HELSINKI, Feb. 25 (Xinhua) -- The Finnish Nuclear Safety Authority (STUK) on Monday gave its security clearance to the third nuclear power reactor on the island of Olkiluoto in western Finland. The owner and operator of the plant is the Finnish company Teollisuuden Voima.

The plant is expected to start in 2020 delivering electricity, 11 years later than originally planned. The construction of OL3 began in 2005 and was intended to be online in 2009, but faced numerous technical obstacles.

The facility is a "European pressurized water reactor" (EPR) based on French and German technology. With its net output of 1,600 megawatts, OL3 is one of the largest nuclear power plants worldwide. It was ordered from a consortium formed by AREVA and Siemens.

It alone will cover some 15 percent of Finnish electricity needs, national broadcaster Yle reported. It will reduce the need for Finland to import electricity from neighboring countries. Local commentators have predicted the start of OL3 will also reduce the market price of electricity in Finland.

The safety clearance by the Finnish nuclear safety authority concerns, besides the operation of the plant, also the management of its fuel and waste. The final disposal location of used fuel will be in deep tunnels in Olkiluoto.

Minna Tuomainen, the project manager at STUK, told the media that the authority closely monitors the operations even after the granting of the operating license. The operator must also correct vibration detected in a short pipe during the recent test run, Tuomainen said.

After the completion of OL3, there will be five operational nuclear power reactors in Finland. They include two older ones in Olkiluoto and two in Loviisa, east of Helsinki.

A sixth nuclear power reactor is being planned for Hanhikivi, northern Finland. To be operated by Finnish Fennovoima company, the plant is based on Russian technology. As in the case of Olkiluoto, the project has experienced delays. Fennovoima has said it hopes to get construction permit in 2021.