Construction time is measured as the time it takes from the first sod to the date commercial
operations start. It is often argued that this period takes far too long with nuclear power compared
to renewable energy. But is that also true?
Historical overview – Nuclear power versus renewable energy
Due to the size difference between the capacity of the energy plants, you cannot compare the
construction time of 1 GW of nuclear power with 1 GW of wind and solar 1:1. It’s like comparing a
truck to a bicycle. Sure, it takes longer to build a truck than a bike, but the truck can carry
significantly more than a bike.
When we compare, one takes the production capacity in kWh per inhabitant/year.
The installed production capacity measured in kWh per inhabitant per year (compounded annually)
over a decade shows that nuclear and hydropower are the fastest-growing clean energy sources.
Countries with nuclear power have increased their production capacity much faster with nuclear
power than with solar and wind combined. As shown in Figure 1. below.
Figure 1.
How long does it take to build a reactor?
Let’s start at the global level and look at the distribution of construction times over time. This
includes all reactors that came into operation in March 2023 (including those that have been shut
down).
The result shows that the median time to build a nuclear reactor was 6.3 years. The average was
slightly higher – 7.5 years. Some reactors were built quickly: one in five in less than five years. Some
in less than three years. As the diagram below shows.
This picture suggests that nuclear power plants take little time to build (with a few exceptions). Most
are built in 8 to 10 years. Many are built much faster.
However, it’s important to note that the Watt bar in the US was paused midway (because the
government decided it didn’t need the power anymore), so this wasn’t 43 years of continuous
construction.
Figure 2. The construction time is on the x-axis, and the percentage of reactors constructed within
this time is shown on the y-axis.
Is global construction time increasing?
It is often claimed that they were built quickly in the past, but modern reactors and regulatory
environments make them much slower. Let’s see if it’s true.
Data show that the global average construction time varies from decade to decade but is similar
today as in the 1970s or 1980s. The conclusion is that the average construction time has mostly
stayed the same globally, as seen from the bar chart below.
Figure 3.
