More than 9 gigawatts (energy) of new nuclear capacity came online in 2016, the largest annual increase in more than 25 years.

By the end of 2016 there were 448 reactors around the world, up from 441 at the start of the year. Ten reactors started to supply electricity and three were closed down, resulting in a net increase in nuclear capacity of just over 8 GWe.

The industry data was reported by the World Nuclear Association in its World Nuclear Performance Report 2017.

The amount of electricity supplied by nuclear globally increased by 35 terrawatt-hours (TWh) to 2,476 TWh. This increased generation is the result of both additional generation from new reactors coming online and continued performance improvements from the existing fleet.

The number of reactors being built remains high, with 61 under construction at the end of 2016. There were only three construction starts last year and, with 10 units having completed construction, the number of reactors under construction has fallen from 68 at the start of 2016.

The report says that Asian countries continue to dominate the market for new nuclear build. At the end of 2016, 20 of the 61 power reactors under construction around the world were in China, with a further 15 spread across India, Pakistan, and Russia. In the U.S. and Europe, retirements of reactors continue to outstrip the rate of capacity addition.

There has been a pause in new reactor construction starts in China; however, the pouring of first concrete for Tianwan 6 in September 2016 marked the resumption of reactor construction.

The first Korean-designed APR-1400, unit 3 at the Shin Kori nuclear power plant, was connected to the grid by Korea Hydro and Nuclear Power in January. Construction of four APR-1400 reactors at Barakah in the United Arab Emirates continued to make good progress and the first reactor is due to startup next year.

In Russia the first VVER-1200 at Novovoronezh II, was connected to the grid in August.

2016 saw the start-up of Watts Bar 2, the first reactor connected to the grid in the United States in 20 years. But it also saw continuing challenges to the operation of some reactors in deregulated markets and the ongoing construction of four reactors at VC Summer and Vogtle.

The process of gaining regulatory approval for the restart of reactors in Japan is proving to be protracted and extensive and some restarts have been delayed by legal challenges. However, five reactors have now restarted and a further 19 have applied to do so.

In the UK in 2016, the go-ahead was given for Hinkley Point C, the first of a planned new generation of nuclear power plants in that country. Nuclear remains the largest single source of low carbon generation in Europe, but political pressure in some countries is threatening this.