How Old Are the World’s Nuclear Reactors?

How Old Are the World’s Nuclear Reactors?

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Since the advent of nuclear electricity in the 1950s, nuclear reactors have played an essential role in meeting our rising energy needs.

Nuclear reactors are designed to operate for decades and are typically licensed for 20 to 40 years, and they can last even longer with license renewals.

So, just how old is the world’s current nuclear reactor fleet?

The bubble chart above looks at the age distribution of the 422 reactors operating worldwide as of March 2023, based on data from the Power Reactor Information System (PRIS).

The Age Distribution of the Global Reactor Fleet

Nuclear power saw a building boom in the 1970s, 1980s, and 1990s as countries expanded their energy portfolios and sought to capitalize on the advancements in nuclear technology.

As a result, the majority of the world’s nuclear reactors began operating during this period.

Age Group (years)	Number of Reactors	Net Electrical Capacity (megawatts)
0–10	67	66,937
11–20	29	20,964
21–30	46	40,905
31–40	155	149,638
41–50	107	88,526
>50	18	10,921
Total	422	377,891

Data as of March 22, 2023.

Of the total of 422 reactors, 262 reactors have been in operation for 31 to 50 years. In other words, about 62% of all current nuclear reactors were connected to the grid between 1973 and 1992.

Growth in nuclear power slowed down by the turn of the 21st century, with decreasing public support and increasing concern over nuclear safety. As a result, only a small number of reactors fall into the 11 to 20 year age group.

But over the last decade, some countries have renewed their interest in nuclear energy, while others like China have continued to expand their reactor fleets. Some 67 reactors are between zero and 10 years old, accounting for 18% of global nuclear electrical capacity.

The oldest operating reactors (five of them) are 54 years old and entered commercial service in 1969. Two of these are located in the United States, two in India, and one in Switzerland.

How Long Can Nuclear Reactors Last?

Although specific lifespans can vary, nuclear reactors are typically designed to last for 20 to 40 years.

However, reactors can operate beyond their initially licensed periods with lifetime extensions. Extending reactor lives requires rigorous assessments, safety evaluations, and refurbishments.

Some countries have granted license renewals for aging reactors. Notably, 88 of the 92 reactors in the U.S. have received approvals to operate for up to 60 years, and some have applied for additional 20-year extensions to operate for up to 80 years.

With safety concerns addressed, reactors with lifetime extensions can offer various advantages. Without the high capital investments needed to build new reactors, they can produce carbon-free electricity at low and competitive costs, which is especially important as the global power sector looks to decarbonize.