A bomb squad with dogs had rushed to the scene and roadblocks were set up around the Forsmark plant, located about 100 kilometers (60 miles) north of Stockholm on the country’s east coast, police said.
The security threat was lifted in the afternoon, TT said.
“Our assessment is that there is no immediate danger surrounding the threat,” Uppsala police spokesman Christer Nordström had told AFP earlier.
Neither police nor Andersson would provide information on the nature of the threat.
But Nordström said police had “not found anything that could be a bomb”.
The Forsmark facility, one of Sweden’s three nuclear power plants, has been hit by a series of safety incidents and shutdowns in recent months, prompting calls for a rethink of the plant’s safety culture.