ML15261A232

Summary of 990824 Meeting with Util Re Cast Austenitic Stainless Steel for Plant License Renewal Application.List of Attendees & Slides Used at Meeting Encl

ML15261A232
Person / Time
Site:	Oconee
Issue date:	09/09/1999
From:	Joseph Sebrosky NRC (Affiliation Not Assigned)
To:	NRC (Affiliation Not Assigned)
Shared Package
ML15261A233	List: ML15261A232
References
NUDOCS 9909130160
Download: ML15261A232 (14)

Text

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UNITED STATES 8

NUCLEAR REGULATORY COMMISSION.

WASHINGTON, D.C. 2055-0001 September 9, 1999 LICENSEE:

Duke Energy Corporation (Duke)

FACILITY:

Oconee Nuclear Station, Units 1, 2, and 3

SUMMARY

OF MEETING BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION (NRC) STAFF AND DUKE REPRESENTATIVES REGARDING CAST AUSTENITIC STAINLESS STEEL (CASS) FOR THE OCONEE LICENSE RENEWAL APPLICATION (LRA)

On August 24, 1999, representatives of Duke met with the NRC staff at Rockville, Maryland, to discuss issues associated with CASS for the license renewal application for Oconee Units 1, 2, and 3. A list of meeting attendees is provided in Enclosure 1. Enclosure 2 contains the slides that Duke used during the meeting.

Prior to the meeting Duke had indicated to the staff that they had concerns regarding CASS related issues. Specifically, Duke believed that the staff's safety evaluations for the following reports were not always consistent regarding CASS: final safety evaluation (FSE) for BAW-2243; "Demonstration of the Management of Aging Effects for the Reactor Coolant System (RCS);" draft safety evaluation for BAW-2248, "Demonstration of the Management of Aging Effects for the Reactor Vessel Internals;" and the open items related to CASS in Section 3.4 of the safety evaluation report (SER) related to the license renewal of Oconee Nuclear Station Units 1, 2, and 3. The SER related open items are 3.4.3.2-1, 3.4.3.3-5, 3.4.3.3-6 and 3.4.3.3-7. Enclosure 3 is an E-mail from Greg Robison of Duke to Joe Sebrosky of the NRC that explains the concerns that Duke had regarding CASS related issues.

As stated in Duke's slides the concerns involving CASS could be separated into the following three groups: RCS piping and boundary isolation valves, reactor coolant pump (RCP) casings, and reactor vessel internals. The staff stated that the pressurizer spray head should also be added as a group that required some discussion.

Regarding the RCS piping and boundary isolation valves, Duke stated that the NRC open item implies that all components not meeting ferrite screening criteria will require supplemental inspections (e.g., enhanced VT-1) or component specific evaluation. Duke did not believe that supplemental inspections were necessary because CASS items requiring volumetric inspection, visual inspection of interior surfaces, and hydrostatic testing should bound the CASS items not inspected. The staff stated that for valve bodies supplemental inspections beyond those required by code requirements were not necessary.

For RCP casings, Duke stated that an evaluation in accordance with ASME Code Case N-481 should be sufficient for license renewal. Duke also stated that for RCP casings not evaluated using the code case that screening criteria would be applied to determine the susceptibility to thermal embrittlement. RCP casings found to be susceptible to thermal embrittlement would be managed in accordance with in service inspection as supplemented by the evaluation procedure found in IWB-3640. The staff agreed with Duke's position regarding RCP casings.

The staff and Duke also agreed on how flaw evaluations would be performed for CASS valve bodies and RCP casings. Because of the favorable comparisons of fracture toughness 9j909130160 990909 97 PDR ADOCK 05000269 f

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P PDR September 9, 1999 between thermally aged CASS with ferrite less than 25 percent and stainless steel submerged arc welds (SAWs), the staff and Duke agreed that flaw evaluations for the CASS valve bodies and RCP casing would be done in accordance with IWB-3640 for SAWs. Flaw evaluations for components with greater than 25 percent ferrite would be treated on a case by case basis. The staff agreed with Duke's position.

For reactor vessel internals, the staff stated that the item associated with CASS in the draft safety evaluation for BAW-2248 should be closed out and made an applicant specific action item. The applicant specific action item would be to address aging management for reactor vessel internal CASS components. The staff further requested that Duke provide the specifics about how inspection items associated with reactor vessel internal CASS components would be performed in its response to the SER open item on this issue. Subsequent to the meeting, Duke stated that it may not be able to provide all the specifics regarding the inspection.

However, Duke could describe a process that it would use to develop the inspections.

Regardless, Duke's response to the SER open item will take the above into account.

For the pressurizer spray head, the staff stated in the-SER that it believes that the aging effects for the spray head are cracking and reduction in fracture toughness due to thermal aging of the cast stainless steel. Duke agrees that this is the aging effect. Duke also stated that the pressuirzer examination in Section 4.3.7.1 of the LRA includes the examination of the pressurizer spray head.

The staff requested that Duke reference the discussions and agreements reached in the meeting regarding CASS in its response to the SER open items related to CASS. A-draft of this meeting summary was provided to Duke to allow them the opportunity to comment on the summary prior to issuance.

Joseph M. Sebrosky, Project Manager License Renewal and Standardization Branch Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287

Enclosures:

As stated (3) cc w/encls: See next page DISTRIBUTION:

See next p2-3 DOCUMENT N, ME:G:\\RLSB\\SEBROSKY\\8-24 SUM.WPD

• See previous concurrence OFFICE LA RLSB/DRIP:PM EMCB/DE RLSB/D NAME EHylton JSebrosky BElliot CIGrm er DATE

/rT/99 i/6/99 18' /99

/99 OFFICIAL RECORD COPY

-2 between thermally aged CASS with ferrite less than 25 percent and stainless steel submerged arc welds (SAWs), the staff and Duke agreed that flaw evaluations for the CASS valve bodies and RCP casing would be done in accordance with IWB-3640 for SAWs. Flaw evaluations for components with greater than 25 percent ferrite would be treated on a case by case basis. The staff agreed with Duke's position.

For reactor vessel internals, the staff stated that the item associated with CASS in the draft safety evaluation for BAW-2248 should be closed out and made an applicant specific action item. The applicant specific action item would be to address aging management for reactor vessel internal CASS components. The staff further requested that Duke provide the specifics about how inspection items associated with reactor vessel internal CASS components would be performed in its response to the SER open item on this issue.

For the pressurizer spray head, the staff stated in the SER that it believes that the aging effects for the spray head are cracking and reduction in fracture toughness due to thermal aging of the cast stainless steel. Duke agrees that this is the aging effect and that the supplemental VT-3 inspection of the pressurizer would examine the pressurizer spray head.

The staff requested that Duke reference the discussions and agreements reached in the meeting regarding CASS in its response to the SER open items related to CASS. A draft of this meeting summary was provided to Duke to allow them the opportunity to comment on the summary prior to issuance.

Joseph M.-Sebrosky, Project Manager License Renewal and Standardization Branch Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287

Enclosures:

As stated (3) cc w/encis: See next page DISTRIBUTION:

See next page DOCUMENT NAME:G:\\RLSB\\SEBROSKY\\8-24 SUM.WPD OFFICE LA RLSB/DRIP:PM EMCB/DE RLSB/DRIP:BC NAME JSebrosky BElliot ClGrimes DATE 7/199

//99

/199

/199 OFFICIAL RECORD COPY

Oconee Nuclear Station (License Renewal) cc:

Mr. Larry E. Nicholson Ms. Lisa F. Vaughn Duke Energy Corporation 422 South Church Street Oconee Nuclear Site Mail Stop PB-05E P. 0. Box 1439 Charlotte, North Carolina 28201-1006 Seneca, South Carolina 29679 Anne W. Cottingham, Esquire Ms. Karen E. Long Winston and Strawn Assistant Attorney General 1400 L Street, NW.

North Carolina Department of Justice Washington, DC 20005 P. 0. Box 629 Raleigh, North Carolina 27602 Mr. Rick N. Edwards Framatome Technologies L. A. Keller Suite 525 Manager - Nuclear Regulatory Licensing 1700 Rockville Pike Duke Energy Corporation Rockville, Maryland 20852-1631 526 South Church Street Charlotte, North Carolina 28201-1 006 Manager, LIS NUS Corporation Mr. Richard M. Fry, Director 2650 McCormick Drive, 3rd Floor Division of Radiation Protection Clearwater, Florida 34619-1035 North Carolina Department of Environment, Health, and Senior Resident Inspector Natural Resources U. S. Nuclear Regulatory Commission 3825 Barrett Drive 7812B Rochester Highway Seneca, South Carolina 29672 Regional Administrator, Region 11Grery oison U. S. Nuclear Regulatory Commission Mail Stop EC-12R Atlanta Federal Center P. 0. Box 1006 61 Forsyth Street, SW, Suite 23T85 Charlotte, North Carolina 28201-1006 Atlanta, Georgia 30303 Robert L. Gill, Jr.

Virgil R. Autry, Director Duke Energy Corporation Division of Radioactive Waste Management Mail Stop EC-12R Bureau of Land and Waste Management P. 0. Box 1006 Department of Health and Charlotte, North Carolina 28201-1006 Environmental Control RLGILL@DUKE-ENERGY.COM 2600 Bull Street Columbia, South Carolina 29201-1708 Douglas J. Walters Nuclear Energy Institute W. R. McCollum, Jr., Vice President 1776 1 Street, NW Oconee Site Suite 400 Duke Energy Corporation Washington, DC 20006-3708 P. 0. Box 1439 DJW@NEI.ORG Seneca, SC 29679 Chattooga River Watershed Coalition P. 0. Box 2006 Clayton, GA 30525

NRC MEETING WITH DUKE ENERGY CORPORATION TO DISCUSS LICENSE RENEWAL ISSUES ASSOCIATED WITH CAST AUSTENITIC STAINLESS STEEL ATTENDANCE LIST AUGUST 24, 1999 NAME ORGANIZATION ROBERT GILL DUKE ENERGY DAVID WHITAKER DUKE ENERGY JOHN CAREY EPRI ROBERT NICKELL EPRI CONSULTANT MARY RINCKEL FRAMATOME GREG ROBISON DUKE ENERGY COLLEEN AMORUSO NUS INFO. SERVICES CAYETANO SANTOS JR NRC/RES ALLEN HISER NRC\\NRR\\DE\\EMCB JOE SEBROSKY NRC\\NRR\\DRIP\\RLSB DOUG WALTERS NEI LEE BANIC NRC\\NRR\\DE\\EMEB BILL BATEMAN NRC\\NRR\\DE\\EMCB SAM LEE NRC\\NRR\\DRIP\\RLSB BARRY ELLIOT NRC\\NRR\\DE\\EMCB BOB WEISMAN NRC\\OGC STAN WALKER EPRI

MDuke Oconee

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License Renewal Project Presentation to:

NRC Staff Regarding CASS Components-August 24, 1999 P Duke Presentation

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Aer, Overview a Introduction a Background

-RCS Piping Report, EPRI TR1 06092, Staff Paper m Oconee SER-NRC Open Item-CASS n Proposed Resolution for License Renewal

-RCS Piping and Boundary Isolation Valves

-RC Pump Casings

-RV Internals Items August 24, 1999 Oconee License Renewal Project 2

1

D Duke Presentation ErPower.

AWerV.

Participants

• Bob Gill (Duke Energy)

• Greg Robison (Duke Energy)

+ David Whitaker (Duke Energy)

+ Bob Nickell (EPRI)

• John Carey (EPRI)

• Mark Rinckel (FTI)

August 24, 1999 Oconee License Renewal Project 3

phDuke APower" Background-RCS Piping Report a RCS Piping Report (BAW-2243A)--June 1996

-Position that all CASS valve bodies susceptible to reduction of fracture toughness by thermal embrittlement-did not apply screening criteria based on amount of ferrite

-Favorable comparison of lower bound fracture toughness of CASS to stainless steel SAWs

-CASS and SS-SAWs may be treated similarly using existing ASME Section XI inspections in combination with IWB-3640 m B&WOG position on CASS valve bodies accepted by NRC through SER of BAW-2243A August 24, 1999 Oconee License Renewal Project 4

2

Duke A 9 PO WEy EPRI TR-106092-Sept. 1997 m Evaluation Procedure--Screening & AMP Screeninq to Determine Siqnificance of TE low-moly statically cast not susceptible to TE if ferrite less than or equal to 20%

low-moly centrifugally cast not susceptible to TE high-moly statically cast susceptible to TE irrespective of ferrite high-moly centrifugally cast not susceptible to TE if ferrite less than or equal to 20%

August 24, 1999 Oconee License Renewal Project 5

Duke A

OWE-,'"

EPRI TR-106092-Sept. 1997 m When TE significant, Aging Management Program Based on periodic ISI and flaw evaluation procedure m Inspections based on current ISI program and flaws evaluated in accordance with IWB-3640 due to favorable comparison of fracture toughness-CASS vs SS-SAWs a Current ISI for valve bodies (B-M-1 and B-M-2),

pump casings (B-L-1 and B-L-2 or CC N-481), and piping (B-J) sufficient to manage TE if supplemented by IWB-3640 when defect is detected August 24, 1999 Oconee License Renewal Project 6

3

Duke Staff Paper-Flaw Evaluation of Thermally Aged CASS-1996 m Staff paper published in 1996 by S. Lee, P.T. Kuo, K.

Wickman, and 0. Chopra reached similar conclusion to EPRI TR-106092 regarding comparison of fracture toughness between thermally aged CASS and stainless steel SAWs a Paper endorsed use of IWB-3640 for flaw evaluation citing favorable comparison of fracture toughness between thermally aged CASS and stainless steel SAWs August 24, 1999 Oconee License Renewal Project 7

Duke Staff Paper-Flaw Evaluation of Thermally Aged CASS-1996 er**

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PowE r Aging Management Options a Screen CASS components out as not susceptible to TE based on ferrite, a Components that are either susceptible or assumed to be susceptible to TE inspected per ISI and evaluated using IWB-3640 if a defect is discovered, or a Replacement of component August 24, 1999 Oconee License Renewal Project 9

P Duke Oconee Application and SER

1. Power.

A D.4h Open Items a Oconee position regarding CASS in Application consistent with BAW-2243A, EPRI TR-1 06092, and Staff paper a Oconee position--Assumed all CASS items susceptible to TE and existing ISI programs, as supplemented by IWB-3640, sufficient to manage TE

• NRC Open Items 3.4.3.3-5, -6, and -7 CASS

+ Requires component screening based on ferrite and fluence (RV internals items only)

+ Supplemental inspection for items exceeding criteria or component-specific evaluation August 24, 1999 Oconee License Renewal Project 10 5

Duke Oconee Application and SER A we.,

Open Items a NRC Screening Criteria

-Endorses screening criteria in EPRI TR-106092 with exception of statically-cast high-moly a Statically cast components with moly content "exceeding" the requirements of SA-351 Grades CF-3 and CF-8 with a delta ferrite content less than 10% will not need supplemental examination.

August 24, 1999 Oconee License Renewal Project 11 SDuke Oconee Application and SER PowerO A Dk,,,,

Open Items a NRC Open Item implies that all components not meeting ferrite screening criteria will require supplemental examination (e.g.,

enhanced VT-1) or component-specific evaluation a Enhanced VT-1 should be defined a NRC Open Item not consistent with NRC finding regarding BAW-2243A

" Supplemental examination may not be practical for small boundary/isolation valves August 24, 1999 Oconee License Renewal Project 12 6

PoDuke Proposed Resolution for License wer.

Renewal A D-k E-V C.yRewa m Separate CASS items into three groups

-RCS piping and boundary/isolation valves

-Reactor Coolant Pump Casings

- Reactor Vessel Internals Items August 24, 1999 Oconee License Renewal Project 13 P

Duke RCS Piping and Boundary A ower..

Isolation Valves

• May either dismiss TE using ferrite screening criteria or identify all CASS valve bodies as susceptible to TE

" Items that are susceptible to CASS to be inspected in accordance with ISI (B-M-1 and B M-2). Supplement ISI using IWB-3640 in the event that defect is detected a CASS items requiring volumetric inspection, visual inspection of interior surfaces, and hydro should bound CASS items not inspected.

August 24, 1999 Oconee License Renewal Project 14 7

Duke

,Powe.

RCP Casings a Update of Code Case N-481 evaluation for the period of extended operation should be sufficient for license renewal n RCP casings not evaluated using CC N-481 may apply screening criteria to determine susceptibility to TE n RCP casings susceptible to TE are managed by 131 (B-L-1 and B-L-2) as supplemented by evaluation procedure in IWB-3640.

August 24, 1999 Oconee License Renewal Project 15 A

Duke A D F

e RV Internals Items m Oconee position regarding CASS RV Internals items is consistent with B&WOG response to BAW-2248 DSE Open Items a B&WOG did not screen based on ferrite and fluence (10E17 n/cm 2).

m Will conduct augmented inspections of selected RV internals CASS items, as necessary August 24, 1999 Oconee License Renewal Project 16 8

PDuke aPower.

ADukeE-Compan, Summary m Favorable comparison of fracture toughness between thermally aged CASS and stainless steel SAWs suggests that CASS items should be treated the same as austenitic stainless steel weldments in piping a Current ISI requirements, as supplemented by IWB-3640 evaluation procedures, should be sufficient for license renewal August 24, 1999 Oconee License Renewal Project 17 9