ML20153B931

Forwards RAI Re GL 97-01, Degradation of Crdm/Cedm Nozzle & Other Vessel Closure Head Penetrations, Responses for Plant,Units 1 & 2

ML20153B931
Person / Time
Site:	Vogtle
Issue date:	09/16/1998
From:	Jaffe D NRC (Affiliation Not Assigned)
To:	Beasley J SOUTHERN NUCLEAR OPERATING CO.
References
GL-97-01, GL-97-1, TAC-M98608, TAC-M98609, NUDOCS 9809230289
Download: ML20153B931 (7)

Text

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p 4 UNITED STATES

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{ NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 3000H001

%*****# September 16, 1998 [8 d[ #[$5 Mr. J. B. Beasley, Jr.

Vice President Southern Nuclear Operating Company, Inc. -

Post Office Box 1295

- Birmingham, Alabama 35201-1295

SUBJECT:

GENERIC LETTER (GL) 97-01, " DEGRADATION OF CRDM/CEDM NOZZLE AND OTHER VESSEL CLOSURE HEAD PENETRATIONS" RESPONSES FOR VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 (TAC NOS.

M98608 AND M98609)

Dear Mr. Beasley:

i On April 1,1997, the staff issued Generic Letter (GL) 97-01, " Degradation of CRDM/CEDM

[ Control Rod Drive Mechanism / Control Element Drive Mechanism) Nozzle and Other Vessel l Closure Head Penetrations," to the industry requesting, in part, that addressees provide a description of the plans to inspect the vessel head penetration (VHPs) nozzles at their respective pressurized water reactor (PWR) designed plants. With respect to the issuance of the GL, the staff required the addressees to submit an initial response within 30 days of issuance informing the staff of the intent to comply with the requested information and a followup response within 120 days of issuance containing the technical details to the staff's information requests. In the discussion section of the GL, the staff stated that " individual .

licensees may wish to determine their inspection activities based on an integrated industry I inspection program...," and indicated that it did not object to individual PWR licensees basing their inspection activitik on an integrated industry inspection program. /

As a result, the Westinghouse Owners Group (WOG) determined that it was appropriate for its I members to develop a cooperative integrated inspection program in response to GL 97-01.

The WOG program is documented in two Topical Reports issued by the Westinghouse Electric Corporation (WEC), WCAP-14901, Revision 0, " Background and Methodology for Evaluation ofh Reactor Vessel Closure Head Penetration integrity for the Westinghouse Owners Group " and WCAP-14902, Revision 0, " Background Material for Response to NRC Generic Letter 97-01: l Reactor Vessel Closure Head Penetration integrity for the Westinghouse Owners Group."

The WOG submitted the integrated programs desenbed in WCAP-14901 and WCAP-14902 to l the staff on July 25,1997.

)

i The staff has determined by letters dated April 28,1997, and July 24,1997, that you were a '

member of the WOG and a participant in the WOG integrated program that was developed to ,

address the staffs requests in GL 97-01. In your letters of April 28,1997, and July 24,1997, l you also indicated that the information in WEC Topical Report WCAP-14901 is applicable with j respect to the assessment of VHP nozzles at Vogtle, Units 1 and 2.

9809230289 980916 PDR ADOCK 05000424 p PDR o f

J. B. Beasley, Jr. September 16, 1998 l

The staff has reviewed your responses to GL 97-01, dated April 28,1997, and July 24,1997, and requires further information to complete its review of your responses as they relato to the WOG's integrated program for assessing VHP nozzles at WOG member plants, and to the contents of Topical Report WCAP-14901. The enclosure to this letter forwards the staff's inquiries in the form of a request for additional information (RAI).

l The staff requests a response to the RAI within 90 days of the receipt of this letter. It should be l noted that similar staff requests have been issued to other WOG member utilities. As was the staff's position before, the staff encourages you to address these inquiries in integrated fashion l with the WOG and the Nuclear Er>ergy Institute; however, the staff also requests that you identify any deviations from the WOG's integrated program that may be specific to your facilities. The staff appreciates the efforts expended with respect to this matter.

Sincerely, l ORIGINAL SIGNED BY:

David H. Jaffe, Senior Project Manager Project Directorate 11-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation Docket Nos. 50-424 and 50-425

Enclosure:

Request for Additional Information cc w/enci: See next page DISTRIBUTION-Docket File EJSullivan PSkinner, Rll PUBLIC OGC PD 11-2 Rdg. ACRS JZwolinski LPlisco, Ril DOCUMENT NAME: G:WOGTLE\M98608.RAI To receive a copy of this document, indicate in the box: "C" = Copy without enclosure "E" = Copy with cttachmenMgdre "N" = No copy s OFFICE P%Pp)[ E LA:PD R ly D:P h l NAME DJ@l$r%) LBerry, Vly' HBefko$/

DATE Q 4Q98 4 /l998 O Iip /9b i '

OFFICIAL RECORD COPY

4 J. B. Beasley, Jr. The staff has reviewed your responses to GL 97-01, dated April 28,1997, and July 24,1997, and requires further information to complete its review of your responses as they relate to the WOG's integrated program for assessing VHP nozzles at WOG member plants, and to the contents of Topical Report WCAP-14901. The enclosure to this letter forwards the staff's inquiries in the form of a request for additional ihformation (RAI).

The staff requests a response to the RAI within 90 days of the receipt of this letter. It should be noted that cimilar staff requests have been issued to other WOG member utilities. As was the staff's position before, the staff encourages you to address these inquiries in integrated fashion with the WOG and the Nuclear Energy Institute; however, the staff also requests that you identify any deviations from the WOG's integrated program that may be specific to your facilities. The staff appreciates the efforts expended with respect to this matter.

Sincerely, m ,

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David H. Jaffe, Senior Project Manager Project Directorate 11-2 Division of Reactor Projects - 1/ll Office of Nuclear Reactor Regulation i Docket Nos. 50-424 and 50-425 l

Enclosure:

Request for Additional Information cc w/ encl: See next page

, Vogtle Electric Generating Plant i

f cc: Harold Reheis, Director Mr. J. A. Bailey Department of Natural Resources Manager, Licensing 205 Butler Street, SE. Suite 1252 Southem Nuclear Operating Atlanta, Georgia 30334 Company, Inc.

P. O. Box 1295 Attomey General i Birmingham, Abbama 35201-1295 Law Department 132 Judicial Building

Mr. J. Gasser. Atlanta, Georgia 30334

General Manager, Vogtle Electric Generating Plant Mr. R. D. Barker

. Southem Nuclear Operating Program Manager Company, Inc. Fossil & Nuclear Operations P. O.. Box 1600 Oglethorpe Power Corporation j Waynesboro, Georgia 30830 2100 East Exchange Place P. O. Box 1349 ,

Regional Administrator, Region ll Tucker, Georgia 30085-1349 U. S. Nuclear Regulatory '

Commission Charles A. Patrizia, Esquire Atlanta Federal Center Paul, Hastings, Janofsky & Walker.

61 Forsyth Street, SW., Suite 23T85 10th Floor Atlanta, Georgia 30303 1299 Pennsylvania Avenue Washington, DC 20004-9500 Office of Planning and Budget Room 615B Arthur H. Domby, Esquire 270 Washington Street, SW. Troutman Sanders Atlanta, Georgia 30334 NationsBank Plaza 600 Peachtree Street, NE.

Mr. J. D. Woodard Suite 5200 Executive Vice President Atlanta, Georgia 30308-2216 Southem Nuclear Operating

. Company, Inc. Resident inspector P. O. Box 1295 Vogtle Plant j Birmingham, Alabama 35201-1295 8805 River Road i Waynesboro, Georgia 30830 Steven M. Jackson Senior Engineer - Power Supply Office of the County Commissioner Municipal Electric Authority Burke County Commission of Georgia Waynesboro, Georgia 30830 1470 Riveredge Parkway, NW.

Atlanta, Georgia 30328-4684 l

1 t

', 1 l

Raouest for Additional Information Reaardina Utilities Particioatina Resoonse to Generic Letter 97-01 "Backaround and Methodoloav for Evaluation of Reactor Vessel Closure Head Penetration Intearity for the Westinohouse Owners Grouo" Tooical Report WCAP-14901. Revision 0 l

l

l. Relationship and Appiicability of WCAP-14901, Revision 0, to Generic Letter 97-01 and the Westinghouse Owners Group (WOG)

On April 1,1997, the staff issued Generic Letter (GL) 97-01, " Degradation of CRDM/CEDM

[ Control Rod Drive Mechanism / Control Element Drive Mechanism] Nozzle and Other Vessel ,

i Closure Head Penetrations," to the industry requesting, in part, that addressees provide a l description of the plans to inspect the vessel head penetration (VHPs) nozzles at their respective pressurized water reactor (PWR) designed pints. With respect to the issuance of the GL, the staff required the addressees to submit an initial response within 30 days of l !ssuance informing the staff of the intent to comply with the requested information and a l

followup response within 120 days of issuance containing the technical details to the staff's information requests. In the discussion section of the GL, the staff stated that " individual licensees may wish to determine their inspection activities based on an integrated industry inspection program...," and indicated that it did not object to individual PWR licensees basing l their inspection activities on an integrated industry inspection program.

As a result, the WOG determined that it was appropriate for its members to develop a cooperative integrated inspection program in response to GL 97-01. The WOG program is l

' documented in two Topical Reports issued by the Westinghouse Electric Corporation (WEC),

WCAP-14901, Revision 0, " Background and Methodology for Evaluation of Reactor Vessel Closure Head Penetration Integrity for the Westinghouse Owners Group," and WCAP-14902, Revision 0, " Background Material for Response to NRC Generic Letter 97-01: Reactor Verel Closure Head Penetration Integrity for the Westinghouse Owners Group."

The technical content provided in WCAP-14901, Revision 0, is basically the same as that provided in WCAP-14902. The difference with regard to the reports is that WOG member plants subscribing to the content of WCAP-14901 have opted to rank the susceptibility of their VHPs according to a probabilistic Weibull analysis method that was developed by WEC. In contrast, the WOG member plants subscribing to the content of WCAP-14902, Revision 0, have l opted to rank the VHPs for their facilities according to a probabilistic methodology that was developed by another vendor of choice. The staff has determined by letters dated April 28,

~ 1997, and July 24,1997, that you were a member of the WOG and a participant in the WOG integrated program that was developed to address the staff's requests in GL 97-01. In your I letters dated April 28,1997, and July 24,1997, you also indicated that the information in WEC

! Topical Report WCAP-14901 is applicable with respect to the assessment of VHP nozzles at

[ Vogtle, Units 1 and 2.

l

( Enclosure

e- :'

The staff has reviewed your responses to GL 97-01, dated April 28,1997, and July 24,1997, and requires further information to complete its review of your responses as they relate to the

' WOG's integrated program for assessing VHP nozzles at WOG member plants, and to the contents of Topical Report WCAP-14901. The staff requests the following information with respect to the content of your responses to GL 97-01, and to the content of WCAP-14901 as it relates to these responses:

1. In WCAP-14901, WEC did not provide any conclusions as to what the probabilistic failure model would lead the WOG to conclude with respect to the assessment of primrry water stress-corrosion cracking (PWSCC) in WEC-designed vessel head penetrations. W;th respect to the probabilistic susceptibility model (e.g., probabilistic failure model) provided in WCAP-14901:

a. Provide the susceptibility rankings compiled for the WOG member plants for which WCAP-14901 is applicable. In regard to other WOG member plants to which WCAP-14901 is applicable, include the basis for establishing the ranking of your plant relative to the others.

b. Describe how the probabilistic failure model in WCAP-14901 for assessinq postulated flaws in VHP nozzles was benchmarked, and provide a list and discussi' of the standards the model was benchmarked against.

c. Provide additional information regarding how the probabilistic failure mcJels in l WCAP-14901 will be refined to allow the input of plant-specific inspection data into the model's analysis methocology.

d. Describe how the variability in product forms, material specifications, and heat treatments used to fabricate each CRDM penetration nozzle at the WOG member utilities are addressed in the probabilistic crack initiation and growth models described or ,

referenced in Topical Report WCAP-14901.

2. Table 1-2 in WCAP-14901 provides a summary of the key tasks in WEC's VHP nozzle assessment program. The table indicates that the Tasks for (1) Evaluation of PWSCC Mitigation Methods, (2) Crack Growth Data arid Testing, and (3) Crack initiation Characterization Studies have not been completed and are stillin progress. In light of the fact that the probabilistic susceptibility models appear to be dependent, in part, on PWSCC crack initiation and growth estimates, provide your best estimate when these tasks will be completed by WEC, ar'd describe how these activities relate to and will be used to update the probabilistic susceptibility assessment of VHP nozzles at your plant.

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3. In the NEl letters of January 29,1998 (Ref.1), and April 1,1998 (Ref. 2), NEl Indicated that inspection plans have been developed for the VHP noules at the Farley Unit 2 plant in the year 2002, and at the Diablo Canyon Unit 2 plant in the year 2001, respectively. The staff has noted that although you have endorsed the probabilistic susceptibility model described in WCAP-14901, Revision 0, other WOG member licensees have endorsed a probabilistic susceptibility model developed by an alternate vendor of choice. The WOG's proposal to inspect the VHP nonles at the Farley Unit 2 and Diablo Canyon Unit 2 plants appears to be based on a composite assessment of the VHP nozzles at all WOG member plants. Verify that such a composite ranking assessment has been applied to the evaluation of VHP nonles at your plant. If composite rankings of the VHP nonles at WOG member plants have been obtained from the composite results of the two models, justify why application of the probabilistic susceptibility model described in WCAP-14901, Revision 0, would yield the same comparable relative rankings of the VHP nonles for your plant as would application of the altemate probabilistic susceptibility model used by the WOG member plants not subscribing to WCAP-14901, Revision 0. Comment on the susceptibility rankings of the VHP noules at your plant relative to the susceptibility rankings of the VHP nonles at the Farley Unit 2 and Diablo Canyon Unit 2 plants.

REFERENCES

1. January 19,1998 - Letter from David J. Modeen, Director of Engineering, Nuclear Generation Division, Nuclear Energy Institde, to Mr. G. C. Lainas, Acting Director, Division I of Engineering, Office of Nuclear Reactor Re.gulation, U.S. Nuclear Regulatory Commission I (Untitled). ,

2. April 1,1995 - Letter from David J. Modeen, Director of Engineering, Nuclear Generation ,

Division, Nuclear Energy Institute, to Mr. G. C. Lainas, Acting Director, Division of I Engineering, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission,

SUBJECT:

Generic Letter 97-01, ' Degradation of Control Rod Drive Mechanism Nonle and Other Vessel Head Penetrations.'"

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