DCL-06-100, Special Report 06-02 - Results of Steam Generator (SG) Tube Inspections for Diablo Canyon Power Plant Unit 2 Thirteenth Refueling Outage

Special Report 06-02 - Results of Steam Generator (SG) Tube Inspections for Diablo Canyon Power Plant Unit 2 Thirteenth Refueling Outage

ML062400518
Person / Time
Site:	Diablo Canyon
Issue date:	08/21/2006
From:	Jacobs D Pacific Gas & Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
DCL-06-100 06-02
Download: ML062400518 (155)

Text

Pacific Gas and Electric Company' Donna Jacobs Diablo Canyon Power Plant Vice President P.0. Box 56 Nuclear Services Avila Beach, CA 93424 Augut 212006805.545.4600 August 21, 2006Fax: 805.545.4234 PG&E Letter DCL-06-100 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Docket No. 50-323, OL-DPR-82 Diablo Canyon Unit 2 Special Report 06 Results of Steam Generator (SG) Tube Inspections for Diablo Canyon Power Plant Unit 2 Thirteenth Refueling Outagie

Dear Commissioners and Staff:

In accordance with Technical Specifications (TS) 5.6.10.e and TS 5.6.10.f, provides the 90-day reporting of results of the Unit 2 steam generator (SG) Wstar (W*) alternate repair criteria (ARC) tubesheet inspections and calculated steam line break leakage from application of all ARC and non-ARC.

In accordance with TS 5.6.10.h, Enclosure 2 provides the 120-day reporting of results of the Unit 2 SG primary water stress corrosion cracking ARC inspections at dented tube support plate (TSP) intersections.

In accordance with Pacific Gas and Electric Company's (PG&E) commitment to Generic Letter 95-05, "Voltage-Based Repair Criteria for Westinghouse Steam Generator Tubes Affected by Outside Diameter Stress Corrosion Cracking (ODSCC)," Enclosure 3 provides the 90-day reporting of results of Unit 2 SG voltage-based ARC inspections for TSP ODSCC, prepared by Areva for PG&E.

As concluded in Section 5.3 of Enclosure 3, reporting to the NRC in accordance with TS 5.6.10.i is not required. There are no new or revised regulatory commitments as defined by the Nuclear Energy Institute 99-04, "Guidelines for Managing NRC Commitment changes," dated July 1999, in this report.

Ifyou have any questions, please contact John Arhar at (805) 545-4629.

Sincerely, Donn A member of the STARS (Strategic Teaming and Resource Sharing) Alliance -)C /

CatLaway

• Comanche Peak

• Diablo Canyon ° Palo Verde

• South Texas Project

• Wolf Creek

Document Control Desk PG&E Letter DCL-06-100 August 21, 2006 Page 2 ddml/469/R0272302 Enclosures cc: Alan B. Wang, Project Manager NRR Diablo Distribution cc/enc: Terry W. Jackson, NRC Senior Resident Bruce S. Mallett, NRC Region IV State of California, Pressure Vessel Unit A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Comanche Peak

• Diablo Canyon

• Palo Verde

• South Texas Project e Wolf Creek

Enclosure 1 PG&E Letter DCL-06-1 00 ENCLOSURE I SPECIAL REPORT 06-02 W* ALTERNATE REPAIR CRITERIA 90-DAY REPORT DIABLO CANYON POWER PLANT UNIT 2 THIRTEENTH REFUELING OUTAGE This report implements the Diablo Canyon Power Plant (DCPP) Technical Specification (TS) 5.6.10.e and 5.6.1O.f steam generator (SG) tube inspection reporting criteria.

Wstar (W*) Alternate Repair Criteria (ARC) was implemented for the fifth time in DCPP Unit 2 during the Unit 2 Thirteenth Refueling Outage (2R13) SG inspections and repairs that were completed in May 2006. This was the first Unit 2 inspection applying the revised W* ARC approved in NRC letter dated October 28, 2005.

One hundred percent of the SG tubes were inspected by bobbin from tube end to tube end, except for Row 1 and 2 U-bends. One hundred percent of the hot leg top of tubesheet (TTS) WEXTEX region was inspected by Plus Point in each SG. Cold leg TTS Plus Point inspections were not required.

Technical Specification 5.6.10.e Reporting Requirements DCPP TS 5.6.1 0.e requires that the results of the inspection of W* tubes be reported to the Commission pursuant to 10 CFR 50.4 within 90 days following return to service of the SGs. This enclosure provides the specific TS reporting requirements, and Pacific Gas and Electric Company's (PG&E) description of compliance.

A comprehensive list of axial primary water stress corrosion cracking (PWSCC) indications detected in the hot leg WEXTEX region during 2R13 Plus Point inspections are provided in Table 1 for SG 2-1 and SG 2-2, Table 2 for SG 2-3, and Table 3 for SG 2-4. The following discussions provide references to columns in these tables where appropriate information is contained.

• Identification of W* tube indicationsand indicationsthat do not meet W*

requirementsand were plugged or repaired.

The Table 1 column labeled "W* Cand" identifies 65 tubes (containing 70 single axial PWSCC indications ["SAI"] in the W* length) that are categorized as W*

candidates (W* tubes) and left in service under W* ARC. No Table 1 indications were plugged because of failure to meet W* ARC.

Table 6 of Enclosure 2 lists one small circumferential outside diameter stress corrosion cracking (ODSCC) indication in SG 2-2 R22C24 that was detected at 0.05 inches below the hot leg top of tubesheet. This indication was plugged because it 1-1

Enclosure 1 PG&E Letter DCL-06-100 did not meet W* requirements; that is, circumferential indications within the flexible W* distance must be repaired.

Not included in Table 2 are multiple Plus Point confirmed PWSCC repeat indications in W* tube SG 2-3 R32C55 in the plug expansion zone (PEZ) near the tube end.

PWSCC indications in the PEZ region of this tube were previously reported in the Unit 2 Twelfth Refueling Outage (2R12) 90-day report, PG&E Letter DCL-05-024.

This tube was previously deplugged in the Unit 2 Ninth Refueling Outage (2R9) and returned to service at that time. In 2R13, this tube was inspected with Plus Point the full length of the hot leg tubesheet because of bobbin distorted tubesheet indications (DTS) located near the tube end, even though Plus Point inspection of DTS indications located below the flexible W* length is not required. Plus Point confirmed the presence of multiple SAls located near the tube end, in the PEZ region. The indications are located below the shop hard roll transition, as in 2R12.

Because the indications are located below the flexible W* length, they were returned to service under W* ARC. As discussed in PG&E Letter DCL-05-017, "Reply to Request for Additional Information Regarding: Special Report 04 Results of Steam Generator Inspections for Diablo Canyon Power Plant Unit 1 Twelfth Refueling Outage," primary-to-secondary leakage from PEZ indications is very unlikely. Therefore, no steam line break (SLB) leakage is attributed to these 2R13 indications for condition monitoring (CM). For operational assessment, potential leakage from these indications is accounted for by use of the tube sever model, which is discussed later.

• Number of indicationsand location of the indications (relative to below the W*

transition[BWT] and top of tubesheet [TTS]).

For each of the 70 indications, the lower crack tip ("LCT") and upper crack tip

("UCT") columns provide the elevation (inch) relative to the TTS. The "Dist UCT to TTS" column provides the distance (inch) between the upper crack tip and the TTS, accounting for nondestructive examination (NDE) uncertainty on locating the crack tip relative to the TTS. The "Dist UCT to BWT" column provides the distance (inch) between the upper crack tip and the BWT, accounting for NDE uncertainty on locating thecrack tip relative to the BWT.

• Orientation(axial, circumferential,volumetric, inclined).

The "Ind" column provides the orientation of the indication. All indications are SAls.

No indications are circumferential or volumetric. One indication was inclined in SG 2-3 R21C38, as discussed below.

• Angle of inclination of clearly skewed axial cracks (if applicable).

SG 2-3 R21C38 repeat axial PWSCC indication in the W* length was identified to be inclined based on a review of the Plus Point data. Per W* ARC requirements, the 1-2

Enclosure 1 PG&E Letter DCL-06-1 00 inclination angle was measured as 32 degrees based on 0.080 inch pancake coil.

The NDE uncertainty on measurement of the crack angle is 6.8 degrees for 0.080 inch pancake coil. Therefore, the total inclination angle is 38.8 degrees, less than the 45-degree plugging limit defined for W* ARC inclined indications. In addition, the total length of the indication was 0.50 inch, and after applying a growth rate of 0.119 inch/effective full power year (EFPY) over the next cycle (1.62 EFPY), the projected end of cycle (EOC) 14 crack length is 0.69 inch. This projected crack length is less than the 2.0 inches plugging limit defined for W* ARC inclined indications. Therefore, based on the shallow inclination angle and projected short length, the indication was left in service under W* ARC.

, Radialposition of the tube within the tubesheet.

The "Tube Radial Position" column provides the radial position of the tube within the tubesheet.

" W* Zone of the tube.

The "W*ZONE" column provides the W* zone of each indication.

" Severity of each indication (estimateddepth).

The "MD-adj" column provides the estimated maximum depth (MD) (percent through-wall) of each indication. The depth is the adjusted depth using the same techniques as PWSCC ARC depth sizing.

• Side of the tube in which the indicationinitiated (inside or outside diameter[ID/OD]).

All indications are ID initiated (i.e., PWSCC).

" W* inspection distance measuredwith respect to the BWT or TTS (whichever is lower).

For the one hundred percent Plus Point hot leg TTS exam, the inspection extent relative to the TTS was specified as plus +2/-8 inches. Assuming no degradation in the W* length, 8 inches below the TTS constitutes the W* inspection distance. If degradation is detected in the W* region, the inspection extent must bound the calculated flexible W* length. The "W* Insp Ext wrt BWT" column lists the W*

inspection distances measured with respect to BWT for tubes in which axial PWSCC was detected. The distances are with respect to BWT because, in all cases, the BWT elevation was located lower than the TTS elevation. In all cases, the W* inspection distance was greater than or equal to the flexible W* length, as indicated by "Yes" in the "lnsp Ext Satisfied" column.

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Enclosure 1 PG&E Letter DCL-06-100 Length of axial indications.

The "Crack Length" column provides the crack length of each axial indication. For tubes with multiple cracks, the "Total Length" column provides the total (summed) length of individual cracks within the flexible W* length.

• Updated 95 percent growth rate for use in operationalassessment.

Of the seventy axial PWSCC indications in the hot leg WEXTEX region that were detected in 2R1 3, four were new indications and sixty-six were repeat W* indications that had been left in service in the prior inspection (2R12). The four new indications were detectable in the prior inspection based on lookup reviews. One repeat indication (SG 2-4 R5C37) was identified as two SAIs in the prior inspection, and one SAI in the current inspection (the two indications merged in cycle 13), such that the growth data for this indication was excluded. As a result, 69 additional length growth rate data points were available for evaluation. The average growth rate was 0.03 inch per EFPY at Thot of 604 degrees, indicating negligible growth. After addition of these 69 data points, the updated W* growth rate distribution now consists of 350 data points from DCPP Units 1 and 2 over 11 cycles. The updated growth rate at 95 percent cumulative probability is 0.104 inch per EFPY at 604 degrees. The W* methodology requires that, if the new growth data and deletion of the oldest cycle(s) of growth data results in a minimum of 200 data points, then the oldest cycle(s) of data is excluded. There are 210 data points combined from the most recent Unit 2 cycles 11, 12, and 13. Therefore, data from all other cycles is excluded. The 95 percent cumulative probability growth rate of the 210 data points is 0.119 inch per EFPY, and this growth rate value was used for the final operational assessment (OA).

In support of growth rate evaluations and W* calculations, the actual length of Unit 2 Cycle 13 was 1.31 EFPY, and the projected length of Unit 2 Cycle 14 is 1.62 EFPY.

Cumulative number of indicationsdetected in the tubesheet region as a function of elevation within the tubesheet.

Table 4 provides the cumulative number of indications detected in the tubesheet region as a function of elevation within the tubesheet. The table includes the distribution of Unit 2 indications before 2R13, the distribution of new 2R13 indications, updated Unit 2 distribution after 2R13, and the Unit 2 cumulative distribution and cumulative frequency after 2R13. In 2R13, four new indications were detected: one at 5.91 inch below the TTS (included in the minus 5 inch bin),

one at 3.27 inch below the TTS (included in the minus 3 inch bin), one at 0.48 inch below the TTS (included in the 0 inch bin), and one at 0.28 inch below the TTS (included in the 0 inch bin).

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Enclosure I PG&E Letter DCL-06-100 Condition monitoringand operationalassessment main steamline break leak rate for each indicationand each SG in accordance with the leak rate methodology described in PG&E Letter DCL-05-018, dated March 11, 2005, as supplemented by PG&E Letter DCL-05-090 dated August 25, 2005.

Condition Monitoring SLB Leak Rate for Indications within Flexible W* Length CM leak rate for axial PWSCC indications detected within the flexible W* length is determined using the DENTFLO leak model in accordance with WCAP-14797-P, Revision 2. (Note: As discussed in DCL-05-090, the constrained crack leak model is not applicable for EOC 13 condition monitoring.) The 95 percent leak rates for each indication, as well as each SG, are provided in column "DENTFLO CM Leak Rate."

The total SG leak rates are repeated in Table 5.

For information only, applying the constrained crack leak model, the 95 percent prediction bound leak rates for each indication, as well as each SG, are provided under column "Constrained Crack Model CM Leak Rate."

OperationalAssessment SLB Leak Rate for Indications within 12 inches from TTS The OA leak rate for axial PWSCC indications detected within 12 inches from the TTS is determined by using the constrained crack leak model. The 95 percent prediction bound leak rates for each indication, as well as each SG, are provided under column "Constrained Crack Model OA Leak Rate." The total SG leak rates are repeated in Table 6.

The OA leak rate for undetected indications between 8 and 12 inches below the TTS is determined by multiplying the number of projected undetected indications between 8 and 12 inches below the TTS at the next inspection by a factor of 0.0033 gallons per minute (gpm). The leak rate value of 0.0033 gpm is the 95 percent prediction bound leak rate, applying the constrained crack model with a Zone B1 contact pressure at a depth of 8 inches below the TTS. Twelve undetected indications are projected between 8 and 12 inches below the TTS based on the more conservative of the 2 methods described below. Therefore, the OA leak rate for undetected indications between 8 and 12 inches below the TTS is 0.0396 gpm for each SG. These SG leak rates are repeated in Table 6.

Historicaldata projection method. The number of undetected PWSCC indications between 8 and 12 inches below the TTS would not be expected to be much greater than the number reported between 4 and 8 inches below the TTS, due to the trend of decreasing number of indications with distance below TTS. Of the 162 cumulative PWSCC indications detected to date in DCPP Unit 2, 5 percent were between 4 to 8 inches below the TTS, and 2 percent were between 8 to 12 inches below the TTS. Two percent of the total historical plus EOC projected indication count will be assumed to be undetected between 8 and 12 inches below the TTS.

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Enclosure 1 PG&E Letter DCL-06-100 Figure 1 illustrates the cumulative number of PWSCC indications versus EFPY in DCPP Unit 2. A linear regression analysis using only data from the last 5 outages shows that about 168 cumulative indications are projected at EOC-14, of which 4 (2 percent of 168) are assumed to be undetected between 8 and 12 inches below the TTS.

Ninety percent probabilityprediction method. Figure 2 presents a plot of the binned PWSCC elevation data for all DCPP Unit 2 historical indications located greater than 2 inches below the TTS. Excluding the expansion transition indications above 2 inches for Unit 2 would be expected to provide the best dataset for estimating indications at deeper depths. Figure 2 provides a best-fit regression of this data, an upper 90 percent probability prediction bound, and an upper 90 percent probability cumulative prediction bound. The number of indications that could be present in the range of 8 to 12 inches below the top of tubesheet is obtained by summing the upper 90 percent probability prediction bound individual values at 8, 9, 10, and 11 inches (approximately 3 in each bin), for a total of about 12 indications. As a result, twelve indications will be applied for OA because it is greater than four indications from the historical data projection method.

OperationalAssessment SLB Leak Rate for Indications Below 12 inches from TTS The OA leak rate for indications located below 12 inches from the TTS is determined by the severed tube model. This model assumes all in-service tubes contain a 3600 tube sever located 12 inches below the TTS and assigns a leak rate of 0.00009 gpm per tube. This value is the 90 percent prediction bound leak rate at 2560 pounds per square inch differential for a contact pressure representative of the 3 inch nominal crevice test specimen from the drilled hole crevice leak rate test data in WCAP-14797-P, Revision 2. The resulting leak rates for each SG are listed in Table 6, and are approximately 0.3 gpm for each SG.

Verification that the upper crack tip of W* indications retumed to service in the prior cycle remain below the BWT by at least the 95 percent confidence NDE uncertainty on locating the crack tip relative to the BVWT.

As stated in DCL-05-090, for 2R1 3 90-day reporting, this reporting requirement is not applicable because the new, more conservative, W* repair criteria was not in effect in the prior inspections. Therefore, for 2R13 90-day reporting, PG&E applies the prior cycle requirement, that is, verification that the upper crack tip of W*

indications returned to service in the prior cycle remain below the TTS by at least the 95 percent confidence NDE uncertainty on locating the crack tip relative to the TTS.

The "Dist UCT to TTS" column provides the as-found elevation of the upper crack tip relative to the top of tubesheet, accounting for NDE uncertainty in locating the crack relative to the top of tubesheet. In all cases, the as-found upper crack tip for 1-6

Enclosure 1 PG&E Letter DCL-06-100 indications returned to service in the prior cycle is below the top of tubesheet, as indicated by "Yes" in the column "UCT below TTS?" Therefore, the performance criterion was satisfied for condition monitoring at EOC 13.

• Assessment of whether the results were consistent with expectations and, if not consistent, a description of the proposed corrective action.

The CM leak rates were consistent with expectations. The column "Prior OA Leak Rate" provides the prior cycle predicted operational assessment leak rates for each repeat indication using the DENTFLO model. This leak rate is compared to the as-found condition monitoring leak rate under column "DENTFLO CM Leak Rate." The prior cycle OA leak rates predicted for each SG are greater (more conservative) than the as-found CM leak rates, as reported in the "OA Underprediction" column.

The number of new PWSCC indications (four) is consistent with expectations, because it was less than the six new indications expected in 2R1 3 based on a linear regression analysis using data from the four prior inspections. Also, comparison of the pre-2R13 and post-2R14 cumulative distribution frequencies in Table 4 shows no significant changes; therefore, the elevations of the new indications are consistent with expectations.

Technical Specification 5.6.10.f Reportingq Requirements DCPP TS 5.6.10.f requires that the aggregate calculated steam line break leakage from application of all ARC and non-ARC be reported to the Commission pursuant to 10 CFR 50.4 within 90 days following return to service of the SGs.

Table 7 (for CM) and Table 8 (for OA) reports the calculated SLB leakage from application of each ARC in each SG, that is, W* ARC, Generic Letter 95-05 voltage-based ARC, and PWSCC ARC. SLB leakage from non-ARC degradation is also provided in these tables. The ARC and non-ARC leak rates are then summed to arrive at an aggregate SLB leakage for each SG.

No in-situ leak testing of indications was performed in 2R1 3, so there is no SLB leakage contribution from in-situ testing.

In order to meet the accident-induced leakage performance criteria (AILPC), the aggregate calculated steam line break leakage from application of all ARC and non-ARC must not exceed 10.5 gpm (at room temperature) in the faulted SG for condition monitoring and operational assessment. The 10.5 gpm limit was approved by the NRC in License Amendment (LA) 156/156. The aggregate calculated condition monitoring SLB leakage at EOC 13 is 1.193 gpm for the limiting SG (SG 2-4) as shown in Table 7. The aggregate calculated operational assessment SLB leakage at EOC 14 is 5.695 gpm for the limiting SG (SG 2-4) as shown in Table 8. In both assessments, SLB leakage is less than the allowable limit. Therefore, the AILPC has been satisfied for condition monitoring at EOC 13 and operational assessment at EOC 14.

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Enclosure 1 PG&E Letter DCL-06-100 Table I 2R13 SG 2-1 and SG 2-2 PWSCC Indications in Hot Leg WEXTEX Tubesheet Region Tube Cak Total Dst UCT W. Dist UCT UCT UCT Dlst EOC (N÷I) Dist EOC EOC (N÷I)

SG Count Row Col Radial Id Volts Crack# CAL LCT UCT MD-adj UCTto below W*ZONE eng t to BWT Below Below St Position Position Length Length Leth to BWTUCTW"? T (N+1) UCT UCT Below W*Cand TTS TTS BWT? toTTS to BWT BWT?

21 1 6 77 38.76 SAI 0.80 29 -1.46 -1.29 0.17 0.17 59 1.07 Yes B4 7.12 -0.40 0.61 No Yes .0.88 0.42 Yes Yes 21 2 7 24 31.69 SAI 0.20 29 -2.01 -1.89 0.12 0.12 44 1.67 Yes B3 7.12 -0.37 1.24 No Yes 1.48 1.05 Yes Yes 21 3 7 62 21.04 SAI 4.91 29 -2.36 -1.44 0.92 0.92 100 1.22 Yes B2 7.12 -1.06 0.10 No Yes 1.03 -0.09 No No 21 4 8 32 22.78 SAI 0.74 29 -2.02 -1.88 0.14 0.14 59 1.66 Yes B2 7.12 -0.39 1.21 No Yes 1.47 1.02 Yes Yes 21 5 9 49 12.58 SAl 1.15 29 -2.14 -1.81 0.33 0.33 62 1.59 Yes BI 7.12 -0.36 1.17 No Yes 1.40 0.98 Yes Yes 21 6 10 49 13.85 SAI 0.17 29 -1.24 -1.09 0.15 0.15 38 0.87 Yes BI 7.12 -0.30 0.51 No Yes 0.68 0.32 Yes Yes 21 7 11 37 20.15 SAI 0.48 29 -7.95 -7.84 0.11 0.62 24 7.62 Yes B2 7.12 -0.41 7.15 Yes Yes 7.43 6.96 Yes Yes 21 8 11 37 20.15 SAI 0.68 2 29 -7.06 -6.86 0.20 0.62 47 6.64 Yes 82 7.12 -0.41 6.17 No Yes 6.45 5.98 Yes Yes 21 9 11 37 20.15 SAI 0.60 3 29 -2.16 -1.85 0.31 0.62 53 1.63 Yes B2 7.12 -0.41 1.16 No Yes 1.44 0.97 Yes Yes 21 10 11 39 18.54 SAI 1.43 29 -1.82 -1.6 0.22 0.22 77 1.38 Yes B1 7.12 -0.42 0.90 No Yes 1.19 0.71 Yes Yes 21 11 11 40 17.81 SAI 0.33 29 -0.97 -0.82 0.15 0.15 41 0.60 Yes B1 7.12 -0.34 0.20 No Yes 0.41 0.01 Yes Yes 21 12 11 48 15.01 SAI 3.20 29 -5.25 -4.76 0.49 0.49 84 4.54 Yes BI 7.12 -0.42 4.06 No Yes 4.35 3.87 Yes Yes 21 13 13 49 17.67 SAI 0.39 29 -1.82 -1.68 0.14 0.14 62 1.46 Yes B1 7.12 -0,66 0.74 No Yes 1.27 0.55 Yes Yes 21 14 16 79 45.68 SAI 0.28 62 -6.06 -5.91 0.15 0.15 40 5.69 Yes A 5.32 -0.44 5.19 No Yes 5.50 5.00 Yes Yes 21 15 23 67 39.33 SAI 0.18 64 -3.38 -3.27 0.11 0.11 54 3.05 Yes A 5.32 -0.34 2.65 No Yes 2.86 2.46 Yes Yes 21 16 23 70 41.88 SAI 1.46 29 -1.67 -1.22 0.45 0.45 62 1.00 Yes A 5.32 -0.22 0.72 No Yes 0.81 0.53 Yes Yes 21 17 30 59 42.01 SAI 3.73 29 -11.36 -10.72 0.64 0.64 80 10.50 Yes B4 7.12 -0.15 10.29 Yes Yes 10.31 10.10 Yes Yes 22 1 5 18 38.50 SAI 1.32 1 22 -1.25 -0.83 0.42 0.42 83 0.61 Yes B4 7.12 -0.24 0.31 No Yes 0.42 0.12 Yes Yes 22 2 10 48 13.73 SAI 0.42 1 22 -3.23 -3.12 0.11 0.11 36 2.90 Yes 81 7.12 -0.09 2.75 No Yes 2.71 2.56 Yes Yes 22 3 10 56 17.52 SAI 0.65 1 22 -1.10 -0.95 0.15 0.15 48 0.73 Yes B1 7.12 -0.35 0.32 No Yes 0.54 0.13 Yes Yes 22 4 13 43 18.48 SAI 0.35 1 22 -1.61 -1.45 0.16 0.16 48 1.23 Yes B1 7.12 -0.45 0.72 No Yes 1.04 0.53 Yes Yes 22 5 31 25 49.81 SAI "4.80 1 22 -2.43 -1.62 0.81 0.81 100 1.40 Yes A 5.32 -0.55 0.79 No Yes 1.21 0.60 Yes Yes 1-8

Enclosure 1 PG&E Letter DCL-06-100 Table I (continued) 2R13 SG 2-1 and SG 2-2 PWSCC Indications in Hot Leg WEXTEX Tubesheet Region CostanesCntrindTube pctW*nsp FlexW* Insp Ext DentFlo CM Prior OA OA Under Constrained Constrained PREVW* Tube SG Count Row Cot ns Exet Ext wrt Crack Model Crack Model Extent BWTCMLarae Ext Length Satisfied ? Leak Rate Leak Rate Prediction CM Leak rate Leak RateOA Tb LaRae Deplugged?

TubePlugged 21 1 6 77 -9.03 8.54 7.34 Yes 0.024 0.027 No 0.043 0.047 Yes Yes 21 2 7 24 -9.23 8.77 7.29 Yes 0.015 0.016 No 0.058 0.064 Yes Yes 21 3 7 62 -12.70 11.55 8.09 Yes 0.042 0.045 No 0.152 0.000 Yes Yes Yes 21 4 8 32 -9.06 8.58 7.31 Yes 0.016 0.017 No 0.104 0.118 Yes 21 5 9 49 -9.11 8.66 7.50 Yes 0.017 0.016 Yes 0.174 0.198 Yes 21 6 10 49 -8.97 8.58 7.32 Yes 0.027 0.031 No 0.271 0.310 Yes 21 7 11 37 -12.82 12.32 7.12 Yes 0.000 0.001 No 0.004 0.004 Yes 21 8 11 37 -12.82 12.32 7.85 Yes 0.001 0.001 No 0.006 0.007 Yes 21 9 11 37 -12.82 12.32 7.90 Yes 0.017 0.018 No 0.123 0.139 Yes 21 10 11 39 -9.30 8.79 7.39 Yes 0.020 0.022 No 0.156 0.177 Yes Yes 21 11 11 40 -9.10 8.67 7.32 Yes 0.038 0.043 No 0.271 0.308 Yes 21 12 11 48 -10.17 9.66 7.66 Yes 0.005 0.005 No 0.024 0.027 Yes 21 13 13 49 -8.89 8.14 7.31 Yes 0.022 0.024 No 0.154 0.175 Yes 21 14 16 79 -9.01 8.48 5.52 Yes 0.000 NA NA 0.004 0.004 No 21 15 23 67 -8.60 8.17 5.48 Yes 0.003 NA NA 0.017 0.018 No 21 16 23 70 -9.42 9.11 5.82 Yes 0.020 0.021 No 0.033 0.036 Yes Yes 21 17 30 59 -12.74 12.50 7.12 Yes 0.000 0.000 No 0.001 0.001 Yes 0.265 0.286 1.593 1.632 22 1 5 18 -9.77 9.44 7.59 Yes 0.033 0.037 No 0.055 0.060 Yes 22 2 10 48 -9.75 9.57 7.28 Yes 0.008 0.008 No 0.070 0.079 Yes 22 3 10 56 -9.56 9.12 7.32 Yes 0.033 0.040 No 0.252 0.287 Yes Yes 22 4 13 43 -9.43 8.89 7.33 Yes 0.023 0.028 No 0.172 0.196 Yes Yes 22 5 31 25 -9.76 9.12 6.18 Yes 0.017 0.022 No 0.012 0.013 Yes Yes 0.113 0.135 0.561 0.635 1-9

Enclosure 1 PG&E Letter DCL-06-100 Table 2 2R13 SG 2-3 PWSCC Indications in Hot Leg WEXTEX Tubesheet Region TRtC Crack Total Dist UCT W* Dist UCT UCT UCT DDist EOC EOC (N+1)

SG Count Row Col Radial Ind Volts IDIOD Crack# CAL LCT UCT Length Length MD-adt UCTto below WZONE oBWT Below Below (N+1) UCT UCT Below WCand Position TTS TTS W* ? BWT? to BWT BWT?

23 1 2 91 55.84 SAI 0.99 ID 26 -1.04 -0.60 0.44 0.44 63 0.38 Yes A 5.32 -0.12 0.20 No Yes 0.19 0.01 Yes Yes 23 2 3 69 27.95 SAI 2.13 ID 26 -1.30 -0.82 0.48 0.48 79 0.60 Yes B2 7.12 -0.34 0.20 No Yes 0.41 0.01 Yes Yes 23 3 4 90 54.78 SAI 0.90 ID 26 -1.20 -0.93 0.27 0.27 50 0.71 Yes A 5.32 -0.19 0.46 No Yes 0.52 0.27 Yes Yes 23 4 5 51 8.58 SAI 0.53 ID 26 -2.27 -2.13 0.14 0.14 63 1.91 Yes B1 7.12 -0.24 1.61 No Yes 1.72 1.42 Yes Yes 23 5 5 55 ID 26 -2.40 -1.99 0.41 0.41 86 12.07 SAI 1.99 1.77 Yes BI 7.12 -0.19 1.52 No Yes 1.58 1.33 Yes Yes 23 6 6 77 38.76 SAI 0.22 ID 26 -1.93 -1.84 0.09 20 B4 1.43 0.09 1.62 Yes 7.12 -0.42 1.14 No Yes 0.95 Yes Yes 23 7 7 52 11.43 SAI 4.97 ID 26 -1.56 -0.76 0.80 0.80 100 0.54 Yes B1 7.12 -0.28 0.20 No Yes 0.35 0.01 Yes Yes 23 8 7 59 17.74 SAI 1.81 ID 26 -1.91 -1.43 0.48 0.48 89 1.21 Yes B1 7.12 -0.31 0.84 No Yes 1.02 0.65 Yes Yes 23 9 7 92 57.86 SAI 1.24 ID 26 -1.17 -0.75 0.42 0.42 53 0.53 Yes A 5.32 -0.24 0.23 No Yes 0.34 0.04 Yes Yes 23 10 8 93 59.35 SAI 1.31 ID 26 -0.93 -0.60 0.33 0.33 44 0.38 Yes A 5.32 -0.12 0.20 No Yes 0.19 0.01 Yes Yes 23 11 9 63 23.43 SAl 0.44 ID 26 -1.34 -1.19 0.15 0.15 39 0.97 Yes B2 7.12 -0.38 0.53 No Yes 0.78 0.34 Yes Yes 23 12 12 48 16.29 SAI 0.21 ID 26 -2.28 -2.20 0.08 0.08 44 1.98 Yes B1 7.12 -0.29 1.63 No Yes 1.79 1.44 Yes Yes 23 13 14 24 35.52 SAI 0.40 ID 26 -2.02 -1.84 0.18 0.18 28 1.62 Yes B4 7.12 -0.16 1.40 No Yes 1.43 1.21 Yes Yes 23 14 16 24 36.94 SAI 0.34 ID 26 -1.43 -1.32 0.11 0.11 53 1.10 Yes 84 7.12 -0.16 0.88 No Yes 0.91 0.69 Yes Yes 23 15 19 71 39.29 SAI 1.01 ID 26 -2.19 -1.87 0.32 0.32 53 1.65 Yes A 5.32 -0.38 1.21 No Yes 1.46 1.02 Yes Yes 23 16 21 38 30.36 SAI 0.93 ID 26 -1.66 -1.16 0.50 0.50 93 0.94 Yes B3 7.12 -0.33 0.55 No Yes 0.75 0.36 Yes Yes 23 17 21 83 53.31 SAI 0.72 ID 26 -1.16 -0.90 0.26 0.26 47 0.68 Yes A 5.32 -0.31 0.31 No Yes 0.49 0.12 Yes Yes 23 18 25 37 35.58 SAI 1.29 ID 26 -1.41 -1.06 0.35 0.35 72 0.84 Yes B4 7.12 -0.31 0.47 No Yes 0.65 0.28 Yes Yes 23 19 32 55 42.99 SAI 1.80 ID 26 -1.30 -0.86 0.44 0.44 72 0.64 Yes A 5.32 -0.37 0.21 No Yes 0.45 0.02 Yes Yes 23 20 45 37 60.09 SAI 1.47 ID 26 -1.68 -1.32 0.36 0.36 60 1.10 Yes A 5.32 -0.28 0.76 No Yes 0.91 0.57 Yes Yes 1-10

Enclosure 1 PG&E Letter DCL-06-100 Table 2 (continued) 2R13 SG 2-3 PWSCC Indications in Hot Leg WEXTEX Tubesheet Region Inspect W* tnsp Flex W* Insp Ext DentFlo CM Prior OA OA Under Constrained Constrained PREVW* Deplugged? Tube SG Count Row Cot Extent Ext wrt Length Satisfied ? Leak Rate Leak Rate Prediction Crack Model Crack Model OA Tube Plugged Exet BWT CM Leak rate Leak Rate 23 1 2 91 -10.04 9.83 5.81 Yes 0.038 0.045 No 0.008 0.008 Yes Yes 23 2 3 69 -9.93 9.50 7.65 Yes 0.038 0.045 No 0.140 0.157 Yes 23 3 4 90 -10.06 9.78 5.64 Yes 0.029 0.034 No 0.008 0.009 Yes 23 4 5 51 -10.04 9.71 7.31 Yes 0.012 0.015 No 0.157 0.179 Yes Yes 23 5 5 55 -9.76 9.48 7.58 Yes 0.013 0.015 No 0.156 0.178 Yes 23 6 6 77 -9.87 9.36 7.26 Yes 0.012 0.017 No 0.033 0.036 Yes Yes 23 7 7 52 -10.09 9.72 7.97 Yes 0.038 0.045 No 0.375 0.430 Yes Yes 23 8 7 59 -9.98 9.58 7.65 Yes 0.021 0.025 No 0.181 0.206 Yes Yes 23 9 7 92 -9.93 9.60 5.79 Yes 0.036 0.042 No 0.006 0.006 Yes Yes 23 10 8 93 -10.42 10.21 5.70 Yes 0.038 0.045 No 0.005 0.005 Yes Yes 23 11 9 63 -10.00 9.53 7.32 Yes 0.027 0.033 No 0.154 0.173 Yes 23 12 12 48 -10.40 10.02 7.25 Yes 0.012 0.015 No 0.117 0.132 Yes Yes 23 13 14 24 -10.11 9.86 7.35 Yes 0.009 0.013 No 0.044 0.048 Yes Yes 23 14 16 24 -10.29 10.04 7.28 Yes 0.017 0.027 No 0.050 0.055 Yes Yes 23 15 19 71 -9.79 9.32 5.69 Yes 0.008 0.009 No 0.031 0.034 Yes Yes 23 16 21 38 -10.06 9.64 7.67 Yes 0.026 0.037 No 0.096 0.106 Yes Yes 23 17 21 83 -9.80 9.40 5.63 Yes 0.033 0.040 No 0.010 0.011 Yes Yes 23 18 25 37 -9.84 9.44 7.52 Yes 0.028 0.034 No 0.065 0.071 Yes Yes 23 19 32 55 -10.07 9.61 5.81 Yes 0.037 0.042 No 0.034 0.037 Yes Yes 23 20 45 37 -10.07 9.70 5.73 Yes 0.018 0.027 No 0.004 0.004 Yes Yes 0.489 0.604 1.674 1.888 1-11

Enclosure 1 PG&E Letter DCL-06-100 Table 3 2R13 SG 2-4 PWSCC Indications in Hot Leg WEXTEX Tubesheet Region TubeDst UCT W* Dist UCT UCT UCT Dst EOC (NI) Dst EOC EOC (N+I)

SG Count Row Col Radial Ind Volts IDIOD Crack # CAL LCT UCT Length Length D it UTwBWT Below Below (NI) UCT UCT Below WCand Position TrS s Length to BWT  ? BWT? UCT to TTS oBWT BWT?

24 1 2 10 48.17 SAI 0.36 18 -1.67 -1.52 0.15 0.15 43 1.30 Yes 5.32 -0.20 1.04 No Yes 1.11 0.85 Yes Yes 24 2 3 5 54.66 SAI 2.81 18 -2.05 -0.77 1.28 1.28 100 0.55 Yes 5.32 -0.29 0.20 No Yes 0.36 0.01 Yes Yes 24 3 3 12 45.73 SAl 0.45 18 -3.08 -2.90 0.18 0.45 66 2.68 Yes 5.32 -0.28 2.34 No Yes 2.49 2.15 Yes Yes 24 4 3 12 45.73 SAI 0.90 18 -2.72 -2.45 0.27 0.45 81 2.23 Yes 5.32 -0.28 1.89 No Yes 2.04 1.70 Yes Yes 24 5 3 17 39.36 SAI 0.68 18 -4.22 -3.98 0.24 0.24 69 3.76 Yes 7.12 -0.06 3.64 No Yes 3.57 3.45 Yes Yes 24 6 4 6 53.51 SAI 0.53 30 -0.52 -0.28 0.24 0.24 84 0.06 Yes 5.32 -0.29 -0.29 No No 0.13 -0.48 No No 24 7 4 24 30.71 SAI 0.45 22 -0.63 -0.48 0.15 0.15 64 0.26 Yes 7.12 -0.19 0.01 No No 0.07 -0.37 No No 24 8 4 35 17.11 SAI 1.28 18 -1.82 -1.53 0.29 0.29 75 1.31 Yes 7.12 -0.25 1.00 No Yes 1.12 0.81 Yes Yes 24 9 5 31 22.37 SAl 0.96 18 -1.38 -0.99 0.39 0.39 72 0.77 Yes 7.12 -0.33 0.38 No Yes 0.58 0.19 Yes Yes 24 10 5 36 16.45 SAI 0.62 18 -2.08 -1.89 0.19 0.19 81 1.67 Yes 7.12 -0.14 1.47 No Yes 1.48 1.28 Yes Yes 24 11 5 37 15.31 SAl 2.46 18 -4.61 -3.93 0.68 0.68 99 3.71 Yes 7.12 -0.28 3.37 No Yes 3.52 3.18 Yes Yes 24 12 5 53 10.16 SAI 1.94 18 -2.00 -1.73 0.27 0.27 78 1.51 Yes 7.12 -0.26 1.19 No Yes 1.32 1.00 Yes Yes 24 13 5 61 18.78 SAI 0.44 18 -10.41 -10.24 0.17 0.17 69 10.02 Yes 7.12 -0.22 9.74 Yes Yes 9.83 9.55 Yes Yes 24 14 6 33 20.47 SAI 1.55 18 -3.13 -2.77 0.36 0.36 84 2.55 Yes 7.12 -0.16 2.33 No Yes 2.36 2.14 Yes Yes 24 15 7 4 56.60 SAI 0.75 18 -1.32 -1.14 0.18 0.18 63 0.92 Yes 5.32 -0.21 0.65 No Yes 0.73 0.46 Yes Yes 24 16 7 38 15.67 SAI 2.05 18 -7.26 -6.95 0.31 1.02 84 6.73 Yes 7.12 -0.25 6.42 No Yes 6.54 6.23 Yes Yes 24 17 7 38 15.67 SAI 2.74 18 -4.84 -4.13 0.71 1.02 87 3.91 Yes 7.12 -0.25 3.60 No Yes 3.72 3.41 Yes Yes 24 18 7 53 12.13 SAI 0.30 18 -2.87 -2.73 0.14 0.14 66 2.51 Yes 7.12 -0.34 2.11 No Yes 2.32 1.92 Yes Yes 24 19 13 4 58.43 SAI 0.38 18 -1.46 -1.32 0.14 0.14 66 1.10 Yes 5.32 -0.23 0.81 No Yes 0.91 0.62 Yes Yes 24 20 13 40 20.02 SAI 3.54 18 -2.17 -1.58 0.59 0.59 100 1.36 Yes 7.12 -0.21 1.09 No Yes 1.17 0.90 Yes Yes 24 21 15 10 52.09 SAI 0.40 18 -1.18 -0.82 0.36 0.36 45 0.60 Yes 5.32 -0.21 0.33 No Yes 0.41 0.14 Yes Yes 24 22 16 10 52.60 SAI 2.95 18 -2.53 -2.08 0.45 0.45 81 1.86 Yes 5.32 -0.29 1.51 No Yes 1.67 1.32 Yes Yes 24 23 20 47 26.54 SAI 2.71 18 -2.02 -1.49 0.53 0.53 81 1.27 Yes 7.12 -0.25 0.96 No Yes 1.08 0.77 Yes Yes 24 24 24 26 41.96 SAI 3.44 18 -2.25 -1.73 0.52 0.68 99 1.51 Yes 5.32 -0.32 1.13 No Yes 1.32 0.94 Yes Yes 24 25 24 26 41.96 SAI 0.75 18 -1.64 -1.48 0.16 0.68 63 1.26 Yes 5.32 -0.32 0.88 No Yes 1.07 0.69 Yes Yes 24 26 25 64 39.14 SAI 1.90 18 -1.52 -1.17 0.35 0.35 72 0.95 Yes 7.12 -0.35 0.54 No Yes 0.76 0.35 Yes Yes 24 27 26 45 34.37 SAI 2.10 18 -4.14 -3.77 0.37 0.37 75 3.55 Yes 7.12 -0.23 3.26 No Yes 3.36 3.07 Yes Yes 24 28 26 64 40.22 SAI 0.75 18 -1.14 -0.84 0.30 0.30 54 0.62 Yes 7.12 -0.36 0.20 No Yes 0.43 0.01 Yes Yes 1-12

Enclosure 1 PG&E Letter DCL-06-1 00 Table 3 (continued) 2R13 SG 2-4 PWSCC Indications in Hot Leg WEXTEX Tubesheet Region inspect W* insp Flex W* Insp Ext DentFlo CM Prior OA OA Under Constrained Model OA PREVW Constrained SG Count Row Col Extnt Ext wrt Crack Model Crack Tubepugged?Tube xBWT Length Satisfied? Leak Rate Leak Rate Prediction CM Leak rate Leak Rate 24 1 2 10 -9.43 9.14 5.52 Yes 0.009 0.018 No 0.015 0.016 Yes Yes 24 2 3 5 -10.26 9.88 6.65 Yes 0.038 0.042 No 0.009 0.009 Yes Yes 24 3 3 12 -9.99 9.62 5.82 Yes 0.003 0.004 No 0.012 0.012 Yes Yes 24 4 3 12 -9.99 9.62 5.88 Yes 0.005 0.006 No 0.014 0.015 Yes Yes 24 5 3 17 -9.71 9.56 7.41 Yes 0.002 0.003 No 0.012 0.013 Yes 24 6 4 6 -9.14 8.76 5.61 Yes NA NA NA 0.012 0.000 No Yes 24 7 4 24 -9.99 9.52 7.32 Yes 0.045 NA NA 0.136 0.000 No Yes 24 8 4 35 -9.47 9.13 7.46 Yes 0.018 0.020 No 0.175 0.199 Yes Yes 24 9 5 31 -9.64 9.22 7.56 Yes 0.031 0.039 No 0.186 0.211 Yes 24 10 5 36 -9.88 9.65 7.36 Yes 0.014 0.015 No 0.142 0.161 Yes 24 11 5 37 -9.61 9.24 7.85 Yes 0.006 0.006 No 0.040 0.045 Yes Yes 24 12 5 53 -9.93 9.58 7.44 Yes 0.016 0.020 No 0.199 0.227 Yes Yes 24 13 5 61 -13.10 12.79 7.12 Yes 0.000 0.000 No 0.001 0.001 Yes 24 14 6 33 -9.33 9.08 7.53 Yes 0.008 0.008 No 0.068 0.076 Yes 24 15 7 4 -10.05 9.75 5.55 Yes 0.023 0.030 No 0.006 0.007 Yes Yes 24 16 7 38 -10.28 9.94 8.19 Yes 0.001 0.001 No 0.006 0.007 Yes Yes 24 17 7 38 -10.28 9.94 8.25 Yes 0.006 0.006 No 0.035 0.039 Yes Yes 24 18 7 53 -10.08 9.65 7.31 Yes 0.009 0.011 No 0.095 0.108 Yes 24 19 13 4 -9.65 9.33 5.51 Yes 0.016 0.027 No 0.005 0.005 Yes 24 20 13 40 -9.91 9.61 7.76 Yes 0.017 0.023 No 0.147 0.166 Yes Yes 24 21 15 10 -10.21 9.91 5.73 Yes 0.032 0.039 No 0.012 0.013 Yes Yes 24 22 16 10 -10.38 10.00 5.82 Yes 0.006 0.009 No 0.008 0.008 Yes Yes 24 23 20 47 -9.83 9.49 7.70 Yes 0.019 0.023 No 0.105 0.117 Yes Yes 24 24 24 26 -10.89 10.48 6.05 Yes 0.008 0.020 No 0.026 0.028 Yes 24 25 24 26 -10.89 10.48 6.11 Yes 0.014 0.027 No 0.029 0.031 Yes 24 26 25 64 -9.60 9.16 7.52 Yes 0.026 0.033 No 0.044 0.048 Yes Yes 24 27 26 45 -10.22 9.90 7.54 Yes 0.002 0.003 No 0.018 0.020 Yes 24 28 26 64 -9.55 9.10 7.47 Yes 0.038 0.045 No 0.046 0.050 Yes 0.413 0.479 1.600 1.633 1-13

Enclosure 1 PG&E Letter DCL-06-100 Column - Tables 1, 2, 3 Legend and Notes for Tables 1, 2 and 3 SG Steam generator Count Indication count per SG Row Tube Row Col Tube Column Tube Radial Position Tube radial position, inch.

Ind Orientation of indication of degradation. SAI means single axial indication.

Volts Peak voltage from Plus Point coil, as adjusted using the same techniques as PWSCC ARC sizing.

Crack # Crack number CAL Plus Point calibration group number LCT Elevation (inch) of lower crack tip (LCT), relative to the top of tubesheet (TTS).

UCT Elevation (inch) of upper crack tip (UCT), relative to the TTS.

Crack Length Length of crack (inch)

Total Length Total length of all cracks (inch).

MD-adj Maximum depth (% through-wall) from Plus Point coil. The depth is the adjusted depth using the same techniques as PWSCC ARC depth sizing.

Dist UCT to TTS Distance (inch) between the UCT and TTS, including ANDEcr.TTs (Plus Point NDE uncertainty on locating the crack tip relative to the TTS).

UCT below TTS? If the UCT (including NDE uncertainty) is located below TTS (i.e., a positive number in the 'Dist UCT to TTS" column), then PC is satisfied for repeat indications.

W* ZONE W* tubesheet zone based on crack location.

W* Length W* length is 7.12 inch for hot leg Zone Band 5.32 inch for hot leg Zone A, and includes ANDEw (NDE uncertainty in measuring the W* depth).

BWT Elevation of the bottom of the WEXTEX transition (BWT), inch, measured by bobbin relative to the TTS.

Dist UCT to BWT Distance (inch) between the UCT and BWT, including 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.

Dist EOC (N+1) UCT to TTS Distance (inch) between the UICT and TTS at the end of the next cycle including ANDEcT.TTS, based on growing the UCT at 0.119 inch/EFPY.

Dist EOC (N+1) UCT to BWT Distance (inch) between the UCT and BWT at the end of the next cycle including ANDEcT-BwT, based on growing the UCT at 0.119 inch/EFPY.

EOC (N+I) UCT below If the UCT (including NDE uncertainty) is located below BWT at the end of the next cycle (i.e., a positive number inthe "Dist UCT (n+l) UCT to BWT" column), the tube is BWT? a W* candidate.

W* Cand? W* candidate, also referred to as W* tube. A tube is a W* candidate (or W* tube) if the UCT is below BWT and the EOC (n+l) UCT is below BWT.

Inspect Extent Elevation of Plus Point inspection relative to TTS (inch).

W* inspection extent with respect to BWT, also referred to as the W* inspection distance (inch). This is the Plus Point inspection extent relative to BWT. The W*

W* Insp Ext wrt BWT inspection distance below BWT is equal to the Plus Point inspection extent below TTS, plus measured distance from BWT to TTS, plus bobbin NDE uncertainty in locating BWT relative to "-S.

Flex W* Length Flexible W* length relative to BWT (inch), equal to W* Length + 2XCI (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, 0.119 inch/EFPY)

Insp Ext Satisfied? If the W* inspection distance is greater than or equal to the flexible W* length, then the inspection extent is satisfied.

DENTFLO CM Leak Rate Condition monitoring (CM) SLB leak rate, gpm at room temperature, using DENTFLO leak model, based on distance of UCT to BWT, using Figure 6.4-3 of WCAP-14797-P Rev 2. No SLB leak rate is assigned to indications with UCT below W* length.

Prior OA Leak Rate Prior cycle projected operational assessment (OA) leak rate, gpm at room temperature, using DENTFLO leak model.

OA Underprediction? If the DENTFLO CM leak rate is greater than the prior cycle DENTFLO OA projected leak rate, then the OA would be underpredicted.

Constrained Crack Model CM Condition monitoring (CM) SLB leak rate, gpm at room temperature, using Constrained Crack leak model, based on distance of UCT to TTS. No SLB leak rate is assigned Leak Rate to indications with UCT located below TUS minus 12 inches. Note: For 1R13, this leak rate is for information only and is not the CM leak rate of record.

Constrained Crack Model OA Operational assessment (OA) SLB leak rate, gpm at room temperature, using Constrained Crack leak model, based on distance of EOC (n+l) UCT to TTS. No SLB leak Leak Rate rate Is assigned to indications with EOC (n+l) UCT located below TTS minus 12 inches.

PREVW* Tube? Previous W* Tube. If the indication was left in service in the prior cycle, it is classified as a previous W* tube (i.e., a repeat indication). Otherwise, the indication is new.

Deplugged? If tube was de-plugged during a previous outage, then "yes" is indicated.

Tube Plugged? If tube was plugged during the current outage, then "yes" is indicated.

1-14

Enclosure 1 PG&E Letter DCL-06-100 Table 4 Cumulative Number of Unit 2 PWSCC Indications Detected in the Tubesheet Region as a Function of Tubesheet Elevation Distance Cumulative Distribution Cumulative Cumulative (inch) Distribution Frequency of New Distribution Distribution Frequency relative to Pre-2R13 Frequenc Indications Post-2R13 Post-2R13 Pos-213 Post-2R13 Pot-R1 "ITS Pre-2R13 in 2R13

-12 0 0.00 0 0 0.00

-11 2 0.01 2 2 0.01

-10 2 0.03 2 4 0.02

-9 0 0.03 0 4 0.02

-8 0 0.03 0 4 0.02

-7 1 0.03 1 5 0.03

-6 2 0.04 2 7 0.04

-5 0 0.04 1 1 8 0.05

-4 4 0.07 4 12 0.07

-3 5 0.10 1 6 18 0.11

-2 19 0.22 19 37 0.23

-1 53 0.56 53 90 0.56 0 68 0.99 2 70 160 0.99 1 2 1.00 2 162 1.00 Total 158 4 162 162 1-15

Enclosure 1 PG&E Letter DCL-06-100 Table 5 DCPP Unit 2 Condition Monitoring Steam Line Break Leak Rates for W* Alternate Repair Criteria EOC 13 Condition Monitoring Leak Rate SG2-1 SG2-2 SG2-3 SG2-4 (gpm at room temperature) _

Axial PWSCC within flexible W* length (DENTFLO model) 0.265 0.113 0.489 0.413 Table 6 DCPP Unit 2 Operational Assessment Steam Line Break Leak Rates for W* Alternate Repair Criteria EOC 14 Operational Assessment Leak Rate SG2-1 SG2-2 SG2-3 (gpm at room temperature) I I Detected indications within TTS minus 12 inches 1.632 0.635 1.888 1.633 Undetected indications within 8 to 12 inches below TTS 0.0396 0.0396 0.0396 0.0396 Undetected indications below TTS minus 12 inches (Note 1) 0.294 0.281 0.293 0.272 Total 1.966 0.956 2.221 1.945 Note 1: Leak rates are based on 0.00009 gpm multiplied by the number of inservice tubes in Cycle 14 (3263, 3120, 3258, and 3021 tubes for SGs 2-1, 2-2, 2-3, and 2-4, respectively.)

Table 7 DCPP Unit 2 Aggregate Condition Monitoring Steam Line Break Leak Rates EOC 13 Condition Monitoring Leak Rate SG2-1 SG2-2 1 SG2-3 (gpm at room temperature) I W* ARC 0.265 0.113 0.489 0.413 Voltage-Based ARC (Note 1) 0.11 0.07 0.09 0.78 PWSCC ARC (Note 2) 0 0 0 0 Non-ARC degradation 0 0 0 0 Aggregate 0.375 0.183 0.579 1.193 Note 1: Voltage-based ARC leak rates are described in Enclosure 3.

Note 2: PWSCC ARC leak rates are described in Enclosure 2.

Table 8 DCPP Unit 2 Aggregate Operational Assessment Steam Line Break Leak Rates (gpm at room temperature)

W* ARC 1.966 0.956 2.221 1.945 Voltage-Based ARC (Note 1) 1.16 0.61 0.53 3.75 PWSCC ARC (Note 2) 0 0 0 0 Non-ARC degradation 0 0 0 0 Aggregate 3.126 1.566 2.751 5.695 Note 1: Voltage-based ARC leak rates are described in Enclosure 3.

Note 2: PWSCC ARC leak rates are described in Enclosure 2.

1-16

Enclosure I PG&E Letter DCL-06-100 Figure 1 DCPP 2 Cumulative Tubesheet Region PWSCC Trending by EFPY Through 2R13

• All Data 0 Post-W* Outages ------EOC Linear (Post-W Outages) 180 ______

160 140o o _

_____ox _.84t __ _" _

120-____ ____ ____

0 100-S80 U60-40-20-0 0 2 4 6 8 10 12 14 16 18 20 EFPY 1-17

Enclosure 1 PG&E Letter DCL-06-1 00 Figure 2 DCPP Unit 2 Tubesheet PW*SCC Elevation vs Number of Indications 60- 1 1 90 M Data I Inch and Greeater Below TTS

-Regression 50 - Upper 90% Predicti on - 8

- - Cumulative Indicati ons 70 40- 60 o

• 50

• 4 30 -

30 20 \ 2(

10

--- - T ______-_30 10 -- _

0 1 2 3 4 5 6 7 8 9 10 11 12 Distannee below TTS (inch) 1-18

Enclosure 2 PG&E Letter DCL-06-100 ENCLOSURE 2 SPECIAL REPORT 06-02 TSP PWSCC ALTERNATE REPAIR CRITERIA 120-DAY REPORT DIABLO CANYON POWER PLANT UNIT I THIRTEENTH REFUELING OUTAGE NRC Reporting Requirements Primary water stress corrosion cracking (PWSCC) alternate repair criteria (ARC) for axial PWSCC at dented tube support plates (TSP) was implemented for the third time in Diablo Canyon Power Plant (DCPP) Unit 2 during Unit 2 Thirteenth Refueling Outage (2R13). 2R13 steam generator (SG) inspections and repairs were completed in May 2006.

For implementation of ARC for axial PWSCC at dented TSPs, DCPP Technical Specification (TS) 5.6.10.h requires that the results of the condition monitoring and operational assessments be reported to the NRC within 120 days following completion of the inspection. This report implements the DCPP TS reporting criteria. To satisfy the TS, this report includes the following:

" Tabulations of indications found in the inspection, tubes repaired, and tubes left in service under the ARC.

" Growth rate distributions for indications found in the inspection and growth rate distributions used to establish the tube repair limits.

• Plus Point confirmation rates for bobbin detected indications when bobbin is relied upon for detection of axial PWSCC in less than or equal to 2 volt dents.

• For condition monitoring, an evaluation of any indications that satisfy burst margin requirements based on the Westinghouse burst pressure model, but do not satisfy burst margin requirements based on the combined Argonne National Laboratory (ANL) ligament tearing and EPRI through-wall (ANL/TW) burst pressure model.

" Performance evaluation of the operational assessment methodology for prediction of flaw distributions as a function of flaw size.

" Evaluation results of number and size of previously reported versus new PWSCC indications found in the inspection, and the potential need to account for new indications in the operational assessment burst evaluation.

• Identification of mixed mode (axial PWSCC and circumferential) indications found in the inspection and an evaluation of the mixed mode indications for potential impact on the axial indication burst pressures or leakage. In addition, as committed in Pacific Gas and Electric Company (PG&E) Letter DCL-02-045, "Response to Final NRC Request for Additional Information Regarding Supplement 3 to License Amendment Request 00-06, 'Alternate Repair Criteria for Axial PWSCC at Dented Intersections in Steam Generator Tubing'," performance of a trending analysis to assess the potential for increasing mixed mode affects over time.

2-1

Enclosure 2 PG&E Letter DCL-06-100

• Any corrective actions found necessary in the event that condition monitoring requirements are not met.

Background:

Dented TSP Plus Point Inspection Scope The 2R1 3 Plus Point dent inspection scope for greater than 2 volt dents was based on greater than 2 volt dents called in the prior Unit 2 Twelfth Refueling Outage (2R12).

The minimum scope for greater than 2 volt dents inspected by Plus Point in 2R1 3 is provided in Table 1.

The dented TSP inspection criteria and expansion plan criteria described below are based on PG&E Letter DCL-01-036, "Revision of Dent Inspection Program Requirements," to the NRC dated April 16, 2001, and WCAP-1 5573, Revision 1, "Depth-Based SG Tube Repair Criteria for Axial PWSCC at Dented TSP Intersections -

Alternate Burst Pressure Calculation."

Plus Pointinspection criteriafor axial PWSCC left in service Plus Point inspections shall be conducted on 100 percent of axial PWSCC indications at dented TSP intersections that were left in service in Unit 2 Cycle 13. Fifty three axial PWSCC indications had been left in service in Cycle 13 under PWSCC ARC.

Plus Point inspection criteria for greaterthan or equal to (?) 5 volt dented intersections For Unit 2, in each SG, Plus Point inspections shall be conducted on 100 percent of> 5 volt dented intersections, both hot leg and cold leg.

Plus Point inspection criteriafor greaterthan 2 and less than 5 volt dented intersections On a SG-specific basis, Plus Point inspections shall be conducted on 100 percent of greater than (>) 2 and less than (<) 5 volt dented intersections up to and including the coldest TSP elevation where PWSCC (at any size dent), circumferential indications (at any size dent), or> 2 inferred volt axial ODSCC not detected by bobbin (AONDB) (at

> 2 and < 5 volt dent) have been previously detected in that SG in the prior two outages, or current outage (implies expansion requirement), plus 20 percent of > 2 and

< 5 volt dent at the next colder TSP elevation. If a SG is free from PWSCC (at any size dent), circumferential indications (at any size dent) and > 2 inferred volt AONDB (at > 2 and < 5 volt dent), then Plus Point inspections shall be conducted on 20 percent of > 2 and < 5 volt dents at 1 H. For any 20 percent sample, a minimum of 50 > 2 and < 5 volt dents shall be inspected. Ifthe population of > 2 and < 5 volt dents at that TSP elevation is less than 50, then 100 percent of the > 2 and < 5 volt dents at that TSP shall be inspected.

2-2

Enclosure 2 PG&E Letter DCL-06-100 The coldest TSP where PWSCC, AONDB with > 5 volt dent, or circumferential indications have been found in the prior two outages (Unit 2 Eleventh Refueling Outage

[2R11] and 2R12) was 5H forSG 2-2, 3H forSG 2-3, and 3H forSG 2-4. In SG 2-1, no PWSCC, AONDB with > 5 volt dent, or circumferential indications have been detected.

In addition, all inferred bobbin voltages for AONDB indications have been less than 2 volts, so AONDB indications do not factor into the inspection scope.

Plus Pointinspection criteriafor detection of circumferentialindicationsat dents On a SG-specific basis, if a circumferential indication or > 2 inferred volt AONDB is detected in a dent of "x" volts in the prior two outages, or current outage (implies expansion requirement), then Plus Point inspections shall be conducted on 100 percent of dents greater than "x - 0.3" volts up to the affected TSP, plus 20 percent of dents greater than "x - 0.3" volts at the next higher TSP. "X" is defined as the lowest dent voltage where a circumferential crack or > 2 inferred volt AONDB was detected in that SG. For any 20 percent sample, a minimum of 50 "x - 0.3" volt dents shall be inspected. If the population of "x - 0.3" volt dents at that TSP elevation is less than 50, then 100 percent of the "x - 0.3" volt dents at that TSP shall be inspected.

The smallest dent in which a circumferential crack has been detected in the prior two outages (2R1 I and 2R1 2) was 6.74 volts (in SG 2-2). Thus, the affected population for potential circumferential cracking is dents greater than greater than 6.44 volts (i.e., 6.74

- 0.3 = 6.44). The existing 2 volt dent cutoff for 2R1 3 Plus Point inspections is much less than the 6.44 volt threshold for circumferential cracking, and was therefore sufficient. Therefore, less than 2 volt dent Plus Point inspections were not required in the inspection plans. In addition, all inferred bobbin voltages for AONDB indications have been less than 2 volts, so AONDB indications do not factor into the inspection scope for detection of circumferential indications.

Summary of Plus Point inspectionplan of dented TSPs Based on the Plus Point inspection criteria listed above, the following Plus Point dent inspection criteria were implemented. The numbers of dent inspections is summarized in Table 1.

> 5 volt dents

- 100 percent in all SGs, both hot leg and cold leg

>2 and < 5 volt dents

• SG 2-1: 20 percent at 1H

• SG 2-2: 100 percent from I H to 5H, 20 percent at 6H

• SG 2-3: 100 percent from 1 H to 3H, 20 percent at 4H

• SG 2-4: 100 percent from 1 H to 3H, 20 percent at 4H 2-3

Enclosure 2 PG&E Letter DCL-06-100

• All 20 percent samples shall contain a minimum of 50 dents. If the population of dents at the TSP elevation is less than 50, then inspect 100 percent of the dents at the TSP.

Plus Point inspection of bobbin distorted indicationsat less than or equal to 2 volt dents One hundred percent of the tubes were inspected full length by bobbin coil (except for Rows 1 and 2 U-bends), and the bobbin coil was relied upon for detection of axial PWSCC in < 2 volt dents. If the bobbin coil detected a distorted ID support signal (DIS) at a dented TSP intersection, then Plus Point inspection was performed.

Summary of Inspection Results Table 5 provides a list of all TSP axial PWSCC indications detected in 2R13. Table 6 provides a list of all TSP circumferential indications detected in 2R13.

No expansion of the Plus Point dent inspection program was required in 2R13, based on the following inspection results:

• No axial PWSCC or circumferential indications were detected in SG 2-1.

• No axial PWSCC or circumferential indications were detected above 5H in SG 2-2.

• No axial PWSCC or circumferential indications were detected above 3H in SG 2-3.

• No axial PWSCC or circumferential indications were detected above 3H in SG 2-4.

" All inferred bobbin voltages for AONDB indications were less than 2 volts.

" The dent voltages associated with TSP circumferential indications were greater than 0.3 volts above the 2.0 volt dent threshold for potential expansion. The smallest 2R1 3 dent voltage coincident with a circumferential indication was 4.03 volts.

Tabulations of indications found in the inspection, tubes repaired, and tubes left in service under the ARC.

Fifty nine axial PWSCC indications at dented TSP intersections were detected in 2R13.

Table 5 provides a tabulation of indications, including the following information:

• SG, row, column, TSP, crack number, calibration group number

• Identifies the indication as repeat or new.

" For indications that were plugged in 2R1 3, the reason for plugging

" Adjusted nondestructive examination (NDE) measurements (length, maximum depth, and average depth), voltage, and adjusted NDE crack location relative to the TSP centerline.

" Burst pressures (free span and total length). For the operational assessment, the pressures are calculated using the ANL/TW burst model. For the condition monitoring assessment, the pressures are calculated using the Westinghouse burst model. A burst pressure of 6100 pounds per square inch (psi) represents a 2-4

Enclosure 2 PG&E Letter DCL-06-100 predicted burst pressure _>6100 psi since all pressures predicted to exceed 6100 psi are grouped at 6100 psi to reduce computer storage requirements in the analysis.

Steam line break (SLB) leak rates (free span and total length) using the ANL ligament tearing model, for condition monitoring and operational assessment.

The PWSCC ARC allows axial PWSCC indications to remain in service at dented TSP intersections if the following PWSCC ARC conditions are satisfied for each indication:

" Operational Assessment (OA) free span burst pressure (based on the ANL/TW model) exceeds 3 times the normal operating differential pressure (3dPNO). The 3dPNO burst pressure is equal to 4419 psi.

" OA total length burst pressure (based on the ANL/TW model) exceeds 1.4 times the SLB differential pressures (1.4dPSLB). The 1.4dPSLB burst pressure is equal to 3367 psi, based on a dPSLB of 2405 psi (pressurizer power operated relief valve (PORV) setpoint plus uncertainty).

• OA free span leak rate, when combined with free span leak rates from other degradation mechanisms, is less than 1 gpm (0.72 gpm at room temperature) in a faulted SG.

" OA total length leak rate, when combined with leak rates from other degradation mechanisms, is less than 10.5 gallons per minute (gpm) (room temperature) in a faulted SG.

" The indication is less than 40 percent through-wall outside the TSP crevice.

In addition to the above PWSCC ARC conditions, axial PWSCC indications must satisfy the following exclusion criteria in order to remain in service:

• The indication is not located at a TSP intersection located in the wedge region or 7H/7C high bending stress region.

" The indication is not located at a TSP intersection that contains cracked or missing TSP ligaments.

" The indication is not located at a TSP intersection that contains a different degradation mechanism.

" The indication is not located in a tube that contains another repairable indication.

Fifty three axial PWSCC indications at dented TSPs had been left in service following 2R12 under PWSCC ARC. Following 2R13 Plus Point inspection, sizing, and application of PWSCC ARC requirements, 6 of the repeat axial PWSCC indications were plugged, as described below:

• Two due to the axial PWSCC indication being greater than or equal to 40 percent depth outside the tube support plate (SG 2-2 R1 I C30 crack 2, SG 2-2 R23C14 crack 1). In addition, SG 2-2 RI I C30 cracks 1 and 3 were plugged because crack 2 was plugged.

• Two due to the axial PWSCC indication being located at a TSP where 2-5

Enclosure 2 PG&E Letter DCL-06-100 circumferential cracking was also detected (SG 2-2 R2C40 crack 1, SG 2-2 R1 0C30 crack 1). This combined degradation is termed PWSCC mixed mode.

In 2R13, six new axial PWSCC indications at dented TSPs were detected, sized by Plus Point, and applied to PWSCC ARC requirements. Two of these were plugged due to combined axial ID/OD degradation (SG 2-4 R22C21 crack 1, SG 2-4 R23C52 crack 1), and all others were allowed to remain in service under PWSCC ARC.

The indications that were located outside the TSP region were reviewed to determine the need for in-situ pressure testing in accordance with the criteria in WCAP-1 5573, Revision 1. Namely, if condition monitoring for axial PWSCC at dented TSPs predicts free span leakage or free span burst pressures less than 3dPNO, then in-situ pressure testing is required. These conditions were not predicted by condition monitoring, and therefore no in-situ pressure testing of axial PWSCC at dents was required nor performed.

Fifty one axial PWSCC indications at dented TSPs were returned to service in 2R13:

forty seven repeat indications and four new indications.

Growth rate distributions for indications used to establish the tube repair limits and for indications found in the inspection The growth rate distribution used to establish the tube repair limits was based on prior outage growth data. The methodology for establishing the growth rate was established in WCAP-1 5573, Revision 1, as further explained in PG&E Letters DCL-02-023, "Response to NRC Request for Additional Information Regarding Supplement 3 to License Amendment Request 00-06, 'Alternate Repair Criteria for Axial PWSCC at Dented Intersections in Steam Generator Tubing'," and DCL-02-045. The methodology is summarized below:

" Ifthere are at least two hundred points in each of the last two cycles on the unit being inspected, the most conservative growth distribution from the last two cycles shall be used.

" Ifthere are at least two hundred points over the last two cycles on the unit being inspected, the growth distribution to be used is the more conservative of the combined data or either of the two cycles.

• Ifthere are less than two hundred points over the last two cycles on the unit being inspected, the growth distribution to be used shall contain data from both units over the last two (or three if necessary) cycles of each unit until 200 data points are obtained. The data from each cycle is compared for consistency in growth magnitude. If a given cycle has lower growth rates than other cycles, it is not included in the growth distribution.

In preparation for 2R13, the third bullet applied. As shown in Table 3, over theprior two Unit 2 inspections (2R1 1 and 2R1 2), there are only 107 data points, less than the 2-6

Enclosure 2 PG&E Letter DCL-06-100 200 points required for a Unit 2 specific growth rate distribution. Therefore, the 2R1 I and 2R1 2 data were supplemented by data from 1R1 2 and 1R1 3, resulting in a total of 548 data points over the last two cycles from each unit: 2R1 1 (49), 2R1 2 (58), 1R1 2 (215), and 1R13 (226). The oldest growth data from 1R8, 2R8, 1R9, 2R9, 1R10, 2R10, and 1R11, does not require evaluation and is excluded per the above methodology because over 200 data points are already available from the more recent inspections.

Per the ARC methodology, the four data sets to be included for evaluation are to be examined for potential exclusion of data points. To bound the ARC method, for the preliminary Cycle 14 operational assessment, PG&E chose to conservatively use the lower bound Cumulative Probability Distribution (CPD) growth rates between each of the four data sets. The lower bound growth rate CPD is provided in Table 2 and was used in the Monte Carlo preliminary cycle 14 OA calculations for determining the need for tube repair.

In accordance with WCAP-1 5573, Revision 1, Unit I Cycle 13 growth rates that could impact the upper tail of the preliminary OA growth distribution were evaluated during 2R13. The methodology requires that if new growth data causes the growth distribution above 90 percent probability to be more conservative, the new data should be added to the growth distribution for the final OA.

57 additional growth rate data points from Cycle 13 were established, 53 from repeat indications and 4 from new indications. The CPD of the growth data is provided in Table 2.

During 2R13, the Cycle 13 growth rates were compared to the 90 percentile growth rates established from the preliminary Cycle 14 OA growth distribution in Table 2 (0.069 inch, 9.65 percent maximum depth [MD], 7.10 percent average depth [AD]). Several Cycle 13 growth rates exceeded these values, and the WCAP methodology required that these Cycle 13 data points be added to the growth distribution for the final OA. To bound the WCAP methodology, PG&E developed a conservative growth distribution based on the lower bound of the CPD from the combined Cycle 13 data set and the preliminary OA data set. This lower bound growth distribution was separately developed for growth in length, maximum depth, and average depth. The lower bound growth rate CPD is provided in Table 2 and was used in the Monte Carlo final Cycle 14 OA calculations for determining the need for tube repair in 2R1 3. When comparing the final OA and preliminary OA growth distributions, the final OA was more conservative for maximum depth and length, and unchanged for average depth. For information, Table 3 compares the 90 percentile growth values per EFPY at 604 degrees for the recent inspections that were evaluated.

Plus Point confirmation rates for bobbin detected indications when bobbin is relied upon for detection of axial PWSCC in less than or equal to 2 volt dents.

In 2R13, the bobbin coil was relied upon for detection of axial PWSCC in less than or 2-7

Enclosure 2 PG&E Letter DCL-06-100 equal to 2 volt dents. As identified in Table 4, there were 193 DIS indications detected by bobbin at less than or equal to 2 volt dented TSP intersections with non-repeat PWSCC indications. Tracking of Plus Point confirmation rates for repeat PWSCC indications is not required because these known flaws are inspected by Plus Point regardless of the bobbin call.

All DIS indications were inspected by Plus Point. None of the DIS indications were confirmed as PWSCC by Plus Point, for a Plus Point confirmation rate of 0 percent, or a 100 percent bobbin overcall rate. The high bobbin overcall rate is greater than the approximately 90 percent overall rate generated during the bobbin coil performance test documented in WCAP-15573, Revision 1. The high bobbin overcall rate establishes a very high probability of detecting significant axial PWSCC indications in less than or equal to 2 volt dents.

For condition monitoring, an evaluation of any indications that satisfy burst margin requirements based on the Westinghouse burst pressure model, but do not satisfy burst margin requirements based on the combined ANL ligament tearing and through-wall burst pressure model.

This item is not applicable. All indications satisfied condition monitoring (CM) burst margin requirements based on the combined ANL ligament tearing and EPRI through-wall (ANLITW) burst pressure model, as well as the Westinghouse (WEC) burst pressure model. The CM Westinghouse model burst pressures are shown in Table 5 for both free span and total length. The ANLITW model burst pressures for total length are shown in Table 6. The total length CM burst requirement was 3367 psi at 1.4dPSLB. The free span length CM burst requirement was 4419 psi at 3dPNO.

Performance evaluation of the operational assessment methodology for prediction of flaw distributions as a function of flaw size.

PG&E evaluated the performance of the PWSCC ARC OA methodology for prediction of flaw distributions as a function of flaw size. WCAP-1 5573, Revision 1, provides guidance for determining when corrective actions are needed when a single indication OA prediction significantly underestimates the burst pressure or leak rate when compared to the CM results. When comparing single indication projected leak and burst data with that obtained for the same indication from the inspection results, additional evaluations are to be performed and included in the 120-day report if: (1) the CM single indication burst pressure is < 5600 psi and more than 500 psi less than the projection obtained using the same burst model; or (2) the CM single indication leak rate is more than 0.2 gpm larger than the projected SLB leak rate.

Performance Evaluation of Single Indication SLB Leak Rates Regarding CM single indication total length SLB leak rates, no CM single indication leakage was calculated in any SG, either from total length or free span. From the prior 2-8

Enclosure 2 PG&E Letter DCL-06-100 cycle OA, no CM single indication leakage was calculated in any SG, either from total length or free span. Therefore, the single indication OA leak rate methodology using the ANL ligament tearing model is determined to be adequately conservative, and no corrective actions are required.

Performance Evaluation of Single Indication Burst Pressures A benchmarking assessment (CM versus prior cycle OA projections) was performed for the repeat indications that had been left in service in Unit 2 Cycle 13 under PWSCC ARC. As required by the PWSCC ARC, the OA burst pressures are 95/95 values, and the CM burst pressures are 95/50 values.

With one exception, all prior cycle projected'EOC 13 burst pressures exceeded the default free span and total length burst pressures of 6100 psi, using the ANL/TW model (the exception was 2R12 indication in SG 2-2 R8C36 with a projected total length burst pressure of 5784 psi using the ANL/TW model). The as-found free span and total length burst pressures for all indications exceeded the default value of 6100 psi for the CM assessment, using both burst models.

Based on this performance evaluation via benchmarking, the OA burst pressure methodology is determined to be adequately conservative.

Performance Evaluation of Total SG Monte Carlo SLB Leakage Page 7-12 of WCAP-1 5573, Revision 1, requires the following: "If the results of the single indication analy~es show leakage for condition monitoring or operational assessment for either free span or total length, then a total SG leak rate Monte Carlo operational assessment is required for each SG that shows leakage. A conservative probability of detection (POD) of 0.6 is used in the SG analysis."

The results of the 2R1 3 single indication analysis did not show CMOA leakage for free span and total length analyses and, as such, a total SG leak rate Monte Carlo OA was not required for any SG per the WCAP requirements. However, as committed in DCL-06-029 dated February 24, 2006, PG&E requires that total SG Monte Carlo analyses be performed in each SG with axial PWSCC indications for CM and OA, regardless of the result of the single indication analyses. Therefore, total SG leak rate analyses were performed for CM (using a POD of 1.0) and OA (using a POD of 0.6) for SGs 2-2, 2-3, and 2-4. The results of the total SG leak rate analyses show that no SG had any CMOA leakage.

2-9

Enclosure 2 PG&E Letter DCL-06-100 Evaluation results of number and size of previously reported versus new PWSCC indications found in the inspection, and the potential need to account for new indications in the operational assessment burst evaluation.

As discussed above, there were 59 axial PWSCC indications detected in 2R13: 6 new indications and 53 repeat indications. The number of new indications continues to be a small fraction of the total number of indications. Of the 5 new indications with prior Plus Point inspection (1 had no prior Plus Point inspection), 4 were detectable in 2R12 based on a lookup review, indicating a small growth rate progression. All of the new indications had CM and OA burst pressures in excess of 6100 psi using both the Westinghouse model and the ANL/TW model. Therefore, because the numbers of new flaws are relatively small, exhibited slow growth rates, and have CMOA burst pressures well in excess of burst margin requirements, there is no need to account for new indications in the OA burst evaluation.

Identification of mixed mode (axial PWSCC and circumferential) indications found in the inspection and an evaluation of the mixed mode indications for potential impact on the axial indication burst pressures or leakage. In addition, performance of a trending analysis to assess the potential for increasing mixed mode affects (e.g., circumferential crack depths, burst pressure reductions, increased leakage rates) over time.

For PWSCC ARC, a mixed mode indication is defined as an axial PWSCC indication and a circumferential indication (either outside diameter stress corrosion cracking (ODSCC) or PWSCC) occurring at the same dented TSP intersection. The indications are termed PWSCC mixed mode. Per the WCAP-1 5573 Revision 1 methodology, a separation distance of 0.25 inch is adequate to reduce mixed mode effects on axial burst pressures to acceptable levels, except for the case when both the axial and circumferential indications are throughwall (in which case a separate mixed mode evaluation is required for any separation distance). Per WCAP-1 5573 Revision 1, the required 0.25 inch separation distance can also be confirmed by the presence of at least 0.075 inch and 0.050 inch null point spacing for circumferential ODSCC indications and circumferential PWSCC indications, respectively. The WCAP methodology recommends that the return to null separation be determined using the 600 kHz 0.080 inch pancake coil instead of the Plus Point coil, due to the potential that the Plus Point coil could provide a false null for closely spaced axial PWSCC indications (which rotate up) and circumferential PWSCC indications (which rotate down) of significant depth.

There were two TSP intersections that contained PWSCC mixed mode indications in 2R13, as described below. Detailed NDE measurements are provided in Table 5 for axial indications and Table 6 for circumferential indications.

2-10

Enclosure 2 PG&E Letter DCL-06-1 00 SG 2-2 R1 0C30 1 H, with dent of 11.84 volts, had one circumferential ODSCC indication, one circumferential PWSCC indication, and one axial PWSCC indication.

The axial indication was a repeat indication from the prior cycle. Figure 4 provides a simplified sketch of the 3 indications, the axial and circumferential separation distances between the axial and circumferential indications, and the lengths and depths of the indications. The separation distance between the axial indication and circumferential PWSCC indication is 0.31 inch. The separation distance between the axial indication and circumferential ODSCC indication is 0.37 inch applying the square root of the sum of the squares (SRSS) of the axial and circumferential separation distances. Because these separation distances are greater than the 0.25 inch threshold value for potential interaction, and because none of the indications are 100 percent throughwall at any point, with allowances for NDE uncertainty, the indications are treated as noninteracting for PWSCC ARC. Therefore, a detailed mixed mode evaluation is not required because there is no potential impact on the axial indication burst pressure or leakage based on PWSCC ARC WCAP-1 5573 Revision 1 methodology. The required 0.25 inch separation distance between the axial indication and the circumferential PWSCC indication was confirmed by the presence of 8 null points (about 0.264 inch null point spacing) using both the 600 kHz 0.080 inch pancake coil and the 300 kHz Plus Point coil. The required 0.25 inch separation distance between the axial indication and the circumferential ODSCC indication was confirmed by the presence of 4 null points (about 0.132 inch null point spacing) using the 300 kHz Plus Point coil. The ODSCC indication could not be detected using the 600 kHz 0.080 inch pancake coil because the depth was very shallow, so null points observed using this coil cannot be applied. The rotating probe coil spacing is 0.033 inch.

SG 2-2 R2C40 I H, with dent of 22.92 volts, had two circumferential ODSCC indications and one axial PWSCC indication. The axial indication was a repeat indication from the prior cycle. Figure 5 provides a simplified sketch of the 3 indications, the axial and circumferential separation distances between the axial and circumferential indications, and the lengths and depths of the indications. The resultant separation distances between the axial indication and circumferential ODSCC indications number 1 and number 2 are 0.81 inch and 0.89 inch respectively, applying the SRSS of the axial and circumferential separation distances. Because these separation distances are greater than the 0.25 inch threshold value for potential interaction, and because none of the indications are 100 percent throughwall at any point, with allowances for NDE uncertainty, the indications are treated as noninteracting for PWSCC ARC. The required 0.25 inch separation distance between the axial indication and circumferential ODSCC indication number 1 and number 2 was confirmed by the presence of 4 null points (about 0.132 inch null point spacing) and 6 null points (about 0.198 inch null point spacing), respectively, using the 300 Khz Plus Point coil. The ODSCC indications could not be detected using the 600 Khz 0.080 inch pancake coil because the depths were very shallow, so null points observed using this coil cannot be applied. The rotating probe coil spacing is 0.033 inch.

2-11

Enclosure 2 PG&E Letter DCL-06-100 Based on the above mixed mode evaluations, a detailed mixed mode evaluation is not required because there is no potential impact on the axial indication burst pressure or leakage based on PWSCC ARC WCAP-1 5573 Revision 1 methodology. Even if the indications are assumed to be interacting, there is no potential impact on the axial indication burst pressure or leakage because (1) the axial and circumferential indications are not throughwall, (2) the axial indications are short and shallow such that their burst pressures exceed 6100 psi, and (3) the average depths of the circumferential indications are less than the 80 percent threshold value after accounting for 95 percent NDE uncertainty for mixed mode affects.

In response to NRC request for additional information, PG&E Letter DCL-02-045 dated April 18, 2002, committed to perform a trending analysis in the 120-day report to assess the potential for increasing mixed mode affects (e.g., circumferential crack depths, burst pressure reductions, increased leakage rates) over time. Since no burst pressure reductions or leakage rate multipliers have been required, there is no data to trend for these parameters. Trending of circumferential depths and number of circumferential indications is provided in Figures 1, 2, and 3.

Figure 1 provides all DCPP Unit 2 TSP PWSCC and ODSCC circumferential indication measured adjusted average depths versus year detected. The adjustments do not include NDE uncertainty. The mean trend line shows a slight increase in average depths, attributed to the three short indications noted above with larger average depths but low amplitudes (i.e., less than or equal to 0.21 volt). The frequency of larger depths tends to show an oscillating up and down pattern between outages, which may be a result of conservative sizing of low amplitude flaws.

Figure 2 data is a subset of Figure 1, showing the PWSCC mixed mode circumferential indication average depths versus year detected. A total of nine Unit 2 circumferential indications have been associated with PWSCC mixed mode indications, including the four circumferential indications detected in 2R13. The mean trend line shows a slight increase in average depths of these nine circumferential indications, attributed to the two largest depth indications detected in 2R13.

Figure 3 provides the number of DCPP Unit 2 TSP PWSCC and ODSCC circumferential indications detected over time. Even though there was an increase in the number of circumferential indications in 2R1 3 compared to recent outages, the overall mean trend line shows a slight decrease due to the large number of indications detected in 1996.

Even though Unit 2 shows increasing recent trends in the number of circumferential indications, circumferential average depths, and mixed mode indications, there is not a significant potential for increasing mixed mode affects over time based on the small Plus Point voltages associated with these circumferential indications (indicating shallow depths), and low probability of interacting mixed mode indications. Of the nine Unit 2 TSP intersections with mixed mode indications, none were determined to be'interacting 2-12

Enclosure 2 PG&E Letter DCL-06-100 based on the WCAP-1 5573 Revision 1 methodology.

Conditions Requiring Evaluation to Determine Need for Corrective Actions There are several conditions related to mixed mode indications and circumferential indications that require evaluation to determine the need for corrective actions. These are discussed below:

" If an interactingPWSCC mixed-mode indication is found to have led to a reduction in the axial indication burst pressure by more than 10 percent and to less than 4000 psi, or to have caused an indication to not satisfy burst margin requirements, the burst margin requirements for implementation in the OA at the next and subsequent outages must be increasedby the percentage reduction in the burst pressure found for the mixed mode indication.

As discussed earlier, there are no interacting mixed mode indications, so no corrective actions are necessary.

" If an interactingPWSCC mixed-mode indicationis found, and the axial indication condition monitoring predicts SLB leakage at 95/50, and the circumferential indicationhas > 50 percent average depth including NDE uncertainty,then the CM leak rate for the axial indication must be increasedby a leakage factor. In addition, the OA SLB leak rate for each SG must be increasedby a leakage factor.

As discussed earlier, there are no interacting mixed mode indications, so no corrective actions are necessary.

• If a previously Plus Point-inspectedTSP intersectionis found to have a circumferentialindication with average depth > 80 percent after accounting for NDE uncertainty,then the OA SLB leak rate for each SG must be increasedby a leakage factor.

There were 16 TSP circumferential indications detected in 2R13. All of the TSPs with circumferential indications detected in 2R13 were previously Plus Point inspected in 2R12. The deepest 2R13 circumferential indications had average depths of 75 percent, 71.5 percent and 71.3 percent, including 95 percent NDE uncertainty, less than the 80 percent average depth threshold. The maximum Plus Point amplitude for these flaws were very small (0.21, 0.15, 0.16 volts, respectively),

and it is expected that the flaws were very conservatively sized. Therefore, no corrective actions are needed to adjust the OA SLB leak rates.

2-13

Enclosure 2 PG&E Letter DCL-06-100 Any corrective actions found necessary in the event that condition monitorinq requirements are not met.

This item is not applicable, because all indications satisfied condition monitoring burst margin requirements and leakage margin requirements.

All CM burst pressures, evaluated at 95 percent probability and 50 percent confidence (95/50), exceeded the 3367 psi total length SLB burst margin requirement and the 4419 psi free span burst margin requirement, using both the Westinghouse model and the ANLITW model.

CM single indication SLB leak rates were evaluated at 95 percent probability and 50 percent confidence (95/50), using the ANL ligament tearing model. No free span leakage was calculated, and no total length leakage was calculated. In addition, total SG leak rate Monte Carlo analyses were performed for each SG with indications, and no free span or total length leakage was calculated at 95/50 confidence levels using a POD of 1.0.

2-14

Enclosure 2 PG&E Letter DCL-06-100 Table I 2R13 Minimum Scope for Plus Point Inspection of Dented TSP Intersections 2-5 Volt Dents TSP SG 2-1 SG 2-2 SG 2-3 SG 2-4 TOTAL 1H 2 85 6 1 94 2H 23 4 4 31 3H 2 8 23 33 4H 38 2 3 43 5H 2 2 6H 7H TOTAL 2 150 20 31 203

> 5 Volt Dents TSP SG 2-1 SG 2-2 SG 2-3 SG 2-4 TOTAL 1H 0 303 1 0 304 2H 0 6 0 0 6 3H 0 1 1 26 28 4H 0 84 0 1 85 5H 2 0 0 0 2 6H 0 0 0 0 0 7H 0 0 1 4 5 7C 0 0 1 0 1 6C 0 0 0 0 0 5C 0 0 0 0 0 4C 0 0 3 0 3 3C 0 0 0 0 0 2C 0 0 0 0 0 1C 0 0 0 1 1 TOTAL 2 394 7 32 435 2R13 Plus Point dent inspection criteria:

0 100% of > 5 volt dents 0 SG 2-1: 20% of > 2 and <5 volt dents at 1 H 0 SG 2-2: 100% of > 2 and <5 volt dents from 1 H to 5H (critical area), 20% at 6H 0 SG 2-3: 100% of > 2 and <5 volt dents from 1H to 3H (critical area), 20% at 4H 0 SG 2-4: 100% of > 2 and <5 volt dents from 1 H to 3H (critical area), 20% at 4H 0 All 20% samples shall contain a minimum of 50 dents. If the population of >2 and <5 volt dents at the TSP elevation is less than 50, then inspect 100% of >2 and <5 volt dents at the TSP.

2-15

Enclosure 2 PG&E Letter DCL-06-100 Table 2 - Axial PWSCC Cumulative Probability Distribution (CPD) Growth Rates per EFPY at 604F 2Rl1 data 1R12 data 2R12 data 1R13 data Prelim OA 2R13 data Final OA Lower BoundPD Lower BounPCP Length Bin (inch) Freq CPD Freq CPD Freq CPD Freq GPO fom C Freq CPD Bound GPO from 4 prior from 5 prior cycles cycles 0 19 0.388 78 0.363 22 0.379 58 0.257 0.257 11 0.193 0.193 0.01 4 0.469 24 0.474 7 0.500 27 0.376 0.376 4 0.263 0.263 0.02 13 0.735 45 0.684 13 0.724 24 0.482 0.482 8 0.404 0.404 0.03 3 0.796 17 0.763 7 0.845 34 0.633 0.633 6 0.509 0.509 0.04 2 0.837 19 0.851 3 0.897 19 0.717 0.717 8 0.649 0.649 0.05 2 0.878 14 0.916 1 0.914 14 0.779 0.779 5 0.737 0.737 0.06 4 0.959 7 0.949 1 0.931 21 0.872 0.872 5 0.825 0.825 0.07 0 0.959 5 0.972 1 0.948 7 0.903 0.903 4 0.895 0.895 0.08 0 0.959 1 0.977 2 0.983 3 0.916 0.916 0 0.895 0.895 0.09 2 1.000 4 0.995 1 1.000 4 0.934 0.934 0 0.895 0.895 0.1 0 1.000 1 1.000 0 1.000 4 0.951 0.951 1 0.912 0.912 0.11 0 1.000 0 1.000 0 1.000 1 0.956 0.956 2 0.947 0.947 0.12 0 1.000 0 1.000 0 1.000 2 0.965 0.965 0 0.947 0.947 0.13 0 1.000 0 1.000 0 1.000 1 0.969 0.969 3 1.000 0.969 0.14 0 1.000 0 1.000 0 1.000 0 0.969 0.969 0 1.000 0.969 0.15 0 1.000 0 1.000 0 1.000 6 0.996 0.996 0 1.000 0.996 0.16 0 1.000 0 1.000 0 1.000 0 0.996 0.996 0 1.000 0.996 0.17 0 1.000 0 1.000 0 1.000 0 0.996 0.996 0 1.000 0.996 1.000 0 1.000 0 1.000 1 1.000 1.000 0 1.000 1.000 0.18 0 Total 49 215 58 226 57 2-16

Enclosure 2 PG&E Letter DCL-06-100 Table 2 - Axial PWSCC Cumulative Probability Distribution (CPD) Growth Rates per EFPY at 604F 2Rl1 data 1R12 data 2R12 data 1R13 data Prelim OA 2R13 data Final OA Lower Lower MD Bin Freq CPD Bound CPD

(%TW FreM CPD Freq CPD Freq CPD Freq CPD Bound CPD fatW from 4 prior from 5 prior fraction) cycles cycles 0 30 0.612 63 0.293 20 0.345 141 0.624 0.293 35 0.614 0.293 0.01 1 0.633 8 0.330 0 0.345 14 0.686 0.330 0 0.614 0.330 0.02 2 0.673 20 0.423 6 0.448 9 0.726 0.423 4 0.684 0.423 0.03 0 0.673 16 0.498 2 0.483 17 0.801 0.483 1 0.702 0.483 0.04 2 0.714 19 0.586 8 0.621 5 0.823 0.586 3 0.754 0.586 0.05 3 0.776 28 0.716 1 0.638 13 0.881 0.638 1 0.772 0.638 0.06 3 0.837 7 0.749 7 0.759 7 0.912 0.749 4 0.842 0.749 0.07 3 0.898 11 0.800 3 0.810 4 0.929 0.800 2 0.877 0.800 0.08 1 0.918 7 0.833 2 0.845 1 0.934 0.833 2 0.912 0.833 0.09 2 0.959 9 0.874 4 0.914 5 0.956 0.874 2 0.947 0.874 0.1 0 0.959 10 0.921 0 0.914 3 0.969 0.914 0 0.947 0.914 0.11 2 1.000 2 0.930 1 0.931 0 0.969 0.930 1 0.965 0.930 0.12 0 1.000 7 0.963 2 0.966 2 0.978 0.963 0 0.965 0.963 0.13 0 1.000 1 0.967 1 0.983 0 0.978 0.967 1 0.982 0.967 0.14 0 1.000 1 0.972 0 0.983 1 0.982 0.972 0 0.982 0.972 0.15 0 1.000 2 0.981 0 0.983 1 0.987 0.981 0 0.982 0.981 0.16 0 1.000 2 0.991 1 1.000 0 0.987 0.987 1 1.000 0.987 0.17 0 1.000 0 0.991 0 1.000 0 0.987 0.987 0 1.000 0.987 0.18 0 1.000 0 0.991 0 1.000 1 0.991 0.991 0 1.000 0.991 0.19 0 1.000 0 0.991 0 1.000 0 0.991 0.991 0 1.000 0.991 0.2 0 1.000 2 1.000 0 1.000 0 0.991 0.991 0 1.000 0.991 0.21 0 1.000 0 1.000 0 1.000 1 0.996 0.996 0 1.000 0.996 0.22 0 1.000 0 1.000 0 1.000 0 0.996 0.996 0 1.000 0.996 0.23 0 1.000 0 1.000 0 1.000 1 1.000 1.000 0 1.000 1.000 Total 49 215 58 226 57 2-17

Enclosure 2 PG&E Letter DCL-06-100 Table 2 - Axial PWSCC Cumulative Probability Distribution (CPD) Growth Rates per EFPY at 604F 2R1l data 1R12 data 2R12 data 1R13 data Prelim OA 2R13 data Final OA Lower Lower AD Bin Bound CPD Bound CPD

(%TW Freq CPD Freq CPD Freq CPD Freq CPD from 4 prior Freq CPD from 5 prior fraction) cycles cycles 0 27 0.551 53 0.247 14 0.241 112 0.496 0.241 28 0.491 0.241 0.01 5 0.653 25 0.363 6 0.345 33 0.642 0.345 7 0.614 0.345 0.02 6 0.776 24 0.474 6 0.448 19 0.726 0.448 4 0.684 0.448 0.03 2 0.816 17 0.553 4 0.517 23 0.827 0.517 4 0.754 0.517 0.04 0 0.816 23 0.660 3 0.569 12 0.881 0.569 2 0.789 0.569 0.05 4 0.898 23 0.767 7 0.690 10 0.925 0.690 4 0.860 0.690 0.06 0 0.898 18 0.851 7 0.810 7 0.956 0.810 2 0.895 0.810 0.07 0 0.898 12 0.907 5 0.897 3 0.969 0.897 0 0.895 0.895 0.08 2 0.939 6 0.935 2 0.931 2 0.978 0.931 3 0.947 0.931 0.09 1 0.959 2 0.944 1 0.948 0 0.978 0.944 0 0.947 0.944 0.1 1 0.980 4 0.963 0 0.948 1 0.982 0.948 2 0.982 0.948 0.11 1 1.000 1 0.967 0 0.948 1 0.987 0.948 1 1.000 0.948 0.12 0 1.000 2 0.977 2 0.983 1 0.991 0.977 0 1.000 0.977 0.13 0 1.000 2 0.986 0 0.983 0 0.991 0.983 0 1.000 0.983 0.14 0 1.000 3 1.000 0 0.983 2 1.000 0.983 0 1.000 0.983 0.15 0 1.000 0 1.000 0 0.983 0 1.000 0.983 0 1.000 0.983 0.16 0 1.000 0 1.000 0 0.983 0 1.000 0.983 0 1.000 0.983 0.17 0 1.000 0 1.000 1 1.000 0 1.000 1.000 0 1.000 1.000 0.18 0 1.000 0 1.000 0 1.000 0 1.000 1.000 0 1.000 1.000 0.19 0 1.000 0 1.000 0 1.000 0 1.000 1.000 0 1.000 1.000 0.2 0 1.000 0 1.000 0 1.000 0 1.000 1.000 0 1.000 1.000 Total 49 215 58 226 57 2-18

Enclosure 2 PG&E Letter DCL-06-100 Table 3 Recent Inspection Growth Rates per EFPY at 604F 90 Percentile Growth oer EFPY Cycle Data Points Length inch Max %

Depth Average Depth %

2R11 49 0.051 7.01 5.37 1R12 215 0.050 9.69 6.88 2R12 58 0.041 8.55 6.92 1R13 226 0.067 5.78 4.40 2R13 57 0.076 7.63 6.30 Table 4 DIS Confirmation Rates SG 2-1 SG 2-2 SG 2-3 SG 2-4 Total Number of bobbin DIS in less than or equal to 2 volt dented TSP intersections (excludes 39 53 72 29 193 repeat PWSCC indications)

Number of new PWSCC indications 0 0 0 0 0 confirmed by Plus Point Plus Point confirmation rate 0% 0% 0% 0% 0%

Bobbin DIS overcall rate 100% 100% 100% 100% 100%

2-19

Enclosure 2 PG&E Letter DCL-06-100 Table 5 - 2R113 PWSCC ARC Summary of Results 21113 Adjusted NDE 21113 CM (WEC Model) 21113 OA (ANLJTW Model)

FS Total Total FS Total Total Length MD AD max Burst FS Length Legh Burst FS Length Lnt SGTP SGTP R C CakCl R Crck Pu esn Id (in).  %)() Volt From TO Press Leakage Burst Lenkgth Pes Leakage Burst Lenkgth Ca lu Rasn Cat pi gpm Press Leakag prss gpm Press Leag pIps psi gp psi gpm 2 2 40 01H 1 22 Mix Mode Repeat 0.10 25.0 15.4 0.38 -0.63 -0.53 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 2 41 011H 1 22 Repeat 0.34 36.0 25.7 0.84 0.39 0.73 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 2 41 011- 2 22 New 0.10 20.0 12.4 0.34 -0.72 -0.62 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 4 28 011- 1 22 Repeat 0.24 30.5 20.1 0.85 0.03 0.27 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 4 34 04H 1 22 Repeat 0.17 20.0 9.5 0.31 0.02 0.19 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 5 13 01H 1 22 Repeat 0.28 25.0 15.3 0.57 -0.19 0.09 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 5 26 01H 1 22 Repeat 0.20 36.0 19.5 0.76 -0.33 -0.13 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 6 24 01H 1 22 Repeat 0.26 33.0 16.8 0.73 -0.36 -0.10 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 6 31 011- 1 22 Repeat 0.25 60.0 42.4 1.36 -0.40 -0.15 6100 0.000 6100 0.000 6100 0.000 5428 0.000 2 6 31 011- 2 22 Repeat 0.15 28.0 18.8 0.44 -0.15 0.00 16100 0.000 6100 0.000 6100 0.000 6100 0.000 2 6 36 011- 1 22 Repeat 0.24 30.0 18.6 10.58 -0.29 -0.05 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 6 49 011-H 1 22 Repeat 0.12 48.0 34.5 0.42 -0.32 -0.20 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 7 5 011-H 1 22 ______ Repeat 0.15 39.0 26.8 0.39 -0.06 0.09 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 7 27 011H 1 22 Repeat 0.17 30.0 15.7 0.61 0.13 0.30 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 7 32 01H 1 22 Repeat 0.22 33.0 23.8 0.94 -0.37 -0.15 16100 0.000 6100 0.000 6100 0.000 6100 0.000 2 8 36 011- 1 22 Repeat 0.49 36.0 28.5 0.94 1-0.26 0.23 6100 0.000 6100 0.000 6100 0.000 5758 0.000 2 8 43 04H 1 22 Repeat 0.23 39.0 28.1 0.92 -0.12 0.11 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 9 132 01H 1 1 22 Repeat 0.30 28.0 13.3 0.71 -0.22 0.08 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 10 14 01H 1 25 New 0.12 39.0 25.0 0.30 0.48 0.60 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 10 14 01H 2 25 New 0.07 33.0 16.5 0.49 0.66 0.73 16100 0.000 6100 0.000 6100 0.000 6100 0.000 2 10 21 04H 1 22 ______ Repeat 0.23 22.0 7.8 0.45 1-0.03 0.20 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 10 30 01H 1 22 1 Mix Mode Repeat 0.13 48.0 128.7 0.47 -0.30 -0.17 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 10 132 0111H 1 22 Repeat 0.09 20.0 12.3 0.23 0.44 0.53 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 11 17 01H 1 1 22 _______Repeat 0.15 36.0 21.8 0.47 -0.50 -0.35 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 11 30 011- 1 22 due to crack 2 Repeat 0.19 39.0 22.7 0.72 -0.28 -0.09 16100 0.000 16100 0.000 6100 0.000 6100 0.000 2 11 30 OH 2 22 >40% DOP Repeat 0.24 54.0 34.3 1.30 -0.52 -0.28 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 11 30 OH 3 22 1due to crack 2 R~epeat 0.12 39.0 26.8 0.60 10.51 0.63 16100 0.000 16100 0.000 6100 0.000 6100 0.000 2-20

Enclosure 2 PG&E Letter DCL-06-100 Table 5 - 21113 PWSCC ARC Summary of Results 21113 Adjusted NDE 21113 CM (WEC Model) 21113 OA (ANLflW Model)

FS Total Toa STotal Total Length MD AD Max Fo To Burst FS Length Tontal Bust FS Length Length SG R C TSP Crack Cal Plug Reason Cat (in.)7o Volt psim gpO PressLekg Bus Leakage Press Lekg Bus Laae Ctpi g Prsi gpm psi gpm Press gpm psi psi 2 12 39 01H 1 22 _______Repeat 0.11 28.0 18.3 0.76 -0.18 -0.07 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 13 25 103H 1 22 Repeat 0.30 42.0 34.4 0.82 -0.19 0.11 6100 0.000 6100 0.000 6100 0.000 5834 0.000 2 13 41 011- 1 22 Repeat 0.27 36.0 26.6 0.74 -0.23 0.04 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 14 45 01H 1 22 _______Repeat 0.15 20.0 11.4 0.43 -0.08 0.07 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 15 22 01H 1 22 _______Repeat 0.20 33.0 20.9 0.58 -0.11 0.09 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 15 42 01H 1 22 _______Repeat 0.27 30.0 13.2 10.49 -0.12 10.15 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 15 51 1O0H 1 22 _______Repeat 0.18 22.5 15.6 0.41 -0.27 -0.09 6100 10.000 6100 0.000 6100 0.000 6100 0.000 2 16 49 01H 1 22 Repeat 0.22 30.0 23.3 0.97 -0.18 0.04 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 17 12 01H 1 22 ______ Repeat 0.23 128.0 18.7 0.69 0.08 0.31 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 17 12 011- 2 22 Repeat 0.24 36.0 24.6 0.48 -0.19 0.05 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 17 12 011- 3 22 Repeat 0.09 20.0 10.4 0.31 -0.46 -0.37 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 18 10 011- 1 22 ______ Repeat 0.14 28.0 113.6 0.48 -0.35 -0.21 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 19 15 011- 1 22 Repeat 0.14 20.0 110.6 0.48 -0.06 0.08 16100 0.000 6100 0.000 6100 0.000 6100 0.000 2 21 35 02H 1 22 Repeat 0.37 28.0 14.1 0.47 -0.22 0.15 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 21 40 011- 1 22 Repeat 0.20 33.0 19.3 0.62 -0.31 -0.11 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 21 41 011- 1 22 Repeat 0.23 30.0 20.3 0.70 0.14 0.37 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 22 44 04H 1 22 Repeat 0.18 22.0 13.4 0.40 -0.36 -0.18 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 22 55 011- 1 22 ______ Repeat 0.18 30.0 21.5 0.50 0.08 10.26 6100 10.000 6100 0.000 6100 0.000 6100 0.000 2 23 14 OI01- 1 22 >40% DOP Repeat 0.11 45.0 32.0 0.55 0.50 0.61 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 25 44 05H 1 22 Repeat 0.40 120.0 10.5 10.50 -0.25 0.15 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2 29 39 01H 1 37 New 0.14 20.0 15.2 0.53 -0.21 -0.07 6100 0.000 6100 0.000 6100 0.000 6100 0.000 3 15 47 02H 1 126 ______ Repeat 0.09 25.0 15.7 0.18 1-0.15 -0.06 16100 0.000 16100 0.000 6100 10.000 6100 0.000 3 21 78 03H 1 26 _______Repeat 0.33 47.0 36.3 1.15 -0.29 0.04 6100 0.000 6100 0.000 6100 0.000 5580 0.000 3 29 41 03H 1 26 Repeat 0.09 33.0 22.0 0.47 -0.11 -0.02 6100 0.000 6100 0.000 6100 10.000 6100 0.000 3 45 56 01H 1 26 Repeat 0.12 28.0 20.5 0.57 0.22 0.34 6100 0.000 6100 0.000 6100 0.000 6100 0.000 43 12 03H 1 25 Repeat 0.24 47.0 33.6 0.98 -0.21 0.03 6100 0.000 6100 0.000 6100 0.000 6100 0.000 45 15 01H 1 18 _______ Repeat 0.12 26.0 18.5 0.30 -0.07 10.05 6100 0.000 6100 0.000 6100 0.000 6100 0.000 48 20 01H 1 1 18 1-Repeat 0.24 51.0 40.0 11.07 -0.30 1-0.06 16100 10.000 6100 0.000 6100 0.000 5705 0.000 2-21

Enclosure 2 PG&E Letter DCL-06-100 Table 5 - 2R13 PWSCC ARC Summary of Results 2R13 Adjusted NDE 2R13 CM (WEC Model) 2R13 OA (ANL/TW Model)

FS Total Total FS Total Total Length MD AD Max From To Burst FS Length Length Burst FS Length Length SG R C TSP Crack Cal Plug Reason Ind Cat (in.) (%) (%) Volt Press pi pm LeaPress Leakage Pesgpm Burst Press Leakage Ctpi gpm Press Lekgem pi Lekae Press Bus psi gpm psi psi gpm 4 12 17 03H 1 18 Repeat 0.20 51.0 34.1 1.09 0.10 0.30 6100 0.000 6100 0.000 6100 0.000 6100 0.000 4 14 53 03H 1 18 Repeat 0.16 31.0 18.2 0.50 -0.03 0.13 6100 0.000 6100 0.000 6100 0.000 6100 0.000 4 22 21 03H 1 51 ID/OD New 0.24 45.0 34.9 0.90 -0.23 0.01 6100 0.000 6100 0.000 6100 0.000 6100 0.000 4 23 52 02H 1 48 IDIOD New 0.11 33.0 23.4 0.52 -0.09 0.02 6100 0.000 6100 0.000 6100 0.000 6100 0.000 2-22

Enclosure 2 PG&E Letter DCL-06-100 Table 6- 2R13 Circumferential Indications and Growth Rates Adjusted for Upper ODSCC Adjusted Unadjusted NDE Adjusted NDE 95% NDE for Upper 95% NDE Growth Rate per EFPY Uncertainty Uncertainty Mix Mode Only SG R C TSP Crk Axial Max Dent Orient Stab Mix Angle MD AD Angle MD AD Angle MD AD Angle MD AD Angle MD AD No. Elev Volt Volt Mode deg  %  % deg  %  % deg  %  % deg  %  % deg  %  %

22 2 40 1H 1 -0.29 0.15 OD Yes 28.2 86 68.7 28.2 77.0 64.2 172.1 91.4 71.5 131.5 91.4 73.4 -6.0 -9.9 -8.4 -0.02 22.92 Yes 22 2 40 1H 2 -0.24 0.21 OD Yes 21.2 94 73.9 21.2 86.0 69.8 169.2 98.0 75.0 127.9 98.0 76.9 -2.1 1.3 0.6 -0.01 22 5 30 1H 1 0.25 0.18 50.10 OD 25.2 1 0.9 25.2 40.0 31.3 170.9 64.3 51.0 0.5 0.0 2.9 0.02 22 10 30 1H 1 0.05 0.16 OD Yes 24.9 1 0.9 24.9 40.0 31.5 170.8 64.3 51.2 129.8 64.3 52.7 0.7 0.0 1.0 0.02 11.84 Yes I1 22 10 30 1H 2 0.14 0.30 ID Yes 25.0 42 27.6 25.0 40.0 27.2 78.9 64.2 44.3 -2.3 0.0 0.0 -0.01 22 11 31 1H 1 -0.17 0.32 31.90 OD 29.1 35 15.9 29.1 40.0 28.7 172.5 64.3 49.4 -3.1 0.0 -0.2 0.12 22 13 24 1H 1 -0.28 0.16 37.29 OD 31.2 94 69.6 31.2 82.0 63.8 173.4 95.0 71.3 NDD 22 14 39 1H 1 -0.33 0.13 29.96 OD 18.2 82 60.0 18.2 68.5 52.1 168.0 85.2 63.9 NDD 22 15 53 1H 1 0.06 0.23 13.95 OD 52.6 12 3.3 52.6 40.0 33.0 182.2 64.3 52.1 4.7 0.0 0.8 0.02 22 17 29 4H 1 -0.08 0.57 18.28 OD 25.4 39 26.4 25.4 40.0 26.3 171.0 64.3 47.9 3.4 0.0 -1.8 -0.06 22 19 26 1H 1 -0.18 0.22 20.08 OD 32.7 34 20.1 32.7 40.0 30.1 174.0 64.3 50.3 NDD 22 19 27 1H 1 -0.32 0.11 OD 18.2 37 20.6 18.2 40.0 27.9 168.0 64.3 48.9 NDD

- 41.38 Yes 22 19 27 1H 2 0.32 0.17 OD 25.4 1 0.9 25.4 40.0 29.7 171.0 64.3 50.1 6.8 0.0 1.6 0.00 22 19 32 1H 1 0.02 0.14 4.03 OD 32.7 21 4.9 32.7 40.0 29.0 174.0 64.3 49.6 0.8 0.0 -0.9 0.02 22 24 30 1H 1 0.06 0.22 5.35 OD 21 26 14.1 21 40.0 28.6 169.2 64.3 49.3 -4.8 0.0 0.8 0.06 24 11 16 3H 1 -0.18 0.44 39.06 ID 25.9 99 77.7 25.9 79.0 57.9 79.8 92.5 65.0 1.7 -3.8 -3.9 0.16 22 22 24 TSH 1 -0.05 0.16 NA OD 73 NDD Note 1: Growth rate based on adjusted NDE, not the uncertainty adjusted NDE.

Note 2: Location (inch) is relative to the centerline of the tube support plate, or top of tubesheet.

Note 3: Tube stabilization determined per evaluation by Westinghouse.

Note 4: NDD means prior outage lookup did not detect any degradation, so no growth rate can be assigned for indication.

Note 5: SG 2-2 R22C24 TSH indication was too small to be sized using line by line technique.

2-23

Enclosure 2 PG&E Letter DCL-06-100 Figure 1 DCPP Unit 2 TSP Circumferential Average Depth Trending S50.

40 30-20.

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Year Detected I Average Depth - Linear Trend (Average Depth) I Figure 2 DCPP Unit 2 TSP PWSCC Mixed Mode - Circumferential Average Depth Trending ec 70- U U

60-50- U z 40. U S30 U U

20- U U 10-0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2008 2007 Year Detected I 0 Circumferental MWxedMode AD -Linear Trend {Circ Mixed Mode AD) I 2-24

Enclosure 2 PG&E Letter DCL-06-100 Figure 3 DCPP Unit 2 Number of New TSP Circumferential Indications M

i 15 I

10 2

1995 1998 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Year Detected Number of ne. U2 circindications -Linear (Number of new U2 circ indications) 2-25

Enclosure 2 PG&E Letter DCL-06-100 Figure 4 SG 2-2 RIO C30 1H Mixed Mode Axial PWSCC and Circumferential Indications ID circ 0.19 inch 40% MD OD cire 27.2% AD 0.19 inch 44.3% AD with unc 40% MD 0.30 v 31.5%AD 52.7% AD with unc 0.19 1/

0*0.30 -

F-"

-f I

0.31 Center of TSP F'-,,

.0.13 inch 48% MD 28.7% AD 0.47 v 2-26

Enclosure 2 PG&E Letter DCL-06-100 Figure 5 SG 2-2 R2 C40 1H Mixed Mode Axial PWSCC and Circumferential Indications Center of TSP OD circ 2 0.16 inch 0.21 OD circ 1 0.22 inch 86% MD 69.8% AD 76.9% AD with unc 7-A- 77% MD 64.2% AD 73.4% AD with unc 0.21 v -V 0.15 v 0.29 0.8 0.78 0.24 0.84

0. 10 inch 25% MD 15.4% AD 0.38 v 2-27

Enclosure 3 PG&E Letter DCL-06-100 ENCLOSURE 3 SPECIAL REPORT 06-02 AREVA REPORT 86-9024635-000 "DCPP UNIT 2 R13 VOLTAGE-BASED ARC 90-DAY

SUMMARY

REPORT"

20697-9 (4/29/05)

A CALCULATION

SUMMARY

SHEET (CSS)

AR EVA Document Identifier 86-9024635-000 Title DCPP Unit 2 R13 Voltage-Based ARC 90-Day Report PREPARED BY: REVIEWED BY:

METHOD: 0 DETAILED CHECK D INDEPENDENT CALCULATION NAME Jeffrey M. Fleck NAME. Alan M. Brown SIGNATUR SIGNATURE lt TITLE Mgr I DATE TITLE Principal Engineer DATE 7 29/?6 COST REF. TM STATEMENT:

CENTER 12742 PAGE(S) 106-107 REVIEWER INDEPENDENCE *--*k-., -. v .l)-  ;',A/

NAME David J. Cislo PURPOSE AND

SUMMARY

OF RESULTS:

This report summarizes the Diablo Canyon Unit 2 - 2R13 inspection of the steam generator tubing with respect to the implementation of the voltage-based repair criteria as specified in NRC Generic Letter 95-05. This document provides the projected probability of burst and leak rate calculations needed for submittal to the NRC. This report provides a non-proprietary summary of the results. The supporting proprietary calculations and necessary code verifications required for safety-related calculations are contained in Reference 23.

THE DOCUMENT CONTAINS ASSUMPTIONS THAT MUST BE VERIFIED PRIOR TO USE ON THE FOLLOWING COMPUTER CODES HAVE BEEN USED IN THIS DOCUMENT: SAFETY-RELATED WORK CODENERSION/REV CODENERSION/REV 1 YES Ikr97v30.exe / Version 3.0 pob97v2O.exe / Version 2.0 ZNONOJ Framatome ANP, Inc., an AREVA and Siemens company Page I of 107

86-9024635-000 Page 2 of 107 RECORD OF REVISIONS Revision Number Affected Page(s) Description of Change(s) 000 All Original Release

86-9024635-000 Page 3 of 107 TABLE OF CONTENTS

1.0 INTRODUCTION

................................................................................................................................................... 8 2.0 EXECUTIVE

SUMMARY

....................................................................................................................................... 8 3.0 EOC-13 INSPECTION RESULTS AND VOLTAGE GROWTH RATES ........................................................ 10 3.1 EOC-13 INSPECTION RESULTS ........................................................................................................................... 10 3.2 VOLTAGE GROWTH RATES .................................................................................................................................. 13 3.2.1 SELECTION OF LIMITING GROWTH DISTRIBUTION FOR EACH STEAM GENERATOR ........................................... 13 3.2.2 VOLTAGE-DEPENDENT GROWTH ANALYSES FOR CYCLE 13 ......................................................................... 14 3.2.3 VOLTAGE-DEPENDENT GROWTH ANALYSES FOR CYCLE 12 ......................................................................... 15 3.2.4 DELTA VOLTS ADJUSTMENT ............................................................................................................................ 16 3.2.5 GROWTH

SUMMARY

....................................................................................................................................... 16 3.3 VOLTAGE DISTRIBUTIONS USED FOR MONTE CARLO ANALYSES ......................................................................... 17 3.4 PROBE WEAR CRITERIA ...................................................................................................................................... 17 3.5 UPPER VOLTAGE REPAIR LIMIT ............................................................................................................................ 19 3.6 NDE UNCERTAINTY DISTRIBUTIONS ..................................................................................................................... 19 3.7 +POINTTMTO BOBBIN VOLTAGE CORRELATION ................................................................................................. 19 4.0 DATABASE APPLIED FOR LEAK AND BURST CORRELATIONS ............................................................. 72 4.1 CONDITIONAL PROBABILITY OF BURST .................................................................................................................. 72 4.2 PROBABILITY OF LEAK AND CONDITIONAL LEAK RATE ....................................................................... ............... 73 5.0 EOC 13 CONDITION MONITORING, BENCHMARKING OF EOC-13 CONDITIONS AND ASSESSMENT OF POTENTIAL UNDERPREDICTIONS ............................................................................................................................ 75 5.1 EOC-13 CONDITION MONITORING RESULTS ......................................................................................................... 75 5.2 EOC-13 BENCHMARK CALCULATIONS .................................................................................................................. 75 5.3 ASSESSMENT OF POTENTIAL UNDERPREDICTIONS ............................................................................................. 76 6.0 PROBABILITY OF PRIOR CYCLE DETECTION AND EOC-14 PROJECTIONS USING DCPP POPCD ........ 85 6.1 UPDATED DCPP POPCD CORRELATION ......................................................................................................... 85 6.1.1 ASSESSMENT OF POPCD CHANGES ............................................................................................................ 85 6.1.2 ASSESSMENT OF DISAPPEARING FLAWS .......................................................................................................... 86 6.2 INPUT TO INDUSTRY POPCD DATABASE .............................................................................................................. 87 7.0 EOC-14 PROJECTIONS FOR PROBABILITY OF BURST AND LEAK RATE ............................................... 100 7.1 INPUTS FOR CALCULATIONS ............................................................................................................................... 100 7.2 PROJECTED EOC-14 VOLTAGE DISTRIBUTIONS .................................................................................................. 101 7.3 PROJECTED TUBE BURST PROBABILITY AND LEAK RATE FOR EOC-14 ................................................................. 105

8.0 REFERENCES

.................................................................................................................................................. 106

86-9024635-000 Page 4 of 107 LIST OF TABLES AND FIGURES G lossary of Acronym s ......................................................................................................... 7 Table 3-1: 2R13 DOS >2 Volts ............................................................................................ 21 Table 3-2: 2R13 AONDB Indications .................................................................................... 22 Table 3-3: Summary of Inspection and Repair for Tubes Affected by ODSCC at TSPs ..... 24 Table 3-4: Summary of Largest Voltage Growth Rates per EFPY ....................................... 26 Table 3-5: DOS/AONDB Voltage and Growth Distribution by TSP ...................................... 27 Table 3-6: DCPP-2 Voltage Growth for Cycles 8 through 13 .............................................. 28 Table 3-7: Summary of Independent Cycle 13 Voltage Growth per EFPY ........................... 29 Table 3-8: Cycle 13 Voltage Dependent Growth for SG 2-3 (Information Only) ........... 30 Table 3-9: Cycle 13 Voltage Dependent Growth for SG 2-4 (Information Only) ........... 31 Table 3-10: Cycle 13 Voltage Dependent Growth for All SGs (Information Only) ................ 32 Table 3-11: Cycle 12 Supplemented Voltage Dependent Growth for SG 2-1 ............ 33 (Used for SG 2-1 EOC-1 4 Projections) .................................................................................. 33 Table 3-12: Cycle 12 Supplemented Voltage Dependent Growth for All SGs ............ 34 (Used for SGs 2-2, and 2-3 EOC-14 Projections) ................................................................ 34 Table 3-13 Cycle 12 Supplemented Voltage Dependent Growth for SG 2-4 ....................... 35 (Used for SG 2-4 EOC-14 Projections) .................................................................................. 35 Table 3-14: Delta Volts Adjustments Based on Cycle 13 Breakpoints (Information Only) ....... 36 Table 3-15: Delta Volts Adjustments Based on Cycle 12 Breakpoints ................................. 37 Table 3-16: BOC-14 Voltage Distributions ........................................................................... 38 Table 3-17: Re-tested DOSs that Failed the Probe Wear Check ......................................... 40 Table 3-18: New 2R13 DOSs >=0.5 Volts In Tubes Inspected With A Worn Probe In 2R12 ... 42 Table 3-19: Summary of New DOS Indications for Probe Wear Comparison ..................... 43 Table 3-20: Summary of ARC In and Out Tube Inspections in 2R12 ................................... 43 Table 3-21: NDE Uncertainty Distributions ........................................................................ 44 Table 3-22: 2R12 RTS AONDB and Results in 2R13 for Each ............................................ 45 Figure 3-1: 2R13 As-Found Voltage Distributions SGs 2-1 and 2-2 ..................................... 48 Figure 3-2: 2R13 As-Found Voltage Distributions SGs 2-3 and 2-4 ..................................... 48 Figure 3-3: 2R13 Repaired Voltage Distributions SGs 2-1 and 2-2 ...................................... 49 Figure 3-4: 2R13 Repaired Voltage Distributions SGs 2-3 and 2-4 ...................................... 49 Figure 3-5: 2R13 RTS Voltage Distributions for RPC Confirmed or Not Inspected SGs 2-1 and 2-2 ..................................................................................................................................... 50 Figure 3-6: 2R13 RTS Voltage Distributions for RPC Confirmed or Not Inspected SGs 2-3 and 2-4 ..................................................................................................................................... 50 Figure 3-7: 2R13 RTS Voltage Distributions SGs 2-1 and 2-2 ............................................ 51 Figure 3-8: 2R13 RTS Voltage Distributions SGs 2-3 and 2-4 ............................................ 51 Figure 3-9: 2R13 DOS and AONDB vs. TSP Elevation ...................................................... 52 Figure 3-10: Cycle 13 Growth Distributions SGs 2-1 and 2-2 .............................................. 53 Figure 3-11: Cycle 13 Growth Distributions SGs 2-3 and 2-4 .............................................. 53 Figure 3-12: Cycle 13 Independent Growth Curves - All SGs ............................................ 54 Figure 3-13: Historical Change in Growth and BOC Voltage - All SGs ................................. 54 Figure 3-14: Cycle 12 vs. Cycle 13 Growth Comparison for SG 2-1 .................................... 55 Figure 3-15: Cycle 12 vs. Cycle 13 Growth Comparison for SG 2-2 .................................... 55 Figure 3-16: Cycle 12 vs. Cycle 13 Growth Comparison for SG 2-3 .................................... 56 Figure 3-17: Cycle 12 vs. Cycle 13 Growth Comparison for SG 2-4 .................................... 56 Figure 3-18: SG 2-1 Cycle 13 Growth vs. BOC Voltage ...................................................... 57

86-9024635-000 Page 5 of 107 Figure 3-19: SG 2-2 Cycle 13 Growth vs. BOC Voltage ....................................................... 57 Figure 3-20: SG 2-3 Cycle 13 Growth vs. BOC Voltage ....................................................... 58 Figure 3-21: SG 2-4 Cycle 13 Growth vs. BOC Voltage .................................................... 58 Figure 3-22: Cycle 13 Growth vs. BOC Voltage for All Steam Generators ......................... 59 Figure 3-23: SG 2-3 Cycle 13 VDG Breakpoint Analysis Results ....................................... 60 Figure 3-24: SG 2-4 Cycle 13 VDG Breakpoint Analysis Results ....................................... 60 Figure 3-25: Composite Cycle 13 VDG Breakpoint Analysis Results ................................... 61 Figure 3-26: Cycle 13 VDG for SG 2-3 ............................................................................... 62 Figure 3-27: Cycle 13 VDG for SG 2-4 ............................................................................... 62 Figure 3-28: Cycle 13 VDG for All SGs ................................................................................ 63 Figure 3-29: SG 2-1 Supplemented Cycle 12 VDG Breakpoint Analysis Results ................ 64 Figure 3-30: SG 2-4 Supplemented Cycle 12 VDG Breakpoint Analysis Results ................ 64 Figure 3-31: Composite SG Supplemented Cycle 12 VDG Breakpoint Analysis Results ........ 65 Figure 3-32: Supplemented Cycle 12 VDG for SG 2-1 ........................................................ 66 Figure 3-33: Supplemented Cycle 12 VDG for SG 2-4 ....................................................... 66 Figure 3-34: Supplemented Cycle 12 VDG for All SGs ....................................................... 67 Figure 3-35: 2R13 Probe Wear Voltage Comparison ......................................................... 68 Figure 3-36: Bobbin Voltage Uncertainty Distributions .......................................................... 68 Figure 3-37: Inferred Voltage / Measured Voltage Comparison ........................................... 69 Figure 3-38: +PointTM Indication to Bobbin Voltage Comparison for SG 2-1 ........................ 70 Figure 3-39: +PointTM Indication to Bobbin Voltage Comparison for SG 2-2 ........................ 70 Figure 3-40: +PointTM Indication to Bobbin Voltage Comparison for SG 2-3 ........................ 71 Figure 3-41: +PointTM Indication to Bobbin Voltage Comparison for SG 2-4 ........................ 71 Table 4-1: Burst Pressure vs. Bobbin Amplitude Correlation .............................................. 72 Table 4-2: Probability of Leak Correlation ........................................................................... 73 Table 4-3: Leak Rate vs. Bobbin Amplitude Correlation (2405 psi) ...................................... 74 Table 5-1: Inputs for EOC-13 Benchmark Projections ......................................................... 75 Table 5-2: Summary of 95-05 ARC Calculations As-found vs. Projected EOC-13 ............... 77 Table 5-3: SG 2-1 BOC-13 Voltage Distribution Used for EOC-13 Benchmark Projections .... 78 Table 5-4: SGs 2-2, 2-3, and 2-4 BOC-13 Voltage Distributions Used for EOC-13 Benchmark Projections ......................................................................................................................... 79 Table 5-5: Cycle 11 Growth Distributions for SG 2-1 ........................................................... 80 Table 5-6: Cycle 11 Growth Distributions for Remaining SGs .............................................. 81 Table 5-7: As-found EOC-13 vs. Projected EOC-13 Conditions .......................................... 82 Figure 5-1: As-found SG 2-1 vs Projected Voltage Distributions (DCPP POPCD) ............... 83 Figure 5-2: As-found SG 2-2 vs Projected Voltage Distributions (DCPP POPCD) ............... 83 Figure 5-3: As-found SG 2-3 vs Projected Voltage Distributions (DCPP POPCD) ................ 84 Figure 5-4: As-found SG 2-4 vs Projected Voltage Distributions (DCPP POPCD) ............... 84 Table 6-1: 2R12 POPCD Results ......................................................................................... 88 Table 6-2: DCPP Composite POPCD Results (through 9 Inspections) ................................ 89 Table 6-3: POPCD Matrix Table for Tracking Indications Between EOCn and EOCn ... . . . . . 90 Table 6-4: 2R12 POPCD Voltage-Specific Summary from 2R13 Inspection Results ........... 91 Table 6-5: 2R12 POPCD Summary from 2R13 Inspection Results Regardless of Voltage ..... 92 Table 6-6: DCPP Composite Voltage-Specific POPCD Summary ....................................... 93 Table 6-7: DCPP Composite POPCD Summary Regardless of Voltage .............................. 94 Table 6-8: DCPP POPCD Log Logistic Parameters ............................................................ 95 Table 6-9: New DCPP POPCD Correlation Comparison to Previous POPCD Correlations .... 96 (B est E stim ates) ........................................................................................................................ 96

86-9024635-000 Page 6 of 107 Table 6-10: 2R12 POPCD Results In Industry Format ........................................................ 97 Table 6-11: DCPP Composite POPCD Results (9 Inspections) In Industry Format ............. 98 Figure 6-1: 2R12 POPCD Comparison to Composite POPCDs .......................................... 99 Table 7-1: Inputs for EOC-14 POB and Leak Rate Projections .............................................. 100 Table 7-2: Projected EOC-14 Voltage Distributions ............................................................... 102 (DCPP POPCD + Cycle 12 Supplemented Growth) ............................................................... 102 Figure 7-1: SG 2-1 EOC-14 Projected Voltage Distribution ................................................... 103 Figure 7-2: SG 2-2 EOC-14 Projected Voltage Distribution ................................................... 103 Figure 7-3: SG 2-3 EOC-14 Projected Voltage Distribution ................................................... 104 Figure 7-4: SG 2-4 EOC-14 Projected Voltage Distribution ................................................... 104 Table 7-3: Projected Leak Rate and Burst Probability at EOC-14 Using DCPP POPCD ....... 105

86-9024635-000 Page 7 of 107 Glossary of Acronyms Term Definition AONDB Axial ODSCC Not Detected by Bobbin ARC Alternate Repair Criteria BOC Beginning of Cycle CDS Computer Data Screening CPDF Cumulative Probability Distribution Function CFR Code of Federal Regulations CLT Cold-Leg Thinning DCPP Diablo Canyon Power Plant DIS Distorted ID Support Signal with possible Indication DOS Distorted OD Support Signal with possible Indication DNF Degradation Not Found EFPD Effective Full Power Day EFPY Effective Full Power Year ECT Eddy Current Test EOC End of Cycle FS Free Span AREVA Framatome Advanced Nuclear Power GL NRC Generic Letter 95-05 GPM Gallons per Minute INR Indication Not Reportable ISI In-service Inspection LRL Lower Repair Limit LU Lookup MSLB Main Steam Line Break NDE Non Destructive Examination NDD No Degradation Detected NRC Nuclear Regulatory Commission ODSCC Outside Diameter Stress Corrosion Cracking PG&E Pacific Gas and Electric Company POB Probability of Burst POD Probability of Detection POPCD Probability of Prior Cycle Detection POL Probability of Leak PWSCC Primary Water Stress Corrosion Cracking RPC Rotating Pancake Coil RSS Retest Support Plate Signal RTS Return to Service SG Steam Generator SER Safety Evaluation Report TS Technical Specification TSP Tube Support Plate VDG Voltage Dependent Growth

86-9024635-000 Page 8 of 107 1.0 Introduction The Diablo Canyon Power Plant (DCPP) Unit 2 completed the thirteenth cycle of operation and subsequent steam generator ISI in May 2006. The unit employs four Westinghouse-designed Model 51 SGs with %-inch OD mill annealed alloy 600 tubing and %-inch carbon steel drilled-hole tube support plates. It should be noted that 2R13 was the last planned inspection of these SGs, as they are to be replaced at EOC-14.

In accordance with the Generic Letter 95-05, ARC implementation requires a pre-startup assessment (Ref. 1) and a 90-day post-startup tube integrity assessment. The NRC Generic Letter 95-05, Reference 2, outlines an alternate repair criterion (ARC) for allowing tubes containing ODSCC indications to remain in service if the indications are contained within the TSP structure and the measured Bobbin voltage is <2.0 volts. A complete list of criteria for excluding TSP intersections from ARC application is provided in section 1.b of Reference 2 and in Reference 3. The NRC has approved implementation of the voltage-based repair criteria at both DCPP units per Reference 3. The steam generator TSP inspection results and the postulated MSLB leak rate and tube burst probabilities are summarized in this report. AREVA uses Monte Carlo codes, as described in References 4 and 5, to provide the burst and leak rate analysis simulations. These evaluations are based on the methods in Reference 6 (for burst) and the slope sampling method for calculating the leak rate as defined in Section 9.5 of Reference 8. These evaluations also use the voltage-dependent POPCD (Probability of Prior Cycle Detection) and the new growth methods as defined in References 16, 25, and 28, and approved by the NRC in Reference 29.

2.0 Executive Summary During the 2R13 inspection, a total of 2457 DOS indications were detected with the bobbin coil.

There were an additional 56 support plate intersections that were identified as containing AONDB (axial ODSCC not detected by bobbin). Since there were no DOS indications at these intersections, a bobbin voltage was inferred from the +PointTM results per the methodology provided in Reference 8.

There were 32 DOS indications greater than the lower repair limit of 2.0 volts. All of these indications were confirmed as axial ODSCC with +PointTM and were subsequently plugged. An additional 33 DOS and AONDB indications less than or equal to 2 volts were also plugged for other reasons, located in the wedge region, same TSP as ligament indication, ID/OD at same TSP, AONDB at dent >5 volts, or pluggable indications at another location in the same tube.

Only one DOS was preventively repaired for high +PointTM volts.

A review of the growth rates over the previous cycle shows that axial ODSCC at support plates is most active in SG 2-4. SG 2-4 had the highest average growth rate, the highest percentage growth rate and the highest individual growth points of the entire population, consistent with past inspections. Voltage dependent growth was only evident in SGs 2-3 and 2-4. SGs 2-1 and 2-2 showed no effects of voltage dependent growth. Following the DCPP Unit 2 2R1 1 inspection in 2003, a significant amount of analysis and evaluation was performed on voltage growth for ODSCC at TSPs (Reference 14). The evaluations primarily involved statistical breakpoint analyses to determine where the data suggests a change in the slope of the

86-9024635-000 Page 9 of 107 regression curve that defines the growth data. These efforts led to the development of guidelines for determining the breakpoints and growth distributions. These guidelines were provided to the NRC via Reference 24, and were used to determine the breakpoints and growth distributions for the current OA.

The POB and leak rate projections for EOC-14 provided in this report use the DCPP-specific POPCD. The use of the voltage-dependent POPCD was approved in Reference 29. The updated POPCD correlation is provided in Section 6. Using the DCPP-specific POPCD, a conservatively estimated cycle length, and the conservative growth rate analyses discussed in Section 3.2, the projected POB at EOC-14 for the limiting steam generator (SG 2-4) was determined to be 5.94 x 103. The projected leak rate for the limiting generator (SG 2-4) was 3.75 gpm. Both of these results are below the acceptance criteria of 1 x 10-2 and 10.5 gpm, respectively.

Section 5 provides the as-found EOC-13 condition monitoring results and results of a benchmarking study that compares the projected EOC-1 3 conditions to the as-found conditions.

The as-found leak rate and POB at EOC-13 for the limiting steam generator (SG 2-4) were determined to be 0.78 gpm and 5.57 x 104, respectively, and are both below the acceptance criteria of 10.5 gpm and 1 x 102. The prior cycle operation assessment was recalculated using the actual cycle length and as shown in Section 6, the recalculated EOC-13 POB, leak rate, and number of indications were conservative in all cases compared to EOC-1 3 actual conditions.

86-9024635-000 Page 10 of 107 3.0 EOC-13 Inspection Results and Voltage Growth Rates 3.1 EOC-13 Inspection Results The DCPP 2R13 bobbin coil inspection consisted of a 100% full-length bobbin coil examination of in-service tubes in all four steam generators except for Rows 1 and 2 U-bends which were inspected with +PointTM. All in-service TSP intersections in the hot and cold legs were inspected with 0.720" replaceable feet bobbin probes.

Special interest +PointTM examinations were conducted as follows in support of the voltage-based ARC, and in accordance with the Degradation Assessment (Ref. 9) and Surveillance Test Procedure STP M-SGTI (Ref. 12).

a 100% of DOS a 1.7 volts

• 100% of DOS in dented intersections

• 100% of DIS (distorted ID support signal at dented intersection)

• 100% of hot leg SPR (Support Plate Residual) > 2.3 volts; minimum of five largest hot leg SPRs in each steam generator

• 100% of prior cycle AONDB indications 0 100% of new DOS in cold leg thinning region

• Dented TSP examinations

• Other Special Interest or test programs that may test TSP intersections Based upon the bobbin inspection of all steam generators, a total of 2457 indications were identified. The results of the inspections are summarized as follows:

1) Voltage Dependent Growth was evident in SGs 2-3 and 2-4, but was not occurring in SGs 2-1 and 2-2.

2) 32 DOS indications were greater than the lower repair limit (2.0 volts). Each of the indications confirmed as ODSCC, required repair by plugging, and were distributed as follows: 2 in SG 2-1, 1 in SG 2-2, 3 in 2-3, and 26 in SG 2-4. Table 3-1 lists the DOS indications that were above the LRL.

3) No indications were identified that exceeded the upper repair limit of 5.57 volts.

4) One less than or equal to 2.0 volt bobbin indication exceeded the 1.9 volt +PointTM threshold for preventive plugging, per industry guidance in Reference 8. R33C55 in SG 2-4 had a 1.94 volt DOS and a 2.07 volt +Point axial indication that was preventively plugged.

5) 64 indications at 56 TSP intersections were identified as AONDB (axial ODSCC not detected by bobbin). Table 3-2 lists the indications that were identified as AONDB. These are +PointTM indications of axial ODSCC that have no signal present in the bobbin coil data (no DOS signal). These locations are typically smaller voltage ODSCC, by +PointTM, and can be accompanied by a dent that masks any bobbin signal. Per Reference 8, a methodology has been developed to assign a bobbin voltage based on a correlation to the

+PointTM voltage. Once the calculated voltages are obtained per Reference 17, the locations are subjected to exclusion criteria defined in Reference 12. All inferred voltages were small, less than about 0.96 equivalent bobbin volts.

86-9024635-000 Page 11 of 107

6) Overall, 65 DOS/AONDB indications were in tubes that were repaired during 2R13. The breakdown is: 3 in SG 2-1, 6 in SG 2-2, 3 in SG 2-3, and 53 in SG 2-4. This population was used in computing the BOC-14 distributions for the OA calculations.

The average voltage was 0.64 volts, including AONDB indications. The 2R12 average was 0.61 volts. The average voltage for new DOS indications was 0.37v, excluding prior AONDB.

The majority of the largest voltages were detected in SG 2-4, with the highest overall average voltage of 0.73 volts. Table 3-3 summarizes the voltage distributions for the as-found condition of the indications, the repaired indications, indications returned to service that were either confirmed by +PointTM or not inspected with +PointTM and the total indications returned to service. 32 confirmed DOS had to be repaired because they exceeded the 2-volt repair limit.

The main reasons for repair of the other 33 DOS/AONDB included DOS < 2.0 volts (preventively, as discussed below), wedge exclusion criterion, AONDB at >5 volt dent, combined ID/OD degradation at the same intersection, or other pluggable tube degradation.

Reference 8 provides guidelines for preventive tube repair of less than or equal to 2.0 volt bobbin indications to reduce the potential for finding large voltage growth rates for indications left in service. PG&E committed to implement the guideline by performing +PointTM inspection of 100% of greater than 1.7 volt bobbin indications, and to repair any +PointTM confirmed ODSCC with +PointTM amplitude greater than 1.9 volts, as this could be near throughwall and potentially result in a large voltage growth rate in the next cycle. 27 less than 2.0 volt bobbin indications were therefore +PointmM inspected in 2R13 (that would not have been inspected otherwise) to meet this commitment. All of the indications were confirmed as ODSCC and the

+PointTM and bobbin voltages were reviewed. Figures 3-38 to 3-41 plot all of the ODSCC

+PointTM voltages versus bobbin voltages. For bobbin amplitudes less than 2.0 volts, only one

+PointTM amplitude was greater than 1.9 volts (see Figure 3-41 for SG 2-4), therefore the tube was required to be preventively plugged per the guideline. This tube (R33C55 in SG 2-4) had a bobbin indication of 1.94 volts and a +PointTM indication of 2.07 volts. No other tubes were repaired less than this criterion. Therefore, it is concluded that the preventive plugging program used at 2R13 meets PG&E's commitment to the NRC.

The largest +PointTM amplitude found in 2R13 was 2.89 volts with a DOS voltage of 4.16, and the largest bobbin voltage growth rate was 1.92 v/EFPY.

The +PointTM inspections required for DOS indications were accomplished as a part of the special interest exams. 306 +PointTM inspections were performed where DOS indications were called by bobbin, excluding the AONDB intersections. Of these inspections, 244 were confirmed yielding an overall confirmation rate of about 80%. However, when excluding the cold leg DOS signals from this count (none of which have ever confirmed as crack-like at DCPP), the confirmation rate is 89%, which is typical at DCPP.

The 2R13 +PointTM TSP inspection scope also included intersections with signals that could potentially mask or cause a flaw to be missed or misread. These inspections included dented intersections based on the criteria in the degradation assessment (Ref. 9) and hot leg intersections with support plate residuals (SPR) > 2.3 volts. Per GL 95-05, a large mixed residual is one that could cause a 1.0 volt bobbin signal to be missed or misread. In Reference 9, DCPP determined that a 2.3 volt SPR is the upper 9 5 th value that could potentially mask bobbin indications > 1.0 volt. Per the inspection requirements specified in References 9 and

86-9024635-000 Page 12 of 107 12, all hot leg intersections with SPRs with voltages > 2.3 volts were inspected with +PointTM.

In addition, References 9 and 12 require that, if there are less than five hot leg SPRs ->2.3 volts in a given steam generator, the five largest hot leg SPRs in that steam generator should be inspected with +PointTM. A total of 3 hot leg SPRs > 2.3 volts were identified and inspected, with no indications detected. Since none of the steam generators contained five SPRs ->2.3 volts, the five largest hot leg SPRs were inspected in each steam generator resulting in a total of 20 inspected with +PointTM. No confirmed ODSCC indications were detected from these

+PointTM inspections.

Figures 3-1 and 3-2 show the as-found voltage distribution (including AONDB) for all indications detected during the 2R13 inspection. Figures 3-3 and 3-4 show the indications removed from service at 2R13. Figures 3-5 and 3-6 illustrate the indications returned to service that were confirmed as axial ODSCC or were not inspected with RPC. Figures 3-7 and 3-8 illustrate all of the indications returned to service following the 2R13 ECT inspection. Table 3-1 lists all of the indications greater than the 2.0-volt lower repair limit. As previously stated, all of these indications were confirmed as axial ODSCC and were removed from service by plugging.

Of all the DOS indications returned to service, the largest bobbin voltage was 2.00 volts. This indication confirmed as two axial ODSCC indications with +PointTM voltages of 0.99 and 0.98 v.

The single largest +PointTM voltage indication returned to service was 1.79 v, with a corresponding DOS bobbin voltage of 1.79 volts.

There were 223 intersections returned to service that contained confirmed axial ODSCC at dented TSP intersections. 53 were AONDB intersections and 170 were confirmed bobbin DOS indications. 207 of these intersections contained dents <2.0 v and 16 of these intersections contained dents between 2 and 5 volts, and there were no intersections containing >5 volt dent since it is an exclusion criteria. The largest bobbin voltage indication returned to service with a dent at the same TSP was 1.93 volts and confirmed as a 1.38v SAL. The largest +PointTM indication with a dent at the same TSP returned to service is 1.55 v, and has a corresponding DOS of 1.49 volts.

The DOS voltage distribution as a function of TSP elevation is provided in Table 3-5. Table 3-5 and Figure 3-9 show that the ODSCC mechanism is most active at the lower hot leg TSPs and the number of indications tends to decrease as a function of higher TSP elevations. This distribution shows the typical temperature dependence of ODSCC.

Table 3-5 and Figure 3-9 include a small number of cold leg DOS indications that were NDD by

+PointTM based on the +PointTM inspection of new cold leg DOS (with no prior Plus Point inspections) located in the cold leg thinning region. 100% of cold leg DOS had been +PointTM inspected in the prior inspection (2R12) to define and validate the cold leg thinning region. No cold leg ODSCC has been confirmed by +PointTM to date at DCPP. Non-confirmed bobbin DOS indications in the cold leg are conservatively retained in the ODSCC ARC calculations.

86-9024635-000 Page 13 of 107 3.2 Voltage Growth Rates For projection of leak rates and tube burst probabilities at EOC-14, voltage growth rates were developed from the 2R12 and 2R13 inspection data. Cycle 13 was 1.31 EFPY in length per Reference 12. For repeat indications reported as DOS in both inspections, growth rates were determined based on comparison of the voltages called in 2R12 and 2R13. For indications not reported during the 2R12 inspection (i.e. new at 2R13), the indications were sized using the 2R12 ECT signals based on a lookup review. Lookups were also performed for all of the 2R13 DOS locations that were previously reported as DIS. In both of these cases, an OD component could not be always found in the bobbin lookup results, and these intersections were excluded from the growth distributions.

Table 3-4 provides a summary of indications with the largest growth during Cycle 13. Table 3-5 provides the maximum and average voltage growth distribution by TSP. Table 3-6 provides the average BOC voltage, average growth rate data and average percent growth for the last six cycles at DCPP-2. Figure 3-13 depicts this information graphically.

Table 3-7 shows the voltage independent growth distributions for each SG, the composite distribution for all four SGs, and the cumulative probability distribution function for each distribution. Figures 3-10 and 3-11 show the voltage growth distributions depicted in bar charts.

Figure 3-12 provides the CPDF curves of the voltage growth distributions. Reviewing the Table 3-5 average and maximum voltage growth for all indications for each SG as well as the number of new indications in each SG shows that the ODSCC mechanism is most active in SG 2-4.

This phenomenon of a leading SG in plants affected by ODSCC is common in the industry.

Reviewing Table 3-6 and Figures 3-10 and 3-11 also supports this conclusion.

As discussed in Section 3.2.1 below, the Cycle 13 growth rates for each SG were less than Cycle 12 growth rates. There were 412 newly reported DOS indications in 2R13, the largest of which was 1.40 volts. 368 of these new indications were detected during the 2R12 lookup, sized appropriately, and subsequently included in the growth distributions. There were 42 new DOS indications that were not detected during the lookup and were, therefore, not included in the growth rate analyses. The largest of these new indications not present in the look up was 1.0v in SG 2-4 R35C65 2H. This particular location was AONDB in the previous inspection (See Section 3.7 and Table 3-22) and had an assigned voltage of 0.78 volts in 2R12. The upper 95% growth rates of all new and repeat indications were 0.18 and 0.31 v/EFPY, respectively. The average growth rates for new and repeat indications were 0.04 and 0.07 v/EFPY, respectively. These data confirm that the new indications continue to grow at a slower rate than the previously detected indications, consistent with prior inspection results at DCPP.

3.2.1 Selection of Limiting Growth Distributionfor Each Steam Generator In June 2004, PG&E received a set of RAls from the NRC on their submittal for a permanent POPCD approval. The responses to these RAIs were provided in Reference

25. In response to one of the questions, PG&E prepared a guideline for determining the appropriate growth distribution to use for the operational assessments. This guideline was used for the determination of the growth rates used for the EOC-14 projections

86-9024635-000 Page 14 of 107 provided in this document. This guideline either meets, or is more conservative than the guidance provided in References 2 and 6 and Enclosure 3 of Reference 24.

The first step in determining the most conservative growth distribution for each steam generator is to compare the SG-specific and the composite growth distributions for each of the last two cycles. These comparisons are initially done without considering the impact of voltage dependent growth. In order to determine which growth distribution to use for each steam generator in the next operational assessment, four different growth curves must be compared (SG-specific for Cycle 12, SG-specific for Cycle 13, composite for Cycle 12, and composite for Cycle 13). Worth noting is the fact that Cycle 12 had no BOC indications >1.2 volts returned to service for Cycle 12, due to the preventive repairs conducted at 2R11. Therefore, the Cycle 12 growth data is supplemented with Cycle 11 growth for BOC indications >1.2 volts at BOC-1 1. This approach is consistent with the 2R12 90 day report.

Figures 3-14 through 3-17 provide graphical comparisons of growth for each steam generator. All of the figures consistently show that the bounding curve comes from the supplemented Cycle 12 growth data (either SG-specific or composite), except in the case for SG 2-1. For SG 2-1, it was not apparent from the curves themselves which was bounding. Therefore, leak rate and probability of burst analyses were performed using both the SG 2-1 specific supplemented Cycle 12 growth and the composite supplemented Cycle 12 growth. These analyses showed that the SG 2-1 specific growth bounds the composite growth. For SG 2-4, the supplemented Cycle 12 SG-specific curve is bounding over the composite curve for supplemented Cycle 12, and all curves from Cycle 13. For SGs 2-2 and 2-3, the supplemented Cycle 12 composite curve is clearly bounding. In summary, for EOC-14 projections, supplemented Cycle 12 growth data was used for all SGs. SGs 2-1 and 2-4 used SG-specific curves, and SGs 2-2 and 2-3 used SG-composite curves.

3.2.2 Voltage-DependentGrowth Analyses for Cycle 13 Even though the Cycle 12 growth rates were determined to be bounding, the voltage-dependent growth analyses for the Cycle 13 data are documented in this report for possible future reference. For Cycle 13, growth rates were plotted against the BOC voltage for all steam generators, including a composite curve. Their data are shown in Figures 3-18 through 3-22. As demonstrated by the figures, a positive slope exists only in SGs 2-1, 2-3, 2-4 and for the composite data. The slope is negative in SG 2-2. A threshold slope of 0.1 was defined in Reference 25 as the point at which voltage-dependent growth should be considered in the operational assessment. Therefore SGs 2-1 and 2-2 are considered not to be experiencing VDG. The slope of the curve for SG 2-3 is slightly above this value at 0.113, with VDG apparent in SG 2-4 with a slope of 0.194.

Voltage-dependent growth is not a new concept, and has been documented by the operators of European steam generators affected by ODSCC. Because of their higher repair limits, their data encompass a much broader and higher range of data than at DCPP and the US plants and provides significant basis for the VDG approach.

86-9024635-000 Page 15 of 107 A significant amount of analysis and evaluation was performed following the 2R1 1 inspection on voltage growth for ODSCC at TSPs. The evaluations primarily involved statistical breakpoint analysis to determine where the data suggests a change in the slope of the regression curve that defines the growth data. These efforts led to the development of a guidelines document for determining the breakpoints. This document was transmitted to the NRC via Enclosure 3 of Reference 24 and currently resides in Reference 8. These methods were used to determine breakpoints for the Cycle 13 growth data.

Cycle 13 VDG breakpoint analyses were performed for SGs 2-3 and 2-4 and for a composite growth distribution (including all steam generators). Figures 3-23 through 3-25 show the scatter charts and the resulting breakpoints for all of these analyses. The analysis for SG 2-3 yielded a single breakpoint at 0.89 volts, and SG 2-4 yielded two breakpoints at 1.06v and 1.53v. The composite analysis also yielded two breakpoints at 0.88v and 1.50v. Tables 3-8 through 3-10 and Figures 3-26 through 3-28 provide the growth distributions and cumulative probability distribution function (CPDF) curves, respectively, for the Cycle 13 VDG analysis, for information only. These tables and figures reflect the results after application of the delta volts adjustments as discussed in Section 3.2.4 of this report. As shown in Figures 3-26 through 3-28, the growth rates for the higher VDG bins bound the lower bins, indicating it would be conservative to apply voltage dependent growth in EOC-14 projections if Cycle 13 growth was to be used.

3.2.3 Voltage-Dependent Growth Analyses for Cycle 12 As discussed in Section 3.2.1, the supplemented Cycle 12 growth rates were determined to bound the Cycle 13 growth rates. This section provides the VDG breakpoint analyses for the growth curves used in the EOC-14 Monte Carlo analyses. In the case of SGs 2-1 and 2-4, SG-specific growth was bounding and in the case of SGs 2-2 and 2-3, the composite growth was bounding.

Tables 3-11 through 3-13 and Figures 3-29 through 3-31 provide the results of the breakpoint analyses for the 2R12 inspection. These tables are similar to those provided in the 2R12 90 day report (Reference 27) except that the delta volts adjustments from Section 3.2.4 of this report were applied in lieu of the delta volts adjustments from Reference 27. SG-specific VDG curves for SG 2-1 and SG 2-4 are provided, as well as a composite VDG analysis curve. As shown in the figures, SG 2-1 had a single breakpoint at 1.12v, SG 2-4 had two breakpoints at 0.47 and 1.03v, and the composite analysis had breakpoints at 1.10 and 1.71 volts. These are the breakpoints that will be utilized in the EOC-14 projections, since the Cycle 12 supplemented growth is bounding.

The CPDF curves of the Cycle 12 supplemented growth resulting from these breakpoints are included in Figures 3-32 through 3-34. These figures are similar to those provided in Reference 27 except for the application of the delta volts adjustments.

86-9024635-000 Page 16 of 107 3.2.4 Delta Volts Adjustment Another part of the growth guideline provided in Reference 25 involves implementation of a "delta volts adjustment" when implementing POPCD in operational assessment calculations. The purpose of this adjustment is to account for the possibility that the growth rates may increase over the next operating cycle. The intent of the adjustment procedure is to increase growth in a specific VDG bin when a comparison between cycle N and cycle N-1 indicates such. The growth rate guidelines that PG&E committed to utilize in combination with POPCD do not specifically address the case where growth rates decrease over subsequent cycles. The guidelines were written on the premise that once VDG is experienced, increasing growth would likely continue to occur. This is not the case in comparing Cycles 12 and 13. However, PG&E conservatively interprets the adjustment procedure applicable to this analysis, even though Cycle 12 is bounding.

The amount of the adjustment is determined by comparing the average growth from Cycle 13 to the average growth from Cycle 12 for each VDG bin. Tables 3-14 and 3-15 provide the details for the Cycle 13 and Cycle 12 breakpoints, respectively. Per the Reference 25 guideline, if the Cycle 13 data has a higher average growth rate than the Cycle 12 data, then the difference between the average growth rates would be added to each growth rate value in the distribution being used prior to binning the data. Per Table 3-14, if Cycle 13 growth rates were being used in the Cycle 14 operational assessment, a small growth adjustment would be required in SG 2-3 Bin 2. Table 3-15 shows a slight increase in the average growth rate for Bin 2 in SG 2-3 when using the Cycle 12 supplemented growth breakpoints. However, the SG-specific curve is not being used for SG 2-3 operational assessment; therefore, no adjustment is required for any of the EOC-14 projections documented in this report.

3.2.5 Growth Summary As discussed in Section 3.2.1, supplemented Cycle 12 growth bounds Cycle 13 growth in all cases. Based on the Cycle 12 SG-specific versus composite growth evaluations, a composite curve should be used for SGs 2-2 and 2-3 and a SG-specific curve should be used for SGs 2-1 and 2-4 for EOC-14 projections.

Tables 3-11 through 3-13 show the supplemented Cycle 12 growth distributions that were used in the Monte Carlo analyses for EOC-14. These curves are shown graphically in Figures 3-32 through 3-34. As mentioned in Section 3.2.3, these tables and figures are similar to those found in the 2R12 90 day report (Reference 27) except for the application of the delta volts adjustments. As required by Generic Letter 95-05, the negative growth values were included as zero growth rates in the ARC calculations.

86-9024635-000 Page 17 of 107 3.3 Voltage DistributionsUsed for Monte CarloAnalyses Now that the breakpoints for the growth bins have been established (from supplemented Cycle 12 data), the BOC-14 voltage distributions to be used in the Monte Carlo simulations can be defined. Table 3-3 shows the voltage distributions for the as-found and repaired indications.

Additional voltage bins must be inserted at the value of the VDG breakpoints, as shown in Table 3-16: an additional voltage bin at 1.12v was inserted into the SG 2-1 voltage distribution, an additional voltage bin at 1.71v was inserted into the voltage distributions for SGs 2-2 and 2-3, and two additional bins at 0.47 and 1.03 volts were inserted into the SG 2-4 voltage distribution. Adding these additional voltage bins forces the Monte Carlo simulation codes to apply each VDG growth distribution to the correct number of indications.

3.4 Probe Wear Criteria In order to maintain consistent detection and sizing capabilities throughout the inspection, probe wear is monitored by following the requirements of Reference 15, which is documented in Reference 13. The first NRC requirement regarding probe wear is to minimize the potential for tubes to be inspected with a probe that had failed the probe wear check. This was accomplished by implementing the bobbin Examination Technique Specification Sheet (ETSS)

1. 1 (Ref. 11), which required the probe have its feet replaced when failing the probe wear check, or in the case of non-changeable feet probes, the probe discarded. Review of the probe wear log sheets and the eddy current test results indicate that no tubes were inspected with a probe known to have failed the probe wear check.

If the DOS voltage is at or above the retest threshold (1.5 volts or higher) and the cal is designated as "ARC Out" on the cal board, the indication code is changed from a DOS to a RSS (retest support plate signal) indicating that a retest is required with a new probe. No new indications were detected in the tubes when retested with the new probe.

The 2R13 eddy current inspection resulted in 21 bobbin indications in excess of 1.5 volts that were inspected with a worn probe, termed as RSS (retest support signal) indications. Table 3-17 shows these RSS indications, including any less than 1.5 volt DOS indications in the same tube inspected with a worn probe, along with the retested DOS indications in a subsequent calibration group with a good probe. Figure 3-35 shows a comparison of the worn probe and good probe voltages. The final acceptable DOS voltage values compare reasonably well with the RSS voltages. In the majority of cases, the voltage of the DOS was lower than the corresponding RSS. The average change between the initial voltages (both DOS and RSS) relative to the final DOS call was 4.18%. There was only one instance (R21C79 in SG 2-4) where the final DOS indication (2.05 volts) exceeded the RSS indication (1.76 volts) by more than 15% (16.5%).

The next requirement involves monitoring tubes that contain new DOS indications that were inspected with probes that failed the wear check in the previous outage. This evaluation is intended to look for "new" large indications or a non-proportionately large percentage of "new"

86-9024635-000 Page 18 of 107 indications in tubes that failed the check in the previous outage. Table 3-18 shows the new 2R13 DOS indications that were >0.5 volts and were inspected on cal groups that failed the probe wear check in 2R12. As shown in Table 3-18, with the exception of R45C57 in SG 2-3, there are no newly reported DOS indications greater than 1 volt in tubes that were inspected with worn probes in 2R12. The lookup voltage for R45C57 for 2R12 was 1.37 volts and the 2R13 DOS voltage was 1.4 volts showing that the voltage change was not due to a probe wear condition, but a matter of POD. Additionally, about 75% of the new indications were < 0.5 volts in 2R12 based on the historical lookups performed. This also indicates that new indications are more a result of probability of detection rather than whether the tube was inspected with a worn probe in 2R12. The percentages do not indicate that a disproportionate number of new DOS

>0.5 are present in tubes that were inspected with a worn probe in the previous outage.

Table 3-19 summarizes new DOS indications for probe wear comparisons. Overall there were 2457 DOS indications detected in the 2R13 inspection. 387 (about 16%) of the DOS indications were truly new indications (not reported as DIS in 2R12). Of the 387 total new indications, 108 (about 28%) were in tubes inspected with a worn probe in 2R12 and 279 were in tubes inspected with a good probe in 2R12. Additionally, the number of new indications > 0.5 volts was determined to be 81. Out of these, 25 (about 31%) were in tubes that were inspected with a worn probe in 2R12. This confirms that a tube tested with a worn probe in 2R12 is no more likely to contain a large DOS in 2R13 than a tube tested with a good probe in 2R12.

Additionally, the 2R12 results were reviewed to determine the number of inspections performed with probes that passed and failed the probe wear check. These results are shown in Table 3-

20. This review showed that the number of inspections performed with "ARC OUT" probes was 3661, compared to 9825 inspections that were performed with "ARC IN" probes. This total number of examinations is greater than the number of tubes in service because several tubes have multiple examinations. The ratio of ARC OUT tube inspections to the total number of bobbin inspections is about 0.27 (or 27%). This percentage is nearly equivalent to the percentage of new DOSs that was previously inspected with worn probes (about 28%). This demonstrates that the number of new indications is not biased towards the tubes that were inspected with worn probes in 2R12.

In summary, the NRC analysis requirements regarding probe wear monitoring were met during the 2R13 bobbin coil inspection and a more stringent wear tolerance is not required at DCPP.

86-9024635-000 Page 19 of 107 3.5 Upper Voltage RepairLimit Per Generic Letter 95-05, the upper repair limit must be calculated prior to each outage. The more conservative of the plant-specific average growth rate per EFPY or 30 percent per EFPY should be used as the anticipated growth rate input for this calculation. Since the average growth rate for Cycle 12 was 23.8% (Ref. 27 and Table 3-6), the required 30%/EFPY was used for the upper repair limit calculation. The structural limit used for this calculation is based on the Addendum 6 database. Based on the following formula, the upper repair limit was calculated to be 5.57v.

VSL VUJ.L

% VNDE  % VCG 1+ +

100 100 where: VURL = upper voltage repair limit, VNDE = NDE voltage measurement uncertainty = 20%,

VCG voltage growth anticipated between inspections = 30%/EFPY x 1.62 EFPY = 48.6%,

VSL voltage structural limit from the burst pressure - Bobbin voltage correlation, where the limit of 9.40 volts was used based on Reference 8.

3.6 NDE UncertaintyDistributions NDE uncertainties must be taken into account when projecting the end-of-cycle voltages for the next operating cycle. The NDE uncertainties used in the calculations of the EOC-13 voltages are described in Reference 6. The acquisition uncertainty was sampled from a normal distribution with a mean of zero, a standard deviation of 7%, and a cutoff limit of 15% based on the use of the probe wear standard. The analyst uncertainty was sampled from a normal distribution with a mean of zero, a standard deviation of 10.3%, and no cutoff limit. These uncertainty distributions are shown in Table 3-21 and Figure 3-36.

3.7 +PointTMto Bobbin Voltage Correlation In Reference 28, PG&E committed to providing an assessment in each 90-day report to ensure that the bobbin voltages assigned to AONDB indications continue to be conservative. That is, for those prior cycle AONDB indications that become detectable by bobbin (DOS), this assessment was to include a review of the current cycle bobbin voltages against the expected bobbin voltages assuming that all of these indications grew at the average growth rate for the DOS population.

In 2R12, 58 AONDB were returned to service for Cycle 13. 21 of these AONDB indications were reported with bobbin as DOS in 2R13 and the remaining 37 remained AONDB. Table 3-22 provides the growth rate (volt/EFPY) comparison of inferred to DOS (apparent growth),

inferred to inferred, and +PointTM to +PointTm. Comparing the 2R12 inferred voltage to the 2R13 DOS voltage (apparent growth), results in an average increase of 0.016 v/EFPY, which is about one-fourth of the average growth rate for DOS indications detectable in both inspections,

86-9024635-000 Page 20 of 107 0.063 v/EFPY. Growth rates using inferred to inferred and +PointTM to +PointTM both indicate an average growth of 0.025v/EFPY, which is also less than the average of the DOS population.

As a prudent measure, the bobbin to +PointTM voltage correlation continues to be assessed by comparing the inferred bobbin voltages against the measured bobbin voltages for all of the intersections that had both bobbin DOS indications and +PointTM indications of axial ODSCC.

The 2R13 +PointTM indications were assigned bobbin voltages based on the following equation from Reference 17.

VBobb_95Uc = V+PT

-:

• 1.0161 + 0.283 5 + V0.00024 + 0.001 l(V+PT - 0.45)2 For cases where more than one +PointTM indication was reported at the same intersection, each indication was assigned an inferred voltage. These multiple voltages were then combined via the square root of the sum of the squares method (SRSS) to obtain a single inferred bobbin voltage for those intersections.

These inferred bobbin voltages were then compared to the measured bobbin voltages to ensure that the inferred voltages are generally conservative relative to the measured bobbin voltages.

There were a total of 245 intersections with DOS indications that were confirmed as containing axial ODSCC with +PointTM. In 152 of these 245 cases (about 62%), the inferred voltage was over predicted relative to the measured bobbin voltage. The average difference between the inferred voltages and the measured voltages was a 0.03v over-prediction, indicating conservatism in the voltage correlation across the entire data set.

In 2R13, the largest inferred voltage for an AONDB indication was 0.96v. Since the +PointTMto bobbin voltage correlation was only used for intersections with inferred voltages less than 0.96v, this is the voltage range of interest for this comparison. When only the inferred voltages less than 0.96v are considered, 108 of 146 (about 74%) inferred voltages were over predicted relative to the measured voltage. The average difference between the inferred voltages and the measured bobbin voltages for this population was a 0.1Ov over-prediction.

Figure 3-37 shows these comparisons graphically. This figure shows the inferred voltages plotted against the measured bobbin voltages. The linear regression fit shows that, in the region of interest (<0.96 inferred volts), the inferred bobbin voltage is comparable to the measured bobbin voltage. Based on the facts that about 74% of the voltages are over predicted and the average difference in voltages is a 0.10v over-prediction in the range of voltages where it is utilized, the +PointTM to bobbin voltage correlation is shown to provide reasonable and conservative results at 2R13.

86-9024635-000 Page 21 of 107 Table 3-1: 2R13 DOS >2 Volts SG Row j Col Ind Elev Volts 21 5 45 DOS 1H 2.23 21 13 39 DOS 1H 2.39 22 19 85 DOS 2H 2.07 23 12 8 DOS 2H 2.13 23 20 32 DOS IH 2.1 23 22 52 DOS 2H 3.19 24 1 60 DOS 2H 3.75 24 6 56 DOS 1H 2.05 24 6 64 DOS 2H 3.82 24 7 10 DOS 2H 2.81 24 7 78 DOS 3H 4.16 24 8 69 DOS 2H 2.19 24 8 76 DOS 2H 3.09 24 11 73 DOS 2H 2.23 24 11 79 DOS 3H 2.63 24 12 90 DOS 2H 2.67 24 13 88 DOS 2H 3.32 24 14 36 DOS 2H 2.58 24 14 69 DOS 2H 2.05 24 16 84 DOS 2H 2.99 24 18 70 DOS 2H 2.06 24 18 71 DOS 2H 2.91 24 19 79 DOS 2H 2.05 24 20 43 DOS 2H 2.35 24 21 42 DOS 1H 2.18 24 21 79 DOS 2H 2.05 24 30 16 DOS 2H 2.25 24 36 34 DOS 3H 3.99 24 38 25 DOS 2H 2.26 24 38 61 DOS 2H 3.24 24 40 30 DOS 1H 2.14 24 40 47 DOS 2H 2.01

86-9024635-000 Page 22 of 107 Table 3-2: 2R13 AONDB Indications Reason for epair Dent Inferred Bobbin Volts SG Row Elev Pt +Pt SGIRownCodElev Volts ReaVoltage Indication Intersection 21 2 47 2H SAI 0.19 0.89 0.494 0.494 21 17 9 3H SAI 0.14 0.41 0.444 0.444 21 44 55 1H SAt 0.13 0.85 0.434 0.434 21 44 57 2H SAI 0.12 0.51 0.424 0.424 22 4 29 1H SAI 0.25 AONDB @ >5V DENT @ 1H 23.65 0.554 0.554 22 8 13 1H SAI 0.20 2.47 0.504 0.504 22 8 30 1H SAI 0.25 2.22 0.554 0.554 22 13 22 1H SAI 0.17 3.88 0.474 0.474 22 14 42 1H SAI 0.25 2.81 0.554 0.554 22 14 50 1H SAI 0.16 2.64 0.464 0.464 22 15 41 1H SAI 0.32 AONDB @ >5V DENT @ 1H 9.01 0.625 0.625 22 17 42 1H SAI 0.30 3.73 0.605 0.605 22 19 45 1H SAI 0.34 0.65 0.645 0.645 22 19 75 1H SAI 0.27 0.86 0.574 0.574 22 22 28 2H SAI 0.17 1.87 0.474 0.474 22 22 62 1H SAI 0.14 0.96 0.444 0.444 22 24 40 2H SAI 0.18 1.12 0.484 0.484 22 25 8 1H SAI 0.23 2.03 0.534 0.534 22 25 46 2H SAI 0.40 1.26 0.706 0.706 22 26 17 3H SAI 0.12 0.39 0.424 0.659 22 26 17 3H SAI 0.20 0.504 22 27 50 3H SAI 0.18 0.36 0.484 0.484 22 29 36 2H SAI 0.12 0.52 0.424 0.424 22 31 22 2H SAI 0.32 1.47 0.625 0.625 22 33 22 1H SAI 0.17 0.42 0.474 0.474 22 35 67 2H SAI 0.11 0.42 0.414 0.414 22 37 46 2H SAI 0.28 1.4 0.584 0.584 22 45 39 2H SAI 0.46 1.3 0.766 0.766 23 5 66 3H SAI 0.19 1.84 0.494 0.494 23 13 58 1H SAI 0.26 0.71 0.564 0.564 23 17 80 1H SAI 0.49 1.4 0.797 0.959 23 17 80 1H SAI 0.23 0.534 23 19 77 2H SAI 0.11 0.84 0.414 0.579 23 19 77 2H SAI 0.10 0.404 23 22 10 1H SAI 0.15 0.44 0.454 0.454 23 26 80 2H SAI 0.11 0.9 0.414 0.414 23 29 61 1H SAI 0.11 0.414 23 29 61 1H SAI 0.31 0.72 0.615 0.891 23 29 61 1H SAI 0.19 0.494 23 29 66 2H SAI 0.15 0.43 0.454 0.454 23 30 15 1H SAI 0.24 0.65 0.544 0.544 23 33 35 2H SAI 0.08 0.69 0.385 0.385 23 33 57 2H SAI 0.15 0.43 0.454 0.650 23 33 57 2H SAI 0.16 0.464 23 35 71 1H SAI 0.07 0.2 0.375 0.375

86-9024635-000 Page 23 of 107 Table 3-2: 2R13 AONDB Indications SG Row 1Pt Ind

+Pt Volts Reason for Repair Dent Voltage Inferred Bobbin Volts Indication Intersection 37 61 1H SAII 0.13 1.39 0.434 0.434 24 2 21 3H SAI 0.28 2.88 0.584 0.584 24 2 36 2H SAI 0.18 0.72 0.484 0.484 24 5 27 1H SAI 0.10 0.83 0.404 0.404 24 7 40 3H SAI 0.10 3.85 0.404 0.404 24 8 41 1H SAI 0.27 0.52 0.574 0.574 24 10 29 3H SAI 0.17 1.52 0.474 0.474 24 11 37 4H SAI 0.27 0.3 0.574 0.703 24 11 37 4H SAI 0.10 0.404 24 16 36 1H SAI 0.14 0.32 0444 0.703 24 16 36 1H SAI 0.24 0.544 24 22 16 1H SAI 0.29 0.71 0.595 0.595 24 22 21 3H SAI 0.11 SAW-ID/OD @ 3H 2.8 0.414 0.414 24 22 22 3H SAI 0.15 0.88 0.454 0.454 24 24 10 1H SAI 0.21 0.85 0.514 0.514 24 25 27 1H SAI 0.13 1.05 0.434 0.434 24 27 19 3H SAI 0.11 0.35 0.414 0.414 24 30 36 3H SAI 0.27 3.37 0.574 0.574 24 42 61 1H SAI 0.15 0.8 0.454 0.454

86-9024635-000 Page 24 of 107 Table 3-3: Summary of Inspection and Repair for Tubes Affected by ODSCC at TSPs SG 2-1 SG 2-2 SG 2-3 DOSs DOSs DOSs As- Returned to Service As- Returned to Service As- Returned to Service Voltage Fud Repaired As-n Reaie Found Repaired Bin Tubes Conf. ODSCC Found Tubes Conf. ODSCC Tubes Conf. ODSCC EOC-13 or Not Insp Total EOC-13 or Not Insp Total EOC-13 or Not Insp Total w/+Pt w/+Pt w/+Pt 0.1 0 0 0 0 0 0 0 0 2 0 2 2 0.2 47 0 47 47 37 0 35 37 30 0 28 30 0.3 83 1 81 82 66 0 61 66 46 0 42 46 0.4 106 0 101 106 85 0 81 85 66 0 64 66 0.5 62 0 60 62 71 2 67 69 50 0 46 50 0.6 57 0 54 57 53 1 49 52 35 0 34 35 0.7 44 0 42 44 44 1 40 43 27 0 27 27 0.8 30 0 30 30 31 0 30 31 25 0 23 25 0.9 27 0 26 27 15 0 15 15 12 0 12 12 1 17 0 17 17 14 0 14 14 9 0 9 9 1.1 17 0 17 17 8 0 8 8 5 0 5 5 1.2 9 0 9 9 7 1 6 6 4 0 4 4 1.3 4 0 4 4 7 0 7 7 2 0 2 2 1.4 11 0 11 11 8 0 8 8 4 0 4 4 1.5 3 0 3 3 3 0 3 3 5 0 5 5 1.6 6 0 6 6 3 0 3 3 2 0 2 2 1.7 2 0 2 2 2 0 2 2 3 0 3 3 1.8 1 0 1 1 0 0 0 0 1 0 1 1 1.9 1 0 1 1 1 0 1 1 0 0 0 0 2 2 0 2 2 0 0 0 0 1 0 1 1 2.1 0 0 0 0 1 1 0 0 1 1 0 0 2.2 0 0 0 0 0 0 0 0 1 1 0 0 2.3 1 1 0 0 0 0 0 0 0 0 0 0 2.4 1 1 0 0 0 0 0 0 0 0 0 0 2.5 0 0 0 0 0 0 0 0 0 0 0 0 2.6 0 0 0 0 0 0 0 0 0 0 0 0 2.7 0 0 0 0 0 0 0 0 0 0 0 0 2.8 0 0 0 0 0 0 0 0 0 0 0 0 2.9 0 0 0 0 0 0 0 0 0 0 0 0 1 '

3 0 0 0 0 0 0 0 0 0 0 0 0

>3 0 0 0 0 0 0 0 0 1 1 0 0 Total 531 3 514 528 456 6 430 450 332 3 314 329

>IV 58 2 56 56 40 2 38 38 30 3 27 27

>2V 2 2 0 0 1 1 0 0 3 3 0 0

86-9024635-000 Page 25 of 107 Table 3-3 (cont): Summary of Inspection and Repair for Tubes Affected by ODSCC at TSPs SG 2-4 Composite of All SGs DOSs DOSs Voltage Found As- Repaired Returned to Service As-A- Re paired Returned to Service Bin EOC-13 Tubes orNo lsp Conf. ODSCC ToalEOC-13 Found Tubes Conf. ODSCC 3orNot nsp Total or Not Insp Total w/+Pt w/+Pt 0.1 1 0 1 1 3 0 3 3 0.2 43 0 39 43 157 0 149 157 0.3 117 2 112 115 312 3 296 309 0.4 168 4 160 164 425 4 406 421 0.5 144 5 137 139 327 7 310 320 0.6 128 2 126 126 273 3 263 270 0.7 118 4 114 114 233 5 223 228 0.8 69 2 67 67 155 2 150 153 0.9 77 3 74 74 131 3 127 128 1 62 0 62 62 102 0 102 102 1.1 57 1 56 56 87 1 86 86 1.2 43 1 42 42 63 2 61 61 1.3 33 0 33 33 46 0 46 46 1.4 39 2 37 37 62 2 60 60 1.5 24 0 24 24 35 0 35 35 1.6 13 0 13 13 24 0 24 24 1.7 12 0 12 12 19 0 19 19 1.8 4 0 4 4 6 0 6 6 1.9 5 0 5 5 7 0 7 7 2 11 1 10 10 14 1 13 13 2.1 6 6 0 0 8 8 0 0 2.2 3 3 0 0 4 4 0 0 2.3 3 3 0 0 4 4 0 0 2.4 1 1 0 0 2 2 0 0 2.5 0 0 0 0 0 0 0 0 2.6 1 1 0 0 1 1 0 0 2.7 2 2 0 0 2 2 0 0 2.8 0 0 0 0 0 0 0 0 2.9 1 1 0 0 1 1 0 0 3 2 2 0 0 2 2 0 0

>3 7 7 0 0 8 8 0 0 Total 1194 53 1128 1141 2513 65 2386 2448

>IV 267 31 236 236 395 38 357 357

>2V 26 26 0 0 32 32 0 0

86-9024635-000 Page 26 of 107 Table 3-4: Summary of Largest Voltage Growth Rates per EFPY SG Row Col Elev Volts Prev Volts (2R12) Growth/EFPY +Pt New?

2-4 6 64 2H 3.82 1.3 1.924 SAI Repeat 2-4 7 78 3H 4.16 1.72 1.863 SAI Repeat 2-4 1 60 2H 3.75 1.41 1.786 SAI Repeat 2-4 36 34 3H 3.99 1.92 1.580 SAI Repeat 2-3 22 52 2H 3.19 1.40 1.366 SAI Repeat 2-4 12 90 2H 2.67 0.990 1.282 SAI Repeat 2-4 13 88 2H 3.32 1.67 1.260 SAI Repeat 2-4 38 61 2H 3.24 1.65 1.214 SAI Repeat 2-4 11 79 3H 2.63 1.22 1.076 SAI Repeat 2-4 18 71 2H 2.91 1.63 0.977 SAI Repeat 2-4 16 84 2H 2.99 1.80 0.908 SAI Repeat 2-4 7 10 2H 2.81 1.640 0.893 SAI Repeat 2-4 8 76 2H 3.09 1.94 0.878 SAI Repeat 2-1 17 20 1H 1.47 0.34 0.863 Not Insp Repeat 2-1 12 86 1H 1.79 0.74 0.802 SAI Repeat 2-1 2 28 1H 1.51 0.50 0.771 Not Insp Repeat 2-4 20 43 2H 2.35 1.410 0.718 SAI Repeat 2-2 5 61 2H 1.20 0.27 0.710 Not Insp Repeat 2-4 38 25 2H 2.26 1.38 0.672 SAI Repeat 2-4 19 79 2H 2.05 1.20 0.649 SAI Repeat 2-4 23 21 1H 1.18 0.35 0.634 Not Insp Repeat 2-4 14 22 2H 1.18 0.35 0.634 Not Insp Repeat 2-4 25 56 2H 1.11 0.30 0.618 Not Insp Repeat 2-4 7 56 3H 1.97 1.18 0.603 SAI Repeat 2-1 24 30 1H 1.32 0.54 0.595 Not Insp Repeat 2-3 17 18 3H 1.63 0.85 0.595 Not Insp Repeat 2-4 16 59 1H 1.12 0.35 0.588 Not Insp Repeat 2-3 36 76 2H 1.38 0.62 0.580 Not Insp Repeat 2-4 11 73 2H 2.23 1.48 0.573 SAI Repeat 2-1 13 39 1H 2.39 1.68 0.542 SAI Repeat 2-4 14 36 2H 2.58 1.87 0.542 SAI Repeat 2-4 16 43 1H 1.07 0.37 0.534 Not Insp Repeat 2-4 10 79 2H 1.59 0.89 0.534 Not Insp Repeat 2-3 12 8 2H 2.13 1.43 0.534 SAI Repeat 2-4 37 64 2H 1.14 0.45 0.527 Not Insp Repeat 2-4 16 74 2H 1.37 0.69 0.519 Not Insp Repeat 2-1 5 45 IH 2.23 1.55 0.519 SAI Repeat 2-4 23 40 3H 1.91 1.23 0.519 SAI Repeat 2-4 23 64 2H 1.81 1.14 0.511 SAI Repeat 2-4 40 30 1H 2.14 1.48 0.504 SAI Repeat 2-2 12 88 3H 1.01 0.35 0.504 Not Insp Repeat 2-4 17 37 IH 1.25 0.59 0.504 Not Insp Repeat

86-9024635-000 Page 27 of 107 Table 3-5: DOS/AONDB Voltage and Growth Distribution by TSP Jrwh SG 2-1 SG 2-2 Tube Tube Support No1fMx vrg Max rwh Average lt Support Indications N Voltage Voltage Max EFY Average FP Plate Nae Growh piat No. of Max Average Growth/ Growth/

Indications Voltage Voltage EFPY EFPY EFPY EFPY 1H 323 2.39 0.60 0.86 0.05 1H 155 1.82 0.57 0.19 0.02 2H 114 1.93 0.47 0.24 0.00 2H 179 2.07 0.56 0.71 0.03 3H 38 1.54 0.52 0.13 0.01 3H 67 1.51 0.49 0.50 0.03 4H 7 0.82 0.42 0.13 -0.01 4H 22 1.07 0.50 0.19 0.00 5H 22 1.07 0.53 0.30 0.03 5H 3 0.84 0.62 0.20 0.04 6H 6 1.18 0.68 0.39 0.06 6H 1 0.41 0.41 0.05 0.05 7H 7H 2 0.59 0.43 0.06 -0.06 CL 21 1.03 0.53 0.17 0.05 CL 27 0.63 0.39 0.20 0.01 All Inds 531 2.39 0.56 0.86 0.03 All Inds 456 2.07 0.54 0.71 0.02 SG 2-3 SG 2-4 Tube Tube Support No. of Max Average Max Average Support No. of Max Average Max Average Plate Noios VMax Avotage Growth/ Growth/ Plate Indications Voltage Voltage rowth Ioltage Vo EFPY EFPY EFPY EFPY 1H 171 2.1 0.58 0.38 0.05 1H 419 2.18 0.69 0.63 0.07 2H 108 3.19 0.54 1.37 0.05 2H 502 3.82 0.84 1.92 0.13 3H 26 1.63 0.51 0.60 0.04 3H 178 4.16 0.64 1.86 0.09 4H 2 0.5 0.40 -0.01 -0.09 4H 66 1.34 0.55 0.32 0.06 5H 6 0.77 0.43 0.05 -0.02 5H 8 0.81 0.50 0.27 0.05 6H 1 0.51 0.51 0.15 0.15 6H 1 0.3 0.30 0.08 0.08 7H 1 0.16 0.16 -0.04 -0.04 7H CL 17 0.75 0.39 0.25 0.07 CL 20 0.51 0.33 0.11 -0.01 All n 332 3.19 0.55 1.37 0.05 [ All Inds 1 1194 4.16 0.73 1.92 1 0.09 Composite of All Four SGs Tube Support Max Average No. of Max Average Growth!

Plate EFPY Growth/

Indications Voltage Voltage EFPY 1H 1068 2.39 0.63 0.86 0.05 2H 903 3.82 0.70 1.92 0.08 3H 309 4.16 0.58 1.86 0.07 4H 97 1.34 0.53 0.32 0.04 5H 39 1.07 0.51 0.30 0.03 6H 9 1.18 0.59 0.39 0.07 7H 3 0.59 0.34 0.06 -0.05 CL 85 1.03 0.41 0.25 0.03 All Inds 2513 4.16 [ 0.63 1.92 0.06

86-9024635-000 Page 28 of 107 Table 3-6: DCPP-2 Voltage Growth for Cycles 8 through 13

¶ V SG 2-1 SG 2-2 SG 2-3 SG 2-4 All Avg BOC Volts 0.34 0.36 0.40 0.42 0.39 Cycle 8 Average Growth Per EFPY 0.05 0.05 -0.01 0.06 0.05 Average Percent Growth Per EFPY '16.0% 15.2% -1.9% 14.3% 13.3%

Avg BOC Volts 0.388 0.362 0.324 0.387 0.377 Cycle 9 Avg Growth Per EFPY 0.04 0.09 0.17 0.17 0.13 Average Percent Growth Per EFPY 9.2% 24.2% 52.0% 44.7% 35.6%

Avg BOC Volts 0.42 0.43 0.48 0.53 0.49 Cycle 10 Avg Growth Per EFPY 0.14 0.08 0.12 0.20 0.16 Average Percent Growth Per EFPY 33.2% 19.0% 25.5% 37.5% 33.4%

Avg BOC Volts 0.42 0.44 0.38 0.51 0.47 Cycle 11 Avg Growth Per EFPY 0.13 0.10 0.13 0.23 0.18 Average Percent Growth Per EFPY 30.9% 23.5% 34.7% 45.3% 38.7%

Avg BOC Volts 0.42 0.43 0.45 0.50 0.46 Cycle 12 Avg Growth Per EFPY 0.11 0.09 0.05 0.14 0.11 Average Percent Growth Per EFPY 25.3% 19.8% 11.2% 27.4% 123.8%

Avg BOC Volts 0.52 0.51 0.49 0.61 0.56 Cycle 13 Avg Growth Per EFPY 0.03 0.02 0.05 0.09 0.06

_ _ Average Percent Growth Per EFPY 6.5% 4.9% 10.5% 15.3% 111.3%

86-9024635-000 Page 29 of 107 Table 3-7: Summary of Independent Cycle 13 Voltage Growth per EFPY Delta SG 2-1 SG 2-2 SG 2-3 SG 2-4 Total Volts EFPY Per No.

Obs.of CPDF No.

Obs. of CPDF No.

Obs. of CPDF No.

Obs. of CPDF No.

Obs. of CPDF

<=0.0 225 0.430 182 0.425 109 0.354 281 0.243 797 0.330 0.1 210 0.832 181 0.848 119 0.740 479 0.657 989 0.740 0.2 62 0.950 53 0.972 45 0.886 225 0.852 385 0.899 0.3 13 0.975 5 0.984 22 0.958 95 0.934 135 0.955 0.4 3 0.981 4 0.993 7 0.981 27 0.958 41 0.972 0.5 4 0.989 1 0.995 2 0.987 19 0.974 26 0.983 0.6 3 0.994 1 0.998 3 0.997 11 0.984 18 0.990 0.7 0 0.994 0 0.998 0 0.997 6 0.989 6 0.993 0.8 1 0.996 1 1.000 0 0.997 1 0.990 3 0.994 0.9 2 1.000 0 1.000 0 0.997 2 0.991 4 0.995 1 0 1.000 0 1.000 0 0.997 2 0.993 2 0.996 1.1 0 1.000 0 1.000 0 0.997 1 0.994 1 0.997 1.2 0 1.000 0 1.000 0 0.997 0 0.994 0 0.997 1.3 0 1.000 0 1.000 0 0.997 3 0.997 3 0.998 1.4 0 1.000 0 1.000 1 1.000 0 0.997 1 0.998 1.5 0 1.000 0 1.000 0 1.000 0 0.997 0 0.998 1.6 0 1.000 0 1.000 0 1.000 1 0.997 1 0.999 1.7 0 1.000 0 1.000 0 1.000 0 0.997 0 0.999 1.8 0 1.000 0 1.000 0 1.000 1 0.998 1 0.999 1.9 0 1.000 0 1.000 0 1.000 1 0.999 1 1.000 2 0 1.000 0 1.000 0 1.000 1 1.000 1 1.000

>2 0 1.000 0 1.000 0 1.000 0 1.000 0 1.000 Total 5231 NA j[ 428 NA 308 N N" 11561 NA 2415 NA Upper 95198 - I 0.280 fif 0.351028 -___

Growth__% 0.198 0.183

86-9024635-000 Page 30 of 107 Table 3-8: Cycle 13 Voltage Dependent Growth for SG 2-3 (Information Only)

Growth I Cycle 13 Data (volts/EFPY) Bin1 Bin2

(<=0.89v) (>0.89v)

<0 100 8 0.1 116 4 0.2 41 3 0.3 17 6 0.4 3 3 0.5 1 2 0.6 2 1 0.7 0 0 0.8 0 0 0.9 0 0 1 0 0 1.1 0 0 1.2 0 0 1.3 0 0 1.4 0 1 1.5 0 0 1.6 0 0 1.7 0 0 1.8 0 0 1.9 0 0

>2 0 0 Total 280 28

86-9024635-000 Page 31 of 107 Table 3-9: Cycle 13 Voltage Dependent'Growth for SG 2-4 (Information Only)

Cycle 13 Data Growth Bin2 (volts/EFPY) Bin1 (1i.07v- 53

(<=1.06v) 1.53v) (>1.53v)

<0 261 19 1 0.1 447 28 4 0.2 190 34 1 0.3 74 15 6 0.4 17 8 2 0.5 10 8 1 0.6 6 4 1 0.7 3 3 0 0.8 0 1 0 0.9 0 0 2 1 0 0 2 1.1 0 1 0 1.2 0 0 0 1.3 1 0 2 1.4 0 0 0 1.5 0 0 0 1.6 0 0 1 1.7 0 0 0 1.8 0 1 0 1.9 0 0 1 2 0 1 0

>2 0 0 0 Total 1009 123 J 24

86-9024635-000 Page 32 of 107 Table 3-10: Cycle 13 Voltage Dependent Growth for All SGs (Information Only)

Cycle 13 Data Growth Bin2 (volts/EFPY) Bin1 (0.89v- Bin3

(<=0.88v) 1.5v) (>1.5v)

<0 705 89 3 0.1 887 95 7 0.2 305 76 4 0.3 90 39 6 0.4 20 17 4 0.5 12 13 1 0.6 9 6 3 0.7 3 3 0 0.8 2 1 0 0.9 2 0 2 1 0 0 2 1.1 0 1 0 1.2 0 0 0 1.3 0 1 2 1.4 0 1 0 1.5 0 0 0 1.6 0 0 1 1.7 0 0 0 1.8 0 1 0 1.9 0 0 1 2 0 1 0

>2 0 0 0 Total 2035 344 36

86-9024635-000 Page 33 of 107 Table 3-11: Cycle 12 Supplemented Voltage Dependent Growth for SG 2-1 (Used for SG 2-1 EOC-14 Projections Cycle 11 Data Combined Growth Cycle 12 Data (volts/EFPY) Bin1 Bin2 Bin1 Bin2 Bin1 Bin2

(<=1.12v) (>1.12v) (<=1.12v) (>1.12v) (<=1.12v) (>1.12v)

<0 75 0 0 3 75 3 0.1 198 0 0 1 198 1 0.2 86 2 0 1 86 3 0.3 43 0 0 1 43 1 0.4 19 1 0 0 19 1 0.5 6 0 0 0 6 0 0.6 2 0 0 0 2 0 0.7 2 0 0 0 2 0 0.8 2 0 0 0 2 0 0.9 1 0 0 2 1 2 1 2 0 0 0 2 0 1.1 1 0 0 0 1 0 1.2 0 0 0 0 0 0 1.3 0 0 0 0 0 0 1.4 0 0 0 0 0 0 1.5 0 0 0 0 0 0 1.6 0 0 0 1 0 1 1.7 0 0 0 0 0 0 1.8 0 0 0 0 0 0 1.9 0 0 0 0 0 0 2 0 0 0 0 0 0 2.1 0 0 0 0 0 0 2.2 0 0 0 0 0 0 2.3 0 0 0 1 0 1 2.4 0 0 0 0 0 0 2.5 0 0 0 0 0 0 2.6 0 0 0 1 0 1 2.7 0 0 0 0 0 0 2.8 0 0 0 0 0 0 2.9 0 0 0 1 0 1 3 0 0 0 0 0 0 3.1 0 0 0 0 0 0 3.2 0 0 0 0 0 0

>3.2 0 0 0 0 0 0 Total 437 3 0 12 437 15

86-9024635-000 Page 34 of 107 Table 3-12: Cycle 12 Supplemented Voltage Dependent Growth for All SGs (Used for SGs 2-2, and 2-3 EOC-14 Projections)

I1.1 Cycle 12 Data Cycle 11 Data Combined Growth (volts/EFPY) Bin1 Bin2 Bi2 Bin3 Bin1 Bin2 B2 Bin3 Bin1 Bin2 (1.v- Bin3

(<=1.lv) (>1.71v) (<=l.lv) - (>1.71v) 1.7v 71v) 1) (=.v 171.71 v) .7v <11) 1.71v)

<0 293 7 0 0 11 0 293 18 0 0.1 856 4 0 0 7 2 856 11 2 0.2 468 9 0 0 5 0 468 14 0 0.3 192 9 0 0 6 2 192 15 2 0.4 75 2 0 0 1 0 75 3 0 0.5 29 4 0 0 1 0 29 5 0 0.6 18 3 0 0 2 1 18 5 1 0.7 9 0 0 0 3 0 9 3 0 0.8 4 0 0 0 2 0 4 2 0 0.9 3 0 0 0 4 0 3 4 0 1 2 1 0 0 1 0 2 2 0 1.1 1 0 0 0 1 0 1 1 0 1.2 0 0 0 0 2 0 0 2 0 1.3 0 0 0 0 2 0 0 2 0 1.4 0 0 0 0 1 1 0 1 1 1.5 1 0 0 0 1 2 1 1 2 1.6 0 0 0 0 2 1 0 2 1 1.7 0 0 0 0 0 1 0 0 1 1.8 0 0 0 0 1 0 0 1 0 1.9 0 0 0 0 1 1 0 1 1 2 0 0 0 0 1 0 0 1 0 2.1 0 0 0 0 0 0 0 0 0 2.2 0 0 0 0 3 1 0 3 1 2.3 0 0 0 0 2 0 0 2 0 2.4 0 0 0 0 0 0 0 0 0 2.5 0 0 0 0 1 0 0 1 0 2.6 0 0 0 0 1 1 0 1 1 2.7 0 0 0 0 0 2 0 0 2 2.8 0 0 0 0 0 0 0 0 0 2.9 0 0 0 0 0 1 0 0 1 3 0 0 0 0 0 1 0 0 1 3.1 0 0 0 0 0 0 0 0 0 3.2 0 0 0 0 0 0 0 0 0

>3.2 0 0 0 0 0 0 0 0 0 Total 1951 39 0 0 62 17 1951 101 17

86-9024635-000 Page 35 of 107 Table 3-13 Cycle 12 Supplemented Voltage Dependent Growth for SG 2-4 (Used for SG 2-4 EOC-14 Projections)

Cycle 12 Data Cycle 11 Data Combined Growth Bin2 Bin2 Bin2 (volts/EFPY) Bin1 (0.48v- Bin3 Bin1 (0.48v- Bin3 Bin1 (048v Bin3

(<=0.47v) 1.06 >1.038v) (<=0.47v) 1.038v) (>1.038v) (<=0.47v) (.0.38v) (>1

<0 47 25 3 0 0 6 47 25 9 0.1 286 98 5 0 0 8 286 98 13 0.2 134 122 10 0 0 4 134 122 14 0.3 47 68 6 0 0 7 47 68 13 0.4 3 38 3 0 0 1 3 38 4 0.5 4 11 6 0 0 1 4 11 7 0.6 1 10 5 0 0 3 1 10 8 0.7 3 3 0 0 0 2 3 3 2 0.8 0 1 0 0 0 2 0 1 2 0.9 0 1 1 0 0 2 0 1 3 1 0 0 1 0 0 1 0 0 2 1.1 0 0 0 0 0 0 0 0 0 1.2 0 0 0 0 0 2 0 0 2 1.3 0 0 0 0 0 2 0 0 2 1.4 0 0 0 0 0 1 0 0 1 1.5 0 1 0 0 0 3 0 1 3 1.6 0 0 0 0 0 2 0 0 2 1.7 0 0 0 0 0 0 0 0 0 1.8 0 0 0 0 0 1 0 0 1 1.9 0 0 0 0 0 2 0 0 2 2 0 0 0 0 0 1 0 0 1 2.1 0 0 0 0 0 0 0 0 0 2.2 0 0 0 0 0 4 0 0 4 2.3 0 0 0 0 0 1 0 0 1 2.4 0 0 0 0 0 0 0 0 0 2.5 0 0 0 0 0 1 0 0 1 2.6 0 0 0 0 0 1 0 0 1 2.7 0 0 0 0 0 1 0 0 1 2.8 0 0 0 0 0 0 0 0 0 2.9 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 1 0 0 1 3.1 0 0 0 0 0 0 0 0 0 3.2 0 0 0 0 0 0 0 0 0

>3.2 0 0 0 0 0 0 0 0 0 Total 525 378 40 0 0 60 525 378 100

86-9024635-000 Page 36 of 107 Table 3-14: Delta Volts Adjustments Based on Cycle 13 Breakpoints (Information Only)

Average Growth (Volts per EFPY)

SG Cycle Breakpoint(s)

Bin1 Bin2 Bin3 Cycle 12 0.126 2-1 Cycle 13 NA 0.033 NA NA Delta <0 Cycle 12 0.102 2-2 Cycle 13 NA 0.025 NA NA Delta <0 Cycle 12 0.046 0.152 2-3 Cycle 13 0.89 0.040 0.167 NA Delta <0 +0.015 Cycle 12 0.130 0.509 1.051 2-4 Cycle 13 1.06/1.53 0.071 0.201 0.544 Delta <0 <0 <0 Cycle 12 0.101 0.337 1.212 Composite Cycle 13 0.88/1.50 0.046 0.126 0.418 Delta <0 <0 <0

86-9024635-000 Page 37 of 107 Table 3-15: Delta Volts Adjustments Based on Cycle 12 Breakpoints Average Growth (Volts per EFPY)

SG Cycle Breakpoint(s)

Bin1 Bin2 Bin3 Cycle 12 0.105 0.722 2-1 Cycle 13 1.12 0.031 0.075 NA Delta <0 <0 Cycle 12 0.083 0.540 2-2 Cycle 13 1.00 0.023 0.046 NA Delta <0 <0 Cycle 12 0.046 0.171 2-3 Cycle 13 0.96 0.041 0.192 NA Delta <0 +0.021 Cycle 12 0.095 0.178 0.638 2-4 Cycle 13 0.47/1.03 0.057 0.084 0.248 Delta <0 <0 <0 Cycle 12 0.108 0.514 1.542 Composite Cycle 13 1.10/1.71 0.050 0.188 0.552 Delta <0 <0 <0

86-9024635-000 Page 38 of 107 Table 3-16: BOC-14 Voltage Distributions SG 2-1 SG 2-2 SG 2-3 As- As-Bin Found Repaired Bin As-Found Repaired Found Repaired 0.1 0 0 0.1 0 0 2 0 0.2 47 0 0.2 37 0 30 0 0.3 83 1 0.3 66 0 46 0 0.4 106 0 0.4 85 0 66 0 0.5 62 0 0.5 71 2 50 0 0.6 57 0 0.6 53 1 35 0 0.7 44 0 0.7 44 1 27 0 0.8 30 0 0.8 31 0 25 0 0.9 27 0 0.9 15 0 12 0 1 17 0 1 14 0 9 0 1.1 17 0 1.1 8 0 5 0 1.12 2 0 1.2 7 1 4 0 1.2 7 0 1.3 7 0 2 0 1.3 4 0 1.4 8 0 4 0 1.4 11 0 1.5 3 0 5 0 1.5 3 0 1.6 3 0 2 0 1.6 6 0 1.7 2 0 3 0 1.7 2 0 1.71 0 0 0 0 1.8 1 0 1.8 0 0 1 0 1.9 1 0 1.9 1 0 0 0 2 2 0 2 0 0 1 0 2.1 0 0 2.1 1 1 1 1 2.2 0 0 2.2 0 0 1 1 2.3 1 1 2.3 0 0 0 0 2.4 1 1 2.4 0 0 0 0 2.5 0 0 2.5 0 0 0 0 2.6 0 0 2.6 0 0 0 0 2.7 0 0 2.7 0 0 0 0 2.8 0 0 2.8 0 0 0 0 2.9 0 0 2.9 0 0 0 0 3 0 0 3 0 0 0 0 3.1 0 0 3.1 0 0 0 0 3.2 0 0 3.2 0 0 1 1 Total 531 3 456 6 332 3

86-9024635-000 Page 39 of 107 Table 3-16 (cont): BOC-14 Voltage Distributions Bi SG 2-4 As-Found Repaired 0.1 1 0 0.2 43 0 0.3 117 2 0.4 168 4 0.47 96 4 0.5 48 1 0.6 128 2 0.7 118 4 0.8 69 2 0.9 77 3 1 62 0 1.03 17 1 1.1 40 0 1.2 43 1 1.3 33 0 1.4 39 2 1.5 24 0 1.6 13 0 1.7 12 0 1.8 4 0 1.9 5 0 2 11 1 2.1 6 6 2.2 3 3 2.3 3 3 2.4 1 1 2.5 0 0 2.6 1 1 2.7 2 2 2.8 0 0 2.9 1 1 3 2 2 3.1 1 1 3.2 0 0 3.3 1 1 3.4 1 1 3.5 0 0 3.6 0 0 3.7 0 0 3.8 1 1 3.9 1 1 4 1 1 4.1 0 0 4.2 1 1 Total 1194 [ 53

86-9024635-000 Page 40 of 107 Table 3-17: Re-tested DOSs that Failed the Probe Wear Check SG Row Col Ind Elev Volts Probe Cal No. ARC Out 2R13 % Difference 6 46 RSS 2H 1.71 720RF CL - 32 Yes 6 46 DOS 2H 1.58 720RF CL -39 -7.6%

16 64 RSS 1H 1.65 720RF HL-8 Yes 1H 1.82 720RF CL - 37 10.3%

2-2 16 64 DOS 16 64 DOS 2H 0.27 720RF HL-8 16 64 DOS 2H 0.21 720RF CL - 37 -22.2%

22 28 RSS 1H 1.66 720RF CL - 19 Yes 22 28 DOS 1H 1.36 720RF CL - 37 -18.1%

16 61 RSS 1H 1.63 720RF CL - 26 Yes 16 61 DOS 1H 1.47 720RF CL-40 -9.8%

18 48 RSS 1H 1.85 720RF CL - 27 Yes 18 48 DOS 1H 1.78 720RF CL-32 -3.8%

2-3 21 42 RSS 2H 1.56 720RF CL -26 Yes 21 42 DOS 2H 1.48 720RF CL - 32 -5.1%

27 51 RSS 1H 1.57 720RF HL-11 Yes 27 51 DOS 1H 1.35 720RF CL - 41 -14.0%

15 39 RSS 2H 1.62 720RF CL-26 Yes 15 39 DOS 2H 1.55 720RF CL-48 -4.3%

15 23 RSS 1H 1.57 720RF CL-22 Yes 15 23 DOS 1H 1.5 720RF CL - 30 -4.5%

18 70 RSS 2H 2.23 720RF HL -9 Yes 18 70 DOS 2H 2.06 720RF CL-28 -7.6%

18 70 DOS 4H 0.52 720RF HL-9 Yes 18 70 DOS 4H 0.45 720RF CL - 28 -13.5%

19 77 RSS 2H 1.91 720RF HL-9 Yes 19 77 DOS 2H 1.78 720RF CL-28 -6.8%

19 79 RSS 2H 1.87 720RF HL- 12 Yes 19 79 DOS 2H 2.05 720RF CL-28 9.6%

2-4 19 79 DOS 3H 0.45 720RF HL - 12 Yes 19 79 DOS 3H 0.35 720RF CL -28 -22.2%

21 79 DOS 1H 0.22 720RF HL - 12 Yes 21 79 DOS 1H 0.31 720RF CL -28 40.9%

21 79 RSS 2H 1.76 720RF HL- 12 Yes 21 79 DOS 2H 2.05 720RF CL -28 16.5%

21 79 DOS 4H 0.61 720RF HL- 12 Yes 21 79 DOS 4H 0.81 720RF CL -28 32.8%

24 75 RSS 2H 2.1 720RF HL-9 Yes 24 75 DOS 2H 1.92 720RF CL -28 -8.6%

26 28 RSS 3H 1.5 720RF CL-16 Yes 26 28 DOS 3H 1.39 720RF CL -28 -7.3%

331 1 RSS 1H 1.78 720RF CL- 16 Yes 331 1 DOS 1H 1.93 720RF CL-28 8.4%

86-9024635-000 Page 41 of 107 Table 3-17: Re-tested DOSs that Failed the Probe Wear Check SG Row Col Ind Elev Volts Probe I No.

_Cal I _ARC 2R13 Out  % Difference 31 I31 IDOS I2H 1.47 I720RF CL- 16 Yes 31 31 DOS 2H 1.42 720RF CL -28 -3.4%

36 32 RSS 2H 1.52 720RF CL - 16 Yes 36 32 DOS 2H 1.36 720RF CL-28 -10.5%

36 32 DOS 3H 0.67 720RF CL- 16 Yes 36 32 DOS 3H 0.6 720RF CL-28 -10.4%

36 34 DOS 1H 0.41 720RF CL - 17 Yes 36 34 DOS 1H 0.41 720RF CL-28 0.0%

36 34 RSS 3H 4.61 720RF CL - 17 Yes 2-4 36 34 DOS 3H 3.99 720RF CL-28 -13.4%

36 34 DOS 4H 0.88 720RF CL - 17 Yes 36 34 DOS 4H 0.78 720RF CL -28 -11.4%

38 28 DOS 1H 1 720RF CL - 17 Yes 38 28 DOS 1H 0.95 720RF CL -28 -5.0%

38 28 DOS 2H 0.62 720RF CL - 17 Yes 38 28 DOS 2H 0.44 720RF CL -28 -29.0%

38 28 RSS 3H 2.22 720RF CL - 17 Yes 38 28 DOS 3H 1.97 720RF CL-28 -11.3%

40 30 RSS IH 2.03 720RF CL- 16 Yes 40 30 DOS IH 2.14 720RF CL - 28 5.4%

40 46 RSS 2H 1.89 720RF CL-11 Yes 40 46 DOS 2H 1.79 1A 720RF CL-28 -5.3%

- & J- ~ - A- A

86-9024635-000 Page 42 of 107 Table 3-18: New 2R13 DOSs >=0.5 Volts In Tubes Inspected With A Worn Probe In 2R12 SG Row Col Ind Elev ] Volts Probe Cal No. JARC Out 2R131 ARC Out 2R12 SG 2-1 36 47 DOS 2H 0.63 720RF HL- 13J Yes Yes 29 58 DOS 2H 0.87 720RF HL - 18 Yes 41 54 DOS 3H 0.58 720RF HL - 18 Yes DOS 2H 0.56 720RF CL-25 Yes Yes SG 2-2 23 34 Yes 38 70 DOS 2H 0.55 720RF HL - 14 12 87 DOS 4C 0.52 720RF CL-36 Yes 38 52 DOS 2H 0.5 720RF HL- 16 Yes 45 57 DOS 1H 1.4 720RF HL- 14 Yes 11 39 DOS 1H 0.85 720RF CL-48 Yes SG 2-3 7 29 DOS 2H 0.67 720RF CL-46 Yes 11 48 DOS 2H 0.58 720RF CL - 38 Yes 43 59 DOS 1H 0.56 720RF HL- 14 Yes 14 48 DOS 2H 0.99 720RF CL - 25 Yes 23 32 DOS 2H 0.83 720RF CL - 24 Yes 27 42 DOS 2H 0.79 720RF CL- 12 Yes 24 83 DOS 1H 0.77 720RF HL- 11 Yes 14 22 DOS 1H 0.76 720RF CL - 23 Yes 22 39 DOS 1H 0.69 720RF CL - 24 Yes SG2-4 24 78 DOS 2H 0.66 720RF HL- 10 Yes 21 42 DOS 2H 0.64 720RF CL - 24 Yes 25 39 DOS 2H 0.58 720RF CL -25 Yes 16 71 DOS 1H 0.56 720RF HL-9 Yes Yes 27 84 DOS 1H 0.52 720RF HL- 11 Yes 23 40 DOS 1H 0.52 720RF CL - 25 Yes 18 70 DOS 4H 0.52 720RF HL-9 Yes Yes 13 49 DOS 2H 0.51 720RF CL - 20 Yes

86-9024635-000 Page 43 of 107 Table 3-19: Summary of New DOS Indications for Probe Wear Comparison 2R13 DOSs New 2R13 New 213 Id. New 2R13 nd. New 2R13 New 2113 Id.

In Tubes >=0.5 Volts in SG in Active Not Insp. w/ In Tubes Insp. Ind. Tubes Insp.

Tubes Detected Worn Probe w/ Good >=0.5 w Worn (Total) in 2R12 in 2112 Probe in 2R12 Volts Probe in 2112 2-1 527 70 9 61 8 1 2-2 433 65 17 48 12 6 2-3 319 61 21 40 11 5 2-4 1178 191 61 130 50 13 Total 2457 387 108 279 81 25 Table 3-20: Summary of ARC In and Out Tube Inspections in 2R12

1. ARC Out # ARC In Total # of SG Tubes (2R12) Tubes (2R12) Inspections 2-1 908 2519 3427 2-2 797 2459 3256 2-3 912 2631 3543 2-4 1044 2216 3260 Total 3661 9825 13486

86-9024635-000 Page 44 of 107 Table 3-21: NDE Uncertainty Distributions Analyst Uncertainty Acquisition Uncertainty Percent Cumulative Percent Cumulative Variation Probability Variation Probability

-40.0% 0.00005 <-15.0% 0.00000

-38.0% 0.00011 -15.0% 0.01606

-36.0% 0.00024 -14.0% 0.02275

-34.0% 0.00048 -13.0% 0.03165

-32.0% 0.00095 -12.0% 0.04324

-30.0% 0.00179 -11.0% 0.05804

-28.0% 0.00328 -10.0% 0.07656

-26.0% 0.00580 -9.0% 0.09927

-24.0% 0.00990 -8.0% 0.12655

-22.0% 0.01634 -7.0% 0.15866

-20.0% 0.02608 -6.0% 0.19568

-18.0% 0.04027 -5.0% 0.23753

-16.0% 0.06016 -4.0% 0.28385

-14.0% 0.08704 -3.0% 0.33412

-12.0% 0.12200 -2.0% 0.38755

-10.0% 0.16581 -1.0% 0.44320

-8.0% 0.21867 0.0% 0.50000

-6.0% 0.28011 1.0% 0.55680

-4.0% 0.34888 2.0% 0.61245

-2.0% 0.42302 3.0% 0.66588 0.0% 0.50000 4.0% 0.71615 2.0% 0.57698 5.0% 0.76247 4.0% 0.65112 6.0% 0.80432 6.0% 0.71989 7.0% 0.84134 8.0% 0.78133 8.0% 0.87345 10.0% 0.83419 9.0% 0.90073 12.0% 0.87800 10.0% 0.92344 14.0% 0.91296 11.0% 0.94196 16.0% 0.93984 12.0% 0.95676 18.0% 0.95973 13.0% 0.96835 20.0% 0.97392 14.0% 0.97725 22.0% 0.98366 15.0% 0.98394 24.0% 0.99010 >15.0% 1.00000 26.0% 0.99420 28.0% 0.99672 Std Deviation = 7.0%

30.0% 0.99821 Mean = 0.0%

32.0% 0.99905 Cutoff = +1-15.0%

34.0% 0.99952 36.0% 0.99976 38.0% 0.99989 40.0% 0.99995 Std Deviation = 10.3%

Mean = 0.0%

No Cutoff 11

86-9024635-000 Page 45 of 107 Table 3-22: 2R12 RTS AONDB and Results in 2R13 for Each r-r I T - - .. - 1~T T 1 2R12 21Z Interred BObbin Apparent Volts 2R13 2R13 Inferred to AONDB 2R13 Growth +Pt to +Pt SG Row Col I Elev Bobbin 2R13 +Pt Inferred Inferred

+Pt (vlEFPY) Growth Result Volts Volts Bobbin Growth Volts Indication I Intersection Volts (Inferred to (v/EFPY)

(v/EFPY DOS*

DOS)__

2 47 2H 0.21 0.514 0.514 AONDB 0.19 0.494 -0.015 -0.015 21 22 58 2H 0.40 0.706 0.706 DOS 0.69 0.43 0.740 -0.012 0.026 0.023 44 55 1H 0.09 0.395 0.395 AONDB 0.13 0.434 0.030 0.031 44 57 2H 0.11 0.414 0.414 AONDB 0.12 0.424 0.008 0.008 8 13 1H 0.22 0.524 0.524 AONDB 0.2 0.504 -0.015 -0.015 8 30 1H 0.24 0.544 0.544 AONDB 0.25 0.554 0.008 0.008 13 22 1H 0.16 0.464 0.464 AONDB 0.17 0.474 0.008 0.008 14 42 1H 0.23 0.534 0.534 AONDB 0.25 0.554 0.015 0.015 17 42 1H 0.29 0.595 0.595 AONDB 0.3 0.605 0.008 0.008 19 75 1H 0.19 0.494 0.494 AONDB 0.27 0.574 0.061 0.061 22 28 2H 0.21 0.514 0.514 AONDB 0.17 0.474 -0.031 -0.031 22 22 62 1H 0.14 0.444 0.444 AONDB 0.14 0.444 0.000 0.000 24 40 2H 0.16 0.464 0.464 AONDB 0.18 0.484 0.015 0.015 25 8 1H 0.24 0.544 0.544 AONDB 0.23 0.534 -0.008 -0.008 25 46 2H 0.26 0.564 0.564 AONDB 0.4 0.706 0.108 0.107 26 17 3H 0.18 0.484 0.484 2 AONDB 0.12, 0.20 0.659 0.133 0.015 31 22 2H 0.30 0.605 0.605 AONDB 0.32 0.625 0.015 0.015 37 46 2H 0.30 0.605 0.605 AONDB 0.28 0.584 -0.015 -0.015 45 39 2H 0.44 0.746 0.746 AONDB 0.46 0.766 0.016 0.015 23 5 66 3H 0.19 0.494 0.494 AONDB 0.19 0.494 0.000 0.000 6 76 2H 0.08 0.385 0.385 DOS 0.08 0.13 0.434 -0.232 0.038 0.038 13 58 1H 0.20 0.504 0.504 AONDB 0.26 0.564 0.046 0.046 16 32 1H 0.09 0.395 0.395 DOS 0.44 0.17 0.474 0.035 0.061 0.061 18 53 2H 0.21 0.514 0.514 DOS 0.25 0.21 0.514 -0.202 0.000 0.000 22 10 1H 0.14 0.444 0.444 AONDB 0.15 0.454 0.008 0.008 24 45 1H 0.09 0.395 0.395 DOS 0.31 0.08 0.385 -0.065 -0.007 -0.008 29 61 1H 0.29 0.595 AONDB 0.11 -0.137 29 61 1H 0.16 0.464 0.842 AONDB 0.31 0.891 0.037 0.115 29 61 1H 0.07 0.375 1 AONDB 0.19 0.092 29 66 2H 0.13 0.434 0.434 AONDB 0.15 0.454 0.015 0.015

86-9024635-000 Page 46 of 107 Table 3-22: 2R12 RTS AONDB and Results in 2R13 for Each P P P P Y 2R12 2R12 Inferred Bobbin Apparent Volts 2R13 2R13 Inferred to AONDB 2R13 2R13 +Pt Growth +Pt to +Pt SG Row Col Elev Bobbin Inferred Inferred

+Pt Result Volts (v/EFPY) Growth Volts Bobbin Growth Volts Indication Intersection (Inferred to (v/EFPY Volts (v/EFPY)

DOS) 33 35 2H 0.09 0.395 0.395 AONDB 0.08 0.385 -0.008 -0.008 23 33 57 2H 0.17 0.474 AONDB 0.15 0.650 0.010 -0.015 33 57 2H 0.12 0.424 AONDB 0.16 0.031 37 19 1H 0.36 0.665 0.665 DOS 0.54 0.45 0.756 -0.095 0.069 0.069 37

___________ I. _________ ~

61 1H 0.14 0.444 0.444

______________ .1. _________________ J. ____________________

AONDB 0.13 0.434 -0.008 -0.008 24 2 21 3H 0.20 0.504 0.504 AONDB 0.28 0.584 0.061 0.061 2 36 2H 0.18 0.484 0.484 AONDB 0.18 0.484 0.000 0.000 5 27 1H 0.14 0.444 0.444 AONDB1 0.10 0.404 -0.030 -0.031 5 67 2H 0.15 0.454 0.454 DOS 0.62 0.26 0.564 0.126 0.084 0.084 7 65 3H 0.28 0.584 0.584 DOS 0.62 0.29 0.595 0.027 0.008 0.008 8 41 1H 0.22 0.524 0.524 AONDB 0.27 0.574 0.038 0.038 10 29 3H 0.12 0.424 0.424 AONDB 0.17 0.474 0.038 0.038 10 77 3H 0.10 0.404 0.601 0.110.8 DOS 0.48 0.20 0.660 -0.092 0.045 10 77 3H 0.14 0.444, 0.20 0.046 10 84 2H 0.22 0.524 DOS 0.7 0.080.010 -0.231 10 84 2H 0.14 0.444 0.24 0.544 0.076 13 77 4H 0.14 0.444 0.444 DOS 0.5 0.2, 0.09 0.640 0.042 0.150 0.046 14 7 2H 0.11 0.414 0.150.3 DOS 1.02 0.28 0.740 0.244 0.030 14 7 2H 0.26 0.564 0.28 0.015 16 36 1H 0.13 0.434 AONDB 0.14 -0.001 0.008 16 36 1H 0.25 0.554 AONDB 0.24 0.000 -0.008 19 82 2H 0.11 0.414 0.600 0.198 -0.127 DOS 0.86 0.13 0.434 19 82 2H 0.13 0.434 0.18 0.038 20 78 4H 0.21 0.514 0.514 DOS 0.34 0.11, 0.21 0.660 -0.133 0.111 0.000 22 16 1H 0.27 0.574 0.574 AONDB 0.29 0.595 0.015 0.015 22 22 3H 0.14 0.444 0.444 AONDB 0.15 0.454 0.008 0.008 24 10 1H 0.18 0.484 0.484 AONDB 0.21 0.514 0.023 0.023 25 27 1H 0.12 0.424 0.424 AONDB 0.13 0.434 0.008 0.008 25 66 2H 0.38 0.685 0.685 DOS 0.63 0.55 0.858 -0.042 0.132 0.130 30 36 3H 0.22 0.524 0.524 AONDB 1 0.27 0.574 0.038 0.038 35 65 2H 0.11 0.414 0.777 DOS 1.00 0.15 0.788 0.170 0.009 0.031

86-9024635-000 Page 47 of 107 Table 3-22: 2R12 RTS AONDB and Results in 2R13 for Each Y P P Y P 2R12 2R12 Inferred Bobbin Apparent Volts 2R13 2R13 Inferred to AONDB 2R13 2R13 +Pt Growth +Pt to +Pt SG Row Col Elev Bobbin Inferred Inferred

+Pt Result Volts Bobbin (v/EFPY) Growth Volts Growth Volts Indication Intersection Volts (Inferred to (v/EFPY (v/EFPY)

DOS) 35 65 2H 0.14 0.444 0.23 0.069 35 65 2H 0.18 0.484 0.25 0.053 36 28 2H 0.13 0.434 0.594 0.11 -0.015 24 DOS 0.87 0.19 0.645 0.211 0.039 0.069 36 28 2H 0.10 0.404 0.19 0.069 36 29 1H 0.26 0.564 0.14 -0.092 DOS 0.49 0.29 0.742 -0.152 0.041 0.153 36 29 1H 0.09 0.395 0.29 0.153 36 33 2H 0.09 0.395 0.395 DOS 0.59 0.19 0.494 0.149 0.076 0.076 37 29 2H 0.08 0.385 0.14 0.046 DOS 0.58 0.27 0.726 -0.054 0.058 0.038 37 29 2H 0.22 0.524 0.27 10.038 41 61 0.15 0.454 0.454 DOS 0.71 0.42 0.726 0.195 0.207 0.206 J 11 L ________ .1. 1 1 Averacies 0.016 0.025 0.025 Averages 0.016 0.025 0.025

86-9024635-000 Page 48 of 107 Figure 3-1: 2R13 As-Found Voltage Distributions SGs 2-1 and 2-2 Voltage Distributions of As-Found DOS/AONDB Indications SG 2-1 and SG 2-2

.2

'U 0

U)

.0 2

z Bobbin Volts Figure 3-2: 2R13 As-Found Voltage Distributions SGs 2-3 and 2-4 Voltage Distributions of As-Found DOS/AONDB Indications SG 2-3 and SG 2-4 180 160 140 120 0

.5 100 80 E

z 60 40 20 0

Bobbin Volts

86-9024635-000 Page 49 of 107 Figure 3-3: 2R13 Repaired Voltage Distributions SGs 2-1 and 2-2 Repaired Tube Voltage Distributions SG 2-1 and SG 2-2 10 MSG 2-1 8 0 SG 2-2 C

0i 6

EU z

4 2

,hl.... .. . . . . . . .. . . . . ..

.1 0

Bobbin Volts Figure 3-4: 2R13 Repaired Voltage Distributions SGs 2-3 and 2-4 Repaired Tube Voltage Distributions SG 2-3 and SG 2-4 0

C 0

z 04( Cn V U0 KO - CO 0) 0- MN Ict LO W0 0 00 N 0) 4( c)~ (0 .- . . cn C~)

Bobbin Volts

86-9024635-000 Page 50 of 107 Figure 3-5: 2R13 RTS Voltage Distributions for RPC Confirmed or Not Inspected SGs 2-1 and 2-2 RTS Voltage Distributions for RPC Confirmed or Not Inspected SG 2-1 and SG 2-2 180 160- n*SG 2-1 0 SG 2-2 140

0) 120 0 100

4) 80O 60 40 20 Il (I

Bobbin Volts Figure 3-6: 2R13 RTS Voltage Distributions for RPC Confirmed or Not Inspected SGs 2-3 and 2-4 RTS Voltage Distributions for RPC Confirmed or Not Inspected SG 2-3 and SG 2-4 180 160 140 120 0

100

4) 80 z 60 40 20 0

e'jV 0~~-~r~- M M ' M N 01 - 0) N'- ('4(M V LO D r--CWD (0 M)

Bobbin Volts

86-9024635-000 Page 51 of 107 Figure 3-7: 2R13 RTS Voltage Distributions SGs 2-1 and 2-2 Voltage Distributions of All DOS/AONDB Indications Returned to Service SG 2-1 and SG 2-2 180 160 140 0

120

'U 100 80

.0 z 60 40 20 0-od6d

, C'4 C! 6 ddd 11 Iq Iq dd r-ý IC 0) 7 N- C!J V: U (q I,- OR 0) ' N C!) V: W0 (p fp-. ( 0) m~ m A

Bobbin Volts Figure 3-8: 2R13 RTS Voltage Distributions SGs 2-3 and 2-4 Voltage Distributions of All DOS/AONDB Indications Returned to Service SG 2-3 and SG 2-4 180 160 ERG 2-3 OSG 2-4 140 In C 120

.2 V 100 C

0 U,

80-

.0 S

z 60-40-20 n

-n n

Bobbin Volts

86-9024635-000 Page 52 of 107 Figure 3-9: 2R13 DOS and AONDB vs. TSP Elevation Distribution of Indications by TSP Location 600 500-0 400- i C

74-300 0

0 200 z

100 H 0

MSG2-1 323 114 38 7 22 6 21 OSG2-2 155 179 67 22 3 1 2 27 MSG2-3 171 108 26 2 6 1 1 17 MSG2-4 419 502 178 66 8 1 20 Tube Support Plate

86-9024635-000 Page 53 of 107 Figure 3-10: Cycle 13 Growth Distributions SGs 2-1 and 2-2 Delta Volts per EFPY SG 2-1 and SG 2-2 500

• SG 2-1 400

• SG 2-2 0

'- 300 4) 200 I

-a E

z 100 1 0 16 . . . . . . . .

N.eb r ý.N

< N V

• s N. el Delta Volts per EFPY Figure 3-11: Cycle 13 Growth Distributions SGs 2-3 and 2-4 Delta Volts per EFPY SG 2-3 and SG 2-4 500 C

0

.1 z

NV 0s Np N NY Det <

Delta Volts per EFPRY

86-9024635-000 Page 54 of 107 Figure 3-12: Cycle 13 Independent Growth Curves - All SGs Cycle 13 Growth Comparison 1l.0o .. 11 . . . . - - - - - - - - - --

0.8- / p

0. 6 LL.

0 I.

L) 4 -SG 2-1

-- SG 2-2

-a- SG 2-3

0. 2---

SG2-4

-All SGs

0. 0 i 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 >2 Voltage Growth per EFPY Figure 3-13: Historical Change in Growth and BOC Voltage - All SGs Change in Average Growth DCPP-2 All SGs 0.3 0.6 0.25 - . 1-- * -0.5 -

0.

0.4 U- 0.2 0.

0.15 0.3 0 0.1 0.2 0 0.05 0.1 0

Cycle 8 Cycle 9 Cycle 10 Cycle 11 Cycle 12 Cycle 13

86-9024635-000 Page 55 of 107 Figure 3-14: Cycle 12 vs. Cycle 13 Growth Comparison for SG 2-1 Cycle 13 vs. Supplemented Cycle 12 Growth Comparison SG 2-1 0.9 0.8 The Cycle 12 results in this chart have been 0.7 supplemented with growth data from Cycle 11 for those indications that were >1.2v at BOC-1 1. This was done to provide a fair comparison since no indications >1.2v were 0.6 returned to service for Cycle 12.

U-0.5 0.4 ---- SG 2-1 Supplemented Cycle 12 0.3 -9B-All SGs Supplemented Cycle 12

-- +- SG 2-1 Cycle 13 0.2

- -- All Cycle 13 0.1 nn -

Voltage Growth per EFPY Figure 3-15: Cycle 12 vs. Cycle 13 Growth Comparison for SG 2-2 Cycle 13 vs. Supplemented Cycle 12 Growth Comparison SG 2-2 1.0 I I..I I I- In-I U 0.7 The Cycle 12 results in this chart have been I'll supplemented with growth data from Cycle 11 for those a.0 1:11 indications that were >1.2v at BOC-1 1. This was done to provide a fair comparison since no indications >1.2v were II" returned to service for Cycle 12.

L.

0 0.5 0.4 - --- SG 2-2 Supplemented Cycle 12

0. -- All SGs Supplemented Cycle 12 0.3

--- SG 2-2 Cycle 13

.24-All Cycle 13 0.1 n00 Voltage Growth per EFPY

86-9024635-000 Page 56 of 107 Figure 3-16: Cycle 12 vs. Cycle 13 Growth Comparison for SG 2-3 Cycle 13 vs. Supplemented Cycle 12 Growth Comparison SG 2-3 1.

I--:~~ 6 -.

0.8 The Cycle 12 results in this chart have been 0.7 supplemented with growth data from Cycle 11 for those -

indications that were >1.2v at BOC-I 1. This was done to 0.6 provide a fair comparison since no indications >1.2v were _

returned to service for Cycle 12.

LL C.)0.5 a.

0.4 - SG 2-3 Supplemented Cycle 12 0.3 -All SGs Supplemented Cycle 12

- "+- SG 2-3 Cycle 13 0.2 All Cycle 13 0.1 0.0 Voltage Growth per EFPY Figure 3-17: Cycle 12 vs. Cycle 13 Growth Comparison for SG 2-4 Cycle 13 vs. Supplemented Cycle 12 Growth Comparison SG 2-4 1.0 0.9 0.8 0The Cycle 12 results in this chart have been 0.7 supplemented with growth data from Cycle 11 for those indications that were >1.2v at BOC-1 1. This was done to 0.6 provide a fair comparison since no indications >1.2v were _

returned to service for Cycle 12.

U.

0 0 . 0.5 (U

0.4 SG 2-4 Supplemented Cycle 12 0.3 --- w-AII SGs Supplemented Cycle 12 0.2 0.2- + - SG 2-4 Cycle 13 All Cycle 13 0.1 0.0 . . EF..

Voltage Growth per EFPY

86-9024635-000 Page 57 of 107 Figure 3-18: SG 2-1 Cycle 13 Growth vs. BOC Voltage Growth Rate vs. BOC Voltage DCPP-2 SG 2-1 o G21Data 1.5 - Linear Regression (Slope = 0.026) 0.

U-LU 4) 0.

'1 C,

4) 0)

4) 5 6 0 0.

4) 0 0o ooo .oo o o° 0 0 0

00 5 0 08

-0.

0 0.5 1 1.5 2 BOC-13 Voltage Figure 3-19: SG 2-2 Cycle 13 Growth vs. BOC Voltage Growth Rate vs. BOC Voltage DCPP-2 SG 2-2 2

1.5 a.

U-0.

-.0.

• 05

-0.5 0 0.5 1 1.5 2 BOC-13 Voltage

86-9024635-000 Page 58 of 107 Figure 3-20: SG 2-3 Cycle 13 Growth vs. BOC Voltage Growth Rate vs. BOC Voltage DCPP-2 SG 2-3 2

1.5 a.

uJ

o. 0.

." 1 0

-0.5 0 0.5 1 1.5 2 BOC-13 Voltage Figure 3-21: SG 2-4 Cycle 13 Growth vs. BOC Voltage Growth Rate vs. BOC Voltage DCPP-2 SG 2-4 a.

U.

UJ 0

a.

0 0

0 0

U 0.5 1.5 2 BOC-13 Voltage

86-9024635-000 Page 59 of 107 Figure 3-22: Cycle 13 Growth vs. BOC Voltage for All Steam Generators Growth Rate vs. BOC Voltage DCPP-2 All SGs 2-o All SGs

- Linear Regression (Slope = 0.134) 1.5

.I1.

.0* 00 0~0 0.5- 00 0 0 0 00 0*40.5 ° ° 04 *9 0 8 ?

-0.5 0 0.5 1.5 2 BOC-13 Voltage

86-9024635-000 Page 60 of 107 Figure 3-23: SG 2-3 Cycle 13 VDG Breakpoint Analysis Results Bilinear Growth Determination for SG 2-3 Cycle 13 4.0 Min. Bin= 15 5.:" Act. Bin = 28 LL 2L SSE =4.147 ]

02.0-1.0 0.0 0.0 0.5 1.0 1.5 2.0 BOC Bobbin Amplitude (Volts)

[o Data - Piece 1 - -Piece2 I Figure 3-24: SG 2-4 Cycle 13 VDG Breakpoint Analysis Results Trilinear Growth Determination for SG 2-4 Cycle 13 4.0 SG 2-4 Cycle 13 Bound 1 = 1.06 V Bound 2 = 1.530 V 3.0 Min. Bin= 10 t .4 a- Act. Bin = 24 Std. Error= 0.152 U-c, 2.0 A z*A 2c A 0

• 4 4044*4 4. "4=. .*A 1.0 0.0 0.0 0.5 1.0 1.5 2.0 BOC Volts A, Data - Piece 1 - -Piece2 - Piece 3]

86-9024635-000 Page 61 of 107 Figure 3-25: Composite Cycle 13 VDG Breakpoint Analysis Results Trilinear Growth Determination for Unit 2 Cycle 13 4.0 3.0 0~

2.0 LL 0

1.0 0.0 0.0 0.5 1.0 1.5 2.0 BOC Volts I & Data - Piece 1 - - Piece 2 - Piece 3 1

86-9024635-000 Page 62 of 107 Figure 3-26: Cycle 13 VDG for SG 2-3 Cycle 13 VDG for SG 2-3 1.0 0.8 0.6 LL a.

Q 0.4 0.2 0.0

<0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 >2 Voltage Growth per EFPY Figure 3-27: Cycle 13 VDG for SG 2-4 Cycle 13 VDG for SG 2-4 4

10- I I a I _______ - II 0.8 This chart is provided for information only since the Cycle 13 growth data were not used for the leak rate and POB analyses.

L-0L a.

0.4 Bin1 (<1.06v) 0.2 Bin2 (1.07v-1,53v)

-4 Bin3 (>1.53v) 0.0

<0 0.1 0,2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 >2 Voltage Growth per EFPY

86-9024635-000 Page 63 of 107 Figure 3-28: Cycle 13 VDG for All SGs Cycle 13 VDG for All SGs 1.0-I

/

/

I 00 0.6

o. 0.6 0.4 0.2

<0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 >2 Voltage Growth per EFPY

86-9024635-000 Page 64 of 107 Figure 3-29: SG 2-1 Supplemented Cycle 12 VDG Breakpoint Analysis Results Bilinear Growth Determination for SG 2-1 Cycle 12 + Cycle 11 >1.2v 4.0 FRegression Break Point= 1.12 Volts I

SG 2-1 Cycle 12 + Cycle 11 >1.2v 3.0 Bound 1 = 1.12V Min. Bin= 15 Act Bin= 15 LUU" l SSE =12.786 .

w 2.0 -

2 03 1.0 0 0'3 a0 0 O-b 0.0 0.0 0.5 1.0 1.5 2.0 BOC Bobbin Amplitude (Volts) oData -Piece 1- -Piece2 Figure 3-30: SG 2-4 Supplemented Cycle 12 VDG Breakpoint Analysis Results Trilinear Growth Determination for SG 2-4 Cycle 12 + Cycle 11 >1.2v 4.0 3.0 0-UI_

o 2.0 2

1.0 0.0 0.0 0.5 1.0 1.5 2.0 BOC Volts A Data - Piece 1 - -Piece2 - Piece3l

86-9024635-000 Page 65 of 107 Figure 3-31: Composite SG Supplemented Cycle 12 VDG Breakpoint Analysis Results Trilinear Growth Determination for Unit 2 Cycle 12 + Cycle 11 >1.2v 4.0 All SGs Cycle 12 + Cycle 11 >1.2v Bound 1 = 1.10 V Bound 2 = 1.71 V 3.0 Min. Bin 15

• " Act. Bin == 17

u. Std. Error = 0.200 U) o 2.0 0

0.0 0.0 0.5 1.0 1.5 2.0 BOC Volts I & Data - Piece 1 - - Piece 2 - Piece 3 1

86-9024635-000 Page 66 of 107 Figure 3-32: Supplemented Cycle 12 VDG for SG 2-1 Supplemented Cycle 12 VDG for SG 2-1 0.8 0,2 -- -

0.41 i1( 11 v 0,6 0

/

I Figur 3-33:

Supplementednludal VDGa Cycle forlus-12 0 ~ i ~~ uplmne Cycl VdGt 12 for thse 2niatostht4re>.

0.8 0.4I Fig rThe data inthis chart include allCycle 12 dataprus 0.8-IL plus Cycle 11 data for those indications that were 0.4 volts at BOC-11.

0.8. . .

0.2 Bin

- (<=0.47v) n1

- Bin2 (0.48v-1.038v) 0.0 Voltage Growth per EFPY

86-9024635-000 Page 67 of 107 Figure 3-34: Supplemented Cycle 12 VDG for All SGs Supplemented Cycle 12 VDG for All SGs 1.0

/

0.8 0.6

u. The data inthis chart include all Cycle 12 data I I plus Cycle 11 data for those indications that were 0 >1.2 volts at BOC-11.

0.4 0.2- Bin1 ( -1.1v)

SBin2 (1.11 v-1. 71 v)

• Bin3 (>1.71 v) 0.0 Voltage Growth per EFPY

86-9024635-000 Page 68 of 107 Figure 3-35: 2R13 Probe Wear Voltage Comparison Probe Wear Comparison 2R13 5

4 3

.5 y = 0.9019X 4 0.0729

.o 0.9615 0.2 z

0 0 1 2 3 4 5 Worn Probe Voltage Figure 3-36: Bobbin Voltage Uncertainty Distributions NDE Uncertainty Distributions

. 0.6 0.5 0.4 0.3 0.2 0.1

-40.0% -30.0% -20.0% -10.0% 0.0% 10.0% 20.0% 30.0% 40.0%

Percent Variation In Voltage

86-9024635-000 Page 69 of 107 Figure 3-37: Inferred Voltage / Measured Voltage Comparison Inferred Voltage vs. Measured Voltage 2R13 AllSGs 4.00- 1 1

• Single Axial Indications 3.50

- Linear (Single Axial Indications) 3.00 a2.50 2

R =0.8682 o2.00-_ _ _ _

Max AONDB Voltage 0.96 V 1.50 1 1- -

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 Measured Bobbin Voltage

86-9024635-000 Page 70 of 107 Figure 3-38: +PointTM Indication to Bobbin Voltage Comparison for SG 2-1 SG 2-1 +Pointm vs. Bobbin Volts 4.50-4.500 Indications 34.00 - Equivalency Line 3.50-3.00 3 2.50 r

Z 2.00 1.50 1.00 0.50 0.00 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 Bobbin Volts Figure 3-39: +PointTM Indication to Bobbin Voltage Comparison for SG 2-2 SG 2-2 +PointTM vs. Bobbin Volts 4.50

-- Equivalency 4.00 -ý Line 3.50 3.00-2.50 S

CO2.00-0.00 0.50 1,00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 Bobbin Volts

86-9024635-000 Page 71 of 107 Figure 3-40: +PointTM Indication to Bobbin Voltage Comparison for SG 2-3 SG 2-3 +Pointm vs. Bobbin Volts I Indications 4.00 - Equivalency Line 3.503 3.00-0 2.502 2.00-1.50 1.00-0.00 jt O(

h0 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 Bobbin Volts Figure 3-41: +PointTM Indication to Bobbin Voltage Comparison for SG 2-4 SG 2-4 +PointTm vs. Bobbin Volts 4.50 S

.=_

0.

+

.00 2.50 4.50 Bobbin Volts

86-9024635-000 Page 72 of 107 4.0 Database Applied for Leak and Burst Correlations Per GL 95-05, the databases used to perform the tube integrity evaluations should be the latest NRC approved industry database. The updated leak and burst correlations in Reference 8 for the ODSCC database include the 2R1 1 and 1R1 2 tube pull results from Diablo Canyon, as well as other recent industry tube pulls.

4.1 ConditionalProbabilityof Burst For the case of the burst pressure versus voltage correlation, the Addendum 6 database contained in Reference 8, meets all GL 95-05 requirements and was used in the as-found EOC-13 calculations and the EOC-14 projections, as well as the benchmarking of the prior cycle operational assessment. The correlation parameters were taken from Reference 8 and are shown in Table 4-1.

Table 4-1: Burst Pressure vs. Bobbin Amplitude Correlation P = a + a , log(Volts)

Parameter Addendum 6 Intercept, ao 7.4801 Slope, al -2.4002 2r 79.67%

Std. Dev., aErmr 0.8802 Mean Log(V) 0.3111 SS of Log(V) 51.6595 N (data pairs) 100 Structural Limit (2560 psi) '1 7.51V Structural Limit (2405 psi) (') 9.40V p Value for al (2) 5.60.10-36 Reference af 68.78 ksi (3)

Notes: The number of significant figures reported simply corresponds to the output from the calculation code and does not represent true engineering significance.

(1) Values reported correspond to applying a safety factor of 1.4 on the differential pressure associated with a postulated SLB event.

(2) Numerical values are reported only to compare the calculated result to a criterion value of 0.05. For such small values the relative change is statistically meaningless.

(3) This is the flow stress value to which all data was normalized prior to performing the regression analysis.

86-9024635-000 Page 73 of 107 4.2 Probabilityof Leak and ConditionalLeak Rate Reference 8 presents the results of the regression analysis for the voltage-dependent leak rate correlation using the Addendum 6 leak rate database for 7/8" tubes. It should be noted that, for the 2405 psi delta pressure, the one-sided p-value for the slope parameter in the voltage dependent leak rate correlation is 0.5%, which meets the 5% threshold for an acceptable correlation specified in Generic Letter 95-05. AREVA computer simulations include the slope sampling method for the leak rate correlation that is presented in Reference 8.

The methodology used in the calculation of these parameters is consistent with NRC criteria in Reference 2. The probability of leak and leak rate correlation parameters used in the CM and OA were taken from Reference 8 and are shown in Tables 4-2 and 4-3.

Table 4-2: Probability of Leak Correlation 1I Pr(Leak) =

1 - +b2 log(Vo+/-s)]

Parameter Addendum 6 Intercept, b, -5.0407 Slope, b2 7.5434 V1 (1) 1.3311 V12 -1.7606 V22 2.7744 DoF 2z 118 Deviance 32.37 Pearson SD 0.611 MSE 0.279 Notes:

1) Parameters Vii are elements of the covariance matrix of the coefficients, bi of the regression equation.

2) Degrees of freedom.

86-9024635-000 Page 74 of 107 Table 4-3: Leak Rate vs. Bobbin Amplitude Correlation (2405 psi)

Q = 1 0 [b3 +b4 log(Volts)]

Parameter Addendum 6 Intercept, b3 -0.8039 Slope, b4 1.2077 Index of Deter., r2 20.0%

Std. Error 0.7774 Mean of Log(Q) 0.5090 Std. Dev. of Log(Q) 22.6667 p Value for b 4 0.5%

Data Pairs, N 32 Mean of Log(V) 1.0871 SS of Log(V) 3.1116 Note: The number of significant figures reported simply corresponds to the output from the calculation code and does not represent true engineering significance.

86-9024635-000 Page 75 of 107 5.0 EOC 13 Condition Monitoring, Benchmarking of EOC-13 Conditions and Assessment of Potential Underpredictions This section provides the EOC-13 condition monitoring, the results of a benchmarking study that compares the projected EOC-13 conditions to the as-found conditions, and an assessment of potential underpredictions as committed to the NRC.

5.1 EOC-13 Condition MonitoringResults EOC-13 as found conditions were evaluated to ensure that CM burst and leakage requirements were not exceeded. The burst probabilities and leak rates are shown in Table 5-2 and at the bottom of Table 5-7. The requirements for burst probabilities are met for all of the SGs, and for the leak rate, the plant-specific value of 10.5 gpm for the faulted steam generator was not exceeded in any steam generator.

5.2 EOC-13 Benchmark Calculations EOC-13 projections using the composite DCPP POPCD through 7 inspections have been previously provided to the NRC in Reference 27. Those projections used an estimated Cycle 13 operating interval of 1.33 EFPY and correlations using Addendum 5 plus DCPP pulled tube data from 2R11. The actual Cycle 13 operating interval was 1.31 EFPY and the correlation database has been revised to Addendum 6, so the EOC-13 projections have been recalculated.

In addition, the composite DCPP POPCD through 8 inspections was used in the recalculations.

Table 5-1 provides a summary of the inputs required and the corresponding section(s) or table(s) that provide these data. If the input was unchanged relative to the input used in the 2R12 90 day report projections, then "no change" is noted in the comment field. For example, the growth distributions used in the benchmark calculations were the same as used in the 2R12 90 day report, and followed the guidelines provided in References 25 and 28.

Table 5-1: Inputs for EOC-13 Benchmark Projections Input Description Section or Table Reference Comments BOC Voltage Distribution Tables 5-3 and 5-4 No change Repaired Voltage Distribution Tables 5-3 and 5-4 No change NDE Uncertainties Section 3.6 and Table 3-21 No change DCPP POPCD Table 6-8 Composite POPCD through 8 from Reference 7. inspections Growth Table 5-5 and 5-6 No change Cycle Length Section 5.2 1.31 EFPY Tube Integrity Correlations Tables 4-1 to 4-3 Addendum 6 Material Properties Section 7.1 No change

86-9024635-000 Page 76 of 107 Table 5-7 provides a comparison of the EOC-13 benchmarking projections to the as-found EOC-13 conditions. This table shows the voltage distributions as well as the POB and leak rate results. In all cases, the leak rate, POB, and the number of indications were over-predicted by wide margins. Therefore, the EOC-13 projections using DCPP POPCD correlation and the growth guidelines provided conservative results relative to the as-found conditions, and no adjustments to either of the methodologies are warranted.

5.3 Assessment of PotentialUnderpredictions DCPP Tech Specs require that, upon implementation of POPCD, if the EOC conditional MSLB burst probability, the projected MSLB leak rate, or the number of indications are underpredicted by the previous cycle operational assessment, the following guidelines must be applied to assess the need for methods adjustments:

• The assessment of the probable causes for the under predictions, proposed corrective actions, and any recommended changes to probability of detection or growth methodology indicated by potential methods assessments.

• An assessment of the potential need to revise the ARC analysis methods if: the burst probability is underpredicted by more than 0.001 (i.e., 10% of the reporting threshold) or an order of magnitude; or the leak rate is underpredicted by more than 0.5 gpm or an order of magnitude.

" An assessment of the potential need to increase the number of predicted low voltage indications at the BOC if the total number of as found indications in any SG are underestimated by greater than 15 percent or by greater than 150 indications. If future inspection results provide additional information that could alter these guidelines, PG&E would provide recommended changes to the guidelines and basis for the changes in the subsequent 90 day report.

As discussed above, EOC-13 benchmark projections were performed using the actual Cycle 13 operating interval, DCPP POPCD through 8 inspections, and Addendum 6 correlations. As shown in Table 5-7, the POBs, leak rates, and numbers of indications (also shown graphically in Figures 5-1 through 5-4) were overestimated in all cases for EOC-13. Therefore, there is no need to perform a method adjustment assessment.

86-9024635-000 Page 77 of 107 Table 5-2: Summary of 95-05 ARC Calculations As-found vs.

Projected EOC-13 SG 2-1 SG 2-2 SG 2-3 SG 2-4 Number of As-Found 531 456 332 1194 DOS Plus AONDB Projected 944 797 609 1715 Leak Rate As-Found 0.11 0.07 0.09 0.78 (gpm) Projected (1) 0.75 0.49 0.30 2.52 As-Found 4.38 x 10"5 2.63 x 10"5 6.52 x 10s 5.57 x 104 POB Projected (1) 9.63 x 104 3.61 x 10-4 2.86 x 10-4 2.76 x 10-3 Acceptance Criteria 1.0 x 10" 2 10.5 gpm Notes: (1) Used actual cycle length of 1.31 EFPY and DCPP POPCD through 8 inspections.

(2) The 95% Upper Confidence Limit (UCL) is based on the number of trials with one or more failures.

(3) Equivalent volumetric rate at room temperature.

(4) The calculated total leak rate reflects the upper 95% quantile value at an upper 95% confidence bound.

(5) The reference leak limits (10.5 gpm) consider contributions from other ARCs. Therefore other ARC Leak rates should be added to the results in this table to assess total leakage.

86-9024635-000 Page 78 of 107 Table 5-3: SG 2-1 BOC-13 Voltage Distribution Used for EOC-13 Benchmark Projections SG 2-1 Voltage Bin As-Found R EOC-12 Repaired 0.1 0 0 0.2 29 0 0.3 74 0 0.4 97 0 0.5 55 1 0.6 54 0 0.7 43 0 0.8 33 0 0.9 25 0 1 14 0 1.06 9 0 1.1 2 0 1.2 10 0 1.3 2 0 1.4 4 0 1.5 8 0 1.6 1 0 1.7 3 0 1.8 2 1 1.9 2 1 2 0 0 2.1 2 2 2.2 2 2 2.3 0 0 2.4 1 1 2.5 0 0 2.6 0 0 2.7 0 0 2.8 0 0 2.9 0 0 3 0 0 Total 472 8

86-9024635-000 Page 79 of 107 Table 5-4: SGs 2-2, 2-3, and 2-4 BOC-13 Voltage Distributions Used for EOC-13 Benchmark Projections SG 2-2 SG 2-3 SG 2-4 Voltage Bin As-Found As-Found As-Found EOC-12 Repaired EOC-12 Repaired EOC-12 Repaired 0.1 0 0 1 0 0 0 0.2 28 1 17 0 31 0 0.3 54 0 42 0 104 0 0.4 70 1 65 0 134 0 0.5 72 2 35 0 141 3 0.59 42 2 35 1 108 1 0.6 5 0 3 0 19 0 0.7 31 0 20 0 100 0 0.8 24 1 18 0 77 2 0.9 23 0 11 0 66 2 1 15 0 5 0 56 0 1.1 5 0 2 0 45 0 1.2 5 0 5 0 38 0 1.3 7 0 5 0 26 0 1.4 4 0 1 0 20 0 1.5 6 0 5 0 18 0 1.6 1 0 2 0 5 0 1.66 2 0 0 0 7 1 1.7 0 0 0 0 4 0 1.8 1 1 0 0 7 2 1.9 0 0 0 0 6 3 2 1 1 0 0 4 2 2.1 1 1 0 0 1 1 2.2 0 0 0 0 0 0 2.3 0 0 0 0 0 0 2.4 0 0 0 0 0 0 2.5 0 0 0 0 1 1 2.6 0 0 0 0 0 0 2.7 0 0 0 0 1 1 2.8 0 0 0 0 0 0 2.9 0 0 0 0 1 1 3.0 0 0 0 0 0 0 Total 397 10 272 1 1020 20

86-9024635-000 Page 80 of 107 Table 5-5: Cycle 11 Growth Distributions for SG 2-1 (Used for EOC-13 Benchmark Projections for SG 2-1)

Growth Bin1 Bin3 (Volts/EFPY) (<=1.06v) (>1.06v)

<=0 38 3 0.1 179 2 0.2 73 1 0.3 19 1 0.4 9 1 0.5 9 1 0.6 0 0 0.7 1 0 0.8 0 0 0.9 0 2 1 0 0 1.1 0 0 1.2 1 0 1.3 1 0 1.4 1 0

,1.5 0 0 1.6 0 1 1.7 1 0 1.8 0 0 1.9 0 0 2 0 0 2.1 0 0 2.2 0 0 2.3 0 1 2.4 0 0 2.5 0 0 2.6 0 1 2.7 0 0 2.8 0 0 2.9 0 1 3 0 0 3.1 0 0 3.2 0 0 3.3 0 0 3.4 0 0 3.5 0 0

>3.5 0 0 Total 332 15

86-9024635-000 Page 81 of 107 Table 5-6: Cycle 11 Growth Distributions for Remaining SGs (Used for EOC-13 Benchmark Projections for SGs 2-2, 2-3, and 2-4)

SGs 2-2 and 2-3 SG 2-4 Growth BinI Bin2 Bin3 Bini Bin2 Bin3 (Volts/EFPY) (<=0.59v) (0.59v to (>1.66v) (<=0.59v) (0.59vto (>1.66v) 1.66v) 1.66v)

<=0 152 68 0 48 28 0 0.1 690 84 2 307 50 2 0.2 374 59 1 220 37 1 0.3 124 53 3 79 29 3 0.4 32 37 0 24 24 0 0.5 17 28 0 5 21 0 0.6 10 19 1 8 13 1 0.7 5 10 0 5 6 0 0.8 3 6 0 3 4 0 0.9 0 10 0 0 7 0 1 1 6 0 1 6 0 1.1 0 7 0 0 6 0 1.2 1 3 0 0 3 0 1.3 1 7 0 1 5 0 1.4 0 3 1 0 1 1 1.5 0 3 2 0 3 2 1.6 0 3 2 0 3 1 1.7 1 1 1 1 0 0 1.8 0 2 0 0 2 0 1.9 0 2 1 0 1 1 2 0 1 0 0 1 0 2.1 0 0 0 0 0 0 2.2 0 3 1 0 3 1 2.3 0 2 0 0 1 0 2.4 0 1 0 0 1 0 2.5 0 1 1 0 1 1 2.6 0 1 1 0 1 0 2.7 0 0 2 0 0 1 2.8 0 0 0 0 0 0 2.9 0 0 1 0 0 0 3 0 0 1 0 0 1

>3.0 0 0 0 0 0 0 Total 1411 420 21 702 257 16

86-9024635-000 Page 82 of 107 Table 5-7: As-found EOC-13 vs. Projected EOC-13 Conditions Voltage SG 2-1 SG 2-2 SG 2-3 SG 2-4 Bin As-Found Projected As-Found Projected As-Found Projected As-Found Projected 0.1 0 1.04 0 0.93 2 5.78 1 0.66 0.2 47 20.70 37 18.18 30 28.79 43 13.69 0.3 83 93.81 66 77.47 46 63.08 117 80.39 0.4 106 147.55 85 113.33 66 90.41 168 160.52 0.5 62 161.14 71 128.43 50 102.70 144 213.60 0.6 57 130.52 53 119.97 35 88.74 128 228.81 0.7 44 97.33 44 92.64 27 67.16 118 202.54 0.8 30 74.19 31 61.51 25 43.83 69 151.93 0.9 27 58.09 15 38.57 12 26.84 77 103.92 1 17 43.02 14 25.95 9 17.28 62 74.26 1.1 17 30.42 8 19.61 5 12.46 57 60.16 1.2 9 20.32 7 16.06 4 9.93 43 53.59 1.3 4 13.14 7 13.57 2 8.24 33 49.74 1.4 11 8.22 8 11.37 4 6.93 39 44.76 1.5 3 5.36 3 9.51 5 5.77 24385 1.6 6 3.80 3 7.70 2 4.68 13 31.95 1.7 2 3.05 2 6.16 3 3.80 12 26.01 1.8 1 2.87 0 5.15 1 3.20 4 21.77 1.9 1 2.92 1 4.42 0 2.78 5 19.05 2 2 2.82 0 3.71 1 2.35 11 16.71 2.1 0 2.49 1 3.14 1 1.96 6 14.68 2.2 0 2.09 0 2.56 1 1.57 3 12.57 2.3 1 1.77 0 2.13 0 1.32 3 10.83 2.4 1 1.91 0 1.96 0 1.21 1 9.64 2.5 0 1.88 0 1.72 0 1.06 0 8.19 1 2.6 0 1.58 0 1.49 0 0.92 1 7.15 2.7 0 1.13 0 1.29 0 0.78 2 6.47 2.8 0 0.79 0 1.09 0 0.66 0 5.60 2.9 0 0.56 0 0.88 0 0.53 1 4.43 3 0 0.39 0 0.75 0 0.45 2 3.78 3.5 0 1.88 0 2.65 1 1.61 3 13.34 4 0 0.96 0 2.20 0 1.33 3 13.22 4.5 0 1.94 0 0.99 0 0.58 1 7.33 5 0 2.83 0 0.20 0 0.12 0 2.44 5.5 0 1.80 0 0.03 0 0.01 0 1.50 6 0 0.31 0 0.01 0 0.00 0 0.92 6.5 0 0.02 0 0.00 0 0.00 0 0.14 7 0 0.00 0 0.00 0 0.00 0 0.01

>7 0 0.00 0 0.00 0 0.00 0 0.00 Total 531 944.62 456 797.31 332 608.86 1194 1714.92

<=I 473 827.37 416 676.98 302 534.60 927 1230.32

>1 58 117.25 40 120.33 30 74.26 267 484.60

>2 2 24.32 1 23.07 3 14.12 26 122.26

>5 0 2.12 0 0.04 0 0.01 0 2.57 POB 4.38E-05 9.63E-04 2.63E-05 3.61 E-04 6.52E-05 2.86E-04 5.57E-04 2.76E-03 LaRae 0.11 0.75 0.07 0.49 0.09 0.3 0.78 2.52

mmmý 86-9024635-000 Page 83 of 107 Figure 5-1: As-found SG 2-1 vs Projected Voltage Distributions (DCPP POPCD)

EOC-13 As-Found vs. Projected Voltage Distributions DCPP-2 SG 2-1 250 E As-Found O]Projected

.o 0

"Z 150 C

. 100 z

50 0

VUf 0O U 0 fl I'- N-0 5 06 C56 6 6 -- -. - - - 'eJ A V LOn (

Bobbin Volts Figure 5-2: As-found SG 2-2 vs Projected Voltage Distributions (DCPP POPCD)

EOC-13 As-Found vs. Projected Voltage Distributions DCPP-2 SG 2-2 250

• As-Found E1Projected 200 O

0 z 100 0 I idAA 50 Bobbin Volts

86-9024635-000 Page 84 of 107 Figure 5-3: As-found SG 2-3 vs Projected Voltage Distributions (DCPP POPCD)

EOC-1 3 As-Found vs. Projected Voltage Distributions DCPP-2 SG 2-3 250 IAs-Found 0 Projected 200 0

150 V

S

.0100 E

z 50 Fiur5-4 As-found . . . . ~ ~ eiNeiNN M

• A Bobbin Volts Figure 5-4: As-found SG 2-4 vs Projected Voltage Distributions (DCPP POPCD)

EOC-13 As-Found vs. Projected Voltage Distributions DCPP-2 SG 2-4 250 U As-Found

[]2Projected 200 o

j 150 r

E -=100 0

0 C aBobbi- N A Bobbin Volts

86-9024635-000 Page 85 of 107 6.0 Probability of Prior Cycle Detection and EOC-14 Projections Using DCPP POPCD The NRC approved use of the voltage-dependent POPCD at DCPP in Reference 29. This section provides the 2R12 POPCD results, which is based on the results of the 2R12 and 2R13 inspections. This section also provides the updated POPCD correlation that was used in the EOC-14 projections provided in Section 7, as well as NRC reporting requirements for continued application of POPCD.

6.1 Updated DCPPPOPCD Correlation The POPCD method, which is based on results from actual field inspections, reflects the DCPP detection results that approach 1.0 at bobbin voltages above 1.6 volts. The resulting larger POD above about two volts realistically lowers the detection uncertainty, thereby lowering the number of the larger undetected indications in the BOC voltage distribution. Reference 7 provided the DCPP-specific correlation through 1R12 (eight inspections). The data from Reference 7 has since been updated to include the 2R13 results, referred to as the 2R12 POPCD data. Tables 6-1 and 6-2 provide the 2R12 POPCD and composite POPCD data, respectively. The composite POPCD includes results from nine inspections (2R8, 2R9, 2R10, 2R11, 2R12, 1R9, 1R10, 1R11, and 1R12). Table 6-3 provides the POPCD tracking matrix with column letters that correspond to the columns in Tables 6-1 and 6-2. Table 6-4 provides the POPCD matrix table including data from only the just completed cycle segregated into voltage bins of <=1.00v, 1.01-2.00v, and >2.00v based on the beginning-of-cycle (BOC) voltage. Table 6-5 provides the POPCD matrix table for the just completed cycle regardless of the beginning-of-cycle voltage. Table 6-6 provides the composite multi-cycle POPCD matrix table segregated into the three voltage bins. Table 6-7 provides the composite multi-cycle POPCD matrix table regardless of the beginning-of-cycle voltage. Table 6-8 provides the correlation parameters for the composite data set.

The largest "undetected" POPCD indication in 2R12 was 1.37v. SG 2-3 R45C57 1H had a 1.40 volt DOS reported in 2R13 that was not reported in 2R12. The location was not inspected with

+PointTM in either inspection (BND w/o RPC to BDD w/o RPC in Table 6-1 Column H) and had a 1.37v DOS look-up in 2R12. POPCD methods conservatively require that new indications at EOCn+1 that were not identified by bobbin or +PointTM at EOCn are counted as no detection at EOCn.

6.1.1 Assessment of POPCDChanges NRC requires an assessment of the POPCD method for potential changes over time, that is, the multi-cycle POPCD distribution applied for the last operational assessment must be compared with the POPCD distribution obtained for only the last operating cycle. Differences in the two POPCD distributions must be assessed relative to the potential for significant changes in detection capability. Figure 6-1 shows the POPCD curves for the just completed cycle as well as three prior composite POPCD curves (data through 2R12, 1R13, and 2R13). The curve labeled "through 1R12 (eight inspections)" was used for the benchmarking calculations

86-9024635-000 Page 86 of 107 provided in Section 5 of this document. The composite POPCD through 2R12 was used for the EOC-14 projections provided in Section 7 of this document.

The 2R12 POPCD distribution for the just completed cycle (based on the 2R13 inspection results) is improved over all voltage ranges compared to the previous composite POPCD distributions. As a result, the composite POPCD through 2R12 (9 inspections) is also improved for voltages less than about 2.0 volts compared to previous composite POPCD distributions.

The improvements are due to the numbers of indications counted as detection in 2R12 in the lower voltage ranges, as well as no significant missed indications (largest missed indication was 1.37 volts). Large voltage missed indications had a negative affect on the 1R12 POPCD distribution in the upper tail as previously discussed in Reference 30. Table 6-9 provides a direct comparison of the best estimates of the previous and current composite POPCD values up through 10 volts. The improvement in the composite POPCD through 9 inspections may not represent a significant change in actual detection capability and may be more reflective of reduced rates of new crack initiation at detectable levels. The growth rates decreased in Cycle 13 compared to Cycle 12. This growth rate decrease may have contributed to the improvement in the POPCD distribution, assuming that slower growth implies reduced rates of new crack initiation at detectable levels and therefore fewer new indications, which translates into fewer misses for POPCD. The improved POPCD continues to move the DCPP POPCD closer to that found across the industry as reflected in the industry POPCD distribution of the EPRI Addendum 6 Database (Ref. 8).

From Table 6-1 which is the POPCD for the just completed cycle based on 2R13 inspections, the number of non-detected indications was only 473, compared to 2017 detected indications.

This is a greater than 4-to-1 ratio. This ratio of detections to non-detections has been increasing over time at DCPP, and was 2.35 for the prior inspection. There were a large number of new small voltage indications detected in 2R12. These new indications were then re-identified in 2R13 and counted as detections at EOCn, which also improved DCPP POPCD based on larger numbers of detected indications.

6.1.2 Assessment of DisappearingFlaws NRC also requires an assessment of disappearing flaws. For RPC confirmed indications at EOCn that are RPC NDD at EOCn, 1 , an assessment is required for the cause of the "disappearing flaws" if the +PointTM voltage is greater than 0.5 volt. If there are a significant number of occurrences of these "disappearing flaws", the cause must be evaluated independent of the +PointTM voltage. (Note: In support of this evaluation, an RPC inspection is required at EOCn+1 for RPC confirmed indications at EOCn (either bobbin detected or bobbin NDD) that are bobbin NDD at EOCn+1 . This inspection is necessary to ensure that all known ODSCC indications are included in the condition monitoring and operational assessments as well as properly categorized for the POPCD method evaluation.)

All 2R12 +PointTM indications were also detected by +PointTM during the 2R13 inspection.

Therefore an assessment is not required.

86-9024635-000 Page 87 of 107 6.2 Input to Industry POPCDDatabase Tables 6-10 and 6-11 provide the 2R12 and the composite POPCD results in the format of EPRI ODSCC Database Report Addendum 6, Table 7-2, for eventual inclusion in the next addendum of the database report. The EPRI format differs slightly from the DCPP format in that DCPP treats EOCn RPC NDD indications as no detection as requested by the NRC (listed in Column G of Table 6-1 and Table 6-2), whereas the EPRI table treats these as detection.

86-9024635-000 Page 88 of 107 Table 6-1: 2R12 POPCD Results Coiumn A B C D I E F G H I I K 2R12 POPCD Data Table Detection at EOC. No Detection at EOCn (New Indications)

EOC. Bobbin Ind. RPC T Confirmed at EOCw EOC. Bobbin Ind. Not RPC Inspected at EOC..4 IEOC. Bobbin Ind. Repaired at EOCý New EOC, Bobbin RPC Confirmed New EOC.* Bobbin Not RPC Ind. Found Only by RPC at EOC.., EOC. RPC NODBobbin Excluded from Totals for POPCD Inspected or at EOC. & Plugged at EOC.pn Indlcations M POPCD Evaluation BODI ROD -,-0BODI ROD BDDw/o RPC -* BDDwlo RPC BDD/ ROD -* Plugged at EOCn BNDw/oRPC --*BDDIRDD BNDw/oRPC -* BDDwloRPC BNDwloRPC-f-rBND/RDD ODDIRND- BODwIoRPC AnRNDATEOC..,

Voltage BOD /ROD -- BND/ROD BOD I ROD -.- BODwlo RPC BODw/o RPC --* Plugged at EOCn BNDIROD -- BODDIROD END/ROD --p BDDwio RPC BNDIRDD BNDIRDD BDDIRND -+ BDOIRDD AnEND wo RPC IDetection No POPCD for Bin SDD w/o RPC ---BOD I ROD BNDIRND -sb-DOIROD BNDIRND --o BODw/o RPC BNDIRND --I BNDIRDD BDDIRND -1 BND/RDD atEOCn+l atEOCn Detection Voltage Bin BO wfo RPC - ONDOROD ONODRDD -. Plugged at EOCn w BfDD/RNfl,*dl/ at EAf'n Note )

at EOCn 0 7 0 0 3 2

1 0 7 0.000 2 85 3 2 0.527 11 121 7 0.653 0731-0.40 21 310 1 2 68 22 14 24 332 106 0.758 0.41-0.50 29 239 6 0 39 17 7 6 0.813 0.51-0.60 26 214 3 0 23 10 5 5 0.865 0.61-0.70 19 166 0 2 10 4 1 3 0.907 0.71-0.80 16 123 3 i0f 6 0 4 0.934 2 142 10 0481-0a90 15 105 2 0 3 4 5 2 0 122 0.961 0.91-1.00 11 77 0 1 2 0 4 1 0 88 0.957 1.01-1.10 9 54 0 0 0 0 0 0 0 63 1.000 1.11-1.20 47 0 0 0 0 0 0 0 58 1.000 1.21-1.30 30 0 0 0 0 0 0 0 40 1.000 1.31-1.40 9 20 0 0 1 0 1 0 0 29 0.967 1.41-1.50 14 23 0 0 0 0 0 0 0 37 1.000 1.51-1.60 6 3 0 0 0 0 0 0 9 1.000 1.61-1.70 4 1 0 0 0 0 0 0 16 1.000 0 4 0 0 0 4 0 0 10 1.000 1 0 0 0 0 0 8 1.000 1.91-2.00 0 3 0 0 0 0 0 5 1.000 2.01, 4 0 0 0 0 0 0 0 4 1.000 0 2 0 0 0 0 0 0 2 1.000 0 0 0 0 0 0 0 0 0 2.31-2.401 0 0 1 0 0 0 0 0 0 1 1.000 0 0 1 00I 0 0 0 0 0 1 1.000 0 0 0 0 0 0 00 0 0 0 2.61-2.70 0 1 0 1 0 0 0 0 0 1.000 0 0 0 0 0 0 0 0 0 0 1 0 1 00 0 0 0 0 2.91-3.00 1 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0- 0 -0 0 0 0 0 3.21-3.30 0 0 0 0 0 0

3.31-3.4 u 0 0 0 0 a 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3.61-3.701 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3.9-4.00 I C0 0 0 -0 4.01-4.10 0 1 0 0 0 Total Notes:

231 1 1748 __38 I 8 1 365 1 0

56 0

4469 00 0 2011 0

413

1) POPCD for each voltage bin calculated as (Detection at EOCny(Detection at EOCn + No Detection at EOCn). Bycolumnn. POPCD = (A.B+C)I(A.B.C+DDE-F-G).

2) EOCn RPC NODbobbin Indications are treated as new Indications per NRC request

3) Includes Indications at EOCn plugged at EOCn and new Indications at EOCn+I. not reported Inthe bobbin Inspection. and found only by RPC inspection of dents, mixed residuats or other reasons for the RPC inspection.

4) BOD - Bobbin detected Indication;BND- Bobbin NODIntersection: ROD - RPC detected Indication; RND =RPC NDDintersection

86-9024635-000 Page 89 of 107 Table 6-2: DCPP Composite POPCD Results (through 9 Inspections)

Column A B C D E F G H I I J K DCPP Specific POPCD Data Table Detection at EOC. No Detection at EOCn (New Indleatlons)

EOC, Bobbin Ind. RPC EOC, Bobbin Ind. Not RPC EOC.Bobbin Ind. Repaired at EOC. New EOC., Bobbin RPC New EOC. Bobbin Not RPC Ind. Found Only by RPC at EOC,, EOC., RPC NODBobbin Excluded from Totals for POPCD Confirmed at EOC.. Inspected at EOC, E Confirmed Inspected or at EOC. & Plugged at EOCm Indicationst') POPCD Evaluation BDDIROD -- BDOIRDD BOOw/o RPC -'BUDDw/oRPC BL)UIIRDD-w Plugged atrCn NU B BNOwIoRPG -WNU I xUu BSD /RND - BDDw/o RP -- AI LUý.,

AN BDDIRDO -o-,B0Dw/oRPC BDDw/oRPC Plugged at EOCn BND /oWP ---*UIUU wI BNDIROD BNOIRDD BNIwIoMP'G "-*

BDOIRDD -I BUD w/o RPC BDDw/oRPC Voltage BDDIRDO -I-BNDIRDD BNDIRDOD-b- NDIRDD BODIRNO -- BODIRDD ANBNDw/o RPC Detection No POPCD for Bin BDD w/o RPC --IBDDIRDD I BNDIRND -4 BDDOI RDD BNDIRND -* BDD w/o RPC BNDIRND -a BNDIRDD BODIRND -- BNDIRDD at EOCn+1 at EOCn Detection Voltage BIn BOD w/o RPC -- BND ROD t BNDIRDD -. Plugged at EOCn BDD/RND/Plugged at EOCn Note at EOCn 0.0 1.0.10 0.11-0.20 0.050 0.21-0.30 0213 0,404 0,31-0.40 0.536 0.41-0.50 0,652 0.51-0,60 0.740 0,61-.70 0816 0.71-0.80 575 0.842 0.81-0.90 455 0.873 0.91.1.00 320 0.92 1.01.1.10 255 1.1 1-1.20 0.934 194 0.931-1.2*1.1.0 118 0.957 1.31-1.40 127 0.969 1.4 1-1.50 1.51 -1 .60 0.991 1.61.1. 70 0.982 1.11-1.80 1.000 21- - 0.964

1. 81-1.90 0.976 1.91-2.00 2.

201-2, 10 19_ - . 1.000 2.11-2.20 1.000 2.21 -2.20 1.0w 2.31 -2.40 18 0 1.000 1.000 1,000 1.000 1000 1.000 1.000 1.000 1.000 2 1.000 4

3.41-3150 4.41-4.50 0 4.51-4.60 0 .000 2

4.61470 0 .000 4.81-4.90 0 .000 0

491-5000 0 0 1.000 5.01-5.10 0 0 1.000 5.21-5.30 0 0 1.000 5.41-5.50 0 0 1.000 5,55.60 0 5461-5.70 6.11-6w20

-. I__-

&6 61-.0 21.41-21*50 Total votes; I) POPCD for each voltage bin calculated as (Detection at EOCny(Delection at EOCn ÷No Detection at EOCn). Bycolumn. POPCD - (A+B+CY(AOB+C+D-E4F+G).

?) EOCn RPC NODbobbin indications are treated as new indications per NRC request

3) Includes Indications at EOCn plugged at EOCn andnew Indications at EOCn+I, not reported Inthe bobbin Inspection. and found only by RPC inspection of dents. mixed residuals or other reasons for the RPC Inspection.

I) BOD = Bobbin detected Indication: BND- Bobbin NOD Intersection: RDD = RPC detected Indication: RND - RPC NOD inlersection

86-9024635-000 Page 90 of 107 Table 6-3: POPCD Matrix Table for Tracking Indications Between EOCn and EOCn~+

BDD at EOCn~+ BND at EOCn+i BDD w/RDD BDD w/RND BND w/o RPC BND w/RDD BND w/RND EOCn BDD w/o RPC Not Not Not Not Not Not Plugged Plugged Plugged Plugged Plugged Plugged, Plugged Plugged Plugged Plugged Plugged Plugged Plugged C _____  : ___

BDD w/o RPC Not Plugged B B A A H H H H A A H H BDD BOD w/ ROD Plugged C . _...__

Not Plugged B B A A H (2) H (2) H (1) H (1) A A H (2) H (2)

BOO wI/RND Plugged H I. . _ _____ _____

Not Plugged G (3) G (3) G (3) G (3) H H H H G (3) G (3) H H Plugged . . .. ... . .. _ ,___ I _ _ .. _r_______

BND w/o RPC Not Plugged E E D D H H No Count No Count F F No Count No Count BND BND w/ RDD Plugged F .__ __. ___.._ _ r__ . .._ ___... ___... ______

at EOC, Not Plugged E E D D H (2) H (2) H (1) H (1) F F H (2) H 2 BND w/ RND Plugged ___, __ _____ ____- __... _ _ __I___ ______

Not Plugged E E D D H H No Count No Count F F No Count No Count General Notes:

The column letters correspond to the column letters in POPCD Tables 6-1 and 6-2.

BDD = Bobbin detected indication BND = Bobbin no detectable degradation (NDD) intersection RDD = RPC detected indication RND = RPC no detectable degradation intersection No Count = Intersections having no bobbin or RPC indication at either EOCn or EOCn÷1. These are not needed for POPCD.

Specific Notes:

1) For EOCn bobbin indications that are confirmed by RPC or detected only by RPC, EOCn÷+ RPC will be performed when bobbin is NDD and the number in this category will be "0" for future inspections.

2) If indications are RPC confirmed at EOCn but RPC NDD at EOCn.+, and the +Pointm voltage is greater than 0.5 volts the causative factors for this change in RPC detection will be discussed in the ARC 90-day report. If there are a significant number of these occurrences of this category, independent of the +PointTM voltage, the cause will be evaluated in the 90-day report.

3) EOCn bobbin indications that were RPC NDD at EOCn, and at EOCn÷+ are either RPC detected or bobbin detected without RPC inspection, are treated as undetected at EOCn in accordance with NRC request.

86-9024635-000 Page 91 of 107 Table 6-4: 2R12 POPCD Voltage-Specific Summary from 2R13 Inspection Results 2R12 POPCD Results POPCD Matrix for Indications <=1.00v at EOCn BDOD at EOCn+1 BND at EOCn+1 NotI1 BND wlRDD EOCn EO nNot BDD wlo RPC BDD w/RDD Not BDD wIRND Not BND w0o RPC Not IPugd

[ BND w/RND Not PluggedPlugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged 8 .. .. . .... .. . .. . ! _ _.

BDD BDD wlo RPC Not Plugged 13 1522 0 2 0 0 0 5 0 0 0 0 at BDD w/ RDD Plugged 8 _ _ _

Not Plugged 1 30 6 141 0 0 0 0 0 1 0 0 EOCnBDD wRND Plugged 0 .......... . , _ ___

__ _ Not Plugged 0 38 0 6 0 48 0 2 0 0 0 0 Plugged _ _

BND BND w/o RPC Not Plugged 5 359 3 4 0 14 No Count No Count 3 11 No Count No Count at BND w/ RDD Plugged 1 .. . . I . .. I. I I Not Plugged 0 0 0 1 0 0 No Count No Count 0 38 No Count No Count EOCn B D Plugged, .

BND wI RND Plge___ ___ _____ ____

Not Plugged 0 0 0 0 01 0 No Count No Count 0 3 No Countl No Count POPCD Matrix for Indications >1.00v and <=2.00v at EOCn BDD at EOCn+I BND at EOCn+I BDD w/o RPC BDD w/RDD BDD wIRND BND wo RPC I BND wRDD I BND w/RND EOCn Not Nt I Not Not Not Not Pluggedj Plugged Plugged Pluggedj Plugged Plugged Plugged Plugged Plugged J Plugged Plugged Plugged Plugged 1 1 I I .I . *1_

_ ... .. 1. ....

BDD BDD wlo RPC Not Plugged 1 175 20 21 0 0 0 0 0 0 0 0 at BDD w/ ROD Plugged 11 _. . . . .. . .. _ ..

Not Plugged 0 6 13 27 0 0 0 0 0 0 0 0 EO BD wIRND Plugged 0 , _ ' , _ *_ . . . ___-

Not Plugged 0 0 0 0 0 0 0 0 0 0 0 0 Plugged _ _ _ .__ _ ... .. __. ... __

BND BND wlo RPC Not Plugged 0 1 0 0 0 0 No Count No Count 0 0 No Count No Count at END w/ RDD Not Plugged 0 __. _ .* - I I I - , I I_ - ,

at _BND Plugged 0 0 0 0 0 0 No Count No Count 0 0 1No Count No Count EOCn -wRND Plugged _ .... _ _ ____.__.

Not Plugged 0 0 0 0 0 0 No Count No Countl 0 0 No Count No Count POPCD Matrix for Indications >2.00v at EOCn BDD at EOCn+1 BND at EOCn+I EOCn EOI BDD WIoRPC Not BDD W/RDD Not BDD wRND Not BND w/oRPCNot BND wTRDD Not BND w/RND Not Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged 0 - ° _,_... ,___ ,

BDD EDD W/o RPC Not Plugged 0 0 0 0 0 0 0 0 0 0 0 0 10 " ______ - .. . .

at BDD w/ RDD Plugged _

EO _nNot Plugged 0 0 0 0 0 0 0 0 0 0 0 0 EOCn R Ptued P 0 BDDw/RNDNot Plugged 0 0 0 0 0 0 0 0 0 0 0 0 Plumged _ _ .

____.. _____ _ r_____

BND END w/o RPC Not Plugged 0 0 0 0 0 0 No Count No Count 0 0 No Count No Counr at END w] RDD at __ND Plugged Not Plugged 0

0 0

0 0 0 I

0 I_,___

No Count No Count 0 0 No Count No Count EOCn Plugged Not Plugged 0 0 0 0 0 0 No Count No Countl 0 0 No Count No Count

86-9024635-000 Page 92 of 107 Table 6-5: 2R12 POPCD Summary from 2R13 Inspection Results Regardless of Voltage POPCD Matrix for All Indications Regardless of Voltage BDD at EOCn+1 BND at EOCn+1 EOCn BDD w/o RPC Not BDD W/RDD Not BDD w/RND Not BND w/o RPC BND w/RDD BND WIRND Not Not Not Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged 9

• __ " . __.. __ _ _ ' '_ _"_""

BDD BDD w/o RPC Not Plugged 14 1697 20 23 5 Plugged 29 .... _ _ _ _ _ " _

at BDD w/ RDD _

Not Plugged 1 36 19 168 1 EOCn -w!RN Plugged ____'__ _ _ ___ _

____w/____ Not Plugged 38 6 48 2  :

Plugged __...._"_. __ ..... .,___....___,_*

BND BND w/O RPC Not Plugg]ed 5 360 3 4 14 No Count No Count 3 11 No Count No Coun at BND w/ROO Plugged Not Plugged 1 __ , _

1

_

• ____ * " Cou No Count No Count 38 No Count No Coun' EOCn - RND Pu r"__

BND wI Plugged __*

SNot Pluged No Count No Count 3 No Count No Couni

86-9024635-000 Page 93 of 107 Table 6-6: DCPP Composite Voltage-Specific POPCD Summary Composite of 1R9, IRIO, IRll, 1R12, 2R8, 2R9, 2R10, 2R11 & 2R12 POPCD Evaluations POPCD Matrix for Indications <=1.00v at EOCn BDD at EOCn+1 BND at EOCn+1 BND w/o RPC BND w/RDD BND w/RND EOCn BDD w/o INot RPC BDD w/RDD INot BDD w/RND Not Not Not Not Plugged Plugged Plugged] Plugged Plugged Plugged Plugged Plugged Plugged Plugged PluggedI Plugged

'. __ _ .. 11 .

Plugged 110 11 __ 1 BDD BDDwfo RPC Not Plugged 95 4685 146 221 2 73 1 67 0 8 0 0 I I- I ... . - ... .

at B60 w/ RDD Plugged 153 s I I 2

37 755 0 2 0 0 0 26 0 EOCn Not Plugged 2 523 BDD w/ RND Plugged 4 - - - - - - - -

Not Plugged 5 175 10 62 0 162 0 40 0 3 0 3 Plugged BND BND w/o RPC Not Plugged 61 3386 115 523 4 159 No Count No Count 48 217 No Count No Count at BND w/ ROD Plugged 47 _1__ _..._,_'___

at Not Plugged 0 3 1 34 0 0 No Count No Count 10 199 No Count No Count EOCn BNDw/RND Plugged. . .

[Not Plugged 0 1 3 5 0 6 No Count No Count 19 25 No Count No Count POPCD Matrix for Indications >1.00v and <=2.00v at EOCn BDD at EOCn+l BND at EOCn+1 BDD w/o RPC BDD w/RDD BDD w/RND BND w/o RPC BND w/RDD BND w/RND EONototNo Not Not Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged P lu g g e d 14 . 7_"_.. _._ _._

BDD BDD w/o RPC Not Plugged 6 373 189 58 0 4 0 0 0 0 0 0 BDD w/ RDD Plugged 189 ". ."_

at Not Plugged 2 94 62 115 0 0 0 0 0 1 0 0 EOCn BDD W/ RND Plugged 2 ... .

• Not Plugged 0 4 0 2 0 5 0 0 0 0 0 0 Plugged -_ I_*

BND BND wlo RPC Not Plugged 0 21 4 15 1 4 No Count No Count 0 0 No Count No Count at BND w/ RDD Plugged 0 ... . . , _,

Not Plugged 0 0 1 1 0 0 No Count No Count 0 0 No Count No Count EOCn BND w/RND Plugged - .. ......- - - - - * -

Not Plugged 0 0 0 0 0 0 No Count No Count 0 0 No Count No Count POPCD Matrix for Indications >2.00v at EOCn BDD at EOCn+1 BND at EOCn+1 EOCE BDD wlo RPC BDD w/RDD BDD w/RND BND wlo RPC BND w/RDD I BND w/RND EO Not Not Not Not Not Not Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged 0 . * .__ - .

BDD EDD w/o RPC Not Plugged 0 0 0 0 0 0 0 0 0 0 0 0 189 ... . . II at BDD w/ RDD Plugged Not Plugged 0 0 0 0 0 0 0 0 0 0 0 0 EOCn BDDOw/ RND Plugged 0 ....... I - ......

Not Plugged 0 0 0 0 0 0 0 0 0 0 0 0 Plugged 0 - - -. N...unt -.-. 0 N u No....

BND END w/o RPC Not Plugged _ 0 0 0 0 0 0 No Count No Count 0 0 No Count No Count EN Dw/ RO D '_  : ' "

at at _BND Plugged Not Plugged 0 . . .....

0 0 0

0 0 0 No Count No Count 0 0 No Count No Count EOCn Plugged - , - -

Not Plugged 0 0 0 0 0 0 No CountjNo Count 0 0 No Count No Count

86-9024635-000 Page 94 of 107 Table 6-7: DCPP Composite POPCD Summary Regardless of Voltage POPCD Matrix for All Indications Regardless of Voltage BDD at EOCn+I BND at EOCn+1 BDD w/o RPC BDD w/RDD BDD w/RND BND w/o RPC BND w/RDD BND w/RND EOCn Not Not Not Not Not Not Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged Plugged 124  : _ .... _______

BDD BDDwlo RPC Not Plugged 101 5058 335 279 2 77 1 67 8 531 _,__* ______

at BDD w/ RDD Plugged Not Plugged 4 617 99 870 2 27 2 EOCn - Plugged 6

____w/___ Not Plugged 5 179 10 64 167 40 3 3 Plugged _ _ __..... . .. _.. .

BND BND w/o RPC Not Plugged _ _ 61 3407 119 538 5 163 NoCount NoCount 48 217 NoCount NoCount at BND wl RDD w_

Plugged Not Plugged 47 -_

3 I

2 35

. , ._ _ I No Count No Count 10 199 I. .I-No Count No Coun EO__ N w__ND Not Plugged 1 3 5 6 No Count No Count 19 25 No Count No Count

86-9024635-000 Page 95 of 107 Table 6-8: DCPP POPCD Log Logistic Parameters POPCD POPCD Updated POPCD Parameter Through 2R11 Through 1R12 Through 2R12 (7 Inspections) (8 Inspections) (9 Inspections)

Number of Data Points 8647 10566 13053 a.0 (intercept) 2.147 2.125 2.258 a.1 (slope) 4.846 4.634 4.466 V11 0.00317 0.00245 0.00203 V12 0.00607 0.00471 0.00383 V 22 0.01454 0.01146 0.00909

86-9024635-000 Page 96 of 107 Table 6-9: New DCPP POPCD Correlation Comparison to Previous POPCD Correlations (Best Estimates)

Volts POPCD Through 1RlI POPCD Through 2R11 POPCD Through 1R12 POPCD Through 2R12 (Six Inspections) (Seven Inspections) (Eight Inspections) (Nine Inspections) 0.1 0.050 0.063 0.075 0.099 0.12 0.072 0.090 0.105 0.135 0.14 0.096 0.120 0.138 0.174 0.16 0.123 0.153 0.173 0.215 0.18 0.152 0.188 0.210 0.256 0.2 0.183 0.224 0.247 0.297 0.22 0.214 0.261 0.285 0.337 0.25 0.262 0.316 0.340 0.394 0.3 0.342 0.404 0.426 0.481 0.35 0.417 0.484 0.503 0.555 0.4 0.485 0.554 0.570 0.618 0.45 0.546 0.615 0.627 0.670 0.5 0.600 0.666 0.675 0.714 0.6 0.686 0.745 0.750 0.780 0.7 0.751 0.802 0.803 0.827 0.8 0.799 0.843 0.842 0.861 0.9 0.836 0.873 0.871 0.886 1 0.863 0.895 0.893 0.905 1.1 0.885 0.913 0.910 0.920 1.2 0.902 0.926 0.924 0.932 1.4 0.927 0.946 0.943 0.948 1.6 0.944 0.958 0.956 0.960 1.8 0.955 0.967 0.965 0.968 2 0.964 0.974 0.971 0.973 2.2 0.970 0.978 0.976 0.978 2.4 0.975 0.982 0.980 0.981 2.6 0.979 0.985 0.983 0.984 2.8 0.982 0.987 0.985 0.986 3 0.984 0.989 0.987 0.988 3.5 0.988 0.992 0.990 0.991 4 0.991 0.994 0.993 0.993 4.5 0.993 0.995 0.994 0.994 5 0.9944 0.9961 0.9953 0.9954 6 0.9962 0.9973 0.9968 0.9968 7 0.9972 0.9981 0.9976 0.9976 8 0.9979 0.9985 0.9982 0.9982 9 0.9984 0.9989 0.9986 0.9985 10 0.9987 0.9991 0.9988 0.9988

86-9024635-000 Page 97 of 107 Table 6-10: 2R12 POPCD Results In Industry Format Column A B CI I E I F IH J DCPP 2R12 Input to Generic POPCD Data Table I

, Detection atEOC. No Detection atEOCn (New Indications)

EOC. BobbinatInd. RPC EOC. Bobbin Ind. Not RPC New EOC,,q Bobbin RPC New EOCm Confirmed EOC_. Inspected at EOC,* EC obnId.Rpie tEC Confirmed 1 Bobbin Not RPC Inspected Ind.Found EOC,Only by RPCatatEOC.1x4de

& Plugged EOCi oral E rm OC Totals for POPCD Evaluation BDDIRDD- BNDIRDD Buu w/o KRPC. BO. W/o RP'C BED BOO w/oI-RPC ROD.-* P-lugged ooPluged at EOCn at EOCn oNruW0 aRs -I OUUODDUU ONUW/o RPG " OUUUW05woRP BND / ROD -* ENDRODD PJlKNL)A I I;.*.;

Voltage BOO I RDO .- ND/IROD BDO I ROD BDw/o RPC BND/ ROD -- BDD RDD BNDI ROD -- EBOOw/o RPC BND/RDD -.6.BND IRDD All BND wlo RPC at EOCýS Detection No POPCB for Bin BDODIRND-a-BDDIRDD BDD I RND -a- BOO w/o RPC BNDI RND BDDI ROD BND I RND EDO w/o RPC BNDIRND --- BNDIRDD BDDIRND/Pkigged at EOCn at EOCn Detection Voltage Bin BDDIRNO --aBNDIRDD BNDIRDD -b-Pugged atEOCn at EOCn (Note 1)

BODwlo RPC -b BODORDD BODw/o RPC -9b BND/RDD 0.01-0.10 0 8-0 0.000 0.11-020 99 2 0.543 0.21-030 12 242 0,672 0.31-0440 24 321 0.790 0.41-0.50 245 30 0.834 0.51-0.60 26 219 23 0.883 0.61-0.70 19 169 10 0.922 0.71-0.80 17 126 0.961 0.81-0.90 15 105 0.961 091-1.O0 11 78 1.01.1.10 54 11

______10 2.91-3.00 1 0

38 1 365 69 Notes:

I) POPCD for each voltage bin calcuilaed as (Detection at EOCny(Detection at EOCn + No Detection at EOCn). By column, POPCD - (A÷B+Cy(A+B+C+D+E+F).

2) Piant specific POPCD to be based upon voftage bins of 0.10volt. Industry POPCD database may use 0.20 volt bins due to diffcult of adjusting existing database to smaller bins.

3) Includes indications at EOCn plugged at EOCn and new Indications at EOCn+I. not reported In the bobbin Inspection, and found only by RPC inspection of dents, mixed residuals or other reasons for the RPC inspection.

4) EOD = Bobbin detected indication: BND = Bobbin NOD intersection: ROD x RPC detected indication: RND = RPC NOD inersection

86-9024635-000 Page 98 of 107 Table 6-11: DCPP Composite POPCD Results (9 Inspections) In Industry Format coiImn A B c 0 1 E I F G H I J DCPP Total Input to Generic POPCD Data Table Detection at EOC. No Detection at EOCn (New Indications)

EOC. Bobbin Ind. RPC EOCo Bobbin idd. Repatred a ECC. New EOC., Bobbin RPC New EOC, Bobbin Not RPC Ind. Found Only by RPC at EOC or at Total$ for POPC C m OInLpected atE O im, nt Confirmed ingpacted EOC, & Plugged EnCOo- Excluded fron POPCD EvaluationU SDU W/oRPC *DO W/oRPC* BUDI RDU Pluged alEuOn tONUOK* '-W *)II'I 0 RPC Nwo -' BOOw/o RPC 6NU W1oRPI -. SNUI RuD Al RND AT EOC.,

Voltage BDDI RDD -a. NDI ROD BOOIRDO -- nBDDw/oRPC BDDw/o RPC -.6 Plugged aEOCn BNO IR .- $ODD IRDOD BNDI RDD -a. BOD w/o RPC BNDIROD -. BNOIRDO Ali SNO w/n RPC at EOC., Detection No POPCD for Bin BDD IRND -- SOD IROD BOD I RND -a BDDw/o RPC BND I RND -BDD I RDD BND I RND -- I-BOD wto RPC BNDIRND.--. BNOIRDD BDDIRNO/Plugged at EOCn at EOCn Detection Voltage Bin BOO IRND -- BND IRDD BND I RDDO- Plugged at EOCn at EOCn (Note 1)

BOO wio RPC -I OD I ROD BDD w/o RPC -- OND I ROD

-otes; I) POPCD for each voltagebin calculated as (Detection at EOCny(Oelection at EOCn .No Detection at EOCn). Bycolumn. POPCD - (AnB+CY(AnB+CnDnE+F).

1) Plant specific POPCD to be based upon voltage bins of 0.10 volt Industry POPCD database may use 0.20 volt bra due to difficulty of adjusting exisling database to smaller bins.

3) Inciudes Indications at EOCn plugged at EOCn and new Indications at EOCn+I. not ryortedIn the bobbin Inspection, and found only by RPC Inspection of dents, mixed residuals or other reasons for the RPC inspection.

4) BDD S Bobbin detected Indication: BND - Bobbin NOD Intersection: RDD - RPC detected indication; RND - RPC NDD intersection

86-9024635-000 Page 99 of 107 Figure 6-1: 2R12 POPCD Comparison to Composite POPCDs DCPP POPCD Comparison 1.0-0.9-0.8-0.7-

.0

£0.6 0.5 -

0.4 -

n ,

0.3 - - - 2R12 POPCD (from 2R13 Results) 0.2- /Composite POPCD Through 2R1 1 (Seven Inspections)

-- Composite POPCD Through 1R12 (Eight Inspections) 0.1 _- - Composite POPCD Through 2R12 (Nine Inspections) 0.0 0

6 EOCn Bobbin Volts

86-9024635-000 Page 100 of 107 7.0 EOC-14 Projections for Probability of Burst and Leak Rate This section provides the results of the EOC-14 POB and leak rate projections. AREVA uses Monte Carlo codes, as described in References 4 and 5, to provide the burst and leak rate analysis simulations. These evaluations are based on the methods in Reference 6 (for burst) and the slope sampling method for calculating the leak rate as defined in Section 9 of Reference

8. In addition, these evaluations use the POPCD and growth methodologies as described in Reference 16, as updated in References 25 and 28.

7.1 Inputs for Calculations Most of the inputs required for the POB and leak rate calculations have been described in other sections of this document. Table 7-1 provides a summary of the inputs required and the corresponding section(s) or table(s) that provide these data. The inputs that have not been previously discussed are provided in this section.

Table 7-1: Inputs for EOC-14 POB and Leak Rate Projections Input Description Section or Table Reference Comments BOC Voltage Distribution Table 3-16 Repaired Voltage Distribution Table 3-16 NDE Uncertainties Section 3.6; Table 3-21 POD Table 6-8 Composite POPCD through 2R12 (9 inspections)

Section 3.2; Tables 3-11 and Cycle 12 supplemented Growth 3-12 growth used for EOC-14 projections Cycle Length Section 7.1 1.62 EFPY Tube Integrity Correlations Tables 4-1 through 4-3 Addendum 6 Material Properties Section 7.1 Material Properties Since the burst pressure for a given flaw varies with the material properties of the tube, the material properties of the tubes must be included as an input into the POB program. This data is obtained from Reference 6. The values used for the EOC-14 projections were taken directly from Reference 6 and were a mean flow stress of 68.78 ksi and a standard deviation of the flow stress of 3.1725 ksi.

Cycle Lengqth The estimated cycle length for Unit 2 Cycle 14 is 1.62 EFPY (Ref. 12). This value was used in all projections for EOC-14 conditions.

86-9024635-000 Page 101 of 107 7.2 ProjectedEOC-14 Voltage Distributions The EOC-14 voltage distributions are obtained by applying a Monte Carlo sampling process to the BOC-14 voltages. The process starts by selecting a random POPCD correlation based on the POPCD parameters through 2R12 shown in Table 6-8. Based on the POPCD correlation, the BOC-14 population of indications is determined (detected plus assumed undetected). The process then randomly assigns NDE uncertainty values and a growth value to each of the BOC-14 indications. The EOC-14 voltage distributions are then used to calculate a leak rate and probability of tube burst. As discussed in Section 3.2, the Cycle 12 supplemented growth rates were determined to bound the Cycle 13 growth rates. Therefore, the Cycle 12 supplemented growth rates were used for projecting the EOC-14 voltages. SG 2-1 used SG-specific Cycle 12 growth rates divided into two growth bins with a breakpoint at 1.12v. SGs 2-2 and 2-3 utilized a composite growth rate divided into three bins with breakpoints at 1.10 and 1.71 volts, and SG 2-4 used a SG-specific Cycle 12 supplemented growth rate divided into three bins with breakpoints at 0.47v and 1.03v. No "delta volts adjustment" was required. Table 7-2 and Figures 7-1 through 7-4 provide the projected EOC-14 voltage distributions.

86-9024635-000 Page 102 of 107 Table 7-2: Projected EOC-14 Voltage Distributions (DCPP POPCD + Cycle 12 Supplemented Growth)

Voltage Bin SG 2-1 Vo n SG 2-3 SG 2-2Projected Distributions EOC-14 SG 2-4

-=01 2.01 1.39 11.41 4-04 0.2 38.98 26.87 34.06 27.11 0.3 77.76 56.96 63.49 83.83 0.4 133.81 101.43 90.92 168.19 0.5 145.41 121.05 96.11 223.79 0.6 126.05 112.60 89.28 222.70 0.7 110.09 102.41 76.72 177.56 0.8 86.15 80.90 59.04 138.57 0.9 68.33 62.95 46.04 117.98 1 52.34 47.24 34.20 103.37 1.1 38.99 34.01 24.77 91.47 1.2 28.88 24.75 17.79 83.05 1.3 21.03 17.52 12.32 70.13 1.4 15.07 12.26 8.58 56.25 1.5 11.53 8.80 6.09 45.44

-1.6 8.58 6.46 4.47 36.03 1.7 6.64 4.98 3.49 27.55 1.8 5.79 3.91 2.78 21.42 1.9 4.74 3.01 2.25 17.53 2 4.04 2.38 1.82 15.10 2.1 2.93 1.86 1.44 13.05 2.2 2.09 1.48 1.15 11.00 2.3 1.42 1.19 0.92 9.11 2.4 1.01 0.96 0.75 7.56 2.5 0.85 0.80 0.66 6.38 2.6 0.90 0.77 0.61 5.47 2.7 0.98 0.73 0.55 4.70 2.8 0.98 0.65 0.49 3.93 2.9 0.86 0.56 0.43 3.37 3 0.69 0.48 0.37 3.20 3.1 0.51 0.42 0.32 3.01 3.2 0.37 0.38 0.28 2.82 3.3 0.26 0.36 0.26 2.67 3.4 0.18 0.33 0.24 2.63 3.5 0.13 0.30 0.22 2.71 3.6 0.14 0.28 0.20 2.80 3.7 0.23 0.26 0.19 2.74 3.8 0.35 0.25 0.18 2.47 3.9 0.41 0.23 0.18 2.16 4 0.41 0.21 0.18 1.94 4.1 0.35 0.21 0.18 1.89 4.2 0.27 0.21 0.19 1.92 4.3 0.20 0.21 0.20 1.88 4.4 0.15 0.21 0.20 1.74 4.5 0.10 0.20 0.19 1.69 4.6 0.07 0.20 0.19 1.95 4.7 0.08 0.23 0.20 2.25 4.8 0.16 0.28 0.21 2.32 4.9 0.29 0.31 0.22 2.15 5 0.39 0.30 0.22 1.87 5.1 0.42 0.27 0.21 1.65 5.2 0.42 0.23 0.19 1.51 5.3 0.45 0.21 0.18 1.45 5.4 0.52 0.19 0.16 1.42 5.5 0.55 0.16 0.13 1.33 5.6 0.52 0.12 0.11 1.15 5.7 0.49 0.09 0.08 0.93 5.8 0.51 0.06 0.07 0.77 5.9 0.56 0.05 0.06 0.72 6 0.57 0.04 0.06 0.69 7 1.97 0.28 0.53 2.44

>7 0.02 0.01 0.03 0.05 Totals 1011.00 848.48 f 699.04 1858.63

86-9024635-000 Page 103 of 107 Figure 7-1: SG 2-1 EOC-14 Projected Voltage Distribution EOC-14 Projected Voltage Distribution for SG 2-1 160 140 120 o 100 M

8so 60 z

40 20 0 ]. .. ..........

QN 'b S N NAN1:

"N N  %ý ýb 1'V ýV 1V 41 1ý b 15A (b b.1 -b~ N11t < b ý l Bobbin Volts Figure 7-2: SG 2-2 EOC-14 Projected Voltage Distribution EOC-14 Projected Voltage Distribution for SG 2-2 140 120 100 0

o 80 0

60 E

z z

40 20 It 11: Nz Nb ND N" I'l 11 qV qV V qV 41 'V1 111 'Vb

.V 'VA V Bobbin Volts

86-9024635-000 Page 104 of 107 Figure 7-3: SG 2-3 EOC-14 Projected Voltage Distribution EOC-14 Projected Voltage Distribution for SG 2-3 140 120 100 80 EU z

60 40 20

"' ' ' 'V:'V 'V'1 'bý 'tb4' A 'V b . bý" b.

N 4P ':y I ~I ~ 4' Bobbin Volts Figure 7-4: SG 2-4 EOC-14 Projected Voltage Distribution EOC-14 Projected Voltage Distribution for SG 2-4 250 200 to C

0 150 -

C E

100-z 50 -

NPlz'bt I ýA ý2I N2,'A I'll Ojý 11 41~"

N b Iý -\ N'b~ 0, N bý~

' A Bobbin Volts

86-9024635-000 Page 105 of 107 7.3 Projected Tube Burst Probabilityand Leak Rate for EOC-14 Calculations to predict SLB leak rate and tube burst probability for each steam generator in DCPP Unit 2 at the projected EOC-14 conditions were performed using the burst pressure, leak rate, and probability of leakage correlations provided in Tables 4-1 through 4-3. The results of these calculations are shown in Table 7-3. As shown in Table 7-3, all of the results for projected EOC-14 conditions are below the acceptance criteria of 1.0 x 10-2 for POB and 10.5 gpm for leakage.

Table 7-3: Projected Leak Rate and Burst Probability at EOC-14 Using DCPP POPCD Projected Probability of Burst SLB Leak Steam Number of Rate Generator Indications 95 UCL at EOC-14 Best Estimate (1 or More Failures) (gpm)

-3 -3 SG 2-1 1011.00 1.91 x 10 2.02 x 10 1.16

-4 -4 SG 2-2 848.48 6.46 x 10 7.08 x 10 0.61

-4 -4 SG 2-3 699.04 6.90 x 10 7.54 x 10 0.53

-3 -3 SG 2-4 1858.63 5.76 x 10 5.94 x 10 3.75

-2 Reporting Threshold 1.0 X 10 10.5

86-9024635-000 Page 106 of 107 8.0 References

1. AREVA Document 86-9019535-000, "DCPP Unit 2R13 Voltage-Based ARC and W-star Startup Report", May 2006.

2. NRC Generic Letter 95-05, "Voltage-Based Repair Criteria for the Repair of Westinghouse Steam Generator Tubes Affected by Outside Diameter Stress Corrosion Cracking," USNRC Office of Nuclear Reactor Regulation, August 3, 1995.

3. NRC SER for Diablo Canyon Units I and 2 for Voltage-Based Repair Criteria, letter to PG&E dated March 12, 1998.

4. AREVA Document 51-5001160-02, "Steam Generator POB Simulation Code -

POB97vbR20.F90", December 2003.

5. AREVA Document 51-5001151-02, "Steam Generator Leak Rate Simulation Code LKR97VB2_r30.F90", December 2003.

6. WCAP 14277, Revision 1, SLB Leak Rate and Tube Burst Probability Analysis Methods for ODSCC at TSP Intersections, December 1996.

7. AREVA Document 86-9011354-000, "DCPP 1R13 Bobbin Voltage ARC 90-Day Summary Report", February 2006.

8. EPRI Report NP 7480-L, Addendum 6, 2004 Database Update, "Steam Generator Tubing Outside Diameter Stress Corrosion Cracking at Tube Support Plates Database for Alternate Repair Limits", Electric Power Research Institute, January 2005.

9. Pacific Gas and Electric, Diablo Canyon Unit 1 Refueling Outage 2R13, "Steam Generator Tubing Degradation Assessment", Revision 1, May 2, 2006.

10. Not used.

11. Diablo Canyon Power Plant Procedure, NDE ET-7, "Eddy Current Examination of Steam Generator Tubing", Revision 8.

12.Pacific Gas and Electric Company, Diablo Canyon Power Plant, Surveillance Test Procedure, STP M-SGTI, Revision 12, "Steam Generator Tube Inspection", March 7, 2006.

13.AREVA Document 51-9019522-000, "Bobbin Coil Probe Wear Monitoring for DCPP 2R13",

May 2006.

14.AREVA Document 86-5029429-00, "DCPP 2R11 Bobbin Voltage ARC 90 Day Summary Report", June 2003.

15. NRC Letter to NEI, dated February 9, 1996, "Probe Wear Criteria."

86-9024635-000 Page 107 of 107

16. PG&E Letter DCL-04-028, License Amendment Request 04-01, "Revised Steam Generator Voltage-based Repair Criteria Probability of Detection Method for DCPP Units 1 and 2",

March 18, 2004.

17.AREVA Document 51-5039454-00, "Bobbin/+PointTM Correlation for AONDB Indications at DCPP", February 2004.

18. Not Used.

19. Not Used.

20. Not Used.

21. Not Used.

22. Not Used.

23.AREVA Document 32-9024634-000, "DCPP Unit 2 R13 Voltage-Based ARC 90-Day Report Supporting Calculation File".

24. NEI Letter to NRC, "Generic Letter 95-05 Alternate Repair Criteria Methodology Updates",

June 2, 2004.

25. PG&E Letter DCL-04-104, "Response to NRC Request for Additional Information Regarding License Amendment Request 04-01", August 18, 2004.

26. Not used.

27.AREVA Document 86-5059194-00, "DCPP Unit 2 R12 Voltage-Based ARC 90-Day Report",

March 2005.

28.PG&E Letter DCL-04-117, "Response to August 24, 2004, NRC Request for Additional Information Regarding License Amendment Request 04-01", September 17, 2004.

29.NRC Letter to PG&E, "Diablo Canyon Power Plant, Unit Nos. 1 and 2 - Issuance of Amendment Re: Permanently Revised Steam Generator Voltage-Based Repair Criteria Probability of Detection Method (TAC Nos. MC2313 and MC2314)", October 28, 2004.

30. PG&E Letter DCL-06-080, "Reply to Request for Additional Information Regarding: Special Report 04 Results of Steam Generator Inspections for Diablo Canyon Power Plant Unit 1 Thirteenth Refueling Outage", June 23, 2006.