Capital cost estimation for advanced nuclear power plants

The first-of-a-kind (FOAK) nuclear plants built in the last 20 years are 2X over budget and schedule in the US and some European countries. One of the nuclear industry's proposed remedies is the small modular reactor (SMR). SMR designs leverage five factors to be more economically competitive than large reactors: 1) multiple units; 2) increased factory production and learning; 3) reduced construction schedules; 4) plant design simplification and 5) unit timing. There are currently no bottom-up studies that quantitatively account for these factors and compare different near-term light water reactor SMRs with Gen III + large plants. This work presents a nuclear plant cost estimating methodology using a detailed bottom-up approach for over 200 structures, systems, and components. The results compare relative costs for two large pressurized water reactors, one with active safety and one with passive safety, to two SMR designs, one with multiple reactor power modules and one with a single reactor module. Passive safety systems showed noticeable savings at both the large and small-scale reactors. The power uprating of an SMR by 20% resulted in ∼15% savings in the overnight unit capital cost. Overall, if built by an inexperienced vendor and work force, the two SMRs' overnight costs were higher than large reactors, since significant on-site labor still remains while losing economy of scale. However, the single-unit SMR had significantly less total person-hours of onsite labor, and if built by an experienced workforce, it could avoid cost-overrun risks associated with megaprojects.