Text

Relief Request for Dissimilar Metal Butt Weld Examinations
	ML16028A156
Person / Time
Site:	Calvert Cliffs
Issue date:	01/28/2016
From:	David Gudger; Exelon Generation Co
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	Download: ML16028A156 (47)
	v • d • e

200 Exelon Way Kennett Square PA 19348 Exelon Generation www.exeloncorp.com 10 CFR 50 .55a January 28, 2016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Calvert Cliffs Nuclear Power Plant, Unit 2 Renewed Facility Operating License No. DPR-69 NRC Docket No. 50-318

Subject:

Relief Request for Dissimilar Metal Butt Weld Examinations

References:

1) Letter from D. Gudger (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Relief Request for Dissimilar Metal Butt Weld Examinations," dated March 5, 2015

2) Letter from D. Gudger (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Relief Request for Dissimilar Metal Butt Weld Examinations," dated November 24, 2015 In accordance with 10 CFR 50.55a, "Codes and standards," Paragraph 10 CFR 50.55a(z)(2),

Exelon Generation Company, LLC (Exelon), is proposing an alternative to the requirements of 10 CFR 50.55a(g)(6)(ii)(F) regarding examination coverage of dissimilar metal butt welds on the basis that complying with the specified requirement would result in hardship or unusual difficulty for Calvert Cliffs Nuclear Power Plant, Unit 2. A similar relief request was submitted for Unit 1 in the Reference 1 letter. In the Reference 2 letter, responses to requests for additional information were supplied for the Unit 1 relief request. These responses are incorporated in this request.

Exelon requests approval of this relief request by January 28, 2017 to support the Spring 2017 outage at Unit 2.

There are no regulatory commitments in this letter.

If you have any questions concerning this letter, please contact Tom Loomis at (610) 765-5510.

Respectfully,

,Jµ,v;JY. A-- )JV-'

David T. Gudger Manager - Licensing & Regulatory Affairs Exelon Generation Company, LLC

Relief Request for Dissimilar Metal Butt Weld Examinations January 28, 2016 Page 2 Attachments: 1) Relief Request RR-ISl-04-11

2) Examination Coverage Plots cc: Regional Administrator, Region I, USNRC USNRC Senior Resident Inspector, CCNPP USNRC Project Manager [CCNPP]

S. T. Gray, State of Maryland

Attachment 1 Relief Request RR-ISl-04-11

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 1 of 44)

Relief Request For Preemptive ISi Relief for Calvert Cliffs Nuclear Power Plant, Unit 2 Dissimilar Metal Butt Weld Examinations (RR-151-04-11) 1.0 ASME CODE COMPONENT($) AFFECTED Code Class: Class 1 - PWR Pressure Retaining Dissimilar Metal Piping and Vessel Nozzle Butt Welds Containing Alloy 82/182.

American Society of Mechanical Engineers (ASME) Code Case N-770-1, Table 1, Examinations Categories.

Inspection Item B: 12 Unmitigated Butt Welds at Cold Leg Operating Temperature (See Table 1A)

Inspection Item D: 4 Uncracked Butt Welds Mitigated with Stress Improvement (See Table 1A) 2.0 APPLICABLE CODE EDITION AND ADDENDA ASME Boiler and Pressure Vessel Code,Section XI, 2004 Edition, no Addenda, and Code Case N-770-1 subject to conditions specified in 10 CFR 50.55a(g)(6)(ii)(F).

3.0 APPLICABLE CODE REQUIREMENT With the issuance of a revised 10 CFR 50.55a in June 2011, the Nuclear Regulatory Commission (NRC) incorporated by reference ASME Code Case N-770-1, "Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated with UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities,Section XI, Division 1" (ASME Approval Date: December 25, 2009). Specific implementing requirements are documented in 10 CFR 50.55a(g)(6)(ii)(F). Requirement (4) states:

(4) The axial examination coverage requirements of Paragraph -2500(c) may not be considered to be satisfied unless essentially 100 percent coverage is achieved.

Additionally, as required by Code Case N-770-1, Paragraph -2420, "Successive examinations are specified in Table 1." Table 1, Inspection Item B, requires inspection every second inspection period not to exceed 7 years. Inspection Item D also requires successive examinations based on defined criteria.

As also discussed in the Reference 1, Question 11, "Alternative inspection requirements to those contained in Code Case N-770-1, with conditions as imposed in 10 CFR 50.55a(g)(6)(ii)(F), should be submitted and authorized by the NRC pursuant to 10 CFR 50.55a(a)(3}(i} or (a)(3)(ii) prior to implementation." Accordingly, attached is the relief request for the successive examination of the dissimilar metal piping and vessel nozzle butt welds containing Alloy 82/182.

10 CFR 50.SSa RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 2 of 44) 4.0 REASON FOR THE REQUEST Calvert Cliffs Nuclear Power Plant (CCNPP) previously submitted relief requests to the U.S. Nuclear Regulatory Commission requesting an alternative to the examination requirements contained in ASME Code Case N-770-1 for selected Dissimilar Metal Welds (DMWs) in References 2 and 3 (Units 1 and 2, respectively} as part of the baseline inspection requirements. These relief requests were approved in the Reference 4 and 5 U.S. Nuclear Regulatory Commission Safety Evaluation Reports.

In preparation for the future examinations of these DMWs, currently scheduled for Unit 2 in 2017, CCNPP, Unit 2 is seeking relief from the N-770-1 requirements to examine DMWs to the required coverage. This relief request will mitigate potential plant startup restraints at a time in which resources to process a relief request will be at a premium.

The examinations are required to be performed during the 2017 refueling outage in order to maintain compliance with the examination periodicity requirements of Code Case N-770-1, paragraph -2420. Exelon Generation Company, LLC (Exelon) is proposing an alternative to the examination coverage requirements of Code Case N-770-1, Paragraph

-2500 and item (4) of 10 CFR 50.55a(g)(6)(ii)(F) in accordance with 10 CFR 50.55a(z)(2) on the basis that complying with the specified requirement would result in hardship or unusual difficulty during the CCNPP, Unit 2 spring 2017 refueling outage.

The welds shown in Table 1A are the applicable welds~ 2 inches Nominal Pipe Size (NPS) covered by the requirements contained in ASME Code Case N-770-1, Section -

1000, where essentially 100 percent coverage was unable to be obtained for the susceptible material examination volume. These welds have been categorized in accordance with Table 1 in ASME Code Case N-770-1. The examination volume coverage achieved during the 2011 refueling outage is also included in Table 1A in three columns, representing different coverage determination criteria.

The 16 welds in Table 1A consist of: 12 welds that are Code Case N-770-1 Inspection Item B, unmitigated at Cold Leg temperature and 4 welds that are Inspection Item D, un-cracked mitigated welds.

The 16 welds listed in Table 1A will be examined during the upcoming 2017 outage using current state of the art examination methodology for DMWs. All but one weld (136090/4-PS-2003-8) involves CASS components on one side. Weld 136090/4-PS-2003-8, which does not involve a CASS component, has its examination volume limited by the geometry of the joint, as illustrated in the figures contained in Attachment 2.

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 3 of 44)

TABLE 1A- UNIT 2 DM WELDS NOT MEETING EXAMINATION COVERAGE REQUIREMENTS Inspection N-770-1 Coverafli Susceptible Material N-770-1 Based Coverage<1><2>

Item Category including CASS 3> Coverage<4>

DMWeld Designator / ID Location NPS N*770-1 Axial Scan I Circ Scan Tetal Axia-1 Circ Scan Scan Total Axial Circ Scan I Scan Total

(%) (%) (%)

- (%) (%) (%) (%) (%) (%)

109280 I 30-RC-21A-7 21A RCP Inlet 30" 8 74 74 74 100 77 88 100 100 100 109310 I 30-RC-21A-10 21A RCP Outlet 30" B 66 70 68 96 100 98 97 100 99 110280 I 30-RC-218-7 218 RCP Inlet 30" 8 63 63 63 100 91 95 100 100 100 110310 I 30-RC-218-10 218 RCP Outlet 30" 8 65 71 68 94 100 97 93 100 97 111280 I 30-RC-22A-7 22A RCP Inlet 30" 8 67 67 67 100 79 90 100 100 100 111310 I 30-RC-22A-10 22A RCP Outlet 30" 8 76 58 67 100 83 91 100 91 96 112280 I 30-RC-228-7 228 RCP Inlet 30" 8 66 66 66 100 88 94 100 100 100 112310 I 30-RC-228-10 228 RCP Outlet 30" 8 78 78 78 100 100 100 100 100 100 PZR Surge@

113010/12-PSL-1 12" D 63 63 63 100 100 100 100 100 100 PZR PZR Surge@

113130I12-PSL-13 12" D 77 77 77 100 88 94 100 100 100 RCS Hot Leg Shutdown 114900 I 12-SC-2004-1 Cooling to RCS 12" D 67 67 67 100 100 100 100 100 100 Hot Leg Safety Injection to 115140I12-Sl-2009-15 12" 8 72 72 72 100 100 100 100 100 100 218 Cold Leg

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 4 of 44)

TABLE 1A- UNIT 2 DM WELDS NOT MEETING EXAMINATION COVERAGE REQUIREMENTS Inspection N-770-1 Based Coverage<1><2> N-770-1 Coveraa,r Susceptible Material Item Category including CASS 3> Coverage<4>

DMWeld - - - -

Location NPS -Axial Circ Axial Circ Axial Circ Designator/ ID Total Total Total N-770-1 Scan Scan Scan Scan Scan Scan

(%) (%) (%) (%) (%) (%) (%)

(%) (%)

Safety Injection to 116190 I 12-Sl-2010-13 12" B 75 75 75 100 100 100 100 100 100 21A Cold Leg Safety Injection to 117120I12-Sl-2011-13 12" B 73 73 73 100 100 100 100 100 100 228 Cold Leg Safety Injection to 118120 I 12-Sl-2012-1 3 12" B 75 75 75 100 100 100 100 100 100 22A Cold Leg 136090 I 4-PS-2003-8 PZR Spray 4" D 100 74 87 N/A N/A N/A 100 100 100 Notes:

( 1) The examination volume is based on Figure 1 from ASME Code Case N-770-1.

(2) Coverage has been calculated based on the limitations contained in the Section XI, Appendix VIII-qualified examination procedure, Sl-UT-130 R3, which is not qualified for examinations performed from the CASS material side of the component.

(3) Calculated coverage values include the CASS material that was interrogated by the examination technique.

(4) Examination coverage of the susceptible material located in the lower 1/3 thickness region of the base material has been estimated based on original design drawings.

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 5 of 44) 5.0 PROPOSED ALTERNATIVE AND BASIS FOR USE In accordance with 10 CFR 50.55a(z)(2), relief is requested for the components listed in Table 1A above on the basis that the required examination coverage of "essentially 100 percent" or "100 percent of the susceptible material volume" for CASS items is unattainable due to physical obstructions and the limitations imposed by design, geometry, and/or materials of construction. Specifically, relief is requested from the examination coverage requirements of Code Case N-770-1, Paragraph -2500 and item (4) of 10 CFR 50.55a(g)(6)(ii)(F).

It should be noted that limited examination coverage for five of the welds listed in Table 1A has been previously addressed and approved by the NRC in Reference 5. Coverage relief requests for Code Case N-770-1 examinations for the remaining 11 welds has not been required previously because the welds had been previously mitigated (Inspection Item D) or baseline examination coverage met NRC expectations per Reference 1. Reference 1, Question 31 allows baseline examination coverage credit for CASS materials using ASME Section XI, Appendix Ill examination techniques; however, ASME Section XI, Appendix VIII examination techniques are required for other than baseline examinations. None of the examinations for the components in Table 1A involve baseline examinations.

CCNPP, Unit 2 has examined these welds in the past. In 2011, CCNPP, Unit 2 used examination techniques qualified to meet the requirements of ASME Section XI, Appendix VIII, as required in 10 CFR 50.55a(g)(6), that achieved the maximum practical amount of coverage obtainable within the limitations imposed by the design, geometry and materials of construction for the components and examination techniques listed. Based on the design configuration of the components and currently available examinations techniques, CCNPP, Unit 2 has not been able to achieve essentially 100 percent coverage of the susceptible material volume and/or essentially 100 percent code coverage for the 16 welds listed in Table 1A without major modifications to the components. Plots of the ultrasonic testing (UT) coverage of the examination volume of those 16 affected welds are contained in Attachment

2. Although essentially 100 percent code coverage was not obtained, every effort was made to obtain the maximum practical coverage. The combination of coverage amount combined with the examination techniques discussed below, contributed to maintaining a high level of quality and safety.

The NRC, in its Safety Evaluation for CCNPP, Unit 2 (Reference 5) stated the following:

The NRC staff finds that the lack of ASME Code Section XI, Appendix VIII-compliant examination of the CASS and carbon steel materials is not a structural integrity concern since they are not known to be susceptible to PWSCC or other service-related cracking in the reactor coolant system environment; thus, the NRC staff accepts the UT examination achieved for these materials. NRC staff further finds that the efforts needed to obtain essentially 100 percent scan coverage of the susceptible material would present a hardship.

In addition, the NRC noted the following:

As set forth above, the NRC staff has concluded that proposed alternative RR ISl 07 A, "Dissimilar Metal Butt Welds Baseline Examinations," provides reasonable assurance of structural integrity and leak tightness of the subject RCP welds and that

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 6 of 44) complying with the specified requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Accordingly, the NRC staff concludes that the regulatory requirements of 10 CFR 50.55a(a)(3)(ii) have been fulfilled and authorizes acceptance of the spring 2011 examination of the subject welds at Calvert Cliffs, as the baseline examination until the scheduled spring 2017 refueling outage.

DMW examinations performed at CCNPP, Unit 2 during the 2011 refueling outage employed phased array (PA) UT technology. Utilizing PA UT technology not only improves the overall effectiveness of the UT examination but also provides significant performance improvements when compared to fixed angle examination methodologies.

In 2011 all DMWs were examined utilizing Structural Integrity's proprietary manual PA procedure, Sl-UT-130 R3. This procedure has been qualified in accordance with the requirements of Section XI, Appendix VIII, Supplement 10, for the manual PA UT examination technique. This technique has been Performance Demonstration Initiative-qualified to detect and characterize (length and depth size) service-induced damage in the form of Primary Water Stress Corrosion Cracking (PWSCC). The Sl-UT-130 R3 procedure is also qualified to scan DMWs with single-sided access. This single-sided access qualification allows for full interrogation of DMWs that have CASS safe ends, or restricted scanning conditions from the opposite side. The application of PA UT technology allows for a reduction in the number of required examination scans across the surface of the component, while matching or exceeding the maximum achievable coverage of the weld and adjacent base material volume of any currently qualified ultrasonic technique. The capability of PA to provide increased examination coverage is inherently evident when applied to limited-access scanning surfaces.

Using the PA technique, examination coverage is greater than fixed angle techniques for constrained configurations. This is because the procedure employs a large number of discrete examination angles (including credit for a low angle of 30-degrees), which, in addition to increased examination coverage, provides superior material insonification by utilizing many different angular sound paths, thereby optimizing penetration into highly attenuative materials. The technique also includes a 1O degree electronic skew for circumferential scanning beam angles, which significantly improves examination coverage.

Where improvement of coverage could be realized, CCNPP, Unit 2 has performed additional surface preparation.

The major limitation to achieving essentially 100 percent coverage and/or 100 percent coverage of the susceptible examination volume in 15 welds listed in Table 1A is the presence of CASS material. All DMWs ~ 12 inches NPS contain CASS safe ends on one side. No component qualification supplement is available in Section XI, Appendix VIII for CASS items. Therefore, the required examination volume was examined by Section XI, Appendix VIII, Supplement 10-qualified procedures to the maximum extent practical. In the case of the 4 inch weld (136090/4-PS-2003-8), the geometry of the joint precluded achievement of 100 percent examination coverage of the weld and the susceptible material.

As specified in IWA-2232 (ASME Section XI, 2004 Edition, no Addenda), the ultrasonic examination of piping welds is required to be performed in accordance with Appendix I of Section XI of the ASME Code. Appendix I requires that ultrasonic examination procedures, equipment, and personnel are to be qualified by Performance Demonstration in accordance

10 CFR 50.SSa RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 7 of 44) with Section XI, Appendix VIII. For examination of the CASS material, the requirements within Section XI, Appendix VIII are in the course of preparation and therefore require the use of Appendix Ill. Subsequently, the requirements for Appendix Ill, Paragraph 111-1100 apply. Paragraph 111-11 OO(c) allows alternative examination techniques, calibration block designs, and materials as provided in IWA-2240, except when the requirements of paragraph 111-3430 apply. Paragraph 111-3430 allows an alternate calibration block layout, provided similar beam paths are utilized, and allows additional reflectors provided they do not interfere with establishing the primary reference. Supplement 1 of Appendix Ill describes additional requirements for examination of austenitic and DMWs which are in combination with cast materials. Supplement 1(b)(4) cautions that CASS materials may preclude meaningful examinations because of geometry and attenuation variables.

DMWs with CASS material were examined using procedures, equipment, and personnel which were qualified on samples containing real cracks, realistic configurations, and cast austenitic materials. The qualified examination process includes calibration requirements with similar ultrasonic beam paths, scanning sensitivity based on the maximum allowable within the materials, and an array of angles from 30 to 70 degrees. These examination processes are superior to the requirements of Appendix Ill which does not require qualification on blind samples containing real cracks or realistic configurations.

This examination process meets IWA-2240 because the application of PA techniques qualified under the rules of Section XI, Appendix VIII provides a superior examination with newly developed techniques that have been reviewed and demonstrated to the Authorized Nuclear lnservice Inspector.

Examination techniques to be used during the 2017 outage for the welds contained in Table 1A are expected to be similar to the techniques and procedure previously used in 2011.

The 12 unmitigated welds included in Table 1A are found in lower temperature regions of the reactor coolant system (at temperatures near Tcaid). Therefore, there is a lower probability of crack initiation and a slower crack growth rate. These welds are also highly flaw tolerant, as demonstrated in MRP-109 (Reference 6). As shown in this reference, continued operation without repair can be demonstrated for substantial flaw sizes. The additional four welds have been mitigated by stress improvement.

It is also noted that each of the welds in Table 1A has received essentially 100 percent (greater than 90%) inspection coverage for potential circumferential flaws in the PWSCC susceptible material thereby mitigating any safety concern, as an axial PWSCC flaw will be arrested in the adjacent non-susceptible material. Flaw tolerance was further documented in the response to the request for additional information contained in Reference 7, which summarized a flaw tolerance that is bounding for all Reactor Coolant Pump (RCP) suction and discharge nozzle DMWs in Unit 2, of which 30-RC-21 B-1 O, an Inspection Item B weld, had 93 percent axial scan coverage for circumferential flaws of the susceptible material.

Figure 7 (contained in Reference 7) showed that a >40% through-wall circumferential flaw with a crack depth to length ratio of 0.1 would still have 84 months before reaching ASME allowable crack depth. Code Case N-770-1 requires reexamination of these Inspection Item B welds on a periodicity not to exceed 84 months. In addition, all locations operating at hot leg temperature or greater have been mitigated with stress improvement.

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 8 of 44)

Where appropriate, contouring has already been completed on the examination surface.

Further actions are limited by the design minimum wall calculations for the piping. Additional axial flaw coverage would require a weld build-up of the DMW followed by additional contouring and a Construction Code required radiography examination. This welding and additional contouring to improve axial coverage is a hardship that does not result in an increase to health and safety of the public.

Additionally, bare metal visual examinations in accordance with ASME Code Case N-722-1 and N-770-1 will continue to be performed. During refueling outages, qualified examiners walk down Class 1 systems at pressurized conditions and cold shutdown conditions. These walk-downs are performed to satisfy ASME Code pressure testing requirements and the Boric Acid Corrosion Control Program. Adverse conditions are addressed by the station's corrective action program.

Therefore, the UT examination coverages, which include a large percentage of the susceptible material for circumferential and axial flaws, combined with the periodic system pressure tests and outage walk downs, provide an acceptable level of quality and safety for identifying degradation from PWSCC prior to the development of a safety significant flaw.

Pre-emptive relief is requested for the 16 welds presented in Table 1A in order to mitigate potential plant startup restraints, following the 2017 Unit 2 outage. The 2017 examinations are expected to obtain coverage similar to the coverage obtained during the 2011 examinations. Due to the current state of the art of UT examination of DMWs involving CASS components associated with 15 welds and the geometric limitation of one weld, it is anticipated that the examination coverage requirements of Code Case N-770-1, and those for essentially 100 percent coverage, is likely not to be achieved. The DMWs in this request have a lower potential for initiation of PWSCC, a slower crack growth rate for any potential flaw, and they have achieved the maximum practical amount of examination coverage. In summary, CCNPP, Unit 2 has demonstrated an acceptable level of quality and safety.

As discussed in Reference 8, Exelon is aware of operating experience with the inservice inspection of dissimilar metal butt welds and works closely with industry issue programs to revise and develop guidelines to improve the examinations. As directed by the NOE Action Plan Committee and the PWR Materials Management Program (PMMP) and Boiling Water Reactor Vessel and Internals Project (BWRVIP) Executive Oversight Committees, the NOE Improvement Focus Group (NIFG) was formed to address NOE improvement and extent of condition actions in response to dissimilar metal butt weld operating experience. Exelon actively participates in these organizations. Specifically, Exelon NOE procedures have adopted the NFIG and applicable Industry Issue Program NEI 03-08 Mandatory, Needed and Good Practice guidance elements. These procedures will be in effect during the CCNPP, Unit 2 dissimilar metal butt weld examinations.

Leakage monitoring used for the reactor coolant pressure boundary, including leak rates or trends that would cause actions to be taken to determine the location of leaks, is discussed in the Reference 8 response to request for additional information and is applicable to this relief request.

Exelon will continue to evaluate new technologies and approaches that offer nondestructive examination improvements, including exam volume coverage improvement, as they become

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 9 of 44) available. As new ultrasonic techniques and tooling are qualified, Exelon reviews the new tooling and techniques for improved performance as well as increased inspection coverage.

6.0 DURATION OF PROPOSED ALTERNATIVE This relief request is applicable for the remainder of the current interval which will conclude on June 30, 2019.

7 .0 REFERENCES

1. Internal U.S. Nuclear Regulatory Commission Memorandum from T. Lupold (Chief, Piping and NOE Branch) to J. Collins (Senior Materials Engineer, Piping and NOE Branch), "Summary of Public Meeting Between the Nuclear Regulatory Commission Staff and Industry Representatives on Implementation of ASME Code Case N-770-1,"

dated August 12, 2011 (ML112240818)

2. Letter from J. Stanley (GENG) to U.S. Nuclear Regulatory Commission, "Relief Request for Unit 1 Dissimilar Metal Butt Welds Baseline Examinations (RR-ISl-04-06A)," dated February 9, 2012(ML12044A020)

3. Letter from J. Stanley (GENG) to U.S. Nuclear Regulatory Commission, "Relief Request for Unit 2 Dissimilar Metal Butt Welds Baseline Examinations (RR-ISl-04-07A)," dated June 7, 2012 (ML12164A372)

4. Letter from G. Wilson (U.S. Nuclear Regulatory Commission) to G. Gellrich (Calvert Cliffs Nuclear Power Plant, LLC), "Calvert Cliffs Nuclear Power Plant, Unit No. 1 - Relief Request RR-ISl-04-06 from ASME Code Case N-770-1 Inspection Coverage Requirement for Volumetric Examination of Reactor System Dissimilar Metal Butt Welds (TAC No. ME7791)," dated December 19, 2012(ML12345A055)

5. Letter from S. Meighan (U.S. Nuclear Regulatory Commission) to G. Gellrich (Calvert Cliffs Nuclear Power Plant, LLC), "Calvert Cliffs Nuclear Power Plant, Unit No. 2 - Relief Request RR-ISl-04-07A for Dissimilar Metal Butt Welds Baseline Examinations (TAC No. ME8871)," dated May 29, 2013 (ML13141A647)

6. "Materials Reliability Program Alloy 82/182 Pipe Butt Weld Safety Assessment for U.S.

PWR Plant Designs (MRP-109) Westinghouse and CE Design Plants," dated April 2005, Electric Power Research Institute

7. Letter from J. Stanley (GENG) to U.S. Nuclear Regulatory Commission, "Response to Request for Additional Information - Relief Request RR-ISl-04-07 A, Dissimilar Metal Butt Welds Baseline Examinations," dated February 18, 2013(ML13051A740)

8. Letter from D. Gudger (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Relief Request for Dissimilar Metal Butt Weld Examinations," dated November 24, 2015

10 CFR 50.SSa RELIEF REQUEST RR-151-04-11 Revision 0 (Page 1Oof44)

Attachment 2 Examination Coverage Plots

10 CFR 50.SSa RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 11 of 44)

CCNPPjU2 LTP # 109280 I 30-RC-2tA-7 Examination Coverage

<;All.IOlll SHD.

~

SA.HIND

(:AST S'f.UNl.11.'iS r------------,

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10 CFR 50.55a RELIEF REQUEST RR-151-04-11 Revision 0 (Page 13 of 44)

CCNPP U2LTP#109310 / 30-RC-21A-10 Examination Coverage 21A Spray .Nozzle Limitation Spray Nozzle TDC CARBON STEFL 10825" PJP.E 5.0" r------------*

I N-77'-1&..V..... I

'--- -- ------ _J

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 14 of 44)

CCNPP U2LTP#109310 I 30-RC-21A-10 Examination Cov.erage Unobstructed Coverage CARBON SI'EEL PIPE I ~,,.,._l_V_ I

10 CFR 50.55a RELIEF REQUEST RR-151-04-11 Revision 0 (Page 15 of 44)

CCNPP U2 LTP # 109310 J 30-RC-21A-10 Examination Coverage CARBON S'11!:EL PIPE

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 16 of 44)

CCNPP U2LTP#110280 I 30-RC-218-7 Examination Coverage CAKBON SIEELPJP£ r - -- -- -- -- -- -,

I !1-,,._IEuaV- I

- -- -- -- -- -- .J

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 17 of 44)

CCNPP U2LTP#110280 / 30-RC-218-7 Examination Coverage CAmlON S'lEELl'll'E r------------*

I :N--,.,._l_V_ I

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 18 of 44)

CCNPP U2LTP#110310 / 30-RC-218-10 Examination Coverage 218 Spray Nozzle Limitation IQll#jgn S1mJMH1 a Spray Nozzle

.... Wide lnsWliln &ipport CARBON Stm.PIPi£ 10025" 5.0" r------------*

I N-'119-l ~ V.i-t I

10 CFR 50.SSa RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 19 of 44)

CCNPP U2LTP#110310 I 30-RC-218-10 Examination Coverage Unobs1ructed Coverage CABllON S1EEL .PJPE.

r------------,

I N-'1'7D-1Es-V.a- I

- -- -- -- -- -- _J

10 CFR 50.55a RELIEF REQUEST RR-151-04-11 Revision 0 (Page 20 of 44)

CCNPP U2LTP#110310 / 30-RC-218-10 Examination Coverage CABBON S'IEELl!ft:

I N-778-lEumV.i- I

10 CFR 50.SSa RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 22 of 44)

CCNPP U2 LTP # 111280 I 30-RC-22A-7 Examination Coverage r------------*

I N-"/'70..1 & - Y . i - I

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 23 of 44)

CCNPP U2LTP#111310 / 30-RC-22A-10 Examination Coverage CAEllClN sn:EL PIP.I:

SA!l'EEND CAST STAINLESS

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 24 of 44)

CCNPP U2LTP#111310 / 30-RC-22A-10 Examination Coverage CARBON SIEELPlll

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 25 of 44)

CCNPP U2 LTP # 112280 / 30-RC-228-7 Examination Coverage CAKllON SAF.EEND SID'.L ELBOW CAST STAINI.ZSS r------------*

I N-771}.l&.R\'..._ I

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 26 of 44)

CCNPP U2 LTP # 112280 I 30-RC-228-7 Examination Coverage CARBON SJEEL ELBOW r------------*

I N-770.l Eu.V.m- I

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 27 of 44)

CCNPP U2LTP#112310 I 30-RC-228-10 Examination Coverage CAIDION STEELPJPE r- -- -- -- -- -- -*

I N-~l EDm \'.a.- I

- -- -- -- -- -- _,1

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 28 of 44)

CCNPP U2LTP#11231*0 / 30-RC-228-10 Examination Coverage SAFE END CARBON CAST STEEL JlllPE STAINLESS

10 CFR 50.55a RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 29 of 44)

CCNPP U2LTP#113010/12-PSL-1 Examination Coverage

N-770-1 Eum Volume I

10 CFR 50.SSa RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 30 of 44)

CCNPP U2lTP#113010/12-PSL-1 Examination Coverage

N-7ro-1 Ellam Volume

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10 CFR 50.SSa RELIEF REQUEST RR-ISl-04-11 Revision 0 (Page 31 of 44)

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