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This paper presents an overview of the first 10 years of the IRIS project, summarizing its main technical achievements and evaluating its impact on the resurgence of small modular reactors (SMRs). SMRs have been recurrently studied in the past, from early days of nuclear power, but have never gained sufficient traction to reach commercialization. This situation persisted also in the 1990s; the focus was on large reactors based on the presumed common wisdom of this being the only way to make the nuclear power plants competitive. IRIS is one of several small reactor concepts that originated in the late 1990s. However, the specific role and significance of IRIS is that it systematically pursued resolving technology gaps, addressing safety, licensing, and deployment issues and performing credible economics analyses, which ultimately made it possible--together with other SMR projects--to cross the "skepticism threshold" and led the making of a convincing case--domestically and internationally--for the role and viability of smaller reactors. Technologically, IRIS is associated with a number of novel design features that it either introduced or pursued more systematically than its predecessors and ultimately brought them to a new technical level. Some of these are discussed in this paper, such as the IRIS Safety-by-Design, security by design, the innovative thermodynamic coupling of its vessel and containment, systematic probabilistic risk assessment-guided design, approach to seismic design, approach to reduce the emergency planning zone to the site boundary, active involvement of academia, and so on. Many individuals and organizations contributed to that work, too many to list individually, and this paper attempts to pay tribute at least to their collective work. [ABSTRACT FROM AUTHOR]

The troubles of major components and structural materials in nuclear power plants have often been caused by flow-induced vibration, corrosion, and their overlapping effects. In order to establish safe and reliable plant operation, it is required to forecast future troubles based on combined analyses of flow dynamics and corrosion and prevent them at very early stages. Corrosion analysis models have been combined with three-dimensional flow dynamics and heat transfer analysis models to evaluate corrosion damage (e.g., stress corrosion cracking [SCC] and flow-accelerated corrosion [FAC]) of major components and structural materials. The models are divided into the following two parts. First is a prediction model of future trouble on materials. The distribution of oxidant concentrations along the flow path are obtained by solving water radiolysis reactions in the boiling water reactor primary cooling water and hydrazine and oxygen reactions in pressurized water reactor secondary cooling water. Then, the distribution of electrochemical corrosion potential (ECP) along the flow path is obtained by oxidant concentration based on a mixed potential model. Higher ECP enhances the possibility of SCC, while lower ECP accelerates FAC. Second is an evaluation model of wall thinning caused by FAC. At the location with a higher possibility for FAC occurrence, a trend of wall thinning is evaluated, and the lifetime is estimated for preventive maintenance. [ABSTRACT FROM AUTHOR]