View source for CP-201200488, Response to Request for Additional Information for Relief Request No. A-I

{{Adams
| number = ML12172A263
| issue date = 06/06/2012
| title = Response to Request for Additional Information for Relief Request No. A-I
| author name = Flores R, Madden F
| author affiliation = Luminant Generation Co, LLC, Luminant Power
| addressee name = 
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000445
| license number = 
| contact person = 
| case reference number = CP-201200488, TAC ME6827, TXX-12082
| document type = Letter type:CP
| page count = 6
| project = TAC:ME6827
| stage = Response to RAI
}}

=Text=
{{#Wiki_filter:Rafael Flores                        Luminant Power
[                                                            Senior Vice President
                                                                  & Chief Nuclear Officer Rafael.Flores@ Luminant.com P 0 Box 1002 6322 North FM 56 Glen Rose, TX 76043 Luminant                                                                                               T 254 897 5550 C 817 559 0403 F 254 897 6652 CP-201200488                                                                                  Ref. # 10CFR50.55a Log # TXX-12082 June 6, 2012 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

==SUBJECT:==
COMANCHE PEAK NUCLEAR POWER PLANT DOCKET NO. 50-445 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION FOR RELIEF REQUEST NO. A-1 (TAC NO. ME6827)

==REFERENCES:==
: 1. Letter logged TXX-11038 dated August 2, 2011 from Rafael Flores to the NRC submitting Relief Request No. A-1 for the Unit 1 Third Interval Inservice Inspection for Application of an Alternative to the ASME Boiler and Pressure Vessel Code Section XI Examination Requirements for Class 1 and 2 Piping Welds (Third Interval Start Date: August 13, 2010).
: 2. Letter logged TXX-12023 dated March 8,2012 from Rafael Flores to the NRC submitting Response to Request for Additional Information for Relief Request No. A-1 (Tac. No. ME6827)

==Dear Sir or Madam:==

Per reference 1, Luminant Generation Company LLC (Luminant Power) previously submitted a request for relief for application of an alternative to the American Society of Mechanical Engineers (ASME)
Boiler and Pressure Vessel Code Section XI examination requirements for Class 1 and 2 piping welds.
Per reference 2, the NRC provided a request for additional information regarding the subject relief request.
Luminant Power provided a response to a request for additional information per reference 2. Attached is the Luminant Power response to the request for additional information as discussed in a telecon on May 14, 2012, between Luminant Power and the NRC.
This communication contains no new commitment regarding Comanche Peak Unit 1.
Should you have any questions, please contact Mr. Jack Hicks at (254) 897-6725.
A member of the STARS (Strategic Teaming and Resource Sharing) Alliance                        P&#xfd;'00 Callaway
* Comanche Peak
* Diablo Canyon     . Palo Verde
* San Onofre
* South Texas Project . Wolf Creek

U. S. Nuclear Regulatory Commission TXX-12082 Page 2 of 2 Sincerely, Luminant Generation Company LLC Rafael Flores By:~           20211L-
                                                                 "Fred W. Madden "
Director, Oversight & Regulatory Affairs :        Response to Request for Additional Information for Relief Request A-1 :       CPNPP Unit 1 - Inspection Location Selection Comparison Between Original Approved and Updated RI-ISI Programs by Risk Category c-         E. E. Collins, Region IV                         Luis Ponce B. K. Singal, NRR                                Environmental & Consumer Safety Section Resident Inspectors, Comanche Peak               Texas Department of State Health Services Jack Ballard, ANII, Comanche Peak                1100 West 49th Street Austin, Texas 78756-3189 to TXX-12082 Page 1 of 2 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION FOR RELIEF REQUEST NUMBER A-1 FOR THE UNIT 1 THIRD 10 YEAR IS1 INTERVAL (THIRD INTERVAL START DATE: AUGUST 13, 2010) (TAC NO. ME6827)
NRC Question 4 from Reference 2:
In the NRC rulemaking dated June 21, 2011, Title 10 of the Code of Federal Regulations (10 CFR),
Paragraph 50.55a(g)(6)(ii)(F) describes examination requirements for American Society of Mechanical Engineers (ASME) Code Class 1 piping and nozzle dissimilar metal (DM) butt welds. Pursuant to 10 CFR 50.55a(g)(6)(ii)(F)(1), licensees shall implement the requirements of ASME Code Case N-770-1, "Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated with UNS N06082 or UNS W86182 Weld Filler Material with or without Application of Listed Mitigation Activities," subject to the conditions specified in paragraphs (g)(6)(ii)(F)(2) through (g)(6)(ii)(F)(10) of 10 CFR 50.55a, by the first refueling outage after August 22, 2011. On July 12, 2011 the NRC staff held a public meeting to discuss the requirements of 10 CFR 50.55a(g)(6)(ii)(F) and the implementation of ASME Code Case N-770-1 (Reference ADAMS Accession No. ML112240818).
Please describe how the proposed CPNPP, Unit 1, RI-ISI program alternative for the third 10-year ISI interval will address the requirements of 10 CFR 50.55a(g)(6)(ii)(F) and the ASME Code Case N-770-1 implementation.
Luminant Power's Response to Question 4 ASME Code Case N-770-1 will be implemented in accordance with the requirements of 10 CFR 50.55a(g)(6)(ii)(F) as a separate program. The RI-ISI program alternative for the third 10-year ISI interval will have no impact on the implementation of requirements for Code Case N-770-1. The Code Case N-770-1 butt welds are included in the RI-ISI weld count, with some of the welds counted in the RI-ISI Program as elements selected to be examined during the third interval for certain risk categories and rankings.
NRC Additional Comments on Reponse to Question 4:
The nickel based DM welds should not be included in the RI-ISI program. They are required to be inspected in accordance w/ CC N-770-1, mandated by 10 CFR 50.55a(g)(6)(ii)(F).
The NRC staff expects the nickel based DM welds will be taken out of RI-ISI program and will be inspected in accordance w/ CC N-770-1, mandated by 10 CFR 50.55a(g)(6)(ii)(F).
to TXX-12082 Page 2 of 2 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION FOR RELIEF REQUEST NUMBER A-1 FOR THE UNIT 1 THIRD 10 YEAR IS1 INTERVAL (THIRD INTERVAL START DATE: AUGUST 13,2010) (TAC NO. ME6827)
Luminant Power's Revised Response:
In accordance with 10CFR50.55a(g)(6)(ii)(F), welds subject to PWSCC are selected for examination per Code Case N-770-1 and examined under that program. Welds for which no other degradation mechanism has been postulated will be examined solely under the Code Case N-770-1 Program and will be removed from consideration during the RI-ISI element selection process. Welds for which a degradation mechanism in addition to PWSCC has been identified during the RI-ISI process may be additionally selected and examined in accordance with the RI-ISI process such that the secondary degradation mechanism is also monitored. Discussion with the NRC representative on the ASME Section XI Working Group on Risk-Informed Activities May 14, 2012 indicated that this was the appropriate action.
Inspection of the Code Category B-F welds that are susceptible to PWSCC and no other postulated degradation mechanism will be removed from the inspections credited under the RI-ISI Program.
Removal of these inspections has no impact on the total CDF or LERF since they result in an impact of 4.OOE-12 and 4.00E-13, respectively, which does not show up in the reduction of 8.3E-09 in regards to CDF and 1.06E-09 in regards to LERF.
Presently, there are eight piping butt welds in the Alloy 600 Program that follow the examination requirements of Code Case N-770-1. Six other welds, associated with the Pressurizer nozzles, have been mitigated with SWOL, have all been re-examined, with no indications identified after each examination, and are identified in the RI-ISI Program.
The Inspection Location Selection Comparison Table has also been changed to reflect the Code Case N-770-1 welds and some other editorial changes to weld counts and is included as Attachment 2. These changes reduce the weld selection for the third interval from 133 to 125 to reflect the non-selection of the Code Case N-770-1 welds.

0 CPNPP Unit 1 - Inspection Location Selection Comparison Between Original Approved and Updated RI-ISI Programs by Risk Category               CD Risk                                       Failure Potential                    Original                  Interval 3 Update ysel)'Consequence                                                         Code     Wedel                                      _SI3(2 System&deg;)    Category         Rank__________________________
Rank             DMs          Rank  Category Weld Count        RI-ISI Other(2 " Weld Count      R-S()
Other Ohr2 0
                                                                                                                                                         -li RCS           2             High            High          TASCS, TT      Medium   B-J       7            2                7            3               x X
RCS           2             High            High            TASCS        Medium   B-J      13            4                13           4 RCS          2(2)           High            High              TT         Medium   B-F       1            0                 1           1             1
___________         ______             (PWSCC)                                  ____
I____        ________                       I____
RCS           2             High            High              TT         Medium   B-J      11            2                11           2               N)
RCS          4(2)        Medium             High             None         Low     B-F      12           10                12           0            12 (High)                           (PWSCC)
Low B-F       7            4       ___      I0          6 4          Medium             High             None RCS B-J     205           29              212          20 RCS           5          Medium           Medium            TASCS        Medium   B-J      20            2               20            2 RCS           5          Medium           Medium              TT         Medium   B-J      45            5               44            5 RCS           5          Medium           Medium              TT         Medium   B-F       0            0                 1           1 (PWSCC)
RCS           6             Low           Medium             None         Low     B-J      61            0               61            0 RCS           7             Low              Low             None         Low     B-J      15            0                15           0 Low           Medium             None         Low     B-J      47            0               47           0 CVCS           6 C-F-1    231            0                18           0 CVCS           6             Low              Low              TT         Medium   B-J       8            0                8            0 7             Low              Low             None         Low     B-J      30            0               30           0 CVCS C-F-1      0            0              235            0 Medium             High             None         Low     B-J      79            7               79           7 SIS           4 C-F-I     98           11              136          18 SIS           5          Medium           Medium            IGSCC        Medium   B-J      12            2               12            2 SIS           6             Low           Medium             None         Low     B-J      95            0               95           0 C-F-I    596            0              425            0 SIS           6             Low              Low            IGSCC        Medium   B-J      22            0               22            0 Low              Low             None         Low     B-J     119            0              119           0 SIS           7 C-F- 1   106            0              246            0 B-J      12            2               12           22 High             None         Low              1        -    2               12 RHRS           4          Medium C-F-1    246           24              120          12 RHRS           6             Low           Medium             None         Low    C-F-1      8            0              134            0 CSS           4          Medium             High             None         Low    C-F-1     10            1              176          18 CSS           6             Low           Medium             None         Low    C-F- 1   178            0              125            0 CSS           7             Low              Low            *None         Low    C-F-1    234            0              122            0

                                                                                                                                                                             =,
3CD CPNPP Unit 1 - Inspection Location Selection Comparison Between Original Approved and Updated RI-ISI Programs by Risk Category Risk              Consequence          Failure Potential        Code                      Original                          Interval 3 Update       5.
System")     Category          Rank           Rank             DMs          Rank       Category        Weld        RI-ISI       Other(2 )     Weld       RJJSV)     Other")
_Count                                 Count                           --I Medium FWS            4(1)          (Hiu)           High        None (FAC) Low (High)         C-F-2            0            0                         100          12              0 FWS            5(3)         Medium          Medium          TASCS,       Medium        C-F-2            8            1                           8          1 (High)                          (FAC)        (High)                                                                                            co 0,
ooa FWS            6(3)        Low (High)       Medium       None (FAC) Low (High)         C-F-2           435           0                         277          0 MSS             6             Low           Medium            None         Low         C-F-2           165           0                         170          0 AFW            4(1)         Medium           High        None (FAC) Low (High)         C-F-2           0(4)         0(4)                        81          9 (High)                     I             I             I                                                    I                       I 3136          106            0          3204         125        14 Notes                                                                                                                change from original:              19 1 Systems were described in Table 3.1-2 of the original submittal, with the exception of AFW - Auxiliary Feedwater. This ASME Code Class 2 system consists of 4 segments with 81 elements.
2 The column labeled "Other" is generally used to identify augmented inspection program locations that are credited beyond those locations selected per the RI-ISI process, as addressed in Section 3.6.5 of EPRI TR-1 12657. At CPNPP this column represents those inspections performed in accordance with Code Case N-770-I. as mandated by 10CFR50.55a.
3 In accordance with IOCFR50.55a(g)(6)(ii)(F), welds subject to PWSCC are selected for examination per Code Case N-770-1 and examined under that program.
Welds for which no other degradation mechanism has been postulated will be examined solely under the Code Case N-770-1 Program and will be removed from consideration during the RI-ISI element selection process. Welds for which a degradation mechanism in addition to PWSCC has been identified during the RI-ISI process may be additionally selected and examined in accordance with the RI-ISI process such that the secondary degradation mechanism is also monitored.
4 Due to a change in ASME Section XI Code criteria, 4" NPS Class 2 auxiliary feedwater piping was added to the ISI Program, and therefore the RI-ISI Program, for the first time during the second RI- ISI period. As such, there were no welds associated with this piping during the original RI-ISI application.}}