World Nuclear Performance Report 2021


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Director General's Preface

In 2020, nuclear reactors supplied 2553 TWh of electricity, down from 2657 TWh in 2019. In any other year an almost four percent decline in nuclear generation would be an unequivocal disappointment. However, in 2020, with overall electricity demand falling by around 1% and nuclear reactors increasingly being called upon to provide load-following support to the increased share of variable renewable generation, the resilience and flexibility shown by the global nuclear fleet tell a very positive story.

Despite some reactors curtailing generation to account for reduced demand or to offer load-following services, the global capacity factor in 2020 was still high at 80.3%, down from 83.1% in 2019, but maintaining the high performance seen over the last 20 years.

At the end of 2020 there were 441 operable nuclear reactors, with a combined capacity of 392 GWe. This total capacity has remained almost unchanged for the last three years. Five new reactors started up, but this increase in capacity was countered by the closure of six reactors. Between 2018 and 2020 there have been 26 reactors permanently shutdown with a total capacity of 20.8 GWe, compared to 20 new reactors starting up, with a total capacity of 21.3 GWe.

The IPCC recently published the first part of its Sixth Assessment Report. This report confirmed what we have known for many years - global greenhouse gas emissions need to fall fast if we are to have any chance of limiting the effects of climate change to manageable levels.
With global electricity demand expected to rebound sharply, there is a real risk that greenhouse gas emissions will do so as well, as they did following the recovery from the economic collapse in 2008.

More than half of the reactors permanently shutdown in the last few years have done so not because of technical limitations, but because of political phase-out policies or the failure of markets to adequately recognize the value of low carbon reliable nuclear power. This is a loss of low-carbon generation that the world can ill-afford to squander.

However, there are promising signs for nuclear. Already in 2021 we have seen four new reactors connected to the grid and construction started on seven new reactors, although two reactors have permanently shutdown.

It is vital that nuclear generation bounces back further and faster, helping displace fossil fuels, thus avoiding a sharp rise in greenhouse gas emissions. The operation of the existing nuclear fleet must be maximized and extended as long as feasible, and the pace and scale of new nuclear construction must increase.


Sama Bilbao y León
Director General
World Nuclear Association

1 September 2021


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