Exelon's Peach Bottom Nuclear Power Station andSIA present a novel approach for developing a conservative justifiable and commercially-sustainable corrosion rates for first-time inspections of isolated pitting corrosion phenomena in raw water piping. Data is applied on a risk-conscious basis to piping systems based upon failure consequence and uncertainty and differs from the typical approach of reporting location-specific time-averaged rates.This paper will provide:• Overview of PBAPS piping / coating design corrosion risk factors / data and performance / design history• Summaries of leak corrosion monitoring and wall thickness data for a varied flow conditions• Characterizations of operational safety financial and other risks to establish consequence of failure• Definition of a corrosion rate bracketing tool based on risk and uncertainty to prescribe corrosion rate risks•Presentation ofprobabilistic model results for internal corrosion to demonstrate value in advanced analysis• Conclusions & Recommended Actions for future integrity assessments and mitigating actionsThis investigationcombined >20 years of operating chemistry maintenance and non-destructive testing data to deliver a strong characterization of corrosion risks throughout the piping network that can be used to bracket future susceptibilities and to drive more complete corrosion prediction evaluation and mitigation projects while minimizing operational and commercial risks.