Materials Performance

NOV 2018

Materials Performance is the world's most widely circulated magazine dedicated to corrosion prevention and control. MP provides information about the latest corrosion control technologies and practical applications for every industry and environment.

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Page 48 of 72

46 NOVEMBER 2018 W W W.MATERIALSPERFORMANCE.COM CM CORROSION MANAGEMENT evaluations. Plants will use phased and interrelated strategies to address multiple corrosion mechanisms throughout the facility. These can play directly into the decision to extend operating licenses and vice versa. Even a decade or more from the facility's proposed retirement, the feasibility and prerequisites for extension are weighed. Operations and maintenance decisions in a modern regulatory and economic envi- ronment are viewed through the lens of risk management. Corrosion and asset integrity activities are key contributors to, and recip- ients of, this approach. However, the indus- try's responsibility to the public drives con- servative results when considering safety implications of taking or not taking actions. This includes deciding if or when to inspect, repair, or replace components or to perform field work modifying the systems they sup- port. Programs must provide strong bases for actions to derive the maximum value from each effort. Plants succeed in prioritiz- ing projects when engineers collaborate with other departments and managers to identify the highest priority initiatives. Relationships across disciplines with sys- tem engineers, project managers, and main- tenance personnel help the corrosion engi- neer provide a balanced, well-informed recommendation and demonstrates that the plant is ready and committed to follow through on the work. Plants look at all potential projects, actions, and decisions by comparing total risk impacts. Probability and consequence are first considered but mitigating strate- gies that can reduce either of these ele- ments are also weighed . Consequences consider direct and indirect safety, environ- mental, financial, and regulatory impacts. Each is considered and the probability of those individual events coming about alone or collectively determines risk. This final, adjusted, aggregate risk is used to drive integrity decisions. Integrity management plans, including failure risk impacts, can provide inputs to net present value budgets forecasting long- term investments. 11 Budgets then address all elements of the inspection, evaluation, management, and mitigation of corrosion across each system over time. Lack of such forecasting puts operators at risk of emer- gent funding crises or scope impacts if com- mitments are not translated into future cost and risk projections. Plans should also con- sider contingent costs for bridging strate- gies and corrective actions, should any large projects or schedule-sensitive actions be deferred . Nuclear power is a long-term industry that both challenges and rewards this long-term thinking toward reliable performance. Results Systemic and programmatic approaches to corrosion identification, monitoring, and mitigation allow nuclear power plants to justify the scopes of their integrity manage- ment programs. By following RBI and work planning practices as inputs to value-driven budget planning, nuclear power plants can consistently implement inspection and repair programs on an annual and ongoing basis to address concerns identified. Where schedules and budgets challenge scope reductions, the empirically based engineer- ing evaluations can support those chal- lenges in an open manner, unbiased by "fear of failure" or emotional rationalizations. The risk-sensitivity and experiential inputs for these decisions enable operators to build bridging strategies to mitigate near- term impacts until long-term solutions are implemented. These will still, however, tar- get compliance and continuous improve- ment by being compared to how other oper- ators in the industry are managing similar concerns via benchmarking initiatives. This enables the industry, as a whole, to provide a consistent, supportable frame- work to drive integrity of its components as a priority and to pursue competitiveness through other areas of their business. It also prevents the industry from falling into the trap of "spending itself out of trouble" to ad dre ss shor t-t erm c onc erns b e cause actions are considered from a broader, stra- tegic view over time. Regulators maintain ongoing evalua- tions of the industry's progress in address- ing high-risk corrosion concerns as out- lin ed in gen eric l ett ers and lic ensin g commitments. The industry is also account- able for self-revealing potential violations or concerns. These assessments and actions feed into the license renewal application process. The number of extended licenses for already aged nuclear power plants in the United States is a testimony to the strength of integrity programs in place (Figure 3). Licenses demonstrate the potential future reliability of the plants. Capacity fac- tors provide the real perspective on how reliable plants are against this potential and is the strongest demonstration of proactive integrity management performance in that, in order to operate, they must meet integ- rity management commitments and also maintain component reliability. However, economic viability plays into the long-term operating life of these plants, as well. The continued extension of licenses and overall cap a c ity rel ativ e to o th er gen eratin g sources is a fair indicator of successful asset integrity management by that metric. FIGURE 3 License renewals granted for operating nuclear power reactors (U.S. NRC). 10

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