* Leak contained within unit, no radiation released (same thing said at first at SONGS)
* Company didn't say when reactor would resume output
* California power supply seen tight with unit shutdown
June 26 (Reuters) - PG&E Corp shut the
1,122-megawatt Unit 1 at its Diablo Canyon nuclear power plant
in California from full power due to a leak that was contained
within the plant, a company spokesman said on Wednesday.
"PG&E made the decision to take Unit 1 offline after routine
inspections detected a small buildup of boric acid on the
residual heat removal system," PG&E spokesman Thomas Cuddy said
in an email, adding there was no release of radiation.
He said the residual heat removal system helps manage
reactor coolant temperatures in the unlikely event of an
emergency. Water leaked from the Diablo plant's unit was
contained, meaning it didn't leak into the environment.
Cuddy said: "Unit 1 remains in a safe condition and will be
restored to service after repairs are complete."
He did not say when the unit would return to service.
"It's a maintenance issue. The repair work will not be
difficult or take long," U.S. Nuclear Regulatory Commission
(NRC) spokeswoman Lara Uselding told Reuters.
She said PG&E plans to "overlay a weld on top of the problem
weld. The residual heat removal system is normally in standby.
The plant is currently shut down and cooling down, so there is
even less of a safety issue."
Electricity traders guessed the reactor would return in
about a week, which they said could cause power supplies in
California to be tight over the next several days with cooling
demand expected to be high amid a heat wave.
Cuddy said PG&E had informed the NRC and appropriate local
and state officials about the shutdown.
Meanwhile, Diablo Canyon 2 was operating at full power,
according to an NRC report Wednesday morning.
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PLANT BACKGROUND/TIMELINE
STATE: California
COUNTY: San Luis Obispo County
TOWN: Avila Beach about 183 miles (294 km) northwest
of Los Angeles
OPERATOR: PG&E
OWNER(S): PG&E
CAPACITY: 2,240 MW
UNIT(S): 1 - 1,122 MW Westinghouse pressurized water reactor
2 - 1,118 MW Westinghouse pressurized water reactor
FUEL: Nuclear
DISPATCH: Baseload
TIMELINE:
1968 - Start of plant construction
1985 - Unit 1 enters commercial service
1986 - Unit 2 enters commercial service
2024 - Unit 1 license to expire unless renewed
2025 - Unit 2 license to expire unless renewed
