AEP-NRC-2018-22, WCAP-18133-NP, Revision 0, Inspection Flaw Acceptance Criteria for D.C. Cook Unit 2 Reactor Vessel Internals MRP-227-A Primary and Expansion Components
| ML18092A085 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 03/31/2017 |
| From: | Carpenter B Westinghouse |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML18092A069 | List: |
| References | |
| AEP-NRC-2018-22 WCAP-18133-NP, Rev 0 | |
| Download: ML18092A085 (7) | |
Text
WCAP-18133-N P Revision 0 Westinghouse Non-Proprietary Class 3 ln!;pection Flaw Acceptance Criteria for D.C. Cook Unit 2 Re~actor Vessel Internals MF~P-227-A Primary and Ex:pansion Components
@ Westinghouse March 2017
Westinghouse Non-Proprietary Class 3 WCAP-18133-NP RevisionO Inspection Flaw Acceptance Criteria for D.C. Cook Unit 2 Reactor Vessel Internals MRP-227-A Primary and Expansion Components Bradley T. Carpenter*
Reactor Internals Aging Management March 2017 Verifier:
Matthew J. Palamara
- Reactor Internals Aging Management Approved:
John L. McFadden*, Manager Reactor Internals Aging Management
- Electronically approved records are authenticated in the electronic document management system.
Westinghouse Electric Company LLC 1000 Westinghouse Drive Cranberry Township, PA 16066, USA
© 2017 Westinghouse Electric Company LLC All Rights Reserved
WESTINGHOUSE NON-PROPRIETARY CLASS 3 iv TABLE OF CONTENTS LIST OF TABLES....................................................................................................................................... vi LIST OF FIGURES.................................................................................................................................... vii ACRONYMS AND ABBREVIATIONS................................................................................................... viii ACKl~OWLEDGEMENTS......................................................................................................................... ix 1
EXECUTIVE
SUMMARY
........................................................................................................... 1-1 2
INTRODUCTION........................................................................................................................ 2-1 2.1 COMPONENTS.............................................................................................................. 2-1 2.2 INSPECTION..........................................................................................................'........ 2-3 2.2.1 Visual (VT-3) Inspection................................................................................. 2-3 2.2.2 Enhimced Visual (EVT-1) Inspection.............................................................. 2-4 2.2.3 Ultrasonic Testing............................................................................................ 2-5 2.2.4 Direct Physical Measurement.......................................................................... 2-5 3
FLAW ACCEPTANCE CRITERIA.............................................................................................. 3-1 3.1 CONTROL ROD GUIDE TUBEASSEMBLY: GUIDE PLATES (CARDS)................ 3-2 3.1.1 Component Description................................................................................... 3-2 3.1.2 Location........................................................................................................... 3-2 3.1.3 MRP-227-A Inspection Recommendations..................................................... 3-2 3.1.4 Acceptance Criteria......................................................................................... 3-2 3.2 CONTROL ROD GUIDE TUBE ASSEMBLY: LOWER FLANGE WELDS............... 3-5
- 3.2.1 3.2.2 Component Description................................................................................... 3-5 Location........................................................................................................... 3-5 3.2.3 MRP-227-A Inspection Recommendations..................................................... 3-5 3.2.4 Acceptance Criteria......................................................................................... 3-5 3.3 CORE BARREL ASSEMBLY: UPPER CORE BARREL FLANGE WELD................ 3-7 3.3.1 Component Description................................................................................... 3-7 3.3.2 Location........................................................................................................... 3-7 3.3.3 MRP-227-A Inspection Recommendations..................................................... 3-7 3.3.4 Acceptance Criteria......................................................................................... 3-8 3.4 CORE BARREL ASSEMBLY: UPPER AND LOWER CORE BARREL GIRTH WELDS.......................................................................................................................... 3-10 3.4.1
.. <::omponent Description................................................................................. 3-10 3.4.2 Location......................................................................................................... 3-10 3.4.3 MRP-227-A Inspection Recommendations................................................... 3-10 3.4.4 Acceptance Criteria....................................................................................... 3-11 3.5 CORE BARREL ASSEMBLY: LOWER CORE BARREL FLANGE WELD............ 3-13 3.5.1 Component Description................................................................................. 3-13 3.5.2 Location......................................................................................................... 3-13 3.5.3 MRP-227-A Inspection Recommendations................................................... 3-13 3.5.4 Acceptance Criteria....................................................................................... 3-14
3.6 BAFFLE-FORMERASSEMBLY
BAFFLE-EDGE BOLTS...................................... 3-16 3.6.1 3.6.2 WCAP** 18133-NP Component Description................................................................................. 3-16 Location......................................................................................................... 3-16 March 2017 Revision 0
WESTINGHOUSE NON-PROPRIETARY CLASS 3 V
3.6.3 MRP-227-A Inspection Recommendations................................................... 3-16 3.6.4 Acceptance Criteria........................................................................ :.............. 3-17
3.7 BAFFLE-FORMERASSEMBLY
ASSEMBLY.......................................................... 3-19 3.7.1 Component Description................................................................................. 3-19 3.7.2 Location......................................................................................................... 3-19 3.7.3 MRP-227-A Inspection Recommendations................................................... 3-19 3.7.4 Acceptance Criteria....................................................................................... 3-20 3.8 THERMAL SHIELD ASSEMBLY: THERMAL SHIELD FLEXURES..................... 3-24 3.8.1 Component Description................................................................................. 3-24 3.8.2 Location......................................................................................................... 3-24 3.8.3 MRP-227-A Inspection Recommendations................................................... 3-24 3.8.4 Acceptance Criteria....................................................................................... 3-25 3.9 UPPER INTERNALS ASSEMBLY: UPPER CORE PLATE...................................... 3-27 3.9.1 Component Description................................................................................. 3-27 3.9.2 Location......................................................................................................... 3-27 3.9.3 MRP-227-A Inspection Recommendations................................................... 3-27 3.9.4 Acceptance Criteria....................................................................................... 3-27 4
CONCLUSIONS.......................................................................................................................... 4-1 5
REFERENCES............................................................................................................................. 5-1 WCAP-l 8133-NP March2017 Revision 0
WESTINGHOUSE NON-PROPRJETARY CLASS 3 3-16 3.6 BAFFLE-FORMER ASSEMBLY: BAFFLE-EDGE BOLTS 3.6.1 Component Description The 1,232 baffle-edge bolts (WCAP-18062-NP [6]) are threaded fasteners that provide baffle plate-to-baffle plate attachment along the interfacing seams among the plates that comprise the baffle-former assembly. The baffle-former assembly forms the interface between the core and the core barrel. Baffle-edge bolts are designated as an MRP-227-A "Primary" component. For reporting purposes, WCAP-17096-NP-A [3] identifies the baffle-edge bolts as Component Category ID: W-ID: 6. There are no expansion links for the baffle-edge bolts.
3.6.2 Location Baffle-edge bolts are located along the full length of the baffle-former assembly where the plates overlap to form a comer. The baffle-edge bolts to be inspected are on the core-side seams joining the baffle plates. Figure 3-1 provides general orientation to locate the component in the reactor vessel. Component Inspection Detail (CID) AMP-CID-0060 in WCAP-18062-NP [6] contains a detailed sketch of the component locations.
3.6.3 MRP-227-Alnspection Recommendations For the baffle-edge bolts, MRP-227-A [1] has designated a visual VT-3 inspection. A VT-3 inspection is intended for use in situations where the degradation is readily observable. It is meant to provide a general indication of condition; quantitative acceptance criteria are not generally required. In any particular recommendation for VT-3, it should be possible to identify the specific conditions of concern. The general relevant conditions for any VT-3 inspection are summarized in Section 2.2.1.
The CNP Unit 2 design includes both baffle-edge bolts and comer bracket bolts, which both fall under this MRP-227-A component. The comer bracket bolts are a type of baffle-edge bolt, and fasten a metal plate on the outside (barrel side) of the baffle-barrel assembly through the comer of the baffle plates. The edge bolts fasten the baffle plates together on the inside of the baffle-barrel assembly. Throughout this document, when referring to baffle-edge bolts, that term encompasses both the baffle-edge and comer bracket bolts.
In the event that a qualified inspection returns a conclusion of unacceptable results, additional consideration for acceptability may be assessed. Reviewing records is critical to assess if the condition is a result of the original installation. Improper or "less than perfect" alignment may be a contributor to the unacceptable inspection result, but could be easily resolved provided that it was not a result of in-service degradation. Relevant conditions specific to a VT-3 inspection of the CNP Unit 2 baffle-edge bolts are:
WCAP-18133-NP March 2017 Revision 0
WESTINGHOUSE NON-PROPRIETARY CLASS 3 3-17 Baffle-Edge Bolt:
Protruding head Cracked or broken head
- Missing head or bolt W om or damaged head Improperly installed Baffle-Edge Bolt Locking Device:
Broken Damaged Missing Improperly Installed MRP-227-A specifies the inspection interval. Foreign object search and retrieval activities and standard refueling activities would provide a measure of assurance between targeted inspections.
Due to current operational experience and the lack of data on the rate of edge bolt failures, if any failures are observed, it is recommended that the inspection interval be evaluated and adjusted, as needed, to ensure continued safe operation.
3.6.4 Acceptance Criteria Observation by a certified inspection of any off-normal relevant condition regarding any portion ofan individual baffle-edge bolt of the accompanying locking device as a result of the VT-3 examination of the baffle-edge bolts is an unacceptable condition.
An acceptable affirmation of the component condition to support return to operation would require that there are no relevant conditions observed for the baffle-edge bolt and the accompanying locking device as a result of the inspection.
Figure 3-7 summarizes the evaluation process flow for the baffle-edge bolts.
WCAP-18133-NP March 2017 Revision 0
VT-3 Examination of 100% of Baffle-Edge Bolts and Locking Devices Acce.$Slb1e from C~re Slda
- WESTINGHOUSE NON-PROPRIETARY CLASS 3 Relevant
,--------<~. Condition t----
Ob$erve-d No Observed
'-----+I *Relevant. 1---~
Conditions Enter Into Correritivo.
Action Program*
KEY INPUTS, Evaluate the Inspection.
Finding for* Acceptability Current Condition is Acceptable for MRP-227-A Inspection Cycle Con9uft
- Inspection Ros*ponse Plan-Perform Cor.rective Actions Figure 3-7: MRP-227-A CNP Unit 2 Reactor Internals Baffle-Edge Bolts Evaluation Flow Chart WCAP-18133-NP 3-18 1* --***. *--
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