Finland's Olkiluoto 3 (OL3) nuclear reactor has begun producing regular output, boosting energy security in a region to which Russia has cut gas and power supplies.

The reactor entered service the day after Germany bid goodbye to nuclear energy, by turning off its last three reactors. 

OL3's operator Teollisuuden Voima (TVO), which is owned by Finnish utility Fortum and a consortium of energy and industrial companies, has said the unit is expected to meet around 14 per cent of Finland's electricity demand and produce energy for at least 60 years. 

"The production of Olkiluoto 3 stabilises the price of electricity and plays an important role in the Finnish green transition," TVO Chief Executive Jarmo Tanhua said in a statement, adding that “the electricity production volume of Europe’s largest nuclear power plant unit is a significant addition to clean, domestic production.”

The construction of the reactor has been a 16-year journey...