Last
January, the Byron Station, Unit 2, automatically shut down its nuclear
reactor because of an electrical power problem. But the way the power
was lost – only one phase of three-phase alternating current was lost –
in addition to a design problem caused the diesel-driven back-up
generators to not start up automatically.
While
operators were able to get the back-up generators started manually and
the plant was shut down safely, this was clearly a problem the NRC has
to look into. Since power can be lost to a plant for any number of
reasons – including a thunderstorm or other natural events – back-up
power is very important to keep vital safety systems working at the
plants.
The
NRC quickly issued an “information notice” to let other nuclear power
plant operators know about the problem. The NRC then, some months later,
followed up with a bulletin to all licensees. This bulletin required
all 104 reactors and the four licensees that had submitted new reactor
designs to provide the NRC with information about their electrical
protection systems. The NRC staff will use the information provided by
the licensees to determine if further regulatory action is needed.
A
bulletin and an information notice are two types of NRC “generic
communications.” Along with generic letters and regulatory issue
summaries, generic communications provide a method to communicate,
primarily with licensees, about issues that might affect all of them,
even if the original event – as in this case – is specific to just one
plant.
The
term “generic” might seem odd in this context – most people probably
think of generic in terms of medicine or consumer products. But for the
NRC, the term refers to important ways we communicate generally about
issues that might affect more than one site.
Andrea Russell
Project Manager
Generic Communications and Power Uprate Branch
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