ML20150B329

COL Docs - FW: Draft 2 of Alternative for Proposed 6/4 Pre-submittal Meeting

ML20150B329
Person / Time
Site:	Vogtle
Issue date:	05/29/2020
From:	NRC
To:	NRC/NRR/DNRL
References
Download: ML20150B329 (8)

Text

From: Gleaves, Billy Sent: Friday, May 29, 2020 2:42 PM To: Vogtle PEmails Cc: Gleaves, Billy

Subject:

FW: Draft #2 of Alternative for Proposed 6/4 Pre-submittal Meeting Attachments: Enclosure ALT-xx Draft 2020-05-29.pdf I am sending the SNC email and the attachment from the SNC email, to ADAMS for capture.

Billy William (Billy) Gleaves Senior Project Manager NRR/Vogtle Project Office US Nuclear Regulatory Commission The contents of this message may be sensitive. If this message has been received in error, please delete it without reading it. Your receipt of this message is not intended to waive any applicable privilege. Do not disseminate this message without the permission of the author. Communications by this author do not represent NRC policy and are not binding on the Commission.

From: Roberts, Kelli Anne <KROBERTS@southernco.com>

Sent: Friday, May 29, 2020 2:10 PM To: Rankin, Jennivine <Jennivine.Rankin@nrc.gov>; Gleaves, Billy <Bill.Gleaves@nrc.gov>

Cc: Leighty, Steven <sleighty@southernco.COM>; Castell, Curtis A. <X2CACAST@SOUTHERNCO.COM>

Subject:

[External_Sender] Draft #2 of Alternative for Proposed 6/4 Pre-submittal Meeting Please see attached for the second draft alternative, which incorporates discussions from first draft during the 5/21 public meeting. We would like to discuss this Thursday, June 4th, if possible.

Thanks, Kelli Roberts l Southern Nuclear Operating Company Vogtle 3&4 Licensing Manager phone: 706.848.6991 l mobile: 229.942.7383 l kroberts@southernco.com

Hearing Identifier: Vogtle_COL_Docs_Public Email Number: 569 Mail Envelope Properties (BL0PR0901MB438727F185E98276068C2FE29F8F0)

Subject:

FW: Draft #2 of Alternative for Proposed 6/4 Pre-submittal Meeting Sent Date: 5/29/2020 2:42:19 PM Received Date: 5/29/2020 2:42:22 PM From: Gleaves, Billy Created By: Bill.Gleaves@nrc.gov Recipients:

"Gleaves, Billy" <Bill.Gleaves@nrc.gov>

Tracking Status: None "Vogtle PEmails" <Vogtle.PEmails@nrc.gov>

Tracking Status: None Post Office: BL0PR0901MB4387.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1447 5/29/2020 2:42:22 PM Enclosure ALT-xx Draft 2020-05-29.pdf 173590 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

ND-20-0590 DRAFT Enclosure Proposed Alternative VEGP 3&4-PSI/ISI-ALT-xx in Accordance with 10 CFR 50.55a(z)(1) -

Requirements for Preservice Inspection Acceptance of Volumetric Examinations Plant Site-Vogtle Electric Generating Plant (VEGP) - Units 3 and 4 Unit:

Interval- Applies to preservice inspection and the first period of the first ISI interval Interval Dates: for reexamination.

Requested Date for Approval is requested by September 30, 2020, to support completion of preservice inspection activities prior to Unit 3 ITAAC completion.

Approval:

ASME Class 1 and Class 2 welds being examined during PSI using volumetric examination methods.

ASME Code Class 1 applies to the reactor coolant system pressure boundary.

Components Affected: Class 2 applies to components that limit the leakage of radioactive material from the containment following a design basis accident.

The welds are listed in the PSI program plan for each unit.

Applicable ASME Boiler & Pressure Vessel Code,Section III, 1998 Edition through Code Editions 2000 Addenda and Addenda: ASME B&PV Code,Section XI, 2007 Edition with the 2008 Addenda ASME Boiler & Pressure Vessel Code,Section III, 1998 Edition through 2000 Addenda NB-5280 Preservice Examination NB-5281 General Requirements Applicable (a) Examinations required by NCA-3252(c) shall be completed prior to Code completion of the N-5 Data Report.

Requirements: (b) All volumetric and surface examinations shall be documented with results and identified in a form consistent with those required in NCA-4134.17 for transfer to the Owner.

NB-5282 Examination Requirements (a) Components shall be examined as specified in Section XI, Table IWB-2500-1. The method of examination for the components and parts of the 1

ND-20-0590 DRAFT Enclosure Proposed Alternative VEGP 3&4-PSI/ISI-ALT-xx in Accordance with 10 CFR 50.55a(z)(1) -

Requirements for Preservice Inspection Acceptance of Volumetric Examinations pressure retaining boundaries shall comply with those tabulated in Table IWB-2500-1. Only the volumetric and surface examinations are required to be performed.

ASME Boiler & Pressure Vessel Code,Section XI, 2007 Edition with the 2008 Addenda IWB-2200 Preservice Examination (a) Examinations required by this Article (with the exception of Examination Category B-P, and the visual VT-3 examination of the internal surfaces of Categories B-L-2 and B-M-2, of Table IWB-2500-1) shall be completed prior to initial plant startup. In addition, these preservice examinations shall be extended to include essentially 100% of the pressure retaining welds in all Class 1 components, except in those components exempted from examination by IWB-1220(a), (b), or (c). However, in the case of Examination Category B-O (Table IWB-2500-1), the examination shall be extended to include essentially 100% of the welds in the installed peripheral control rod drive housings only.

(b) Shop and field examinations may serve in lieu of the on-site preservice examinations provided:

(1) in the case of vessels only, the examination is performed after the hydrostatic test required by Section III has been completed; (2) such examinations are conducted under conditions and with equipment and techniques equivalent to those that are expected to be employed for subsequent inservice examinations; (3) the shop and field examination records are, or can be, documented and identified in a form consistent with those required in IWA-6000.

(c) Steam generator tube examination shall be governed by the plant Technical Specification.

IWB-2500 Examination and Pressure Test Requirements (a) Components shall be examined and tested as specified in Table IWB-2500-1. The method of examination for the components and parts of the pressure retaining boundaries shall comply with those tabulated in Table IWB-2500-1 except where alternate examination methods are used that meet the requirements of IWA-2240.

IWB-3100 Evaluation of Examination Results IWB-3110 Preservice Volumetric and Surface Examinations IWB-3111 General (a) The preservice volumetric and surface examinations required by IWB-2200 and performed in accordance with IWA-2200 shall be evaluated by 2

ND-20-0590 DRAFT Enclosure Proposed Alternative VEGP 3&4-PSI/ISI-ALT-xx in Accordance with 10 CFR 50.55a(z)(1) -

Requirements for Preservice Inspection Acceptance of Volumetric Examinations comparing the examination results with the acceptance standards specified in Table IWB-3410-1, except where IWB-3112(b) is applicable.

(b) Acceptance of components for service shall be in accordance with IWB-3112, IWB-3113, and IWB-3114.

IWB-3112 Acceptance (a) A component whose volumetric or surface examination either confirms the absence of or detects flaws that do not exceed the standards of Table IWB-3410-1 shall be acceptable for service, provided the verified flaws are recorded in accordance with the requirements of IWA- 1400(h), IWA-2220(b), and IWA-6230 in terms of location, size, shape, orientation, and distribution within the component.

(b) A component whose volumetric or surface examination (IWB-2200) detects flaws that meet the nondestructive examination standards of NB-2500 and NB-5300, as documented in Quality Assurance Records (NCA-4134.17), shall be acceptable.

(c) A component whose volumetric or surface examination (IWB-2200) detects flaws, other than the flaws of IWB-3112(b), that exceed the standards of Table IWB-3410-1 is unacceptable for service, unless the component is corrected by a repair /replacement activity to the extent necessary to meet the acceptance standards prior to placement of the component in service.

Additionally, IWC-3112 provides the commensurate requirements for Class 2 Components.

PSI Ultrasonic Testing (UT) examinations may potentially identify indications that were not found by the ASME Section III Radiographic Testing (RT) examinations or that do not meet the ASME Section XI PSI acceptance standards. Limited use of ASME Section XI flaw evaluation methodology in Reason for accordance with IWB-3600 and IWC-3600 will allow disposition of these Request: indications without weld repairs that could be detrimental to the component.

The currently identified need for this alternative is based on indications detected in three Core Make-up Tank (CMT) inlet and outlet nozzle-to-head welds. This request is also provided based on the possibility that remaining PSI examinations could identify additional locations where flaw evaluation is needed for Vogtle Units 3 and 4.

As of May 27, 2020, the approximate total number of Class 1 welds that are being examined using UT Preservice examination is 607. For Unit 3, approximately 432 of these examinations have been completed, with about 175 remaining. The approximate total number of Class 2 welds that are being 3

ND-20-0590 DRAFT Enclosure Proposed Alternative VEGP 3&4-PSI/ISI-ALT-xx in Accordance with 10 CFR 50.55a(z)(1) -

Requirements for Preservice Inspection Acceptance of Volumetric Examinations examined using UT Preservice examination is 206. For Unit 3, approximately 50 of these examinations have been completed, with about 156 remaining.

Progress of PSI for Unit 3 substantially leads progress on Unit 4.

Proposed Alternative:

As an alternative to the requirements of ASME Section XI, 2007 Edition with 2008 Addenda, the requirements of ASME Section XI 2017 Edition Acceptance Standards, IWB-3112 and IWC-3112, including Applicable Tables IWB- and IWC-3410-1 and referenced paragraphs, may be applied:

IWB-3112 Acceptance (a) A component whose volumetric or surface examination in accordance with IWB-2200 meets (1), (2), or (3) below shall be acceptable for service, provided the verified flaws are recorded in accordance with the requirements of IWA-1400(i) and IWA-2220(b) in terms of location, size, shape, orientation, and distribution within the component.

(1) The volumetric or surface examination confirms the absence of flaws or identifies only flaws that have already been shown to meet the nondestructive examination standards of NB-2500 or NB-5300, as documented in Quality Assurance Records (NCA-4134.17).

(2) Volumetric examination detects flaws that are confirmed by surface or volumetric examination to be non-surface-connected and that do not exceed Proposed the standards of Table IWB-3410-1.

Alternative (3) Volumetric examination detects flaws that are confirmed by surface or and Basis volumetric examination to be non-surface-connected and that are accepted for Use: by analytical evaluation in accordance with the provisions of IWB-3132.3 to the end of the service lifetime of the component and reexamined in accordance with the requirements of IWB-2420(b) and IWB-2420(d).

(b) A component whose volumetric or surface examination detects flaws that do not meet the criteria established in (a) shall be unacceptable for service, unless the component is corrected by a repair/replacement activity in accordance with IWB-3113 to the extent necessary to meet the provisions of (a) prior to placement of the component in service.

(c) A component whose volumetric or surface examination (IWB-2200) detects flaws, other than the flaws of (b), that exceed the standards of Table IWB-3410-1 is unacceptable for service, unless the component is corrected by a repair/replacement activity to the extent necessary to meet the acceptance standards prior to placement of the component in service.

The following additional conditions shall be applied to welds accepted under ASME Section XI 2017 Edition IWB or IWC 3112(a)(3):

• This Alternative can be applied to a maximum of twelve (12) Class 1 welds and eight (8) Class 2 welds. These limits are applicable to each unit.

4

ND-20-0590 DRAFT Enclosure Proposed Alternative VEGP 3&4-PSI/ISI-ALT-xx in Accordance with 10 CFR 50.55a(z)(1) -

Requirements for Preservice Inspection Acceptance of Volumetric Examinations

• This Alternative is not applicable to the Steam Generator to Reactor Coolant Pump (SG-to-RCP) welds.

• The flaw evaluation performed in accordance with IWB or IWC-3600 shall demonstrate that the flaw is predicted to remain non-surface-connected for the entire service life of the component.

• Subsequent examination for each weld that has been evaluated using this Alternative shall be conducted during the first inservice inspection (ISI) period.

Basis for Use:

The proposed alternative establishes that flaws, which are confirmed by surface or volumetric examination to be non-surface-connected and that are accepted by analytical evaluation in accordance with the provisions of IWB-3132.3 to the end of the service lifetime of the component, are acceptable.

IWB-3132.3 establishes the requirements for acceptance of flaws by analytical evaluation, as described in IWB-3600. This requirement for analytical evaluation of flaws is consistent with the requirements for flaws identified during inservice inspection. Therefore, the use of analytical flaw evaluation is an acceptable method to demonstrate weld integrity consistent with the requirements for operating nuclear plants. Hence this alternative will provide an acceptable level of quality and safety, in accordance with 10 CFR 50.55a(z)(1).

There are additional conditions proposed for the use of this alternative. These additional conditions establish the applicability of the alternative and limits for its use.

Specifically, the proposed alternative is applicable to a maximum of twelve (12)

Class 1 welds and eight (8) Class 2 welds. Also, the alternative is not applicable to the SG-to-RCP welds, which are fabricated component-to-component welds. These additional requirements for the overall use of the alternative are proposed to establish limits for use of analytical flaw evaluation for PSI. Limiting the total number of welds to twelve Class 1 and eight Class 2 in each unit is intended as a conservative limitation on the use of this alternative. These limits are less than 2% of Class 1 and 4% of Class 2 required welds being examined by UT for PSI. If additional application of analytical flaw evaluation is needed beyond these conservative limits, then it is intended that this restriction will assure that the process of accepting such evaluations is an iterative one, by requiring an additional request for alternative.

Additionally, a limitation is proposed that the flaw evaluation shall demonstrate the flaw is predicted to remain non-surface-connected for the service life of the component. This limitation provides added assurance of weld and pressure boundary integrity. Also, a requirement to conduct reexamination, in excess of the ASME Section XI 2017 Edition requirement, is also proposed. These subsequent examinations, to be performed during the first inservice inspection 5

ND-20-0590 DRAFT Enclosure Proposed Alternative VEGP 3&4-PSI/ISI-ALT-xx in Accordance with 10 CFR 50.55a(z)(1) -

Requirements for Preservice Inspection Acceptance of Volumetric Examinations period, ensure that the flaw evaluations have adequately accounted for potential growth during startup and initial plant operation.

The proposed additional limitations provide assurance that the use of this alternative will ensure that weld integrity is maintained and provide conservative limitations on the number of welds that can be subjected to flaw evaluation under IWB and IWC-3600.

UT methods being used during PSI ensure reliable flaw detection and characterization, as demonstrated by the detection of indications during PSI UT examination that were not found during ASME III RT exams. The fracture mechanics methods, which have been developed for use under the flaw evaluation methods described in ASME Section XI, allow for very accurate assessment of the impact of such flaws on the integrity of the structure.

Further, experience has shown that local repair of flaws can result in high residual stresses that can aggravate stress corrosion cracking. Studies have also shown that such weld repairs can reduce weld reliability, as compared to use of flaw evaluation techniques. This is highly relevant when considering repairs of embedded flaws in components welds, which often are larger thickness welds, as compared to piping system welds. In order to maintain the integrity of plant components, particularly fabricated vessels, the use of flaw evaluation with the conditions above, which includes the consideration of potential for flaw growth to become surface connected, and specific requirements for reexamination, establish the optimal conditions for maintaining weld integrity for the construction of Vogtle Units 3 and 4.

Therefore, the use of this alternative will provide an acceptable level of quality and safety, in accordance with 10 CFR 50.55a(z)(1).

Duration of Proposed PSI through the first period of the first ISI interval for reexamination.

Alternative:

Reference:

None Status: Awaiting NRC authorization 6