Economic Comparison of Different Size Nuclear Reactors

TLDR

Smaller nuclear reactors are expected to play a key role in the global nuclear renaissance, yet they are often deemed economically uncompetitive due to a misapplied economy‑of‑scale argument that assumes higher capital costs per kWe. This study identifies the non‑size factors influencing capital cost of small reactors and preliminarily evaluates their impact. Using the IRIS reactor as a case study, the authors analyze capital‑cost determinants, a methodology that extends to all small nuclear plants. When these factors are considered, the final capital costs of small and large plants are essentially equivalent.

Abstract

Smaller size reactors are going to be an important component of the worldwide nuclear renaissance. However, a misguided interpretation of the economy of scale would label these reactors as not economically competitive with larger plants because of their allegedly higher capital cost ($/kWe). Economy of scale does apply only if the considered designs are similar, which is not the case here. This paper identifies and briefly discusses the various factors which, beside size (power produced), contribute to determining the capital cost of smaller reactors and provides a preliminary evaluation for a few of these factors. When they are accounted for, in a set of realistic and comparable configurations, the final capital costs of small and large plants are practically equivalent. The IRIS reactor is used as the example of smaller reactors, but the analysis and conclusions are applicable to the whole spectrum of small nuclear plants.