Russian officials on August 18 shut off a block of the Byeloyarsk nuclear power station after picking up a "false" response from the Urals facility's safety system, according to a Rosatom subsidiary.
The early morning incident affected Block 4 at the half-century-old plant, it said.
"The stoppage was carried out under a routine algorithm," Rosenergoatom said in a statement.
The company said there was nothing unusual about the radiation background at or around the facility.
The incident comes with heightened concerns about Russian nuclear activities following a deadly accident at an Arkhangelsk testing facility during Russia's apparent testing of a new propulsion system that officials have yet to fully explain.
Russian officials ordered an evacuation of the nearby town that was later called off.
Some U.S. officials have said they believe radioactive elements were involved, and many analysts have focused attention on a nuclear-powered cruise missile that President Vladimir Putin announced was under development last year.
On August 13, Russia's federal weather agency announced a brief rise in radiation levels in Severodvinsk after the August 8 explosion, even as local authorities told people not to be alarmed.
Norway's radiation-monitoring agency said on August 15 that it had recorded tiny amounts of airborne radioactive iodine at monitoring equipment hundreds of kilometers from the Arkhangelsk accident site.
The Byeloyarsk nuclear power plant was opened in 1964.
A Russian nuclear power plant northwest of Moscow has returned to operation since it turned off three of its four generating units last month after a transformer reportedly short-circuited.
Stoppage At Russian Nuclear Power Plant