EVAL: A methodological approach to identify NPP total capital investment cost drivers and sensitivities

A proper understanding of the key parameters that affect Total Capital Investment Cost (TCIC) is necessary to support successful deployment of advanced nuclear reactors. Modularization is a construction method that is intended to reduce TCIC. Through modular construction, pieces of equipment, called modules, are manufactured in off-site factories and then assembled at the on-site assembly areas to super modules. Super modules are then lifted to the construction site and integrated to complete the nuclear island. Modularization may allow a reduction in TCIC through a higher level of components standardization and a more efficient construction as activities are performed in more dedicated and better controlled environments. In this work a methodology called EVAL is presented. EVAL is based on a methodological approach that can evaluate construction cost for an entire Nuclear Power Plant (NPP). EVAL was applied to assess and compare different construction strategies for the Westinghouse Small Modular Reactor (WEC-SMR) nuclear island, and was used to demonstrate and quantify the benefits of modularization. For this NPP design, modularization allows a 42% decrease in TCIC as compared to standard construction techniques (stick-built construction). EVAL was used to evaluate the effect of several decision variables on TCIC through sensitivity analyses. Specifically, the effect on construction costs of the discount rate, the size of the on-site assembly area, the use of different welding technologies, and testing was evaluated for the nuclear island of the WEC-SMR. The tool presented in this paper, used at an early stage of a reactor development, can inform both the design team and the decision maker and lead to economically more competitive design.