The cause of the fire at Didcot B power station is not yet known, the plant's station manager said.
Neil Scott said investigations would be carried out over the next few weeks into what was behind the blaze.
He said they did not yet know the full extent of the damage but that part of the plant is continuing to operate and that there would be no power outages.
"Half of the plant is running normally. Over these next few days and i'm pretty confident by the end of the week we'll have this plant back up and running".
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