Nuclear Power is the Most Reliable Energy Source

 Nuclear energy is America’s work horse.

It’s been rolling up its sleeves for six decades now to provide constant, reliable, carbon-free power to millions of Americans.

Just how reliable has nuclear energy been?

Electricity generation from commercial nuclear power plants in the United States began in 1958. At the end of 2021, the United States had 93 operating commercial nuclear reactors at 55 nuclear power plants in 28 states. The average age of these nuclear reactors is about 40 years old. The oldest operating reactor, Nine Mile Point Unit 1 in New York, began commercial operation in December 1969. The newest reactor to enter service, Watts Bar Unit 2, came online in 2016—the first reactor to come online since 1996 when the Watts Bar Unit 1 came online. According to the U.S. Nuclear Regulatory Commission as of November 2021, there were 23 shut down commercial nuclear power reactors at 19 sites in various stages of decommissioning

U.S. nuclear electricity generation capacity peaked in 2012 at about 102,000 MW when there were 104 operating nuclear reactors. At the end of 2021, there were 93 operating reactors with a combined generation capacity of about 95,492 MW. In 2013 through 2019, annual nuclear generation capacity and electricity generation increased each year (except in 2017) even as the number of operating reactors declined. Power plant uprates—modifications to increase capacity—at nuclear power plants have made it possible for the entire operating nuclear reactor fleet to maintain a relatively consistent total electricity generation capacity. These uprates, combined with high-capacity utilization rates (or capacity factors), helped nuclear power plants maintain a consistent share of about 20% of total annual U.S. electricity generation from 1990 through 2021. Some reactors also increased annual electricity generation by shortening the length of time reactors are offline for refueling.

Ons you can see, nuclear energy has by far the highest capacity factor of any other energy source. This basically means nuclear power plants are producing maximum power more than 92% of the time during the year.

That’s about nearly 2 times more as natural gas and coal units, and almost 3 times or more reliable than wind and solar plants.

Why Are Nuclear Power Plants More Reliable?

Nuclear power plants are typically used more often because they require less maintenance and are designed to operate for longer stretches before refueling (typically every 1.5 or 2 years).

Natural gas and coal capacity factors are generally lower due to routine maintenance and/or refueling at these facilities.

Renewable plants are considered intermittent or variable sources and are mostly limited by a lack of fuel (i.e. wind, sun, or water). As a result, these plants need a backup power source such as large-scale storage (not currently available at grid-scale)—or they can be paired with a reliable baseload power like nuclear energy.

Why Does This Matter?

A typical nuclear reactor produces 1 gigawatt (GW) of electricity. That doesn’t mean you can simply replace it with a 1 gigawatt coal or renewable plant.

Based on the capacity factors above, you would need almost two coal or three to four renewable plants (each of 1 GW size) to generate the same amount of electricity onto the grid. December 2, 1942, under the bleachers of the football stadium at the University of Chicago, Dr. Enrico Fermi initiated the first controlled nuclear chain reaction. The experiment, conducted as part of the wartime atomic bomb program, also led to peaceful uses of the atom, including construction of the first U.S. commercial nuclear power plant at Shippingport, Pennsylvania, in 1958.

Twenty eight states have at least one commercial nuclear reactor

Most U.S. commercial nuclear power reactors are located east of the Mississippi River. Illinois has more reactors than any state (11 reactors at 6 plants), and at the end of 2021, it had the largest total nuclear net summer electricity generation capacity at about 11,582 megawatts (MW). The Grand Gulf Nuclear Station in Port Gibson, Mississippi, has the largest U.S. nuclear reactor with an electricity generating capacity of about 1,400 MW. The two smallest operating reactors, each with a net summer generating capacity of about 520 MW, are at the Prairie Island nuclear plant in Red Wing, Minnesota. Two new nuclear reactors are under construction in Georgia, each with a planned electricity generation capacity of about 1,100 MW.Twenty eight states have at least one commercial nuclear reactor

Most U.S. commercial nuclear power reactors are located east of the Mississippi River. Illinois has more reactors than any state (11 reactors at 6 plants), and at the end of 2021, it had the largest total nuclear net summer electricity generation capacity at about 11,582 megawatts (MW). The Grand Gulf Nuclear Station in Port Gibson, Mississippi, has the largest U.S. nuclear reactor with an electricity generating capacity of about 1,400 MW. The two smallest operating reactors, each with a net summer generating capacity of about 520 MW, are at the Prairie Island nuclear plant in Red Wing, Minnesota. Two new nuclear reactors are under construction in Georgia, each with a planned electricity generation capacity of about 1,100 MW.