ML19010A307

Relief Request 63 -Unit 3 Impractical Examinations for the Third 10-Year Inservice Inspection Interval

ML19010A307
Person / Time
Site:	Palo Verde
Issue date:	01/10/2019
From:	Lacal M Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-07851-MLL/TNW
Download: ML19010A307 (25)

Text

10 CFR 50.55a MARIA L. LACAL Qaps Senior Vice President, Nuclear Reguiatory & Oversight Palo Verde Nuclear Generating Station P.O. Box 52034 Phoenix, AZ 85072 102-07851-MLL/TNW Mail Station 7605 January 10, 2019 Tel 623.393.6491 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station Unit 3 Docket No. STN 50-530 Renewed Operating License Number NPF-74 Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year Inservice Inspection Interval Pursuant to 10 CFR 50.55a(g)(5)(iii), Arizona Public Service Company (APS) hereby requests NRC approval of Relief Request 63 for the third ten-year interyal for the In-Service Inspection (ISI) Program for Palo Verde Nuclear Generating Station (PVNGS),

Unit 3. Certain ultrasonic examinations of welds required by Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, sub-articles IWB-2500 and IWC-2500 have been determined to be impractical; therefore, relief is requested from those requirements to achieve essentially 100 percent weld coverage while proposing the enclosed alternatives. The enclosed information supports the determinations of impracticality which are based on demonstrated limitations experienced while attempting to comply with the Code requirements for the identified interval. The details of the 10 CFR 50.55a relief request are enclosed.

By letter number 102-07604 [Agency Documents Access and Management System (ADAMS) Accession number ML17318A472], dated November 10, 2017, APS submitted Relief Request 56, which better aligned fourth 10-year ISI interval start dates for all three units. Relief Request 56 was approved by NRC letter dated March 9, 2018 (ADAMS Accession number ML18067A073). Relief Request 63 is being provided within the specified one year of the close of the original third 10-year interval for PVNGS Unit 3 and does not rely on the revised interval dates described in Relief Request 56.

No new commitments are being made in this submittal.

A member of the STARS Alliance LLC Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek

102-07851-MLL/TNW ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Page 2 If you have any questions about this request, please contact Matthew S. Cox, Licensing Section Leader, at (623) 393-5753.

Sincerely,

-nu L. LoCc^\

MLL7TNW/MDD/mg

Enclosure:

Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year Inservice Inspection (ISI) Interval cc: S. A. Morris NRC Region IV Regional Administrator S. P. Lingam NRC NRR Project Manager for PVNGS C. A. Peabody NRC Senior Resident Inspector for PVNGS

Enclosure Relief Request 63 Unit 3 Impractical Examinations for the Third 10-Year Inservice Inspection (ISI) Interval

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval 10 CFR 50.55a Request Number 63 Relief Request in Accordance with 10 CFR 50.55a(g)(5)(iii)

Inservice Inspection Impracticality The Palo Verde Nuclear Generating Station (PVNGS), Unit 3, Class 1 and 2 welds with limited examinations are included in Tables 1, 2, and 3 of Attachment 1 of this relief request. The content of this relief request includes the insights gained from guidance provided in Reference 1.

1. ASME Code Component(s) Affected The following Code Classes, Examination Categories, and Item Numbers apply.

Code Classes: 1 and 2 Examination Categories: B-D, C-B, and C-F-1 Item Numbers: B3.110, C2.21, C2.22, C5.ll, and C5.21

2. Applicable Code Edition and Addenda

The Code of Record for the third 10-year Inservice Inspection interval is the 2001 Edition of ASME,Section XI, through the 2003 Addenda.

The applicable edition of the ASME Boiler and Pressure Vessel (BPV) Code,Section XI, Appendix VIII program is the 2001 edition.

3. Applicable Code Requirement

The applicable Code Classes, Item, and Examination Categories are included in Attachment 1 of this enclosure for each of the welds and areas limited. Table 1 is organized utilizing a sequence number that refers directly back to the specifics for each of the limitations for which relief is being sought.

4. Impracticality of Compliance Arizona Public Service Company (APS) has determined that compliance with the Code requirements of achieving essentially 100 percent coverage of the welds listed in this request is impractical for Unit 3. In accordance with 10 CFR 50.55a(g)(5)(iii), this relief request is based on actual demonstrated limitations when attempting to comply with the Code requirements in the performance of the examinations listed in Tables 1, 2 and 3.

The Unit 3 program for the third 10-year ISI interval utilizes ASME Code Case N-460, Alternative Examination Coverage for Class 1 and Class 2 Welds,Section XI, Division 1.

Utilization of this Code Case allows the acceptance of examinations that obtained greater than 90 percent coverage, (but less than 100 percent due to interference by another component or part geometry); therefore, such examinations are not included in this submittal.

The design of the plant has provided access for examinations; however, component design configurations with conditions resulting in examination limitations, such as geometric configurations of components or their welds, do not allow full required examination volume and/or coverage, thus this relief request addresses those

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval conditions. Details for examination limitations in required examination coverage are provided in Attachment 1 of this enclosure.

5. Burden Caused by Compliance Components and welds associated with the items listed in this reiief request are constructed of standard design items meeting typical national standards that specify required configurations and dimensions including Class 1 Category B-D, Class 2 Category C-B, and Class 2 Category C-F-1.

For the Class 1 Category B-D Nozzle-to-Vessel Welds of the Pressurizer, the design configurations of these welds and obstructions do not allow for the required examination coverage.

For the Class 2 Category C-B Nozzle-to-Shell Welds at the steam generator blowdown line, the weld configuration and materials do not allow for the required examination coverage. Available ultrasonic testing (UT) equipment could not be successfully calibrated for the configuration and materials at these nozzle locations.

For the Class 2 Category C-B Nozzle Inside Radius (IR) Sections, the design configuration of these nozzles does not allow for UT of the IR sections of these nozzles from the outside surface of the steam generator (SG) nozzles. The only way these limitations could be improved would be to modify the nozzle design.

The Class 2 Category C-F-1 Piping Welds are Pipe-to-Valve, Pipe-to-Tee, and Pipe-to-Flange welds (including similar configurations at orifices and penetrations).

Examinations are limited as the UT examination coverage is only accessible from the pipe side of the weld.

Examinations have been performed and/or attempted to the maximum extent possible.

Therefore, APS has determined that obtaining essentially 100 percent coverage is not feasible and is impractical without adding undue burden, and/or potential damage to the plant or the component itself.

6. Proposed Alternative and Basis for Use Proposed Alternative

1) Periodic system pressure tests and visual examinations are performed in accordance with ASME Section XI, Examination Category B-P, for Class 1 pressure retaining welds and items each refueling outage and Examination Category C-H for Class 2 pressure retaining welds and items each inspection period in accordance with Table IWB-2500-1 and Table IWC-2500-1, respectively.

2) Conduct UT examinations to the maximum extent possible and when required by ASME Section XI, perform a 100 percent surface examination as noted in Attachment 1 of this enclosure.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Basis for Use 10 CFR 50.55a(g)(4) recognizes that throughout the service iife of a nuciear power facility, components which are classified as ASME Code Class 1, Class 2, and Class 3 must meet the requirements set forth in the ASME Code to the extent practical within the limitations of design, geometry, and materials of construction of the welds and items described in Attachment 1 of this enclosure.

There is no plant-specific or industry operating experience regarding potential degradation specific to the subject welds in this relief request.

For the Class 1 and 2 welds located inside the containment of Unit 3, with limited examinations listed in Attachment 1 of this enclosure, operational leakage is monitored in accordance with the Technical Specification requirements. In addition, during outages, engineers perform walk-downs of systems inside the containment. This walk-down is performed to look for evidence of leakage accumulation and boric acid as well as system abnormalities that could affect plant performance. Also, system pressure tests are performed as required by the ASME Code,Section XI.

For the ASME Class 2 welds examined in accordance with Appendix VIII, Supplement 2, Qualification Requirements for Wrought Austenitic Piping Welds, ASME Section XI required examination coverage is limited when the weld can only be scanned from one side. The Performance Demonstration Qualification Summary for the qualified Electric Power Research Institute procedure, PDI-UT-2, PDI Generic Procedure for the Ultrasonic Examination of Austenitic Pipe Welds PDI-UT-2, in part states, "The austenitic single side qualifications documented in this summary demonstrate application of best available technology, but do not meet the requirements of 10 CFR 50.55a(b)(2)(xvi)(B)." It should be noted that UT was performed through the weld to obtain the maximum possible Code required volume and, as shown in Attachment 1 of this enclosure, the theoretical beam path extends into the far side of the weld for the UT examinations performed. Therefore, the UT examinations conducted using the Appendix VIII, Supplement 2, qualified procedures, provide reasonable assurance for the detection of flaws on the far side of welds where the ultrasonic beam has been transmitted even though not presently qualified.

No reasonable action can be taken by APS at this time to improve these examinations without applying impractical options. Based on the limited UT examinations achieved, surface examinations (where applicable), any applicable leakage monitoring, and required system pressure tests with VT-2 visual examinations, the proposed alternative in this relief request will provide assurance of an acceptable level of quality and safety by providing reasonable assurance of structural integrity.

7. Duration of Proposed Alternative This relief request is applicable to the original PVNGS Unit 3 Third 10-Year ISI Interval which began on January 11, 2008 and ended May 31, 2018 and covers all the limited examinations that have been identified for the entire interval in Unit 3.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval

8. Precedents

• NRC SER, Surry Power Station Unit No. 2 - Requests for Relief LMT-ROl, LMT-SSOl, LMT-CSOl, LMT-POl, LMT-COl, LMT-C02, LMT-C03, and LMT-C04 - For Limited Coverage Examinations Performed in the Fourth 10-Year Inservice Inspection Intervai, dated February 17, 2017, (ADAMS Accession No. ML16365A118)

• NRC SER, Diabio Canyon Power Plant, Unit No. 1 - Relief Request NDE-SIF-Ul To Aiiow Use of Aiternate American Society of Mechanicai Engineers Boiier and Pressure Vessel Code Section XI Examination Requirements for the Third Inservice Inspection Intervai, dated July 27, 2016, (ADAMS Accession No. ML16207A397)

• NRC SER, Miilstone Power Station, Unit No. 2 - Reiief Requests For Limited Coverage Examinations Performed In The Fourth 10-Year Inservice Inspection Interval, dated July 13, 2016, (ADAMS Accession No. ML16172A135)

9. References

1. NRC presentation Coverage Relief Requests, Industry/NRC NDE Technical Information Exchange Public Meeting January 13-15, 2015, (ADAMS Accession No. ML15013A266)

2. NRC letter dated March 9, 2018, Palo Verde Nuclear Generating Station, Units 1, 2, and 3 - Relief Request No. 56 to Extend Third 10-Year Inservice Inspection Interval for Unit 2, and to Adopt 2013 Edition of the ASME Code,Section XI, for the Fourth 10-Year Interval for Units 1, 2, and 3 (ADAMS Accession number ML18067A073)

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 Introduction This attachment contains figures and tables that are used to depict the applicable locations, limitations, and calculations for obtained coverage, materials, product forms, UT examination angles, wave forms used, and the examination results for the welds or items associated with this relief request, (including any appiicable previous examination history).

Table 1 - Categories B-D and C-B Relief Weld System Weld Materiais Indications Examination Examination Applicable Request Identification Description Detected Code Limitations Figures and Sequence Number and Coverage Tables No Zone Size/Thickness Obtained Class: 1, Category: B-D, Item: B3.110 Requirement: Essentiaiiy 100% examination of the weid length 1.1 5-9 RC PZR Surge Vessel UT = None UT = 65.2% Geometric Location Figure Nozzle-to-Vessel SA-533 Nozzle 1-1, Picture 1-Zone 005 Weld Grade A Design 1, Figure 1-1-1, Class 1 Configuration 1-1-2, Table 5'T x 12" Dia 1-1-1 Nozzle SA-541 1.2 5-10 RC PZR Spray Vessel UT = None UT = 80.8% Geometric Location Figure Nozzle-to-Vessel SA-533 Nozzle 1-2, Figure 1-Zone 005 Weld Grade A Design 2-1, Table 1 Class 1 Configuration 1 5'T X 4" Dia Nozzle SA-541 1.3 5-11, 12, 13 & RC PZR Vessel-to- Vessel UT = None UT = 74.7% Geometric Location Figure 14 Nozzle Weld SA-533 Nozzle 1-3, Figure 1-Grade A Design 3-1, Table 1 Zone 005 5'T X 6" Dia Class 1 Configuration 1 Nozzles SA-541 Class: 2, Category: C-B, Item: C2.21 Requirement: Essentiaiiy 100% examination of the weid length 1.4 42-100 SG SG 2 Nozzle-to- Tube UT = NA UT = Not Unable to Location Shell blowdown Sheet Performed calibrate UT Figure 1-4,

& SA-508 at Tube Sheet 0% on mock-up Figures 1-4-1,42-101 Class 3a PT = None calibration and 1-4-2 6" Dia nozzle PT = 100%

Nozzle block due to welded onto SA-336 weld materials Tube Sheet and Zone 042 Class F12 configuration

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 Relief Weld System Weld Materials Indications Examination Examination Applicable Request Identification Description Detected Code Limitations Figures and Sequence Number and Coverage Tables No Zone Size/Thickness Obtained Class: 2, Category: C-B, Item: C2.22 Requirement: Essentially 100% examination of the weld length 1.5 41-114-IR SG SG 1 Nozzle Tod Head UT = NA UT = Not Geometric Location/Design Inside Radius SA-533 Performed Nozzle Figure 1-5 Section for Main Grade B 0% Design 41-115-IR Steam Class 1 Configuration Limitation Zone 041 4.3"Tx 32" Dia Nozzle SA-508 Class la 1.1 Weld 5 B3.110: Pressurizer Surge Nozzle-to-Vessel Weld Location Figure 1-1 IPressurizer J This weld is in Zone 005 and was examined in inspection period 3 during the 3R19 outage. The Code Required Voiume (CRV) was determined based on Section XI, Figure IWB-2500-7(a) and the corresponding required examination volume is shown in the Figures 1-1-1 and 1-1-2. Note that during the scan of the pressurizer surge nozzle-to-vessel weld 0°, 45°, and 60° scans were performed. The volumetric examination only credits the 45° and 60° scans as shown in Table 1-1-1. It should be noted that there is no scan from the nozzle side of the weld due to geometry of the nozzle. This weld was examined in interval 2 with no rejectable indications, and no limitations however; the configuration of the adjacent area was changed during pressurizer heater replacement modifications. The current configuration has additional limitations in the form of obstructions from pad welds (Picture 1-1). These pads limit the scan of the required volume that prevents full coverage from being obtained.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 Picture 1-1 Typical Pressurizer Weld Pads I **'

( -V ,

v\ /

O' tu.4 I

Jll I

( '! J yf mma.

The measured distance from the weld pads to the Pressurizer Surge Nozzle is approximately eight inches. The weld pads extend the majority of the way around the nozzle. Two weld pads are also installed for instrumentation nozzles shown on the right side of the photo above. These weld pads are just over 11.5 inches from the nozzle.

Modeling in the Figures 1-1-1 and 1-1-2 shows areas of the CRV that were scanned. These figures utilize the same nomenclature showing areas that were scanned and not scanned. The dotted lines with angles represent the beam paths from the different scans performed on the components. The 45° and 60° angles are drawn off of the tangent line where the 0° scans normal projection would have occurred. The scans near the nozzle were terminated where lift off would be expected for a given nozzle design. For circumferential scans, skews were not accounted for; rather the volumes of the circumferential scans were calculated by using the 0° normal projection from the scanned surface. Using the 0° scan volume to calculate the circumferential volume is considered conservative as any skewing performed by examiners would have provided an increased volume than the volume presented in the calculations contained in Table 1-1-1.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 Figure 1-1 Weld 5-9 Scan Coverage Diagram 0°, 45° and 60° Weld Pads 8 inches from the Nozzle Figure 1-1 Weld 5-9 Scan Coverage Diagram 0°, 45° and 60° Weld Pads 11.5 inches from the Nozzle

Enclosure Relief Request 63 - Unit 3 Impracticai Examinations for the Third 10-Year ISI Interval Attachment 1 Table 1-1 Examination Coverage Summary Weld 5 12" Pressurizer Surge Nozzle-to-Vessel Weld CRV<^'<<)= 2624.48 Circumferential Scan 45° Volume = 60° Volume = 921.60 In*

in^* Volume = 1835.42 in^ 1514.30 in*

(1589.62 ln*)<*>

Angle and Wave Axial Scans Clockwise Counterclockwise Mode Circumferential Circumferential 45°S 57.6% 69.9% 69.9%

60°S 35.1% (60.5%)<=>> 69.9% 69.9%

Code Coverage Total = 65.2%

NOTES:

(1) S = Shear Wave (2) Clockwise and counterclockwise circumferential scans use the same percentage coverage as a 0° scan. This percent calculation for the circumferential scans is considered conservative as it does not credit the skews typically used by examiners to obtain greater coverage in a nozzle to shell weld.

(3) Code Coverage Total refers to the maximum percentage of the required examination volume that is effectively examined with the qualified examination procedures used. The total volume scanned for axial scans is credited to 50% of the code coverage total and the other 50% of the scan volume is credited towards the two circumferentiai directions.

(4) Drawings used to build CAD models for the volumetric calculations are part of the Combustion Engineering Analytical Report for the Unit No. 3 Pressurizer, Document ID NOOl-0604-00075.

(5) Note that the percent coverage of the 60° is 35.1% coverage; however, the 45° and 60° scans are being credited for the total axial scan volume. The combined volume scanned for the 45° and 60° axial scans is 1589.62 in^ or 60.5% volume for the axial scan contribution to the Code Coverage Total.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 1.2 Weld 5 B3.110: Pressurizer Sorav Nozzle-to-Vessel Weld Location Figure 1-2 MANWAY TOP VIEW This weld is in Zone 005 and was examined in Inspection Period 2 during the 3R17 outage.

The CRV was determined based on Section XI, Figure IWB-2500-7(a) and the corresponding required examination volume is shown in Figure 1-2-1. Note that during the scan of the pressurizer spray nozzle-to-vessel weld 0°, 45°, and 60° scans were performed. The volumetric examination only credits the 45° and 60° scans as shown in Table 1-2-1. It should be noted that no scan was performed on nozzle side of weld due to geometry.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 Figure 1-2 Weld 5-10 Scan Coverage Diagram 0°, 45° and 60° Scans Table 1-2 Examination Coverage Summary Weid 5 4" Pressurizer Spray Nozzle-to-Vessei Head Weid Crv(3*)= 1148.13 Circumferential Scan 45° Volume = 60° Volume = 1048.60 in*

in* Volume = 807.40 in* 1023.73 in*

Angle and Wave Axial Scans Clockwise Counterclockwise Mode Circumferential <*> Circumferential 45°S 89.1% 70.3% 70.3%

60°S 91.3% 70.3% 70.3%

Code Coverage Total = 80.8%

NOTES:

(1) S = Shear Wave (2) Clockwise and counterclockwise circumferential scans use the same percentage coverage as a 0° scan. This percent calcuiation for the circumferential scans is considered conservative as it does not credit the skews typically used by examiners to obtain greater coverage in a nozzie to shell weld.

(3) Code Coverage Total refers to the maximum percentage of the required examination volume that is effectively examined with the quaiified examination procedures used. The total volume scanned for axial scans is credited to 50% of the code coverage totai and the other 50% of the scan volume is credited towards the two circumferential directions.

(4) Drawings used to buiid CAD models for the volumetric calculations are part of the Combustion Engineering Analytical Report for the Unit No. 3 Pressurizer, Document ID NOOl-0604-00075.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 1.3 Weld 5-11. 5-12. 5-13 and 5 B3.110: Pressurizer Safety Nozzle-to-Vessel Weld Location Figure 1-3 MANWAY TOP VIEW Welds 5-11, 5-12, 5-13 and 5-14 are all Pressurizer Safety Nozzle-to-Vessel welds located in Zone 005. Weld 5-11 was examined in Inspection Period 1 during the 3R15 outage; Weld 5-12 was examined in inspection period 3 during the 3R19 outage; Weld 5-13 was examined in inspection period 2 during the 3R17 outage, and Weld 5-14 was examined in inspection period 1 during the 3R15 outage.

The CRV was determined based on Section XI, Figure IWB-2500-7(a) and the corresponding required examination volume is shown in Figure 1-3-1. Note that during the scan of the pressurizer safety nozzle-to-vessel welds 0°, 45°, and 60° scans were performed. The volumetric examination only credits the 45° and 60° scans as shown in Table 1-3-1. It should be noted that there was no scan performed on nozzle side of weld due to geometry.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 Figure 1-3 Weld 5-11, 5-12, 5-13 and 5-14 Scan Coverage Diagram

^A^TY VALVE NOZZLE

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 Table 1-3 Examination Coverage Summary Weid 5-11, 5-12, 5-13, 5 6" Pressurizer Safety Nozzie-to-Vessei Head Welds Crv(3-4)= 1096.43 In^ Circumferential Scan Volume = 695.79 45° Voiume = 60° Volume in" 915.02 in" 944.1 in" Angie and Wave Mode ' Axial Scans Clockwise Counterclockwise Circumferential Circumferential 45°S 83.4% 63.4% 63.4%

60°S 86.1% 63.4% 63.4%

Code Coverage Total 74.7 NOTES:

(1) S = Shear Wave (2) Clockwise and counterclockwise circumferential scans use the same percentage coverage as a 0° scan. This percent calculation for the circumferential scans is considered conservative as it does not credit the skews typically used by examiners to obtain greater coverage in a nozzle to shell weld.

(3) Code Coverage Total refers to the maximum percentage of the required examination volume that is effectively examined with the qualified examination procedures used. The total volume scanned for axial scans is credited to 50% of the code coverage total and the other 50% of the scan volume is credited towards the two circumferential directions.

(4) Drawings used to build CAD models for the volumetric calculations are part of the Combustion Engineering Analytical Report for the Unit No. 3 Pressurizer, Document ID NOOl-0604-00075.

(5) Due to the complex geometry of the Pressurizer Safety Nozzle-to-Vessel Head weld, the lower portion of the weld and the upper portion were both modeled and rotated about an axis for volumes. Averages of the two volumes were used for the credited examination volumes.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 1.4 Welds42-100 and 42-101 - C2.21: Steam Generator No. 2 Blowdown Nozzle at Tube Sheet Location Figure 1-4 Steam Generator - Secondary Secondary Handhole Feedwater Secondary

{Tube Sheet)

The blowdown nozzles on the Palo Verde Steam Generators are welded directly to the outer surface of the Tube Sheet. The blowdown path through the Tube Sheet was machined vertically, then horizontally to the outer-most surface. This nozzle configuration is less common because it is not welded to a shell penetration. The 6-inch nozzle is welded to the side of a tube sheet that is approximately 25 inches thick and 202 inches in diameter. This configuration, as shown in Figures 1-4-1 and 1-4-2, would calculate the CRV based on Section XI, Figure IWC-2500-4(d).

Inconel buttering was used on both the Nozzle and the Tube Sheet at the weld preparation areas, and Inconel weld material was used to complete the weld as shown in Figure 1-4-1.

Numerous attempts were made to calibrate the UT equipment for the examination via mock-ups that reflected the as-built configuration and materials. Attempts were repeated by Palo Verde Level III NDE personnel, outside vendors, and industry groups with UT expertise. The attempts included the most current phased array methods of UT. Repeatable and satisfactory results could not be attained during the attempts to calibrate for the examination.

The requirements to perform surface examinations at these locations have been met with no indications noted. Surface examinations were performed during refueling outage 3R19 and noted no rejectable indications. In addition, pressure tests are performed during each refueling outage where leakage would be detected via visual examination.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 Figure 1-4 Welds42-100 and 42-101 Configuration Detail Steam Generator Tube Sheet

-0 3.50 :

- .00 l[68,9mml INCONEL WELD 1 (06 7mm] I INCOHEL BUnCRlHO Tube Sheet Blowdown Nozzle INCONEL BUnERING ,11.50 ,

(292.1mm]

O 3.00 i ,03 - - *

(76.2mm]

0 6.675 +/- .030

[174.6mm]

+ 03 2:3 MAX

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 Figure 1-4 Welds42-100 and 42-101 Alternate View Top View of Tube Sheet at Blowdown Nozzle Blowdown (Tubesheet)

Nozzle Steam Generator OD at Tube Sheet

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISl Interval Attachment 1 1.5 Weld 41-114-IR and 41-115-IR - C2.22: Steam Generator No. 1 Head-to-Nozzle Inside Radius Section Location Figure 1-5 2X .375 WT 11.00l279.<nn)*

DIM. 'A*

SEE TABLE IH-4) 0.7S[l9.1nnl ONE LXATlON ONLT-v n 1.0[25.4fimH SEE DETAIL It A A t* (A-7)

The steam nozzles on the Palo Verde steam generators protrude into the vessel by approximately 13 inches and do not have a typical IR area as depicted on IWC-2500-4(a)-(d).

Rather, the Palo Verde steam nozzle design is similar to the design depicted in the annulled Code Case N-311, Alternative Examination of Outlet Nozzle on Secondary Side of Steam GeneratorsSection XI, Division 1. Code Case N-311 provided an alternate IR surface examination where part of the surface would only be accessible from the inside of the secondary side of a steam generator. Code Case N-311 was to be incorporated in ASME Section XI when annulled in 2004; however, the alternate examination provided in N-311 has not been included in any recent versions of ASME Section XI.

Scan plans were discussed with vendors to ultrasonically examine the alternate area identified in N-311. No ultrasonic methods were determined to be practical so no relief was sought for an alternative ultrasonic examination volume.

Access to the inside surface of the steam nozzles is not readily available due to the internal design of the Steam Generator. Access requires removal of multiple components and removal of welds internal to the secondary side of the steam generator. The work would expose the steam generator to foreign material risks. In addition, internal access to the steam nozzles poses a potential risk to employees as egress by the examiner, and/or immediate emergency retrieval efforts by response personnel, would be delayed due to the tortuous access path.

From a design standpoint, an analysis has been performed on this nozzle as documented in ANSALDO PV-RPM-13-000012 Rev. 2, Structural and fatigue analysis of the steam outlet 18

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 nozzle. The results of this analysis show that the nozzle, including its IR Section, do not exceed ASME Class 1 or 2 requirements, Table 2 - Item No. C5.ll Welds Table 2 - Unit 3 Limited Examinations within Category C-F-1, Item C5.11, for the Third 10-Year ISI Interval NDE Reports Weld Pipe Pipe Weld Volumetric / Ultrasonic Exam Surface Exam Configuration Pressure Rejectable Rejectable DIam.

Zone No. No. Ultrasonic Code Required Scan Angles Surface Rating System or Line Description Volume Used Indications? Indications? (inches) (In Direction of Flow) (psi)

Report No. Completed (degrees) Y/N Report No. Y/N 74-105 15-UTE-3162 50% 15-PT-3166 400 Shutdown Cooling KTX Outlet Zone 83 45. 70 sweepdet to pipe to Pool Cooling KTX Low Pressure Safety Injection Zbne90 85-9 13-UTE-3037 50% 13-PT-3032 300

45. 60. 70 flange to pipe Suction to Containment Sump Isolation Low Pressure Safety Injection 85-11 13-UTE-3036 50% 13-PT-3033 300 Zone 90 45. 60. 70 pipe to valve Suction to Containment Sump Isolation 76-7 15-UTE-3137 50% 15-PT-3153 400 Shutdown Cooling KTX to Zbne 91 45. 60. 70 orifice to pipe Reactor Coolant Loops 15-UTE-3138 50% 15-PT-3154 400 Low Pressure Safety Injection Zbne 91 45. 60. 70 orifice to pipe to Reactor Coolant Loops 77-14 15-UTE-3135 50% 45,60 15-PT-3156 1500 Low Pressure Safety Injection Zbne 91 pipe to valve to Reactor (^ant Loops 77-16 15-LTTE-3136 50% 15-PT-3155 1500 Low Pressure Safety Injection Zbne 91 45. 60 valve to pipe to Reactor Coolant Loops 76-47 15-UTE-3153 50% 15-PT-3169 1500 Low Pressure Safety Injection Zbne 98 45. 60 pipe to valve to Reactor Coolant Loops71-123 13-UTE-3069 50% 13-PT-3059 300 Shutdown Cooling to Low Zbne 101 45. 60. 70 valve to pipe Pressure Safety Injection Low Pressure Safety Injection 85-46 16-U7E-3052 50% 16-PT-3057 300 Zbne 104 45. 60. 70 pipe to valve Suction to Containment Sump Isolation Low Pressure Safety Injection 85-47 16-UTE-3051 16-PT-3058 300 Zone 104 45. 60. 70 valve to pipe Suction to Containment Sump Isolation Note: All piping material for C-F-1 welds in the Table above are Austenitic Stainless Steel.

Note: The first two numbers of the NDE Report No. indicate the year that the exam was performed for the third interval.

Note: All Surface Exams referenced in Table 2 are Dye Penetrant Exams The welds noted in Table 2 were examined from one side only during the third 10-year Inservice Inspection Interval. Each of these welds joins a pipe with another item which, due to configuration and/or shape on at least one side of the weld for the entire circumference, limits the volume which can be examined via ultrasonic examination.

The CRVs for these welds are determined per Figure IWC-2500-7(a),Section XI, ASME BPV Code. Figures 2a and 2b illustrate the typical volumes scanned by the examiner from a single side using the corresponding angles listed in Table 2 for each weld. Scan angles included a combination of 45, 60, and/or 70 degrees as identified in Table 2. EPRI PDI procedures and techniques were used for the C-F-1 volumetric examinations. The applicable refracted longitudinal or 2.25 MFIz 70 degree sheer wave scans were utilized to examine the far side of the examination volumes limited by component geometry.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 Figure 2a - Typical Weld Coverage Diagram; 45 and 60 Degree Scans 60 deg.

60R.L 45 deg.

] E Required Exam Vol.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISl Interval Attachment 1 Figure 2b - Typical Weld Coverage Diagram; 45, 60, and 70 Degree Scans 60 deg-70 deg.

45 deg.

] > Required Exam Vol.

Enclosure Relief Request 63 - Unit 3 Impractical Examinations for the Third 10-Year ISI Interval Attachment 1 Table 3 - Item No. C5.21 Welds Table 3 - Unit 3 Limited Examinations within Category C-F-1, Item C5.21, forthe Third 10-Year ISI Interval NDE Reports Volumetric I Ultrasonic Exam Surface Exam Weld Pipe Pipe Weld Code Scan Configuration Pressure System or Line Zone No. No. Rejectable Rejectable DIam. Rating Description Ultrasonic Required Angles Surface (In Direction of Indications? Indications? (Inches) Flow) (pai)

Report No. Coverage Used Report No.

Y/N Y/N Completed (degrees)

High Pressure Safety Zone 110 110-17 16-UTE-3005 50% 45, 60, 70 16-PT-3005 pipe to \al\e 1500 Injection Discharge to Reactor Coolant Loop High Pressure Safety Zbne 110 110-52 15-UTE-3148 50% 45, 70 15-PT-3158 pipe to tee 1500 Injection Discharge to Reactor Coolant Loop High Pressure Safety Zbne 111 111-34 15-UTE-3146 50% 45, 60, 70 15-PT-3164 pipe to orlUce 1500 Injection Discharge to Reactor Coolant Loop High Pressure Safety Zone 113 113-28 15-LTTE-3141 50% 45, 60, 70 15-PT-3159 valve to pipe 1500 Injection Discharge to Reactor Coolant Loop High Pressure Safety zone 118 118-46 15-UTE-3184 50% 45, 60, 70 15-PT-3182 penetration to pipe 1500 Injectio Pump Discharge to Long Term Recirc.

High Pressure Safety zone 118 118-49 154JTE-3188 50% 45, 60, 70 15-PT-3185 pipe to valve 1500 Injectio Pump Discharge to Long Term Recirc.

High Pressure Safety zone 119 119-52 16-UTE-3021 50% 45, 60, 70 16-PT-3019 pipe to valve 1500 Injectio Pump Discharge to Long Term Recirc.

Charging Pump to High zone 119 119-53 16-UTE-3008 50% 45, 60, 70 16-PT-3003 valve to pipe 1500 Pressure Long Term Recirc.

Note: All piping material for C-F-1 welds in the Table above are Austenitic Stainless Steel.

Note: The first two numbers of the NDE Report No. indicate the year that the exam was performed for the third interval.

Note: All Surface Exams referenced in Table 3 are Dye Penetrant Exams The welds noted in Table 3 were examined from one side only during the third 10-year Inservice Inspection Interval. Each of these welds joins a pipe with another item which, due to configuration and/or shape on at least one side of the weld for the entire circumference, limits the volume which can be examined via ultrasonic examination.

Code required volumes for these welds are determined per Figure IWC-2500-7(a),Section XI, ASME BPV Code. Figures 2a and 2b illustrate the typical volumes scanned by the examiner from a single side using the corresponding angles listed in Table 3 for each weld. Scan angles included a combination of 45, 60, and/or 70 degrees as identified in Table 3. EPRI PDI procedures and techniques were used for the C-F-1 volumetric examinations. The applicable refracted longitudinal or 2.25 MHz 70 degree sheer wave scans were utilized to examine the far side of the examination volumes limited by component geometry.