During 2022, the International Atomic Energy Agency (IAEA) unexpectedly withdrew 17 nuclear power reactors from its statistics of operating reactors, created a new status category called “Suspended Operation”, and retroactively modified its data series accordingly.
As of 1 January 2023, WNISR considers 411 reactors in operation whereas the IAEA-PRIS website counts 422, a difference of 11 units, the smallest difference between the two data-series in a decade. According to the updated data, the IAEA operating-reactor number peaked in 2005 at 440 reactors while the WNISR data shows a peak in 2002 at 438 reactors—very close.
As three remaining reactors in Germany with 4 gigawatt (GW) installed capacity have not been closed at year-end, according to the WNISR data-series, world operating nuclear capacity exceeded the previous 2006-record by 2 GW to reach 369.3 GW. The revised IAEA data shows an “operating” capacity of 378.3 GW with the historic maximum reached in 2018 at 381 GW.
Seven new reactors started operating in 2022 of which three in China and one each in Pakistan (built by Chinese companies), Finland, South Korea, and the United Arab Emirates (UAE). This outcome compares with 15 expected grid connections at the beginning of the year as the startup of eight units was delayed until at least into 2023. One reactor, Hanbit-4 in South Korea, restarted after a 5-year Long-Term Outage (LTO) for “maintenance”, while four units—two each in Canada and India—entered the category and were withdrawn from operating status.
Five reactors were closed of which three in the United Kingdom (UK) and one each in Belgium and the United States (US). This brings the total number of closed reactors around the world to 207. Following a last-minute change of the German Nuclear Law, the operation of the three remaining reactors in the country, previously scheduled to close by year-end, has been stretched to mid-April 2023 at the latest. The operators are not allowed to refuel the reactors, so their power generation will progressively decline until they are closed.
Construction started on 10 reactors, including five in China, two in Egypt, and one in Turkey. All the projects underway outside China are of Russian design; in addition, the Russian industry designed four of the projects in China. On the other hand, construction of two barges planned to be equipped with Russian reactors in Russia has been launched in China. In addition, construction has officially restarted at Angra-3 in Brazil following a 7-year-long suspension triggered by a massive corruption scandal.
Figure 1 • Changes affecting the world nuclear reactor fleet during the year 2022
There are 59 nuclear power reactors under construction in 17 countries as of 1 January 2023. While China is hosting by far the largest number of construction projects—with 22 reactors—the Russian nuclear industry is by far the largest builder in the world with 25 reactors in work in nine countries, (including Russia, and Slovakia where two Russian-designed reactors are being completed by a Czech-led consortium).
Thus, four in five reactors under construction in the world are built either by the Chinese or Russian nuclear industries. The only two other countries building abroad are France (in the UK) and South Korea (in the UAE) while Argentina, India, and the US are implementing nuclear projects only domestically. Only three of 17 countries implement nuclear power projects at multiple sites, the other 14 have work limited to a single site.
Until September 2022, the IAEA’s online Power Reactor Information System (PRIS) database counted 33 reactors as operational/operating in Japan, whereas 20 of these had not produced power since 2010–2012, and an additional three units had been shut down even since the Niigata Earthquake in 2007.
Ten years ago, on 16 January 2013, the IAEA moved 47 reactors in Japan, most of them shut down in the aftermath of the Fukushima events in 2011, from the category “in operation” into “Long-term shutdown” (see “Historic Move: IAEA Shifts 47 Japanese Reactors Into ‘Long‑Term Shutdown’ Category”) that existed in the IAEA statistical system until October 2022. Only two days later, the move was labelled a “clerical error” and the action was reversed at the request of the Japanese government.
Since 2014, the WNISR has been calling for “an appropriate reflection in world nuclear statistics of the unique situation in Japan”, stressing that “the approach taken by the IAEA, the Japanese government, utilities, industry and many research bodies as well as other governments and organizations to continue classifying the entire stranded reactor fleet in the country as ‘in operation’ or ‘operational’ is misleading.” This situation led the WNISR to introduce the Long-Term Outage (LTO) category, with a simple empirical definition:
A nuclear reactor is considered in Long-Term Outage or LTO if it has not generated any electricity in the previous calendar year and in the first half of the current calendar year. It is withdrawn from operational status retroactively from the day it has been disconnected from the grid.
All reactors matching those criteria were then placed in LTO in the WNISR statistics.
Figure 2 • Status of Reactors in the World Officially Operational vs. WNISR Assessment (as of end of 2022)
It is only in September 2022, that in the IAEA-PRIS database, twelve Japanese reactors  were gradually retrieved from the list of “operating/operational reactors”, and their status changed to “Long-term Shutdown” (LTS). Eventually, by mid-October 2022, this category was changed to “Suspended Operation”, and in November 2022, four more Japanese reactors  joined this newly created category as well as one Indian reactor (Rajastan-1) that had not generated any power since 2004 and which is considered closed by WNISR. Thus, as of 10 January 2023, there are a total of 17 reactors in the category “Suspended Operation” (WNISR considers 28 units in LTO).
The definition of the new category is as follows:
A reactor is considered in the suspended operations status, if it has been shut down for an extended period (usually more than one year) and there is the intention to re-start the unit but:
1. restart is not being aggressively pursued (there is no vigorous onsite activity to restart the unit) or
2. no firm restart date or recovery schedule has been established when unit was shutdown.
Suspended operations may be due to due to technical, economical, strategic or political reasons. This status does not apply to long-term maintenance outages, including unit refurbishment, if the outage schedule is consistently followed, or to long-term outages due to regulatory restrictions (licence suspension), if restart (licence recovery) term and conditions have been established. Such units are still considered “operational” (in a long-term outage). If an intention not to restart the shutdown unit has been officially announced by the owner, the unit is considered “permanently shutdown”.
While reflected on the PRIS homepage and the Japan Country Detail page, all those changes happened without any public announcement or explanation. The IAEA has argued in the past that they only serve as the “database manager”, they can only provide suggestions, but ultimately all changes are being decided by member states officials and implemented in the PRIS database by the respective Government appointed data providers. Apparently, there have been lengthy discussions for several years between the IAEA and the Japanese correspondents on how to address the obvious mislabeling of stranded reactors as “in operation”. In view of public perception, the Japanese government was eager to avoid the term “shutdown” as many of the reactors were officially planned to be restarted. In the end, the new category name and definition represents “a compromise”.
As of the end of 2022, the PRIS database still counts 17 Japanese reactors as “in Operation”. Whereas ten have effectively restarted since 3/11, the remaining seven have not provided any electricity since 2010–2012. The Agency claims that they do not necessarily have insights on the data provided, nor on the rationale behind the choice of the reactors that changed status, while others are still considered in operation.
As the new status is retroactively applied in the IAEA-PRIS statistics—in most cases as of the year of last production—the changes applied to the Japanese fleet have an impact not only on the present situation, but actually since 2007, and dramatically modify the IAEA’s representation of the Japanese nuclear reactor fleet’s evolution.
Figure 3 • Evolution of the Japanese Nuclear Reactor Fleet 1963 to mid-2022
The differences with WNISR statistics are reduced, and mostly relate to official closure dates, as WNISR statistics take into account the end of electricity production as reference for dating closures, and not the “announcement” or “political decision” to permanently withdraw a reactor from the grid.
Figure 4 • Status of Reactors Officially Operational in Japan vs. WNISR Assessment, as of year-end 2022
The changes applied to Japan’s nuclear statistics also have an important impact on the IAEA’s representation of the long-term evolution of the entire global nuclear power reactors fleet.
As of July 2022, according to the IAEA-PRIS statistics, the evolution of the world nuclear fleet showed a peak of officially operating reactors in 2018, both in terms of number and capacity, with 449 reactors and a maximum capacity of 396.4 GW, declining since.
Figure 5 • Evolution of the World Nuclear Reactor Fleet, according to IAEA-PRIS data as of July 2022
The corresponding data for the end of 2021 showed 437 reactors in Operation with a capacity of 389.5 GW. Although the data had been modified as of November 2022, this information was still displayed on the IAEA-PRIS homepage as of early 2023.
The November 2022 data obviously offers a different picture: If the operating capacity still peaked in 2018 in those revised statistics, it only reached 381.1 GW, 15.3 GW less than the 396.4 GW previously indicated. According to the revised data, the number of operating reactors never exceeded 440, reached already in 2005.
Figure 6 • Evolution of the World Nuclear Reactor Fleet, according to revised IAEA-PRIS data
For an in-depth analysis of the history of differences between IAEA and WNISR statistics, see WNISR2022.