51316-7679-Prospective Techniques for Monitoring Degradation in Passive SSCs for NPP SLR

Available for download

Product Number: 51316-7679-SG

ISBN: 7679 2016 CP

Author: Iouri Prokofiev

Publication Date: 2016

Member Price: $0.00

Non Member Price: $20.00

Price: $20.00

Qty:

NRC staff recently completed the analysis ofover 50 aging management programs (AMPs) for mechanical structural and electrical systems in the process of developing new license renewal guidance documents (LRGDs) for a second license renewal (SLR) for commercial nuclear power plants (NPPs). Expert panels (EPs) were conducted in 2014-2015 charged to develop guidance such that if followed will provide NRC reasonable assurance that the applicant will perform adequate aging management such that the systems structures and components (SSC) within the scope of license renewal will perform their intended functions during the second period of extended operation (PEO). Anyproposedchangesmustbebasedonsoundtechnicallydefensibleassessments. MorespecificallytheEPdeterminedwhether(1)newagingmechanismsandeffectsmaybeexpectedduringthe SLR period(2)therateofchangeofcurrentagingmechanismsandeffectsmaybe expectedtochangeduring theSLRPEOand(3)thecurrentLRGDsneedtobe modifiedtoaddresstheanticipatedchanges.As part of anearlier research project sponsored by the U.S. NRC Argonne National Laboratory(ANL) conducted scoping studies to identify viable and promising sensors and techniques for in-situ inspection and real-time monitoring of degradation in passive SSCs. Early detection of damage and degradation in safety-critical passive components (e.g. piping tubing pressure vessel) is challenging and will likely remain so for the foreseeable future. Ensuring the structural integrity of the reactor pressure vessel (RPV) and piping systems in particular is a prerequisite to long term safe operation of NPPs. The current practice is to implement inservice inspection (ISI) and preventive maintenance programs.A viable plant-wide on-line structural health monitoring program for continuous and automatic monitoring of critical SSCs could be a more effective approach for guarding against unexpected failures. Specifically online monitoring (OLM) information about the current condition of the SSCs could be input to an online prognostics (OLP) system to forecast their remaining useful life in real time.This paper provides an overview of scoping studies performed at ANL on assessing the viability of OLM and OLP systems for real time and automated monitoring and remaining of condition and the remaining useful life of passive components in NPPs. This paper will give illustrations from insights serving as a subject matter expert on NRC expert panels for BWR Penetrations Cracking of Nickel-Alloy Components and Loss of Material Due to Boric Acid-Induced Corrosion in Reactor Coolant Pressure Boundary Components (PWRs only) BWR Reactor Water Cleanup System and One-time Inspection of ASME Code Class 1 Small bore piping (AMPs XI.M8 XI.M11 XI.M25 and XI.M35 in NUREG-1801).