The operator of the Onagawa nuclear power station in Miyagi Prefecture, northeastern Japan, said Friday that it will halt the facility's No. 2 reactor after radioactive steam was detected within its turbine building.

Tohoku Electric Power Co. said a small amount of radioactive steam was found in the reactor unit's turbine building at around 5:10 p.m. local time on Friday, adding no radioactive materials had leaked into the environment and that the halt was for inspection purposes.

The company also dismissed any link between the incident and a 6.4-magnitude earthquake that struck northeastern Japan on Friday night.

The No. 2 reactor at the plant had previously been taken offline for a regular inspection and was only brought back online on Monday, with commercial operations scheduled to resume on June 9.