On August 1, 5:45 PM, smoke was noticed at the decommissioned deaerator room 719.
The incident was immediately reported to Visaginas fire services and all necessary measures to ensure safety have been taken, the plant said in a statement.
Firefighters arrived at the site in about 15 minutes and found small wooden items burning in room 719.
The incident did not interrupt operations at Ignalina Nuclear Power Plant, according to the statement.
Unit 1 of the plant, where the incident happened, was closed down in December 2004. Unit 2 was switched off in 2009. The plant is to be fully decommissioned by 2029.