Current Programs and Projects
Nuclear power capacity worldwide is increasing steadily, with about 55 reactors under construction. The steady growth is being witnessed in most regions worldwide but more plans are in the Asian region, though there are major plans for new units in Russia. Further emphasis is also being put on upgrading and restarting nuclear power plants in nations like Germany and Japan. Nuclear Power Plants lifetime extension programmes are maintaining capacity, particularly in the USA.
Currently, there are about 440 nuclear power reactors operating in 32 countries plus Taiwan, with a combined capacity of about 390 GWe. In 2021 these provided 2,653 TWh, about 10% of the world’s electricity.
The present situation of plants developed and other factors such as carbon reduction are monitored by the OECD’s International Energy Agency (IEA) in its World Energy Outlook (WEO) report each year. In the 2021 edition (WEO 2021), the IEA’s ‘Stated Policies Scenario’ sees installed nuclear capacity growth of over 26% from 2020 to 2050 (reaching about 525 GWe). The scenario envisages a total generating capacity of 17,844 GWe by 2050, with the increase concentrated heavily in Asia, and in particular, India and China.
Nuclear plant construction
About 90 power reactors with a total gross capacity of about 90,000 MWe are on order or planned, and over 300 more are proposed. Most reactors currently planned are in Asia, with fast-growing economies and rapidly-rising electricity demand. Many countries with existing nuclear power programmes either have plans to, or are building, new power reactors.
In 2021 nuclear plants supplied 2,653 TWh of electricity, up from 2,553 TWh in 2020.

Plants under development worldwide.
Increased capacity
Increased nuclear capacity in some countries is resulting from the uprating of existing plants. This is a highly cost-effective way of bringing on new capacity in the nuclear industry. Numerous power reactors in the USA, Switzerland, Spain, Finland, and Sweden, for example, have had their generating capacity increased.
In the USA, the Nuclear Regulatory Commission has approved about 165 uprates totalling over 7500 MWe since 1977, a few of them ‘extended uprates’ of up to 20%.
In Switzerland, all operating reactors have had uprates, increasing capacity by 13.4%.
Spain has had a programme to add 810 MWe (11%) to its nuclear capacity through upgrading its nine reactors by up to 13%. Most of the increase is already in place. For instance, the Almarez nuclear plant was boosted by 7.4% at a cost of $50 million.
Finland boosted the capacity of the original Olkiluoto plant by 29% to 1700 MWe. This plant started with two 660 MWe Swedish BWRs commissioned in 1978 and 1980. The Loviisa plant, with two VVER-440 reactors, has been uprated by 90 MWe (18%).
Sweden’s utilities have upgraded three plants. The Ringhals plant was uprated by about 305 MWe over 2006-14. Oskarshamn 3 was uprated by 21% to 1450 MWe at a cost of €313 million. Forsmark 2 had a 120 MWe uprate (12%) to 2013.
Plant lifetime extensions and retirements
Most nuclear power plants originally had a nominal design operating lifetime of 25 to 40 years, but engineering assessments have established that many can operate longer. By the end of 2016, the Nuclear Regulatory Commission (NRC) had granted license renewals to over 85 reactors, extending their operating lifetimes from 40 to 60 years. Such license extensions at about the 30-year mark justify significant capital expenditure needed for the replacement of worn equipment and outdated control systems.
In France, there are rolling ten-year reviews of reactors. In 2009 the Nuclear Safety Authority (ASN) approved EDF’s safety case for 40-year operation of its 900 MWe units, based on generic assessment of the 34 reactors. There are plans to take reactor lifetimes out to 60 years, involving substantial expenditure.
The Russian government is extending the operating lifetimes of most of the country’s reactors from their original 30 years, for 15 years, or for 30 years in the case of the newer VVER-1000 units, with significant upgrades.
The technical and economic feasibility of replacing major reactor components, such as steam generators in PWRs, and pressure tubes in CANDU heavy water reactors, has been demonstrated. The possibility of component replacement and license renewals extending the lifetimes of existing plants is very attractive to utilities, especially in view of the public acceptance difficulties involved in constructing replacement nuclear capacity.
On the other hand, economic, regulatory and political considerations have led to the premature closure of some power reactors, particularly in the USA, where reactor numbers have fallen from a high of 110 to 92, as well as in parts of Europe and likely in Japan.
Importantly, it should not be assumed that a reactor will close when its existing license is due to expire, since operating license extension is now common. However, new units coming online have more or less been balanced by the retirement of old units in recent years often due to poor government decisions. Over 2002-2021, 108 reactors were retired as 97 started operation. There are no firm projections for retirements over the next two decades, but the World Nuclear Association’s 2021 edition of The Nuclear Fuel Report has 123 reactors closing by 2040 in its reference scenario, using conservative assumptions about license renewal, and 308 coming online.