ML20198P001
| ML20198P001 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 12/29/1998 |
| From: | Maynard O WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-97-01, GL-97-1, WM-98-0130, WM-98-130, NUDOCS 9901060272 | |
| Download: ML20198P001 (6) | |
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W44.F CREEK NUCLEAR OPERATING CORPORATION Otto L. Maynard President and Chief Exocutive Omcer DEC 2 91998 1
WM 98-0130 U. S. Nuclear Regulatory Commission ATTN:
Document Control Desk Mail Station F1-137 Washington, D. C.
20555 t
Reference:
- 1) NRC Generic Letter 97-01, dated April 1, 1997, " Degradation of Control Rod Drive Mechanism Nozzle and Other Vessel Closure Head Penetrations"
- 3) Letter ET 97-0085, dated July 24, 1997, from R.
- 5) NRC Request for Additional Information dated August 20, 1998, from K. M. Thomas, USNRC, to O. L. Maynard, WCNOC
- 6) NEI Letter dated December 11, 1998, from D.
J. Modeen, NEI, to G. C. Lainas, USNRC, " Responses to NRC Requests for Additional Information on Generic Letter 97-01"
Subject:
Docket No. 50-482:
Response to Request for Additional Information Regarding NRC Generic Letter 97-01 (TAC NO. M98612) l l
l Gentlemen:
i Reference 1 requested Licensees to provide a description of their program for ensuring the timely inspection of pressurized water reactor control rod drive i
mechanism (CRDM) and other reactor vessel head penetrations.
Two responses were requested; one within 30 days, and another within 120 days, of the date of the Generic Letter.
References 2 and 3 provided the requested responses, and Reference 4 provided supplemental information to Reference 3.
Reference 5 requested Wolf Creek Nuclear Operating Corporation (WCNOC) provide
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further information needed for the NRC staff to complete its review of WCHOC's responses (i. e., References 2, 3 and 4) as they relate to the Westinghouse Owners' Group (WOG) integrated program for assessing reactor vessel head j
penetration nozzles at WOG wember plants.
Because the NRC requested this m
information from several licensees, the industry requested the Nuclear Energy Institute (NEI) to coordinate a generic response to Reference 5.
A meeting was held September 29, 1998, between NRC Staf f and representatives from NEI and several pressurized water reactor. (PWR) licensees.
Discussed during this meeting'was a generic-industry response to GL 97-01 being developed by the Electric Power Research Institute (EPRI) Materials Reliability Project, the plan to submit the generic industry response to che NRC by December 11, 1998, and the submittal of plant-specific responses referencing the generic response 9901060272 981229 PDR ADOCK 05000482 P
PDRA P.O. Box 411/ Burlington, KS 66839 / Phone: {316) 364-8831 An Equal Opportunity Employer M F HCNET J
9
- WM 96-0130 Ngo 2 of 2 '
a by mid-January 1999.
Reference 6 provided the generic response discussed above.
Attachment I to this letter provides WCNOC's plant-specific response to Reference 5.
Attachment II provides a summary of commitments made in this submittal.
If you have any questions regarding this response, please contact me at (316) 364-4000, or Mr. Michael J. Angus at (316) 364-4077.
Very truly yours, a
i Otto L. Maynard OLM/dic Attachments cc:
W.
D. Johnson (NRC), w/a E. W. Merschoff (NRC), w/a K. M. Thomas (NRC), w/a Senior Resident Inspector (NRC), w/a i
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STATE OF KANSAS
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- COUNTY OF COFFEY
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I Otto L. Maynard, of lawful ego, being first duly sworn upon oath says.that he is President - and Chief Executive officer of Wolf Creek Nuclear Operating Corporation; that he has read the foregoing document and knows the content
- thereof;.that.he has executed that same for anC on behalf of said Corporation-with full:-power and authority.to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.
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Otto L. Maynard President and Chief Executive Officer SUBSCRIBED and sworn.to before me this 2.
- day of Dec ember, 1998.
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. LINDA DELONG OHMIE otary Public' ' C Notary Pubhc. State of Kansas My Appt Expires August 31.2002 '
Expiration Date Om A Jl.2002 i
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Attachment I to WM 98-0130 Page 1 of 2 Response to NRC Request for Additional Information Regarding Generic Letter 97-01, " Degradation of Control Rod Drive Mechanism Nozzle and Other Vessel Closure Head Penetrations" The information requested by the NRC in a Request for Additional Information (RAI) dated August 20, 998, is provided below.
Most of the items requested were provided by the Nuclear Energy Institute (NEI) in the generic response to the RAI (NEI Letter dated December 11, 1998, from D.
J.
Modeen, NEI, to G.
C.
Lainas, USNRC, " Responses to NRC Requests for Additional Information on Generic Letter 97-01").
Wolf Creek Wuclear Operating Corporation (WCNOC) has referenced t. t generic response for the applicable items.
1.
" Indicate which Westinghouse Topical Report, WCAP-14901, Revision 0, or WCAP-14902, Revision 0,
is being endorsed for the assessment of VHP nozzles at WCGS, and which crack initiation and growth susceptibility model is being used for the assessment of the VHP nozzles at WCGS."
RESPONSE: WCNOC endorses WCAP-14901, Revision 0, for the assessment of VHP nozzles, and the Westinghouse crack initiation and growth susceptibility model for the assessment of the VHP nozzles, at WCGS.
2.
" Provide the following info'mation if Topical Report WCAP-14901 Revision 0,
is being endorsed for the VHP nozzles at WCGS; otherwise skip to Information Request 3.
a.
In WCAP-14901, Revision 0, 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 PWSCC in WEC-designed vessel head penetrations.
With respect to the probabilistic susceptibility model (e.g.,
probabilistic failure model) provided in WCAP-14901:
(1) 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 WCGS relative to the others."
RESPONSE
See NEI Response, Enclosure 2, Question 4.
"(2) Describe how the probabilistic failure model in WCAP-14901 for assessing postulated flaws in vessel head penetration nozzles was bench-marked, and provide a list and discussion of the standards the model was bench-marked against."
RESPONSE
See NEI Response, Enclosure 2, Question 2.b.
"(3) Provide additional information regarding how the probabilistic failure models in WCAP-14901 will be refined to allow the input of plant-specific inspection data into the model's analysis methodology."
RESPONSE
See NEI Response, Enclosure 2, Question 3.b.
"(4)-
Describe how _the variability in product forms, material specifications, and heat treatments used to fabricate each
Attachment I.to WM 98-0130 Page 2'of 2 CRDM penetration nozzle at the WOG member utilities are addressed in the probabilistic crack initiation and growth models described or ref a reed in Topical Report No. WCAP-
~14901."
+
See NEI Response, Enclosure 2, Question 1.b.
RESPONSE
"b.
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) 2 crack growth data and testing, 'and (3) crack initiation characterization studies have not been completed and are still
. in' progress.
In light of the fact that the probabilistic susceptibility models appear to be dependent in part on PWSCC i
crack. initiation and growth estimates, provide your best j
4 estimate when these tasks will be completed by WEC, and describe l
how-these activities relate to and will be used to update the probabilistic susceptibility assessment of VHP nozzles at WCGS."
. RESPONSE: See NEI Response,. Enclosure 2, Question 5.
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"c.
In the NEI letters of January 29, 1998 (Ref. 1), and April 1,
1998 (Ref. 2),
NEI indicated that inspection plans have been 5
developed for the VHP nozzles at the Farley Unit 2 plant in the s-year.2002,.and the Diablo Canyon Unit 2 plant in the year 2001,
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respectively.
The staff has noted that although ;ou have l
endorsed the probabilistic susceptibility model described in e
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 nozzles at WCGS.
If j
composite rankings of the VHP nozzles 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-14 901, Revision 0, would yield the same comparable relative rankings of the VHP nozzles for WCGS as would application of the alternate probabilistic susceptibility model used by the ' WOG member plants not subscribing to WCAP-14901, Revision 0. Comment on the susceptibility rankings of the VHP nozzles at WCGS relative t-the susceptibility rankings of the VHP nozzles at the Farle; Unit 2 and Diablo Canyon Unit 2 plants."
RESPONSE: See NEI Response, Enclosure 5 i
"3'.
' Provide. the ; following information. only if Topical Report WCAP-14902, e
Revision'0, is being endorsed for the VHP nozzles at your plant."
4 RESPONSE: This question is - not applicable to WCGS since WCNOC endorsed WCAP-14901.
See Item 2 above.
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e Attachment II to WM 99-0130 Page 1 of 1 LIST OF COMMITMENTS The following table identifies those actions committed to by Wolf Creek Nuclear Operating Corporation (WCNOC) in this document.
Any other statements in this submittal are provided for information purposes and are not considered to be commitments.
Please direct questions regarding these commitments to Mr.
Michael J.
Angus, Manager Licensing and Corrective Action at Wolf Creek Generating Station, (316) 364-4077.
COM4ITMENT Due Date/ Event None N/A 6 -- -
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