Northern Ohio could have experienced America’s
worst nuclear accident during the Aug. 14 blackout if Davis-Besse
had gone back into service last year with its severely corroded
reactor head, a report issued yesterday by a nationally known
watchdog group claims.
But the Union of Concerned Scientists,
based in Cambridge, Mass., said it didn’t conjure up a nightmarish
scenario just for the sake of scaring people.
Its goal is to
push the Nuclear Regulatory Commission into being as aggressive
toward fixing long-standing design flaws at 68 other nuclear plants
as it has been at Davis-Besse, David Lochbaum, the group’s nuclear
safety engineer, said.
"These reactors are one broken pipe
away from turning this narrative into a tragic prophecy," he wrote.
"Congress must ensure this clear and present danger is removed
before our collective luck runs out."
Davis-Besse was taken
offline for refueling Feb. 16, 2002. Three weeks later, a
football-shaped cavity was found in its reactor head. Tests show the
steel liner beneath the head was starting to crack.
Recent
laboratory tests at the U.S. Department of Energy’s Oak Ridge
National Laboratory suggest the reactor head could have been closer
to blowing open than previously thought.
The sudden loss of
offsite power at several nuclear plants during the August blackout
could have been catastrophic for northern Ohio if the problem with
Davis-Besse’s reactor head hadn’t been caught.
That’s because
the weakened head would have made the plant far more susceptible to
a loss-of-coolant accident, Mr. Lochbaum said.
His theory
maintains that the power loss would have resulted in a sudden upward
pressure spike, which would have popped open the head and allowed
radioactive steam to form in Davis-Besse’s containment structure. If
the sump and the reactor pumps had clogged, as expected, a meltdown
would have been inevitable, he wrote.
The region would have
had two to five hours to evacuate, but that would have been
complicated by inoperable warning sirens because of the power
outage. "Hundreds, perhaps thousands" would have died of
radiation-induced illnesses in a few years, the report
claims.
Richard Wilkins, a FirstEnergy spokesman, said he
believes Mr. Lochbaum’s scenario is flawed because Davis-Besse has
emergency diesel generators that can temporarily supply backup power
to plant operations when the nuclear station loses offsite power.
That likely would have mitigated the effect on reactor pressure, he
said.
He also said the sequence of events leading to a
two-to-five-hour window of time to evacuate would not be
realistic.
Davis-Besse is one of 69 U.S. nuclear plants -
two-thirds of the nation’s 103 nuclear plants - that have
pressurized water reactors. The other 34 are built
differently.
For earlier stories on Davis-Besse, go to
www.toledoblade.com/davisbesse
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