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Regional News
| Article published Thursday, July 31, 2003
Plants replacing reactor heads
Davis-Besse’s woes are a wake-up call for the nuclear
power industry
By TOM HENRY
BLADE STAFF
WRITER
Two more nuclear plants have joined a growing
list of those taking the drastic - and highly expensive - measure of
swapping out their reactor heads in the wake of unprecedented
corrosion revealed on March 6, 2002, at FirstEnergy Corp.’s
Davis-Besse nuclear plant.
American Electric Power yesterday
confirmed plans to spend $44 million to replace both vessel heads at
its dual-unit D.C. Cook complex in southwest Michigan.
One
unit is to have a new lid installed in the fall of 2006; the other
will be done a year later, spokesman Bill Schalk
said.
Including Davis-Besse, that brings to 30 the number of
nuclear plants that have either swapped out their reactor heads or
announced plans to do so by the end of 2007, costing the nuclear
industry hundreds of millions of dollars.
Steve Kerekes,
spokesman for the Nuclear Energy Institute in Washington, the
industry’s trade association, said there will "unquestionably" be
more plants following suit as they age. Davis-Besse’s woes prompted
the Nuclear Regulatory Commission to adopt tougher inspection
regulations for reactor heads.
"A lot are making the
decision. It’s just in their best business interests [to replace
their reactor heads]," he said.
The enormous task was once
thought of as unnecessary in the United States, even though it has
been done as a precautionary measure in France and Spain.
The
NRC and the industry have said they never accounted for the
possibility of a reactor head becoming so weakened by rust that it
could burst open and allow radioactive steam to fill up the
containment shell, the public’s last line of defense. But
Davis-Besse’s problems have drawn a global audience: The
pineapple-sized cavity that was found on its reactor head last year
had thinned out the six-inch-thick lid to a mere two-tenths of an
inch in one spot, where the liner had started to buckle and
crack.
The NRC has described that as the nation’s closest
brush with a nuclear accident since Three Mile Island in
1979.
FirstEnergy became the first U.S. nuclear plant to swap
out a reactor head last year. The utility installed one that was
built in 1975 for the Midland 2 plant in central Michigan, which was
mothballed in 1985. FirstEnergy opted for the former Midland head,
rather than wait until April of 2004 for one with state-of-the-art
metal that it had ordered prior to its Feb. 16, 2002
shutdown.
D.C. Cook 2 joined Davis-Besse in 2001 on a list of
13 nuclear plants that an industry group called the Electric Power
Research Institute had deemed as most susceptible to having cracks
in their reactor head nozzles.
Those plants were singled out
due to their age, operating temperatures, and operating
pressures.
That drew heightened scrutiny from the NRC,
contributing to the discovery of Davis-Besse’s massive corrosion
that had been shrouded beneath the insulation of its reactor head.
D.C. Cook 1 and 2 did not have any such problem, although minor
axial flaws had to be repaired in one of the second unit’s nozzles,
Mr. Schalk said.
Sixty-nine of the nation’s 103 nuclear
plants operate with pressurized reactors similar to Davis-Besse and
D.C. Cook. The NRC has said they are the most likely to develop
nozzle cracks in their reactor heads.
The other 34, including
Detroit Edison Co.’s Fermi II nuclear plant in Monroe County, have
boiling water reactors that do not operate under such high
temperatures and pressures.
For earlier stories on
Davis-Besse, go to www.toledoblade.com/davisbesse
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