WNISR, 4 January 2021
The year 2020 saw two newcomer countries starting up their first reactor, the United Arab Emirates and Belarus. These are the first new countries to join the nuclear power club since Iran commissioned its first reactor in September 2011.
Two other countries started up new units in 2020, China added two, after more than a year without any new grid connections, and Russia one. The total of five startups in the world compares with 13 units scheduled for grid connection at the beginning of the year. The startup of one unit, Leningrad-2-2 in Russia, took place after more than 10 years of construction with many delays but earlier than finally anticipated at the beginning of 2020.
Over the decade 2011–2020, 63 new units were started up in the world of which 37 in China, while 59 units were closed, none in China. In other words, outside China, with only 26 grid connections in a decade—or two and a half per year—closures were exceeding startups by 33.
The global decline, ongoing for years, has been merely confirmed in 2020 with another negative annual startup/closure balance.
Six units were permanently closed during the year, two each in France (Fessenheim-1 and -2) and the U.S.(Duane Arnold-1 and Indian Point-2) and one each in Sweden (Ringhals-1) and Russia (Leningrad-2). Thus, the total number of commercial reactors that have closed is now 192.
A total of 29 reactors are in Long-Term Outage (LTO), 24 are sited in Japan, two in the U.K. and one each in China, India and South Korea.
Therefore, at the beginning of 2021, there are 412 operating reactors, three less than at the beginning of 2020, four less than in 1990, and 26 units below the historic peak of 438 in 2002.
Work on five reactors started in 2020, four in China and one in Turkey. The total number of reactors under construction remained stable at 51.  As a matter of comparison, there were 68 units listed as under construction in 2013, and their number peaked at 234 in 1979.
The nuclear power sector was severely impacted by the COVID-19 pandemic. In particular, refueling and maintenance outages were delayed, rescheduled, shortened or extended in order to adjust to specific conditions in a given country (see Nuclear Power in the Age of COVID-19). In France, for example, nuclear plants generated 12 percent less power in 2020 than in 2019 and 22 percent or close to 100 TWh below the peak in 2005. Besides operational issues, many nuclear utilities were or are still suffering economically from a significant drop in electricity consumption due to the crisis.
Some construction sites, including Vogtle in the United States and Barakah in the United Arab Emirates, turned into clusters with hundreds of infected workers. The impact of the pandemic on nuclear operation and construction will likely be felt for several years to come.
 Note: The apparent increase compared to the WNISR original assessment on 2019 from early 2020 (49 reactors under construction) is due to the fact that WNISR now considers the High Temperature Reactor (HTR) at Shidao-Bay, under construction since 2012, as two units (two 100-MW modules), and that construction start of Taipingling-1 in 2019 was first reported later in 2020.