Millstone's Safety Planning Guide: note the evacuation routes all point north or west based on the assumption that winds will blow from west to east (that is, in Charlestown's direction) |
The
release says the inspection will focus on “Dominion’s
responses to the issues, including the adequacy and completeness of testing on
the pump and root-cause evaluations of the problems. For example, the
third-quarter integrated inspection report for the plant includes a finding for
an inadequate operability determination by the company related to the
performance of the speed-controller for the pump.”
The
NRC’s follow-up report using the findings of this special inspection should be
issued within 45 days.