NDE Inspection Qualification: An Inspection Service Provider s Perspective. June 18-20, 2012

Transcription

1 NDE Inspection Qualification: An Inspection Service Provider s Perspective June 18-20, 2012

2 NDE Inspection Qualification: An Inspection Service Provider s Perspective by S. Sullivan, A. Fenuta, P. Kwan and S. Shokralla Ontario Power Generation Fourth International CANDU In-Service Inspection and NDT in Canada 2012 Conference June 18-21, 2012

3 Outline of Presentation Why follow an IQ Process? Components subjected to IQ at OPG Nuclear Stations Summary of some NDE Techniques being qualified by CIQB CIQB Process Follows European Network for Inspection Qualification (ENIQ) recommendations Summary of OPG/COG Procedures that have been qualified or in process to-date Comments on the IQ process from an ISP s perspective Conclusion 3

4 Why is an IQ process Followed? IQ process not used for all inspection areas Followed for areas deemed critical and to be managed. On nuclear systems and/or components whose failure can impact on : Nuclear Safety - safe shutdown of reactor and/or safe cooling of the nuclear fuel Environmental - significant release of radioactive substances into environment On critical components where degradation must be managed through fitness- for- service assessments and where a high level of rigor is required for NDE processes 4

5 Components subjected to IQ at OPG Nuclear Stations Fuel Channels Steam Generators Feeder Piping Piping Welds Dry Storage Containers for Spent Fuel 5

6 Fuel Channel NDE Summary UT Flaw Detection and Sizing Flaw Replication Detection/Locating of Garter Springs Fuel Channel SAG Measurement of Gap between Pressure Tubes & Calandria Tubes 6

7 Steam Generator NDE Summary Basic (Bobbin Probe) and Enhanced (X-Probe) Eddy Current Testing (ET) Magnetic Biasing ET Probes for Pickering Tubes Ultrasonic Testing (UT) using Tiny Rotating Ultrasonic Testing Inspection Equipment (TRUSTIE) Normal Beam (NB), Shear Wave for Circumferential Flaws (CSW) and Shear Wave for Axial Flaws (ASW) Some Flaws encountered in OPG SG tubes so far are Axial Cracks, Axial Laps, Pit-Like Wastage, Thinning from Flow Assisted Corrosion, Support Plate Fretting Wear Scars, Intergranular Attack (IGA) and Debris Frets from Foreign Material Some Plausible Flaws include Circumferential Cracks and Tubeto-Tube Fretting Wear Scars 7

8 SG NDE Qualification Summary 1 Technique Qualified So Far: ET for Pit-Like Volumetric Flaws in Pickering B Tubes 4 Technique Packages Being Reviewed by CIQB: UT for Pit-Like Volumetric Flaws in Pickering and Darlington SG Tubes, UT for Fretting Wear Scars in Darlington Tubes and ET for Fretting Wear Scars in Darlington Tubes 2 Packages in Preparation for Submission to CIQB: UT and ET for Volumetric Flaws at Pickering Future Packages: Capabilities of UT and ET for Volumetric Flaws in Darlington SG Tubes, and Cracks and IGA in Pickering and Darlington Tubes 8

9 NDE Summary for Feeder Pipes Degradation Mechanisms Addressed: High ID Thinning rate due to FAC on outlet feeders Bend /Weld Cracking due to high residual stress areas OD Fretting due to contact with adjacent components NDE Prescribed High accuracy/precision wall thickness measurements focused on specific areas using UT thickness measurement systems Bend/weld volumetric flaw detection using UT systems OD fret replication and characterization systems 9

10 Summary of NDE Qualification for Feeder Pipes Manual and Automated Bend Cracking UT IQ packages accepted by CIQB in March 2010 CAPT (Under Weld Thinning) package submitted to CIQB March process in final stages METAR (Bend Thinning UT ) package submitted to CIQB in May 2012 comments received and dispositions in-progress. OD Fretting (Replica Characterization) submitted to CIQB May 2012 GAIT/6-Probe (Adjacent to Weld Thinning UT) package to be submitted in June 2012 Weld Cracking PAUT IQ package preparation deferred 10

11 Comments on IQ from ISP s Perspective CIQB decision to follow ENIQ recommendations provides ISP s with a process to follow for IQ assessments The ENIQ approach provides; 11 An opportunity to clearly identify the requirements to which the inspection method must meet to allow a proper fitness for service assessment. Specific needs of the component under the operating conditions and OPEX involved is addressed. A flexible process allowing qualification to the specific requirements of the client and/or component; opening opportunities to involve a number of different NDE methods for application. Clearer identification of method/procedural limitations and/or gaps in meeting the inspection requirements for the component. Allowing for more knowledgeable engineering evaluation for FFS and determination for further research to address what is now known as a gap in capability.

12 Comments on IQ from ISP s Perspective - cont d The Technical Justifications developed to satisfy the process provide useful summaries of Essential Parameters Ability to deal more effectively with impact of changes to procedures/equipment on qualified procedures Discussions with CIQB reviewers are helpful in deepening the understanding of the techniques Independent expert review by CIQB review team has resulted in improvements to Inspection procedures overall CIQB governance instructions provide ISP s with a methodical and consistent approach for the preparation of IQ documentation i.e. IP, TJ and TP. 12

13 Comments on IQ from ISP Perspective - cont d Provides assurance that IP s meet the Inspection Specification requirements with supporting documentation i.e. TJ Documentation of performance data in TJ (detection capabilities and sizing accuracies) are valuable to the data analysts and for fitness-for-service assessments Overall the IQ process is healthy for verifying the capabilities of specific applications of NDE Process provides a structured plan for training and qualifying NDE personnel ensuring that the IP can be applied effectively and repeatedly demonstrating competency of assigned staff. 13

14 Comments on IQ from ISP Perspective - cont d Demonstrates compliance with CAN/CSA N adequacy of IP s and proficiency of personnel in use of IP s CNSC is supportive of CIQB process for IQ ISP s have the option to use the CIQB for qualification of nonstandard NDE, - and not only for N285.4, but also for N285.0, N285.5 standards. CNSC has permitted ISP s to utilize the CIQB to carry out third party inspection qualification reviews and verifications creating opportunities to save time and effort. 14

15 Conclusion Benefits of Following an IQ Process : Licensees subject to CAN/CSA N285.4 standard show compliance with clause 3.6(e) - performance demonstration of the adequacy of procedures and the proficiency of the personnel using the assigned equipment to detect and size flaws in representative samples CIQB established by COG to oversee IQ process using proven methodology Provides Licensees/ISP s with option to use CIQB to carry out a third party inspection qualification reviews as permitted by the CNSC Provides Licensees/ISP s with a consistent process for IQ (ENIQ adopted by CIQB and accepted by CNSC) for inspection procedures required for N285.4 periodic inspection program (PIP) IQ dossiers are formally reviewed by a team of experts assembled by the CIQB in the field of NDE suited to each submission Procedures that may be subjected to IQ process has been expanded as CIQB will accept IQ applications for procedures beyond PIP procedures for any inspection, component and NDE method/technique. 15

16 Conclusion Benefits of Following IQ Process: - cont d: Flexibility - CIQB is able to assemble a review team consisting of independent experts to qualify any inspection procedure developed to meet the application and performance requirements detailed in the customer s IS. Since all CANDU licensees are subject to the same CSA standard a collective approach to IQ has resulted in cost savings overall e.g the feeder IQ program under FIJP auspices 16

17 Challenges from an ISP s Perspective Going Forward 1. Change in NDE practices More structured formalized training programs in a number of areas and the concept of requalification and frequency of testing Managing procedural changes and maintaining qualification status ( e.g. administrative, minor and major equipment substitutions, changes to system essential parameters etc. ) e.g changes to NDE equipment and procedures may result in revision or expansion to TJ and re-qualification Training program audits by CIQB CNSC audits of NDE programs through CIQB 2. Controls have increased and flexibility decreased 3. Change in culture/approach challenging modus operandi amongst NDE practitioners 4. Management of an increasing inventory of test specimens for 17 operator training and qualification

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