OAK HARBOR -- When workers found massive amounts of corrosion in
the Davis-Besse nuclear reactor head last March, it sent a shockwave
through the nuclear industry.
It's an industry, too, that's been controversial since its
inception in the late 1950s and can't take too many more black eyes
before consumers lose confidence, said Nuclear Scientist Dave
Lochbaum, who works for the Washington watchdog group Union of
Concerned Scientists.
"They need to learn as much as they can so they don't have more
Davis-Besse surprises down the road," Lochbaum said during a recent
telephone interview. "It doesn't take too many more of these before
confidence in the industry beings to wane."
As rattling as the discovery at the Carroll Township plant was,
however, the industry and its regulators felt tremors far before
unearthing the hole that could hold a football at FirstEnergy's
power station.
The three nuclear units at Oconee in South Carolina first gained
industry attention when inspections revealed what is called
circumfrential cracking in nozzles on the reactor heads in August
2001.
That cracking -- which worst case scenario would creep part or
all the way around a large circular nozzle -- had never been seen
before on the reactor head.
"There was, prior to Davis-Besse, the thought that if you had
damaged nozzles the worst thing that would happen ... would be
ejection of the nozzle," he said.
That means the nozzle would have essentially popped off like a
cork, allowing coolant water to gush from the reactor.
Now, however, Davis-Besse has shown that the circumfrential
cracking can lead to other problems than just the potential for an
ejected nozzle.
"They found even small leakage could damage the head itself," he
added.
Compounded by at least six years and hundreds of pounds of
solidified boric acid crystallizing on the reactor, what likely
started as a small amount of corrosion turned into a hole considered
massive by nuclear industry standards.
The findings at the Carroll Township facility sent the NRC into a
tailspin, at first prompting officials to send out requests to all
similarly built power plants asking for responses with inspection
reports and potentials for comparable findings.
Then, early this year, the NRC required all like plants to
conduct interim inspections of the reactor heads -- a consequence
brought on by reports that Davis-Besse's management knew of the
boric acid on the reactor head but did little to clean it off.
"It expanded the scope a little bit of what the NRC was doing and
accelerated the pace of what was happening," Lochbaum said.
The findings bucked not only what the nuclear industry expected
to happen to aging nuclear plants (Davis-Besse turns 25 this year)
but emphasized that scientists are still dealing with a relatively
new technology.
"It's had a lot of impact in many ways," FirstEnergy Chief
Financial Officer Richard H. Marsh said recently during an interview
at his office in Akron. "The whole way this evolved, it challenged
the ways of thinking because with the technology it wasn't supposed
to be possible."
FirstEnergy senior management officials, too, have been active in
speaking to the rest of the industry about the difficulties
Davis-Besse has been through and how workers are fixing the problems
-- not only technically, but on the human performance side as well.
The impact wasn't only on those who owned the plants -- although
many are now taking a good, hard look at the critical safety systems
that are used in the event of an emergency.
On the regulatory side, the NRC has tried to learn a few lessons
of its own from Davis-Besse.
It commissioned a Lessons Learned Task Force to find out what
happened on the regulatory side and come up with recommendations for
fixes.
The task force submitted a list of 51 recommendations to its
commission. Out of those, 49 were accepted.
The entire industry and its peripheral supporters have been going
through an intense introspection, resulting in self-assessments and
plans to deal with "material performance" problems, such as metals
that degrade and nozzles that crack.
Originally published Saturday, March 8, 2003