Caption: Calvert Cliffs nuclear power plant
The U.S. Nuclear Regulatory Commission (NRC) started a
special inspection at the
Calvert Cliffs nuclear power plant in Maryland following
the shutdown of both units.
A grid disturbance due to the failure of a transmission line
on April 7 caused both units to automatically shut down as
designed and led to widespread blackouts in Washington DC.
Following the disturbance, one of Unit 2’s emergency diesel
generators started, but tripped after 11 seconds. In
addition, one of three saltwater pumps on Unit 2 failed to
automatically restart when power switched to the emergency
diesel generators. Per procedure, operators manually started
the pump, which provides cooling water to certain plant
equipment.
The three-member inspection team that arrived on-site is
tasked with developing a sequence of events; reviewing and
assessing equipment response to the event; reviewing
operator performance; and assessing the effectiveness of
Exelon (NYSE:
EXC)’s response to the problem. An inspection report
documenting the team’s findings will be issued within 45
days of the end of the inspection.
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http://www.power-eng.com/articles/2015/04/nrc-begins-special-inspection-at-nuclear-power-plant.html