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Online Companion Guide to the ASME Boiler and Pressure Vessel Codes: Criteria and Commentary on Select Aspects of the Boiler & Pressure Vessel Codes

ASME Press
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This chapter addresses the requirements of IWA-4000 for repair/replacement (R/R) activities for nuclear power plant items. It examines the background of these R/R activities, notes some of the changes in R/R activity requirements since the original 1970 Edition, and reviews in detail the requirements in IWA-4000 in the 2015 Edition of Section XI of the ASME Boiler and Pressure Vessel Code. The discussion of the scope and applicability of Section XI R/R activities is informative to both new and longtime users. The chapter discusses the alternative requirements for small items, which is described in IWA-4131.1 and covers the requirements for items that are rotated from stock and for those involving mechanical clamping devices. It describes the responsibilities of two organizations, identified in IWA-4000, that may perform R/R activities: the Owner and the R/R Organization. The chapter explains the content of the R/R program and the R/R plan and discusses three additional general requirements included in IWA-4000: verification of acceptability, inspection by an Authorized Inspection Agency, and documentation. The new provisions that have been added in IWA-4200, such as provisions for addition of new systems, and improved and expanded provisions for reconciliation of Construction Codes and Owner’s Requirements, are also described. The chapter includes numerous Code Interpretations and Code Cases to help clarify and implement R/R activities. It looks at the design provisions that were added in the new Subarticle IWA-4300. The chapter details the changes and addenda made to IWA-4400 in the area of welding, brazing, metal removal/defect removal, fabrication, and installation and explains the specific requirements of IWA-4400. It discusses the examination and pressure testing requirements provided by IWA-4500 as part of the R/R activity. The chapter also provides a general overview of the alternative, specialized welding methods mentioned in IWA-4600.

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