* GE says problem could occur under limited conditions
* NRC says problem not an "immediate" safety issue
* Boiling-water design similar to GE reactors at Fukushima
By Jim Brumm
WILMINGTON, NC Sept 30 GE Hitachi Nuclear
Energy has warned operators of boiling water reactors (BWR)
worldwide -- including 35 in the U.S. -- that the plants could
fail to shut automatically during an earthquake, potentially
risking the safety of the power plant.
In an event notification posted by the Nuclear Regulatory
Commission this week, GE Hitachi told nuclear operators to
conduct tests to determine what conditions would prevent the
reactors from shutting safely during an earth quake.
GE Hitachi Nuclear Energy is a venture between General
Electric Co (GE.N) and Hitachi Limited (6501.T).
GE Hitachi spokesman Michael Tetuan said most nuclear
plants could fix the problem by replacing fuel channels, if
needed. A typical boiling water reactor has between 400 and 800
The affected plants are of the same GE design as Japan's
Fukushima reactors which were crippled by an earthquake and
tsunami in March.
GE said the probability of a reactor not shutting properly
is very low. Because of the limited circumstances under which a
unit might not shut automatically, NRC spokesman Scott Burnell
said the issue "is not an immediate safety issue."
He said GE's notice is information the agency wants nuclear
vendors to raise so that companies can respond.
Affected by the potential glitch are type 2-5 BWRs designed
by General Electric and built between the late 1960s and the
In the U.S., 12 of those nuclear units are owned by Exelon
Corp (EXC.N); five by Entergy Corp (ETR.N); and three by the
Tennessee Valley Authority.
Other affected plants are owned by Constellation Energy
Group CEG.N, Progress Energy PGN.N, Southern Co (SO.N),
NextEra Energy (NEE.N), DTE Energy (DTE.N), Public Service
Enterprise Group (PEG.N), PPL Inc (PPL.N), Xcel Energy (XEL.N),
Energy Northwest and the Nebraska Public Power District.
GE Hitachi identified the problem in July 2010 and reported
to the NRC last September, months before an earthquake-spawned
tsunami crippled GE reactors in Japan.
U.S. reactors included are Nine Mile Point Units 1 and 2;
Fermi 2; Columbia; FitzPatrick; Pilgrim; Vermont Yankee; Grand
Gulf; River Bend; Clinton; Oyster Creek; Dresden 2 and 3;
LaSalle 1 and 2; Limerick 1 and 2; Peach Bottom 2 and 3; Quad
Cities 1 and 2; Perry; Duane Arnold; Cooper; Monticello;
Brunswick 1 and 2; Hope Creek; Hatch 1 and 2; and Browns Ferry
1, 2 and 3.
"We've proactively identified a very unique set of
conditions in which a plant rarely operates where this is a
concern," Tetuan said. "With the guidance provided to our
customers, they will be able to monitor potentially affected
fuel channels and avoid a safety concern."
Tetuan said the company also notified operators of BWRs
The World Nuclear Association (WNA) website lists 53 BWRs
outside the U.S., including 29 operating in Taiwan, Sweden, the
Netherlands, Mexico, Japan, Italy, Germany and Finland.
The seven operating Japanese BWRs include Fukushima Daiichi
5 and 6 which were shut when the March earthquake hit.
GE Hitachi told the NRC the problem does not affect BWR/6
or ABWR - advanced boiling water reactor plants.
(Additional reporting by Eileen O'Grady in Houston; Editing
by Bob Burgdorfer)