View source for NPL-99-0031, Informs That Wepc Reviewed Contents of NEI to NRC & Have Verified Info Provided in Ltr Pertaining to WOG Member Plants Is Applicable to Pbnp.Attachment Responds to NRC Questions by Ref to Info in 981211 NEI Ltr

{{Adams
| number = ML20199G018
| issue date = 01/15/1999
| title = Informs That Wepc Reviewed Contents of NEI to NRC & Have Verified Info Provided in Ltr Pertaining to WOG Member Plants Is Applicable to Pbnp.Attachment Responds to NRC Questions by Ref to Info in 981211 NEI Ltr
| author name = Kaminskas V
| author affiliation = WISCONSIN ELECTRIC POWER CO.
| addressee name = 
| addressee affiliation = NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
| docket = 05000266, 05000301
| license number = 
| contact person = 
| document report number = GL-97-01, GL-97-1, NPL-99-0031, NPL-99-31, TAC-M98586, TAC-M98587, NUDOCS 9901220155
| title reference date = 12-11-1998
| document type = CORRESPONDENCE-LETTERS, INCOMING CORRESPONDENCE
| page count = 5
| project = TAC:M98586, TAC:M98587
| stage = Other
}}

=Text=
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7.
Wisconsin
                       ' Electnc POWER COMPANY Point Beach Nuclear Piont                                                                     (920) 755-2321 6610 Nuclear Rd., Two Rivers. WI 54241 NPL 99-0031                                                                            10 CFR 50.54(f)
January 15,1999 Document Control Desk U.S. NUCLEAR REGULATORY COMMISSION Mail Station PI-137 Washington, D.C. 20555 Ladies and Gentlemen:
DOCKETS 50-266 AND 5-301 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION GENERIC LETTER 97-01," DEGRADATION OF CONTROL ROD DRIVE MECHANISM AND OTHER VESSEL IIEAD PENETRATIONS."
POINT BEACil NUCLEAR PLANT, UNITS 1 AND 2 (TAC NOS. M98586 and M98587)                                                                                       :
On April 1,1997, Nuclear Regulatory Commission (NRC) staffissued Generic Letter (GL) 97-01,                        l
        " Degradation Of Control Rod Drive Mechanism And Other Vessel Head Penetrations." Wisconsin                        i Electric Power Company (WE), licensee for the Point Beach Nuclear Plant, Units 1 and 2, provided the required response to information requested by the GL in Letters dated April 30,1997, and July 30.1997.
By {{letter dated|date=September 2, 1998|text=letter dated September 2,1998}}, NRC staff requested further information to complete its review of our responses as they relate to the Westinghouse Owner's Group (WOG) integrated program for assessing reactor vessel head penetration (VHP) nozzles at WOG member plants, and to the contents of Topical Report WCAP 14901 referenced in our response. By {{letter dated|date=October 27, 1998|text=letter dated October 27,1998}}, we committed to provide our response to the NRC staff request by January 15.1999.
The NEl, in a {{letter dated|date=December 11, 1998|text=letter dated December 11,1998}}, to Mr. Gus C. Lainas, Acting Director, Division of             i Engineering, transmitted a comprehensive generic response to the NRC's requests developed by the Alloy 600 Issue Task Group with input from the PWR Owners' Groups and EPRI. We have reviewed                  ('
the contents of this letter and have verified that information provided in the letter pertaining to WOG member plants is applicable to our Point Beach Nuclear Plant.
gj The attachment to this letter provides the appropriate response to each of the staff's questions by reference to the applicable information in the December 11,1998, NEl letter.
9901220155 990115 PDR        ADOCK 05000266 p                            PDR
                                                 .4 subsWhy of Mkvnskt Eney Corporathn

1 NPL 99-0031                                                                                            :
January 15,1999 Page 2 -
We believe the information provided is responsive to the staff s request. Please contact me if you require any additional information.
Sincerely, 1
J    . &,4%           2 Vito A. Kaminskas Manager Regulatory Services and Licensing tat Attachment cc: NRC Regional Administrator NRC Resident Inspector .
Subscribed to and sworn before me this 4 day of .u-,,-                       , 1999 i
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:Notar9Public,      State of Wisconsin hly cornmission expires W
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NPL 99-0031 January 15,1999 Attachment Page 1 of 3 1
1 DOCKETS 50-266 AND 3-301                                                                                     I RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION l             GENERIC LETTER 97-01," DEGRADATION OF CONTROL ROD DRIVE MECliANISM                                           I AND OTHER VESSEL IIEAD PENETRATIONS,"(TAC NOS. M98586 and M98587)                                             l POINT BEACH NUCLEAR PLANT UNITS 1 AND 2 The following is provided in response to the NRC staff's request for additional information concerning our response to Generic Letter 97-01. Wisconsin Electric is a Westinghouse Owner's Group (WOG) member plant. The references provided in response to the indindual requests are to the appropriate section(s) and enclosure (s) to the {{letter dated|date=December 11, 1998|text=December 11,1998 letter}} fron, Mr. David Modeen, NEl to Mr. Gus. C.
Lainas, Acting Director, Division of Engineering as summarized in Enclosure 5 to that letter.
: 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 PWSCC in WEC-designed vessel head penetrations. With respect to the probabilistic susceptibility mode (e.g., probabilistic failure model) provided in WCAP-14901:
I l                     a. Provide the susceptibility rankings compiled for the WOG member plants for which l                            WCAP-14901 is applicable. In regard to other WOG member plants to which l
WCAP-14901 is applicable, include the basis for establishing the ranking of your plant (s) relative to the others.

===Response===
l Susceptibility rankings for WOG member plants, including the Point Beach Nuclear Plant, for which WCAP-14901 is applicable, as well as the bases for establishing the relative risk ranking for PBNP, is provided in Enclosure 2, response to Question 4, and illustrated in the histogram included as Enclosure 1.                                                                              l l
: a. Describe how the probabilistic failure model in WCAP-14901 for evaluating i
postulated flaws in vessel head penetration nozzles was hench-marked, and
!                            provided a list and discussion of the standards the model was bench-marked l                            against.

===Response===
 !                                                                                                                          l The probabilistic failure model in WCAP-14901 was benchmarked as described in Enclosure 2, response 2.b to Question 2.
s a

NPL 99-0031 January 15,1999
         . Attachment Page 2 of 3                                                                                            '
: c.       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.
l

===Response===
The probabilistic failure models in WCAP-14901 will be refined to allow input of plant-specific inspection data into the model's analysis methodology as described in Enclosure 2, response 3.b to Question 3.
: d.       Describe how the variability on 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 No. WCAP-1490 %

===Response===
Variability in product forms, material specification and heat treatments was addressed as described in Enclosure 2, response 1.b to Question 1.
: 2. Table 1-2 in WCAP-14901 provides a summary of the key tasks in WEC's vessel head penetration 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 still in           i 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 VIIP nozzles at your plant (s).

===Response===
As described in Enclosure 2, response to Question 5, programs on crack growth testing and initiation are essentially complete and programs for mitigation underway. The models will be reviewed and updated as necessary as additional information becomes available.
: 3. In NEI letters of January 29,1998, and April 1,1998, NEl indicated that inspection plans         j 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 :: Jei described in WCAP-14901, Revision 0, other WOG member licensees hau .ndorsed 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

NPL 99-0031 January 15,1999
            . . Attachment Page 3 of 3 l
l l                      be based on a composite assessment of the VIIP nonles at all WOG plants. Verify that such a composite ranking assessment has been applied to the evaluation of VilP nonles at your plants. If composite rankings of the VIIP noales at WOG member plants have been obtained from the composite results of the two models, justify why application of the                     l probabilistic susceptibility model described in WCAP-14901, Revision 0, w ould yield the same comparable relative rankings of the VIIP nonles for your plant (s) 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 ranking of the VilP nonles at your plant (s) relative to the susceptibility rankings of the VIIP nonics at the Farley Unit 2 and Diablo Canyon Unit 2 plants.

===Response===
1 As previously discussed, the relative susceptibility rankings are provided in the histogram               I contained in Enclosure 1. This ranking is only one factor in evaluating inspection decisions as described in Enclosure 5, Secticn 11, response to Question 1.
i l
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