The New Yorker recently published a short article about environmentalists who support nuclear power because they believe it is an essential component of any strategy to reduce greenhouse gas emissions. The article discussed the risks from nuclear accidents, such as Fukushima and correctly noted that more than a thousand people died in the forced evacuation of the area, dwarfing the expected direct health effects of radiation exposure.

A recent paper extended that analysis by examining the effects of the shut‐​down of all nuclear power plants in Japan following the Fukushima accident in March 2011. The absence of nuclear power was accompanied by an increase in electricity prices (38 percent in the Tokyo region) to pay for the cost of imported fossil fuels used to substitute for nuclear generation. The increased electricity prices reduced electricity use and increased mortality from reduced heating in homes. From 2011 to 2014, higher electricity prices resulted in 1,280 additional deaths in Japan’s 21 largest cities. In contrast, the estimated cumulative deaths that will occur from excessive radiation exposure caused by the reactor meltdown is 130.

One characteristic of nuclear power conspicuously absent from the New Yorker discussion was its cost. In theory, low‐​cost nuclear power has been the answer to many energy and environmental policy questions ever since the 1950s. In practice, its costs have increased inexorably. Why?

In the Spring issue of Regulationreview a recent paper that documents the history of nuclear power plant construction in the United States and the increase in costs. From 1967 through 1978, 107 were constructed. Rather than costs going down over that time because of learning by doing, plant costs more than doubled with each doubling of cumulative U.S. capacity. The problem was declining “materials deployment productivity”—that is, the amount of concrete and steel that workers put together per unit time.

About 30 percent of the productivity reduction stems from nuclear regulatory safety concerns. According to the authors:

While our analysis identifies the rebar density in reinforced concrete as the most influential variable for cost decrease, changes to the amount and composition of containment concrete are constrained by safety regulations, most notably the requirement for containment structures to withstand commercial aircraft impacts. New plant designs with underground (embedded) reactors could allow for thinner containment walls. However, these designs are still under development and pose the risk of high excavation costs in areas or at sites with low productivity.

The sources of the other 70 percent of productivity slowdown were construction management and workflow issues, including lack of material and tool availability, overcrowded work areas, and scheduling conflicts between crews of different trades. Craft laborers, for example, were unproductive during 75 percent of scheduled working hours.

Plant builders attempted to address these problems by increasing the use of standardized prefabricated modules that could be shipped to site and installed. These were employed in later reactors, but whatever advantages they provided did not improve aggregate productivity.

Since the 1990s, two nuclear projects have begun construction in the U.S. Both are two‐​reactor expansions of existing generating stations. The VC Summer project in South Carolina was abandoned in 2017 with sunk costs of $9 billion, and the Vogtle project in Georgia is severely delayed. Recent estimates place the total price of the Vogtle expansion at $25 billion, almost twice as high as the initial estimate of $14 billion, and costs are anticipated to rise further.

These problems are not unique to the United States. Projects in Finland and France also have experienced cost escalation, cost overrun, and schedule delays, which I also described ten years ago.

The paper provides an important reality check for those who believe nuclear power is an essential component of any strategy to reduce greenhouse gas emissions.