Capital Cost Estimation for Advanced Nuclear Power Plants

The first-of-a-kind (FOAK) nuclear plants built in the last 20 years are on average 2X over budget and schedule. 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 size reactors: 1) multiple units at a site; 2) increased factory production and learning; 3) reduced construction schedules; 4) plant design simplification and 5) unit timing. There are currently no studies that quantitatively account for these factors and compare different SMR architectures with Gen III+ large plants. This work presents a nuclear plant cost estimating methodology using a detailed bottoms-up approach for over 200 structures, systems, and components. The results compare relative cost 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 scale and small modular scale reactors. The power uprating of a SMR by 20% resulted in ~15% savings in the overnight capital cost. Overall, if built by an inexperience vendor and work force, the two SMRs’ overnight cost 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 vendor and workforce, its overnight construction cost showed potential to be competitive and avoid cost-overrun risks associated with megaprojects.