Test for leaks
sought at Davis-Besse
11/01/02
John Mangels and
John Funk
Plain Dealer Reporters
With two rounds of lab trials still
unable to determine whether the bottom of Davis-Besse's reactor is leaking,
FirstEnergy Corp. plans a much larger-scale test - taking the reactor up
to operating conditions to see if any coolant seeps out.
The possibility of cracks and leaks
in the nozzles that carry instruments up through the bottom of the reactor
into the core emerged as a concern at Davis-Besse last month.
Before that, the Toledo-area plant
had been dealing with cracks and leaks in the nozzles atop the reactor's
lid, which led to a large rust hole.
The damage has kept the plant shut
down nearly nine months and has prompted federal regulators and the nuclear
industry to re-think how they deal with corrosion.
The seven-day power-up test, which
the company wants to do in late December, involves reloading the fuel rods,
bolting down the reactor's new lid, and turning on the coolant-circulating
pumps. The pumps' heat and the natural decay of the radioactive fuel will
bring the reactor to its normal operating temperature and pressure.
The control rods will remain in the
core, however, preventing the nuclear reaction from starting, said FirstEnergy
spokesman Todd Schneider.
After a week of simulated operation,
the reactor will be shut down and its fuel removed. Inspectors will look
underneath the reactor for any sign of the rust stains that initially triggered
the leak fears.
Although FirstEnergy informed investors
of its testing plans yesterday, the Nuclear Regulatory Commission has not
yet approved the approach.
"We have not said, 'Yes, that's the
thing to do,' or, 'No, it's not,' " said NRC spokesman Jan Strasma We expect
there will be additional discussions on this and other possible options."
If leaks are found, FirstEnergy believes
it can make repairs and stay on schedule to restart the plant early next
year.
That presumes, though, that such cracks
won't raise a new set of regulatory and research issues for the company
to overcome. No utilities have ever found cracks in the bottom nozzles,
where metal stresses are supposedly less because of the lower temperature
there.
"We don't think we do [have leaks],"
Schneider said. Instead, the company thinks the rust stains were caused
by workers power-washing the rusty lid, or from runoff when the lid was
removed for refueling. Though chemical tests couldn't trace the stains
back to the lid, he said, the low level of radioactivity in them suggests
that the coolant that caused the rust did not leak from the core through
the reactor's base.
The corrosion that has scarred Davis-Besse's
reactor continues to erode the NRC's confidence that 68 other similar reactors
are rust-free. This week the agency ratcheted up the pressure on those
plants to prove that they are doing thorough corrosion inspections in vital
parts of the reactor other than the lid.
The NRC is unsatisfied with the plants'
responses so far to a Davis-Besse-inspired bulletin this spring warning
of corrosion danger and seeking assurances that the utilities are doing
proper checks.
The agency's concerns are twofold:
that it can't tell whether some operators are doing adequate inspections
throughout their plants, and that the engineering code that guides inspections
isn't thorough enough in light of Davis-Besse.
"Davis-Besse threw into question the
efficacy of [corrosion] inspection programs," said Brian Sheron, the NRC's
associate director for licensing and technical analysis. "We have confidence
there are no plants with any kind of corrosion [on the lid] like Davis-Besse,
but we want to . . . make sure the industry has a program in place so that
we know there is not going to be corrosion" elsewhere.
To reach these reporters:
jmangels@plaind.com, 216-999-4842
jfunk@plaind.com 216-999-4138
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