July 16 (Reuters) - Oregon power company Portland General Electric Co said it expected to spend up to $12 million to replace the power lost from the shutdown of two coal-fired plants, one in its home state and one in Montana, for unplanned repairs.
The 740-megawatt Unit 4 at the Colstrip power plant in Montana shut on July 1 and is likely to remain down for at least six months, PGE said in a federal filing.
Workers found damage to the generator in Colstrip 4, which PGE said would require repairs to the stator, core and rotor, among other components.
PGE owns a 20 percent share (about 148 MW) in Colstrip 4, which is operated by PPL Montana LLC, a unit of PPL Corp of Pennsylvania.
PGE also said the 585-MW Boardman plant in Oregon shut on July 1 and should remain down for at least a month.
Boardman tripped offline when a thermal water hammer damaged the cold reheat piping line that runs between the turbine and the boiler, PGE said.
PGE operates Boardman and has a 65 percent ownership interest (about 374 MW) in the plant.
Because of these unplanned outages, PGE said it would incur incremental costs to replace its share of the output of the plants.
Although the operators have not determined the actual time needed to fix the plants, PGE said it estimates its replacement power costs at $10 million to $12 million.
PGE also said the plant operators were filing insurance claims for the repair work, with each facility having a $2.5 million deductible for each event.
Shares of PGE were down 1.2 percent at $31.99 in morning trading.