View source for DCL-01-138, Special Report 00-01, Revision 1-90 Day Report, Results of Steam Generator Alternate Repair Criteria for Diablo Canyon Power Plant Unit 2 Ninth Refueling Outage

{{Adams
| number = ML020240233
| issue date = 01/03/2002
| title = Special Report 00-01, Revision 1-90 Day Report, Results of Steam Generator Alternate Repair Criteria for Diablo Canyon Power Plant Unit 2 Ninth Refueling Outage
| author name = Womack L
| author affiliation = Pacific Gas &amp; Electric Co
| addressee name = 
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000323
| license number = DPR-082
| contact person = 
| case reference number = DCL-01-138
| document type = Letter type:DCL, Report, Miscellaneous
| page count = 9
}}

=Text=
{{#Wiki_filter:SPacificGas and Electric Company Lawrence F. Womack Diablo Canyon Power Plant Vice President      PO.Box 56 Nuclear Services    Avila Beach, CA 93424 805. 545.4600 January 3, 2002                                                                   Fax: 805.545.4234 PG&E Letter DCL-01 -138 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-323, OL-DPR-82 Diablo Canyon Unit 2 Special Report 00-01, Revision 1 - 90 Day Report, Results of Steam Generator Alternate Repair Criteria for Diablo Canyon Power Plant Unit 2 Ninth Refueling Outage

==Dear Commissioners and Staff:==

Special Report (SR) 00-01, Revision 1, is enclosed to transmit a revised 90 day report for WStar (W*) alternate repair criteria implemented during the Unit 2 ninth refueling (2R9)- SR 00-01 Revision 0 was submitted via DCL-00-008, dated February 20, 2000.
Revision bars in the right hand margin identify revision 1 changes.
Revision 1 corrects a flaw location in steam generator (SG) 22, row 28, column 15.
The flaw is located -11.48 to -11.35 inches relative to the top of tubesheet, and the upper tip of the flaw is located -11.13 inches relative to the top of tubesheet, including NDE uncertainty. The minus signs were inadvertently truncated in revision 0. Revision 1 also clarifies that the W* performance criteria to limit free span cracking is not applicable to 2R9 because 2R9 was the first implementation of the W* ARC.
Sincerely, Lawrence F. Womack cc:      Ellis W. Merschoff David L. Proulx Girija S. Shukla State of California Diablo Distribution Enclosures DDMW469

Enclosure 1 PG&E Letter DCL-01-138 SPECIAL REPORT 00-01 90 DAY REPORT W* ALTERNATE REPAIR CRITERIA DIABLO CANYON POWER PLANT UNIT 2 NINTH REFUELING OUTAGE NRC Reportingq Requirements Diablo Canyon Power Plant (DCPP) Technical Specification (TS) 4.4.5.5.e requires that the results of the inspection of W* tubes be reported to the Commission pursuant to TS 6.9.2 (i.e., as a Special Report) within 90 days following return to service of the steam generators (SGs). The report shall include:
: 1. Identification of W* tubes.
: 2. W* inspection distance measured with respect to the bottom of the W* transition (BWT) or the top of tubesheet, whichever is lower.
: 3. Elevation and length of axial indications within the flexible W* distance and the angle of inclination of clearly skewed axial cracks (if applicable).
: 4. The total steam line break leakage for the limiting steam generator per WCAP-14797.
DCPP TS 4.4.5.5.f requires that the aggregate calculated steam line break leakage from application of all alternate repair criteria (ARC) be reported to the Commission pursuant to TS 6.9.2 (i.e., Special Report) within 90 days following return to service of the SGs.
W* Inspections and Results This report implements the DCPP TS reporting criteria. W* ARC was implemented for the first time in DCPP Unit 2 during the ninth refueling outage (2R9). Following inspections and maintenance, the SGs were returned to service on October 23, 1999, upon entry into Mode 4.
100 percent of the SG tubes were inspected by bobbin from tube end to tube end.
100 percent of the hot leg top of tube sheet (TTS) region was inspected by Plus Point.
Cold leg TTS inspections by Plus Point were not required.
Table 1 provides a comprehensive list of axial primary water stress corrosion cracking (PWSCC) indications detected in the WEXTEX region during 2R9 Plus Point inspections. The following TS-required reporting information is extracted from the table:
: 1. Identification of W* tubes. See "W* Tube" column in Table 1. Fifty-seven tubes are categorized as W* tubes: 10 in SG 21, 6 in SG 22, 20 in SG 23, and 21 in SG 24.
1

Enclosure 1 PG&E Letter DCL-01-138 An additional 5 tubes with axial PWSCC were plugged because they did not meet W* ARC (upper crack tip was located above BWT, including uncertainty). One circumferential PWSCC indication (not listed) was also detected and plugged because circumferential indications in the W* region are excluded from W* ARC.
: 2. W* inspection distance measured with respect to BWT or TTS, whichever is lower.
For the 100 percent Plus Point hot leg TTS exam, the inspection extent relative to the TTS was specified as +2/-8 in. Assuming no degradation in the W* length, 8 in.
below the TTS constitutes the W* inspection distance. This distance bounds W*
lengths for Zone A and Zone B (5.2 in. and 7.0 in., respectively, relative to BWT),
and includes margin for a nominal distance from BWT to TTS plus non-destructive examination (NDE) uncertainty in measuring W* length. If degradation is detected in the W* region, the inspection extent must bound the calculated flexible W* length.
The "W*Insp Dist" column in Table 1 lists the W* inspection distances measured with respect to BWT for tubes in which axial PWSCC was detected (in all cases, BWT was lower than the TTS).
: 3. Elevation and length of axial indications within the flexible W* distance. See "From,"
   "To," and "L" columns in Table 1 for elevation and length of axial indications.
: 4. Angle of inclination of clearly skewed axial cracks (if applicable). None of the axial indications were skewed, so the angle of inclination was reported as 0 degrees for all axial indications.
: 5. The total steam line break leakage for the limiting steam generatorper WCAP-14797. Steam Line Break (SLB) leakage attributed to each W* indication at end of cycle (EOC) 9 (condition monitoring) and EOC 10 (operational assessment) are listed in "CM LR" and "OA LR" columns in Table 1. The limiting W* SLB leak rates for condition monitoring and operational assessment are 0.1468 gpm and 0.6330 gpm, respectively (see Table 2).
Table 2 reports the following SLB leak rates, pursuant to TS 4.4.5.5.e.4 and 4.4.5.5.f:
: 1. Total W* ARC SLB leakage for each SG at EOC 9.
: 2. Total W* ARC SLB leakage for each SG at EOC 10.
: 3. Total Generic Letter (GL) 95-05 voltage based ARC SLB leakage for each SG at EOC 9 and EOC 10.
: 4. The aggregate calculated SLB leakage from application of both ARC at EOC 9.
: 5. The aggregate calculated SLB leakage from application of both ARC at EOC 10.
Table 3 provides the updated cumulative probability distribution for growth of W* region axial PWSCC indications. The updated 95 percent cumulative probability DCPP Units 2

Enclosure 1 PG&E Letter DCL-01-138 1 and 2 growth rate is 0.18 in./effective full power year (EFPY), and the distribution includes 28 data points (19 of which are Plus Point to Plus Point). The updated 95 percent cumulative probability combined industry data growth rate is 0.24 in./EFPY (which is lower than the prior 0.25 in./EFPY growth rate documented in WCAP-14797, Rev 1), and the distribution includes the 28 DCPP data points plus 31 data points from plants W1 and W2 documented in WCAP -14797, Rev 1. The W* operational assessment documented herein applies the 0.24 in./EFPY growth rate.
In-situ Leak Testing In an effort to validate the leak rate model in WCAP-14797, Rev 1, three W* indications were in-situ leak tested in 2R9: SG 21 R3C59, SG 21 R7C62, and SG 22 R31C25. All three indications were in deplugged tubes. The in-situ guidelines for selecting indications for leak testing were established in PG&E letter DCL-98-148, "Response To NRC Request For Additional Information, Dated August 6, 1998, Regarding Proposed W* Steam Generator Tube Repair Criteria," dated October 22, 1998. The peak voltage for R3C59 and R31 C25 exceeded the 4.0 volt critical voltage and the peak voltage for R31 C35 was 3.99 volts (approximately 4 volts), requiring that all three indications be leak tested. The indications were locally tested to normal operating pressure differential. Because they did not leak, the test was terminated at that pressure. Plus Point inspections were performed again and verified that the indications satisfy the W*
repair criteria. The indications were returned to service.
Tube Integrity Performance Monitoring Performance Criteria to Limit Free Span Cracking: The upper crack tip of W*
indications returned to service under W* ARC shall remain below the TTS by at least the NDE uncertainty on locating the crack tip relative to the TTS. Since 2R9 was the first time implementation of W* ARC on DCPP Unit 2, this performance criteria is not applicable to 2R9 condition monitoring. This performance criteria is applicable to subsequent inspections following 2R9.
Accident-Induced Leakage Performance Criteria: Calculated W* leak rates under postulated SLB conditions, when combined with calculated leak rates from application of GL 95-05 voltage-based ARC, shall not exceed 12.8 gpm (at room temperature) in the faulted SG for condition monitoring and operational assessment. Based on Table 2, the aggregate calculated SLB leakage from application of both ARC at EOC 9 is 0.4683 gpm for limiting SG 24, and 1.7247 gpm at EOC 10 for limiting SG 24. In both assessments, SLB leakage is less than the allowable limit of 12.8 gpm for a faulted SG.
Therefore, the performance criteria has been satisfied for condition monitoring at EOC 9 and operational assessment at EOC 10.
3

Enclosure 1 PG&E Letter DCL-01-138 Table 1 DCPP Unit 2 - 2R9 Axial PWSCC Indications in Hot Leg WEXTEX Region SG R    C   IND  +Pt    From     To    L   UCT W* W* L BWT       UCT UCT      UCT  EOC    UCT   W*   Insp   W*   Flex  CMLR EOCl00ALR        Deplug Plug volt                         to Zone              to  Below Below   10  Below Tube   Ext   Insp W* L          UCT TSH                   BWT    W*    BWT  UCT TSH at               Dist               BWT
[7         IEOC1O 21 7   24   SAI  0.23   -1.92  -1.78 0.14  -1.56  B3  7.121-0.26 1.24   No    Yes  -1.20  Yes  Yes -21.4   21.05 7.48          -0.95  0.019    Yes 21 8   32   SAI  0.48   -1.88  -1.79 0.09  -1.57  B2  7.12 -0.24 1.27   No    Yes  -1.21  Yes  Yes    -9.2  8.87 7.43  0.015   -0.98  0.019 21 11  37   SAI   0.5   -7.49   -7.4 0.09  -7.18  B2  7.12 -0.32  6.8   No     Yes -6.82  Yes  Yes -9.31     8.9 7.63  0.0005  -6.51  0.0005 21          SAI  0.68   -6.61  -6.48 0.13  -6.26  B2  7.12 -0.32 5.88   No     Yes -5.90  Yes  Yes -9.31     8.9 7.63  0.0005  -5.59  0.0008 21          SAI  0.28   -2.02  -1.95 0.07  -1.73  B2  7.12 -0.32  1.35  No     Yes -1.37  Yes  Yes -9.31     8.9 7.63  0.015   -1.06  0.019 21 11  39   SAI  1.27    -1.7  -1.56 0.14  -1.34  81  7.12 -0.33 0.95   No     Yes -0.98  Yes  Yes -21.08  20.66 7.48          -0.66  0.023    Yes 21 11  40   SAI  0.45   -0.98  -0.81 0.17  -0.59  B1  7.12 -0.34 0.19   No     Yes -0.23  Yes  Yes -9.46    9.03 7.51  0.038    0.10  0.045 21 11  48   SAI  1.21   -4.86  -4.47 0.39  -4.25  B1  7.12 -0.31 3.88   No     Yes -3.89  Yes  Yes -9.36    8.96 7.73  0.005   -3.59  0.0055 21 3   59   SAI  5.58   -1.39   -0.9 0.49  -0.68  B1  7.12 -0.39 0.23   No     Yes -0.32  Yes  Yes -21.4   20.92 7.83           0.06  0.045    Yes 21 7   62   SAI  4.17   -2.13  -1.66 0.47  -1.44  B2  7.12 -1.07 0.31   No     Yes -1.08  Yes  Yes -21.4   20.24 7.81          -0.02  0.045    Yes 21 28  62   SAI  0.31   -0.55  -0.46 0.09  -0.24   A  5.32 -0.27 -0.09  No     No   0.12   No   No   -9.96   9.6 5.63   0.043                       Yes 21 .23 70   SAI   0.9   -1.57  -1.24 0.33  -1.02   A  5.32 -0.12 0.84   No     Yes -0.66  Yes   Yes -21.4  21.19 5.87          -0.55  0.025    Yes 21 6   77   SAI  1.31   -1.33   -1.2 0.13  -0.98  B4  7.12 -0.5  0.42   No     Yes -0.62  Yes   Yes -21.4  20.81 7.47          -0.13  0.041    Yes 22 28  15   SAI  0.76  -11.48 -11.35 0.13 -11.13   A  5.32 -0.49 10.58  Yes    Yes 10.77  Yes   Yes -21.4  20.82  N/A         -10.29           Yes 22          SAI  0.68   -2.53   -2.4 0.13  -2.18   A  5.32 -0.49  1.63  No     Yes -1.82  Yes   Yes -21.4  20.82 5.98          -1.34   0.007   Yes 22          SAI  0.66   -2.04  -1.86 0.18  -1.64   A  5.32 -0.49  1.09  No     Yes -1.28  Yes   Yes -21.4  20.82 5.98          -0.80   0.013   Yes 22 5   18   SAI  0.46   -1.14  -0.97 0.17  -0.75  B4  7.12 -0.3   0.39  No     Yes -0.39  Yes   Yes -11.04 10.65 7.51   0.03   -0.10   0.043 22 31  25   SAI  3.99   -2.06  -1.59 0.47  -1.37   A  5.32 -0.61  0.70  No     Yes -1.01  Yes   Yes -21.4   20.7 6.01          -0.41    0.03   Yes 22 13  43   SAI  1.03   -1.57  -1.36 0.21  -1.14  B1  7.12 -0.45  0.63  No     Yes -0.78  Yes   Yes -21.4  20.86 7.55          -0.34   0.031   Yes 22 10  48   SAI  0.51   -3.17  -3.05 0.12  -2.83  81  7.12 -0.31  2.46  No     Yes -2.47  Yes   Yes -9.04   8.64 7.46  0.0083 -2.17   0.0095 22 10  56   SAI  0.96   -1.05  -0.90 0.15  -0.68  B1  7.12 -0.35  0.27  No     Yes -0.32  Yes   Yes -21.4  20.96 7.49           0.02   0.045   Yes 23 28   12  SAI  0.72   -1.86   -1.7 0.16  -1.48   A  5.32 -0.59  0.83  No     Yes -1.12  Yes   Yes -8.88    8.2 5.70   0.012  -0.54   0.028 23 9   22   SAI  0.26   -0.15  -0.01 0.14   0.21  B4  7.12 -0.45 -0.72  No     No   0.57   No   No   -8.19  7.65 7.48   0.043                        Yes 23 14  24   SAI  0.59   -1.87  -1.64 0.23  -1.42  B4  7.12 -0.14  1.22  No     Yes -1.06  Yes   Yes -21.4  21.17 7.57          -0.93   0.015   Yes 23 16  24   SAI  0.35   -1.39  -1.28 0.11  -1.06  B4  7.12 -0.24  0.76  No     Yes -0.70  Yes   Yes -21.4  21.07 7.45          -0.47   0.028   Yes 23 25  37   SAI  2.41   -1.44  -0.96 0.48  -0.74  B4  7.12 -0.59  0.09  No     Yes -0.38  Yes   Yes -21.4  20.72 7.82           0.20   0.043   Yes 23 45  37   SAI  1.65   -1.76  -1.27 0.49  -1.05   A  5.32 -0.36  0.63  No     Yes -0.69  Yes   Yes -21.4  20.95 6.03          -0.34   0.028   Yes 23 21  38   SAI  1.17   -1.68  -1.09 0.59  -0.87  B3  7.12 -0.43  0.38  No     Yes -0.51  Yes   Yes -21.4  20.88 7.93          -0.09    0.04   Yes 23 12 48   SAI  0.35   -2.09  -1.97 0.12  -1.75  B1  7.12 -0.35  1.34  No     Yes -1.39  Yes   Yes -21.4  20.96 7.46          -1.05   0.018   Yes 23 5   51  SAI   0.3   -2.04  -1.94  0.1  -1.72  B1  7.12 -0.32  1.34  No     Yes -1.36  Yes   Yes -21.4  20.99 7.44          -1.05   0.018   Yes 23 7   52  SAI  3.44   -1.61  -1.11  0.5  -0.89   81 7.12 -0.15  0.68  No     Yes -0.53  Yes   Yes -21.4  21.16 7.84          -0.39    0.03   Yes 23 5   55  SAI  0.51   -1.82  -1.72  0.1    -1.5 B1  7.12 -0.22  1.22  No     Yes -1.14  Yes   Yes -9.66   9.35 7.44   0.015   -0.93  0.015 23 32  55   SAI 0.94   -1.22  -1.02  0.2    -0.8  A  5.32 -0.46  0.28  No     Yes -0.44  Yes   Yes -21.4  20.85  5.74          0.01   0.043   Yes 23 7   59   SAI 0.98   -1.49  -1.17 0.32  -0.95  B1  7.12 -0.24  0.65  No     Yes -0.59  Yes   Yes -21.4  21.07  7.66          -0.36  0.031   Yes 23 3   69   SAI 0.31   -1.16  -0.98 0.18  -0.76  B2  7.12 -0.29  0.41  No     Yes -0.40  Yes   Yes -9.71   9.33  7.52   0.03   -0.12   0.04 23 19  71   SAI 1.22   -1.99  -1.59  0.4  -1.37   A  5.32 -0.32  0.99  No     Yes -1.01  Yes   Yes -21.4  20.99  5.94          -0.70   0.02   Yes 23 17  72   SAI 1.75   -1.01  -0.60 0.41  -0.38   A  5.32 -0.25  0.07  No     Yes -0.02  Yes   Yes -21.4  21.06  5.95          0.22   0.043   Yes 23 6   77   SAI 0.39    -1.6  -1.50  0.1  -1.28  B4  7.12 -0.34  0.88  No     Yes -0.92  Yes   Yes -21.4  20.97  7.44          -0.59  0.021   Yes 4

Enclosure 1 PG&E Letter DCL-01-138 SG R    C  IND  +Pt  From    To    L  UCT W* W*L BWT UCT UCT              UCT  EOC    UCT   W*    Insp   W*  Flex CMLR EOC11 OALR Deplug     Plug volt                     to  Zone                to Below Below   10  Below Tube    Ext  Insp W* L        UCT TSH                    BWT    W*   BWT   UCT TSH at               Dist             BWT EOC10 23  21  83 SAI 1.39  -1.23 -0.90 0.33 -0.68  A   5.32  -0.31  0.31  No    Yes  -0.32  Yes  Yes -21.4     21  5.87        -0.02 0.043    Yes 23   2  91 SAI 0.61  -0.94 -0.59 0.35 -0.37  A   5.32  -0.12  0.19  No    Yes  -0.01  Yes  Yes -21.4   21.19 5.89        0.10  0.043    Yes 23   7  92 SAI 0.68  -1.22 -1.00 0.22 -0.78  A   5.32  -0.38  0.34  No    Yes  -0.42  Yes  Yes -21.4   20.93 5.76        -0.05 0.043    Yes 23   8  93 SAI 1.54  -0.95 -0.59 0.36 -0.37  A   5.32  -0.12  0.19  No    Yes  -0.01  Yes  Yes -21.4   21.19 5.90        0.10  0.043    Yes 24   7   4 SAI 1.02  -1.36 -1.15 0.21 -0.93  A   5.32  -0.26  0.61  No    Yes  -0.57  Yes  Yes -21.4   21.05 5.75        -0.32 0.031    Yes 24  13   4 SAI 0.44   -1.4 -1.27 0.13 -1.05  A   5.32  -0.41  0.58  No    Yes  -0.69  Yes  Yes -9.21    8.71 5.67 0.023  -0.29 0.031 24   3   5 SAI  1.1    -2  -0.97 1.03 -0.75  A   5.32  -0.34  0.35  No    Yes  -0.39  Yes  Yes -21.4   20.97 6.57        -0.06 0.043    Yes 24   2  10 SAI 0.61  -1.61  -1.5 0.11 -1.28  A   5.32   -0.1  1.12  No    Yes  -0.92  Yes  Yes -21.4   21.21 5.65        -0.83 0.013    Yes 24  15  10 SAI 0.47  -1.07  -0.8 0.27 -0.58  A   5.32  -0.36  0.16  No    Yes  -0.22  Yes  Yes -21.4   20.95 5.81         0.13 0.043    Yes 24  16  10 SAI 1.17  -2.57 -2.15 0.42 -1.93  A   5.32  -0.48  1.39  No    Yes  -1.57  Yes  Yes -21.4   20.83 5.96        -1.10 0.009    Yes 24   3  12 SAI 0.57  -2.98 -2.85 0.13 -2.63  A   5.32   -0.3  2.27  No    Yes  -2.27  Yes  Yes -21.4   21.01 5.86        -1.98 0.004    Yes 24         SAI  1.2  -2.61 -2.42 0.19  -2.2  A   5.32   -0.3  1.84  No    Yes  -1.84  Yes  Yes -21.4   21.01 5.86        -1.55 0.006    Yes 24  26 24  SAI 3.94  -2.42 -1.77 0.65 -1.55  A   5.32  -0.39   1.1  No    Yes  -1.19   No   No   -21.4 20.92  6.3                       Yes  Yes 24         SAI 0.57  -0.49 -0.38 0.11 -0.16  A   5.32  -0.39 -0.29  No     No  0.20    No   No   -21.4 20.92  6.3                       Yes  Yes 24  24 26  SAI 0.55  -1.93 -1.77 0.16 -1.55  A   5.32  -0.43  1.06  No    Yes  -1.19  Yes  Yes -9.69    9.17  5.7 0.0083 -0.77 0.022 24   2 29  SAI  1.7  -4.77 -3.85 0.92 -3.63  B2  7.12  -0.58  2.99  No    Yes  -3.27  Yes  Yes -21.4   20.73 8.94        -2.70 0.007    Yes 24         SAI 0.39  -3.56 -3.38 0.18 -3.16  B2  7.12  -0.58  2.52  No    Yes  -2.80  Yes  Yes -21.4   20.73 8.94        -2.23 0.0082   Yes 24         SAI 0.49  -2.46 -2.14 0.32 -1.92  B2  7.12  -0.58  1.28  No    Yes  -1.56  Yes  Yes -21.4   20.73 8.94        -0.99 0.019    Yes 24         SAI 0.23  -2.08 -2.03 0.05 -1.81  B2  7.12  -0.58  1.17  No    Yes  -1.45  Yes  Yes -21.4   20.73 8.94        -0.88  0.02    Yes 24         SAI 0.32    -2  -1.87 0.13 -1.65  B2  7.12  -0.58  1.01  No    Yes  -1.29  Yes  Yes -21.4   20.73 8.94        -0.72 0.022    Yes 24   6  33 SAI  0.4  -2.87 -2.75 0.12 -2.53  B2  7.12  -0.14  2.33  No    Yes  -2.17  Yes  Yes -10.82  10.59 7.46  0.008 -2.04 0.009 24  13  34 SAI  0.4  -0.14 -0.01 0.13  0.21  B2  7.12  -0.34 -0.61  No     No   0.57   No   No -9.42    8.99 7.47  0.043                     Yes 24   4  35 SAI 1.15  -1.79 -1.34 0.45 -1.12  B1  7.12  -0.24  0.82  No    Yes  -0.76  Yes  Yes -21.4   21.07 7.79        -0.53 0.025    Yes 24   6  35 SAI 0.91   -2.3 -2.14 0.16 -1.92  B1  7.12  -0.31  1.55  No    Yes  -1.56  Yes   Yes -21.4    21   7.5        -1.26 0.015    Yes 24   5  36 SAI 0.22  -1.53 -1.44 0.09 -1.22  B1  7.12  -0.17  0.99  No    Yes  -0.86  Yes   Yes -8.45   8.19 7.43  0.019 -0.70 0.022 24  5  37 SAI 0.36  -4.58 -4.43 0.15 -4.21  B1  7.12  -0.43  3.72  No    Yes  -3.85  Yes   Yes -21.4  20.88 8.02        -3.43 0.006    Yes 24        SAI 1.06   -4.4 -3.87 0.53 -3.65  B1  7.12  -0.43  3.16  No    Yes  -3.29  Yes   Yes -21.4  20.88 8.02        -2.87 0.0075   Yes 24  7  38 SAI 3.04  -7.16 -6.65 0.51 -6.43  Bi  7.12  -0.35  6.02  No    Yes  -6.07  Yes   Yes -21.4  20.96 8.58        -5.73 0.0009   Yes 24        SAI 2.16  -4.73   -4  0.73 -3.78  81  7.12  -0.35  3.37  No    Yes  -3.42  Yes   Yes -21.4  20.96 8.58        -3.08 0.007    Yes 24  13 40 SAI 1.35  -1.91 -1.48 0.43 -1.26  B2  7.12  -0.28  0.92  No    Yes  -0.90  Yes   Yes -21.4  21.03 7.77        -0.63 0.023    Yes 24 29  42 SAI 0.52  -0.23 -0.11 0.12  0.11  B4  7.12  -0.38 -0.55  No     No   0.47   No   No -10.56  10.09 7.46  0.043                     Yes 24 26  45 SAI 0.52  -3.76 -3.61 0.15 -3.39  B4  7.12  -0.36  2.97  No    Yes  -3.03  Yes   Yes -10.52 10.07 7.49 0.0025 -2.68 0.0033 24 31  45 SAI 1.59  -2.09 -1.57 0.52 -1.35  A   5.32  -0.34  0.95  No    Yes  -0.99  Yes   Yes -21.4  20.97 6.06        -0.66  0.021   Yes 24 20  47 SAI 0.55   -1.7 -1.54 0.16 -1.32  B2  7.12  -0.24  1.02  No    Yes  -0.96  Yes   Yes -21.4  21.07  7.5        -0.73  0.021   Yes 24   5 53 SAI 1.22  -2.03 -1.62 0.41  -1.4  81  7.12  -0.32  1.02  No    Yes  -1.04  Yes   Yes -20.86 20.45 7.75        -0.73  0.021   Yes 24 25  64 SAI  1.54 -1.62 -1.16 0.46 -0.94  B4  7.12  -0.31  0.57  No    Yes  -0.58  Yes   Yes -21.4    21   7.8        -0.28   0.02   Yes 5

Enclosure 1 PG&E Letter DCL-01-138 Column - Table 1                                                                Legend and Notes for Table 1 SG                Steam generator R                 Row C                 Column IND               Plus point indication. SAI is single axial indication. Some tubes have multiple non-parallel SAL.
+P Volt           Peak voltage from Plus Point coil.
From - To         Elevation (in.) of lower crack tip (from) to upper crack tip (to), relative to the hot leg top of tubesheet (TSH).
L                 Length of crack (in.)
UCT to TSH        Elevation (in.) of the upper crack tip (UCT) relative to TSH, including ANDECT-TTS (Plus Point NDE uncertainty on locating the crack tip relative to the TTS).
W* Zone           W* tubesheet zone based on crack location.
W* L              W* length based on W'* Zone, plus ANDEw (NDE uncertainty in measuring the W* depth).
BWT               Bottom of the WEXTEX transition (in.), measured by bobbin relative to TSH.
UCT to BWT        Distance (in.) from the upper crack tip (UCT) to BWT, minus ANDECT-BWT (Plus Point NDE uncertainty on locating the crack tip relative to the BWT).
UCT below W*      If the UCT is located below the W* length, then the tube is a W* tube. Any type of degradation below the W* length is acceptable.
UCT below BWT     If the UCT is located below BWT, then the tube is a W* candidate.
EOC 10 UCT        UCT location (in.) relative to TSH at the end of the next operating cycle, EOC 10, based on growing the UCT at 0.25 in./EFPY. Unit 2 Cycle 10 is projected to be 1.44 EFPY.
UCT below TSH at   Ifthe UCT is below TSH at EOC 10, a free span indication is precluded and the tube is a W* candidate.
EOC 10 W* Tube            If the UCT is below BWT and the UCT is below TSH at EOC 10, then the tube is a W* tube. If the UCT is located below the W* length, then the tube is a W* tube.
Insp Ext           Inspection extent of Plus Point relative to TSH (in.).
W* Insp Dist      W* inspection distance (in.). This is the +Point inspection extent relative to BWT. The W* inspection distance below BWT is equal to the Plus Point inspection extent below TSH, plus measured distance from BWT to TSH, plus bobbin NDE uncertainty in locating BWT relative to TSH.
The W* inspection distance must be greater than or equal to the flexible W* length.
Flex W* L          Flexible W* length relative to BVVT (in.), equal to W* Length + 7-CIj (total axial crack length) + NcL*ANDEcL(number of indications times Plus Point NDE uncertainty with measuring length of axial cracks) + NCL*ACG (number of indications times crack growth allowance from prior cycle tube integrity assessment, 0.25 in./EFPY)
CM LR              Condition monitoring SLB leak rate at EOC 9 conditions, gpm at room temperature, based on distance of UCT to BWT using Figure 6.4-3 of WCAP-14797 Rev 1. No accident leakage is assigned to an indication with an UCT below the W* length. No accident leakage is assigned to an indication in a tube deplugged and returned to service.
EOC 10 UCT to      Distance of UCT to BWT (in.) at EOC 10 for operational assessment, based on growing the UCT at the latest updated industry combined 95%
BWT                growth rate (0.24 in./EFPY).
OA LR              Operational assessment leak rate at EOC 10 conditions, gpm at room temperature, based on distance of UCT (at EOC 10) to BWT using Figure 6.4-3 of WCAP-14797 Rev 1.
Deplug             Tube was deplugged in 2R9.
Plug               Tube was plugged in 2R9.
6

Enclosure 1 PG&E Letter DCL-01-138 Table 2 DCPP Unit 2 Steam Line Break Leak Rates for Alternate Repair Criteria EOC 9 Condition Monitoring Leak Rate    SG 2-1     SG 2-2   SG 2-3   SG 2-4 (gpm at room temperature)                             _
W*ARC                    0.1170     0.0383   0.1000    0.1468 Voltage-Based ARC               0.0627    0.0244   0.0312    0.3215 Aggregate ARC                 1.1797    0.0627       -
0.8688    1.5317 EOC 10 Operational Assessment Leak      SG 2-1     SG 2-2   SG 2-3   SG 2-4 Rate (gpm at room temperature)
VV*ARC                    0.2818    0.1765   0.6330    0.4799 Voltage-Based ARC               0.2349    0.1267   0.1500    1.2448 Aggregate ARC                 1.5167    0.3032   -0.217 0.2753 7

Enclosure 1 PG&E Letter DCL-01-138 Table 3 DCPP Unit 2 Cycle 10 Growth Rate for Axial PWSCC in W* Region Cumulative Probability Distribution for Growth of Axial PWSCC Indications in W* Region 1
0.9 0.8 0.7 0
..- , 0.6 a)  0.5 0.4 E 0.3 0 0.2 0.1 0
         -0.30    -0.20   -0.10    0.00      0.10   0.20    0.30     0.40     0.50 WEXTEX Axial Crack Growth per EFPY (inches) 8}}