Number of nuclear reactors operable and under construction

There are currently 454 operable civil nuclear power nuclear reactors around the world, with a further 54 under construction. A list of reactors operable, under construction, planned and proposed can be found here World Nuclear Power Reactors and Uranium Requirements, updated monthly.

Details of individual reactors operable and under construction can be found in our Reactor Database, which uses information supplied by the International Atomic Energy Agency.

It may be useful to consider the sequence in bringing a new nuclear power plant into operation: It starts with planning, then site works which usually last about a year. The official start of construction is when the first concrete is laid the reactor plant itself and then main construction work takes about 6 years on average. The reactor is that started-up (known as criticality), connected to the grid and begins commercial generation of electricity a few weeks later.  

The following guide explains some of the definitions.

What is meant by 'operable'

An operable reactor is one that is connected to the electricity grid. In most cases these reactors will be generating and supplying electricity to consumers. However, for short periods reactors don't supply electricity to the grid, for example during a scheduled outage for refuelling or maintenance.

What is meant by 'under construction'

World Nuclear Association uses the convention that a reactor is under construction only once 'nuclear concrete' has been poured for the reactor building itself. This is concrete of a specific grade or specification that is used in the construction of the nuclear facilities on a reactor site. It would not include planned reactors when site preparations are under way or concrete is being used for ancillary buildings or cooling towers.

What is meant by 'civil nuclear power reactors'

Civil nuclear power reactors are those reactors used to generate electricity that is supplied to customers through electricity grids. There are hundreds of other nuclear reactors in operation around the world. These include research reactors used at universities and other research establishments, reactors used to power ships and submarines and reactors used to make medical isotopes.


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