Nuclear powerStudy Identifies Reasons for Soaring Nuclear Plant Cost Overruns in the U.S.

By David L. Chandler

Published 19 November 2020

Analysis points to ways engineering strategies could be reimagined to minimize delays and other unanticipated expenses. Many analysts believe nuclear power will play an essential part in reducing global emissions of greenhouse gases, and finding ways to curb these rising costs could be an important step toward encouraging the construction of new plants.

A new analysis by MIT researchers details many of the underlying issues that have caused cost overruns on new nuclear power plants in the U.S., which have soared ever higher over the last five decades. The new findings may help the designers of new plants build in resilience to the factors that tend to cause these overruns, thus helping to bring down the costs of such plants.

Many analysts believe nuclear power will play an essential part in reducing global emissions of greenhouse gases, and finding ways to curb these rising costs could be an important step toward encouraging the construction of new plants, the researchers say. The findings are being published Tuesday in the journal Joule, in a paper by MIT professors Jessika Trancik and Jacopo Buongiorno, along with former students Philip Eash-Gates SM ’19, Magdalena Klemun PhD ’20, Goksin Kavlak PhD ’18, and Research Scientist James McNerney.

Among the surprising findings in the study, which covered 50 years of U.S. nuclear power plant construction data, was that, contrary to expectations, building subsequent plants based on an existing design actually costs more, not less, than building the initial plant.

The authors also found that while changes in safety regulations could account for some of the excess costs, that was only one of numerous factors contributing to the overages.

“It’s a known fact that costs have been rising in the U.S. and in a number of other locations, but what was not known is why and what to do about it,” says Trancik, who is an associate professor of energy studies in MIT’s Institute for Data, Systems and Society. The main lesson to be learned, she says, is that “we need to be rethinking our approach to engineering design.”

Part of that rethinking, she says, is to pay close attention to the details of what has caused past plant construction costs to spiral out of control, and to design plants in a way that minimizes the likelihood of such factors arising. This requires new methods and theories of technological innovation and change, which the team has been advancing over the past two decades.