Nuclear power

Nuclear power plays an important role in Fortum's energy production. As a CO2-free and reliable base-load source, nuclear power is needed to secure the supply of energy and to mitigate climate change. Its greenhouse gas emissions during its lifecycle are as low as in wind, hydro and solar power.

Fortum generated 24.1 terawatt-hours of nuclear power in 2016, contributing to one third of the company's total electricity production.

In 2016, nuclear power accounted for approximately 11% of electricity production globally. In Europe and in Finland, nuclear power accounts for about one third of the electricity production. The majority of the world's nuclear power plant reactors are light water reactors that use water as the neutron moderator and as the fuel coolant. There are two basic types of light water reactors: boiling water reactors and pressurised water reactors. Of the world's nuclear reactors used for electricity production, about 66% are pressurised water reactors and about 23% boiling water reactors. The Loviisa power plant has two pressurised water reactors (VVER), Loviisa 1 and Loviisa 2, with capacities of 507 MW net (unit 1) and 502 MW net (unit 2).

Light water reactors use enriched uranium as fuel. Uranium fuel is described in more detail on the page Fuels.

Fortum has long experience in the responsible operation of nuclear power. We develop our nuclear power plants in accordance with the principle of continuous improvement of safety. We also provide nuclear power-related professional services to other operators in the sector who are seeking Fortum's internationally recognised nuclear power expertise.



The overarching principles of Fortum's nuclear operations


​The most important task of our nuclear power operations is to produce electricity safely, reliably and competitively, in the short- and long-term, while complying with the principles of nuclear and radiation safety, waste management safety, and nuclear material control.

Our operations are based on a high-level safety culture and quality and on continuous improvement.

Our own world-class expertise is a prerequisite for safety and competitiveness.
Source: Fortum's safety and quality policy in nuclear power operations

Nuclear power plants

Fortum owns a total of 2,811 megawatts (MW) of nuclear power capacity, 1,477 MW of which is located in Finland and 1,334 MW in Sweden (2016).

Our fully-owned Loviisa power plant in Finland has two nuclear power units, which we operate. In addition, we  have co-owned nuclear capacity in eight reactors in Finland and Sweden:

- Loviisa power plant (Fortum's share 100%)

- Forsmark Kraftgrupp AB (Fortum's share 22.2%)

- OKG AB (Fortum's share 43.4%). Two of OKG AB's three reactors have been closed down in Oskarshamn, Sweden (stock exchange release on 14 Oct 2015).

- TVO Oyj, Olkiluoto units 1 and 2 (Fortum's share 26.6%). Through our holding in TVO, we are participating in the new Olkiluoto 3 power plant unit currently under construction.


We participate in the Fennovoima nuclear power project in Finland with a 6.6 per cent share and on the same terms and conditions as the other Finnish companies participating in the project (stock exchange release on 5 Aug 2015). Participation will be carried out through Voimaosakeyhtiö SF.


Light water reactors

The majority of the world's nuclear power plant reactors are light water reactors.

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Nuclear reaction

Nuclear power production is based on the utilisation of the thermal energy generated by a controlled chain reaction.

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Uranium as fuel

Instead of conventional fuel (e.g. coal, natural gas or peat), a nuclear power plant uses uranium as a source of energy.

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In general, radiation is energy generated in the change of an atom's excitation state or in nuclear reactions, and is in the form of electromagnetic or particle radiation.

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Loviisa power plant, Finland

Loviisa power plant generates 8 TWh of electricity annually for the national grid. That covers about one-tenth of Finland's electricity production.

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Nuclear services

We provide nuclear safety and waste management services as well as system-related supplies for the nuclear power industry.

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News on nuclear

Nuclear power related news and topical items.

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