Becht Engineering Blog

Bringing Order and Logic to the Evaluation Process There is a multitude of documents and reports that describe the damage mechanisms of ASME pressure equipment (vessels, pumps, valves, piping, and tanks, and their supports) in nuclear power plants. Thousands of pages published by EPRI, the NRC, ASME, NACE, research laboratories, utilities, contractors, and others, to read, study, and understand. The plant engineer must understand these thousands of pages of damage mechanisms, first to take the right preventive measures, and second, when the damage occurs despite our best efforts, to correctly diagnose the remaining life of the equipment, i.e. determine its fitness-for-service, its operability. In December 2018, EPRI published “Roadmap to Integrity Evaluation and Repair of Nuclear Plant Piping” EPRI report number 3002013156, to help the plant engineer navigate through the technical and regulatory complexities of damage mechanisms and the methods for the evaluation of remaining life. This is an important step...

EPRI has just published the report “Roadmap to Integrity Evaluation and Repair of Nuclear Plant Piping” EPRI report number 3002013156, dated December 2018, prepared by Becht Nuclear Services, under EPRI Project Manager T. Eckert. The methods and criteria for the evaluation of degraded and non-conforming conditions in piping systems in nuclear power plants are dispersed among a number of ASME XI Code sections, Appendices, Code Cases, and US NRC regulatory requirements, generic letters, and inspection manual sections. This multitude of requirements makes it necessary to have this roadmap to help the engineer make the right fitness-for-service evaluation and the right repair decision. The EPRI road map addresses the fitness-for-service evaluation methods and criteria for the two most common damage mechanisms in nuclear power plant piping systems: Wall thinning, and cracking. The roadmap also addresses non-conformance caused by overloads, i.e. operating loads that exceed the design loads. Regarding repairs of nuclear plant...