ML20237E995
| ML20237E995 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 08/27/1998 |
| From: | Jacob Zimmerman NRC (Affiliation Not Assigned) |
| To: | Dennis Morey SOUTHERN NUCLEAR OPERATING CO. |
| References | |
| GL-97-01, GL-97-1, TAC-M98564, TAC-M98565, NUDOCS 9809010384 | |
| Download: ML20237E995 (7) | |
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UNITED STATES
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NUCLEAR' REGULATORY COMMISSION o
WASHINGTON, D.C. 20006 4001 4
August 27, 1998 Mr. D. N. Morey Vice President - Farley Project
' Southem Nuclear Operating l
Company, Inc.
l 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 JOSEPH M. FARLEY NUCLEAR PLANT (FARLEY), UNITS 1 AND 2 (TAC NOS.
M98564 AND M98565)
Dear Mr. Morey:
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
- Closure Head Penetrations," to the industry requesting, in part, that addressees provide a description of the plans to inspect the vessel head penetration nozzles (VHPs) 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 i
follow-up 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.
l As's result, the Westinghouse Owner's Group (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 documented in two Topical Reports issued by the Westinghouse Electric j
Corporation (WEC), WCAP-14901, Revision 0, " Background and Methodology for Evaluation of-
]g-f 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 Vessel Closure Head Penetration Integrity for the Westinghouse Owners Group."
The WOG submitted the integrated programs described in WCAP-14901 and WCAP-14902 to the staff on July 25,1997.
9 The staff has determined by letters dated April 29, July 25, and December 30,1997, that you
' developed to address the staffs requests in GL 97-01. In your letter of July 25,1997, you also 2 indicated that the information in WEC Topical Report WCAP-14901 is applicable with respect to the assessment of VHP nozzles at Farley Units 1 ana 2.
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D. N. Morey August 27, 1998 i
The staff has reviewed your responses to GL 97-01, and requires further information to i
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 staffs inquiries in the form of a request for additionalinformation (RAI).
1 The staff requests a response to the RAI within 90 days of the submittal date. It should be noted that similar staff requests have been issued to other WOG member utilities. As was the staffs position before, the staff encourages you to address these inquiries in integrated fashion I
I with the WOG and the Nuclear Energy Institute (NEI); 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, ORIGINAL SIGNED BY:
l Jacob 1. Zimmerman, Project Manager Project Directorate ll-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation Docket Nos. 50-348 and 50-364
Enclosure:
Request for Additional Information cc w/ encl: See next page l
DISTRIBUTION:
ocket File ACRS PUBLIC LPlisco, Ril
' PD 11-2 Rdg.
PSkinner, Ril JZwolinski JHarold EJSullivan OGC DOCUMENT NAME:G:\\FARLEY\\M98564.LTR To receive a copy of this document, indicate in the box: "C" = Copy without attachment / enclosure "E" = Copy with attachment / enclosure "N",= No copy OFFICE PM:P,ffil/2 lE LA:PD:ll-2 /M y D:@h NAME JZifijfr 6/ man:cn LBerry y L{ '
HBefdnfv DATE 7/g/98 t/ 6998
%/ T/98 l OFFICIAL RECORD COPY l
I
l D. N. Morey The staff has reviewed your responses to GL 97-01, 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 staffs inquiries in the form of a request for additionalinformation (RAI).
The staff requests a response to the RAI within 90 days of the submittal date. It should be noted that similar staff requests have been issued to other WOG member utilities. As was the staffs 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 l
l facilities. The staff appreciates the efforts expended with respect to this matter.
Sincerely, J cob 1. Zim erman, Project Manager Project Directorate 112
-l Division of Reactor Projects - 1/II Office of Nuclear Reactor Regulation Docket Nos. 50-348 and 50-364 l
Enclosure:
Request for Additional Information l
cc w/ encl: See next page 1
i
i l
Joseph M. Farley Nuclear Plant -
l cc:
Mr. L. M. Stinson Rebecca V. Badham General Manager -
SAER Supervisor
. Southem Nuclear Operating Company Southem Nuclear Operating Company Post Office Box 470 P. O. Box 470 Ashford, Alabama 36312 Ashford, Alabama 36312 i-Mr. Mark Ajiuni, Licensing Manager Southem Nuclear Operating Company Post Office Box 1295 l
Birmingham, Alabama 35201-1295 Mr. M. Stanford Blanton Balch and Bingham Law Firm Post Office Box 306 1710 Sixth Avenue North l
Birmingham, Alabama 35201 Mr. J. D. Woodard
. Executive Vice President Southem Nuclear Operating Company Post Office Box 1295 Birmingham, Alabama 35201 State Health Officer Alabama Department of Public Health j
434 Monroe Street Montgomery, Alabama 36130-1701 Chairman.
Houston County Commission Post Office Box 6406 i
Dothan,- Alabama 36302 Regional Administrator, Region II U.S. Nuclear Regulatory Commission '
Atlanta Federal Center 61 Forsyth Street, S.W., Suite 23T85 Atlanta, Georgia. 30303 Resident inspector l
U.S. Nuclear Regulatory Commission 1
7388 N. State Highway 95 Columbia, Alabama 36319
l' Reauest for AdditionalInformation Resoonse to Generic Letter (GL) 97-01 "Backaround and Methodoloav for Evaluation of Reactor Vessel l
Closure Head Penetration Intearity for the Westinghouse Owners Grouo" i
Igrk:al Reoort WCAP-14901. Revision 0 l.
Relationship and Applicability of WCAP-14901, Revision 0, to GL 97-01 and the 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 l
' 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 plants. With respect to the issuance of l
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 follow-E up 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 their inspection activities on an integrated industry inspection program.
As a result, the Westinghouse Owner's Group (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 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 Vessel 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 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 29, July 25, and December 30,1997, 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 letter dated July 25,1997, you also indicated that the information in WEC Topical Report WCAP-14901 is applicable with respect to the assessment of VHP nozzles at Farley Units 1
- and 2.
I Enclosure
- l The staff has reviewed your responses to GL 97-01, and requires further information to l
complete its review of your responses as they relate to the WOG's integrated program for l
assessing VHP nozzles at WOG member plants, and to the contents of Topical Report I
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 primary water stress-corrosion cracking (PWSCC) in WEC-designed VHPs. With respect to the j
probabilistic susceptibility model (e.g., probabilistic failure model) provided in WCAP-14901:
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- 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.
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- b. Describe how the probabilistic failure modelin WCAP-14901 for assessing postulated l
flaws in VHP nozzles was benchmarked, and provide a list and discussion of the i
standards the model was benchmarked against.
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- c. Provide additionalinformation regarding how the probabilistic failure models in WCAP-14901 will be refined to allow the input of plant-specific inspection data into the i
model's analysis methodology.
- 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 and 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, and describe how these activities relate to and will be used to update the probabilistic susceptibility assessment of VHP nozzles at your plant.
- 3. In the Nuclear Energy Institute (NEI) letters of January 29,1998 (Ref.1), and April 1,1998 (Ref. 2), NEl indicated that inspection plans have been developed for the VHP nozzles at the Farley Unit 2 plant in the year 2002, and 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 nozzles 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 plants. 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 for the VHP noules at the Farley Unit 1 and Unit 2 plants as would application of the attemate probabilistic susceptibility model used by the WOG member plants not subscribing to WCAP-14901, Revision O. Comment on the susceptibility rankings of the VHP nonles at the Farley Unit 1 j
and Unit 2 plants relative to the susceptibility rankings of the VHP nonles at other WOG member plants.
l REFERENCES
- 1. January 19,1998 - Letter from David J. Modeen, Director of Engineering, Nuclear Generation Division, Nuclear Energy Institute, to Mr. G. C. Lainas, Acting Director, Division of Engineering, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission (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, 4
SUBJECT:
Generic Letter 97-01, ' Degradation of Control Rod Drive Mechanism Nonle and Other Vessel Head Penetrations."
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