RA-14-098, Response to Request for Additional Information - End of Interval Relief Requests Associated with the Fourth 10-Year Lnservice Inspection (Isi)Interval
| ML14321A044 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 11/14/2014 |
| From: | Jim Barstow Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RA-14-098 | |
| Download: ML14321A044 (13) | |
Text
10 CFR 50.55a RA-14-098 November 14, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Oyster Creek Nuclear Generating Station Renewed Facility Operating License No. DPR-16 NRC Docket No. 50-219
Subject:
Response to Request for Additional Information - End of Interval Relief Requests Associated with the Fourth 10-Year lnservice Inspection (ISi)
Interval
References:
- 1) Letter from J. Barstow (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "End of Interval Relief Requests Associated with the Fourth 10-Year lnservice Inspection (ISi) Interval," dated January 7, 2014
- 2) Letter from J. G. Lamb (U.S. Nuclear Regulatory Commission) to M. J. Pacilio (Exelon Generation Company, LLC), "Oyster Creek Nuclear Generating Station - Request for Additional Information Regarding the Fourth 10-Year Interval lnservice Inspection Program Plan Requests for Relief (TAC Nos. MF3406 and MF3407)," dated September 17, 2014 In the Reference 1 letter, Exelon Generation Company, LLC (Exelon) requested relief from the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV)
Code,Section XI, "Rules for lnservice Inspection of Nuclear Power Plant Components."
These reliefs apply to the fourth 10-year lnservice Inspection (ISi) interval, which concluded on January 14, 2013, for the Oyster Creek Nuclear Generating Station. The fourth 10-year ISi interval utilized the ASME Boiler and Pressure Vessel Code,Section XI, 1995 Edition with 1996 Addenda.
In the Reference 2 letter, the U.S. Nuclear Regulatory Commission requested additional information. Attached is our response.
End of Interval Relief Requests Associated with the Fourth lnservice Inspection Interval November 14, 2014 Page 2 There are no regulatory commitments in this letter.
If you have any questions concerning this letter, please contact Tom Loomis at (610) 765-5510.
Respectfully, James Barstow Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC
Attachment:
Response to Request for Additional Information cc: Regional Administrator, Region I, USNRC USNRC Senior Resident Inspector, OCNGS Project Manager [OCNGS] USNRC
ATTACHMENT Response to Request for Additional Information
ATTACHMENT Response to Request tor Additional Information Page 1 By letter dated January 7, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. Ml 14028A579), Exelon Generation Company, LLC (Exelon or the licensee) submitted Requests for Relief R-44 and R-45 from the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code),Section XI for Oyster Creek Nuclear Generating Station (Oyster Creek). The requests for relief apply to the fourth 10-year inservice inspection (ISi) interval, in which the licensee adopted the 1995 Edition through the 1996 Addenda of ASME Code Section XI as the code of record.
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the Relief Requests R-44 and R-45, and has determined that a request for additional information (RAI) is needed to complete its technical review. The NRC staff's RAls are listed below.
Question:
2.1 Request for Relief R-44, Part A, Examination Category 8-A, Items 81 .12, 81 .21, 81 .22, and 81 .40, Pressure Retaining Welds in Reactor Vessels 2.1.1 The ASME Code states that essentially 100% of the "accessible length" of the subject welds must be examined. Please state the accessible length of each of the reactor pressure vessel circumferential and meridional head welds, and clarify whether the volumetric coverage percentages obtained are applicable to the accessible length, as opposed to the entire length of the weld.
Response
The volumetric coverage percentages obtained are applicable to the entire weld length.
Essentially 100% of the accessible length was examined for all welds listed in Table 1. Relief for the Examination Category 8-A, Items 81 .21 and 81 .22 is withdrawn. Relief still applies to Items 81 .12 and 81 .40 because the "accessible length" requirement does not apply to these Items. See Table 1 below for the welds that remain applicable to this relief request.
Question:
2.1.2 Fully clarify the wave modality and insonification angles used for all ultrasonic examinations, if not already provided.
Response
See Table 1 below.
ATTACHMENT Response to Request for Additional Information Page 2 Table 1 Shear mode, L = Longitudinal mode Weld Descriotion Coveraae Item Anale Mode NR02 1-574 Reactor Head to 58°/o 81.40 45S.60L Flanqe NR02 2-5630 Upper Intermediate 64.3% I 81.12 45S, 70L Shell Course NR02 2-563E Upper Intermediate 67.6% 81.12 45S, 70L Shell Course NR02 2-563F Upper Intermediate 53% 81.12 45S, 70L Shell Course NR02 2-564A Lower Intermediate 50.7% 81.12 45S, 70L Shell Course NR02 2-564C Lower lnterme 49.4% 81 .12 45S, 70L Shell Cours-NR02 2-5640 Lower Shell Course 55.2% 81 .12 45S, 70L Assemblv NR02 2-564E Lower Shell Course 48.3% 81 .12 45S, 70L Assembly NR02 2-564F Lower Shell Course 67.9% 81 .12 45S, 70L Assembly Question:
2.2 Request for Relief R-44, Part 8, Examination Categorv 8-D, Items 83.90 and 83.100, Full Penetration Welded Nozzles in Vessels 2.2.1 Fully clarify the wave modality and insonification angles used for all ultrasonic examinations, if not already provided.
Response
See Table 2 below.
ATTACHMENT Response to Request for Additional Information Page 3 Table 2 Shear mode, L Longitudinal mode Weld Description Coverage Item Angle Mode NR02 3-565A N1A Recirc Outlet 45.2% 83.90 45S,60L Nozzle NR02 3-5658 N18 Recirc Outlet 45.2% 83.90 45S,60L Nozzle NR02 3-565C N1C Recirc Outlet 22% 83.90 45S,60L, 70L,60S Nozzle NR02 3-5650 N1O Rec ire Outlet 22% 83.90 45S,60L, 70L,60S Nozzle NR02 3-565E N1 E Recirc Outlet 47.9% 83.90 45S,60L Nozzle NR02 6-566A N3A Main Steam Nozzle 52.9% 83.90 45S,60L 02 6-5668 N38 Main Steam Nozzle 52.9% 83.90 45S,60L NR02 4-566A N4A Feedwater Nozzle 51.8% 83.90 60L NR02 4-5668 N48 Feedwater Nozzle 52.5% 83.90 60L NR02 4-566C N4C Feedwater Nozzle 49.5% 83.90 60L NR02 4-5660 N40 Feedwater Nozzle 52.5% 83.90 60L NR02 2-566A N5A Isolation 29% 83.90 45S,60L, 70L,60S Condenser Nozzle I NR02 2-566A N5A Isolation Condenser 78.9% 83.100 60S,65S, 70S Nozzle Inner Radius NR02 2-5668 N58 Isolation 22% 83.90 45S,60L, 70L,60S Condenser Nozzle NR02 2-5668 N58 Isolation Condenser 68.8% 83.100 60S,65S, 70S Nozzle Inner Radius NR02 2-567A N6A Core Spray Nozzle 28.1% 83.90 45S,60L NR02 2-567A N6A Core Spray Nozzle 44% 83.100 45S,60L Inner Radius NR02 2-5678 N68 Core Spray Nozzle 61.7% 83.90 45S,60L NR02 2-5678 N68 Core Spray Nozzle 60.9% 83.100 60S,66S, 70S Inner Radius NR02 1-576 N7A Closure Head 76% 83.90 45S,60S,60L Nozzle NR02 1-576 N7A Closure Head 74% 83.100 60S, 70S,80S Nozzle Inner Radius NR02 3-576 N78 Closure Head 78% 83.90 45S,60S,60L Nozzle NR02 3-576 N78 Closure Head 88% 83.100 60S, 70S,80S Nozzle Inner Radius NR02 5-576 Na Closure Head Nozzle 89% 83.90 60L NR02 6-567 N9 CRO Return Nozzle 69% 83.90 55S,60L
ATTACHMENT Response to Request for Additional Information Page4 Question:
2.3 Request for Relief R-44, Part C, Examination Category 8-F, Item 85.10, Pressure Retaining Dissimilar Metal Welds in Vessel Nozzles 2.3.1 The licensee has provided only general information regarding the impracticality of obtaining ASME Code-required volumetric examinations for Category 8-F, Item 85.10 welds. The statements "OD [outside diameter] safe end configuration," and "Nozzle OD configuration," are inadequate to explain the bases for not obtaining the ASME Code required examination volumes. Please submit detailed and specific information to support the bases for limited examination coverage for each weld in ASME Code, Category 8-F, and therefore, demonstrate impracticality. Include detailed descriptions (written and/or sketches, as necessary) of the interferences to applied nondestructive examination techniques, if not already provided.
Response
Weld NR02 4-565D: Downstream examinations were limited due to the nozzle to safe-end configuration. All scans were limited due to incomplete machining of the corrosion resistant cladding (CRC) on the OD surface. Machining of the OD surface CRC stopped near the weld centerline, and left a step approximately 0.020" to 0.040" in height, 360 degrees. Reference photo page A40 from the January 7, 2014 submittal. During the recent 2014 outage, the step was eliminated and the required examination volume was examined with 100% coverage.
Weld NR02 5-567: Nozzle configuration and CRC geometry limited the scanning. Surface preparation of this weld was limited due to its location close to the bioshield and the adjacent main steam line. See the sketch below for the nozzle configuration and CRC geometry.
configuration geometry
ATTACHMENT Response to Request for Additional Information Page 5 Question:
Please confirm that the required surface examinations were performed for the Category 8-F, Item 85.10 welds, whether these surface examinations were full ASME Code examinations (>90% coverage per Code Case N-460), and describe any indications that were detected.
Response
A surface examination (liquid penetrant) was performed on 100°/o of weld NR02 4-5650 during 1R20 (2004). No indications were recorded during examination.
A surface examination (liquid penetrant) was performed on 100% of weld NR02 5-567 during 1R24 (2012). No indications were recorded during examination.
Question:
2.4 Request for Relief R-45, Part D, Examination Category 8-J, Item 89.11, Pressure Retaining Welds in Piping 2.4. 1 State the materials of construction and the wall thicknesses for all Category 8-J welds and base materials.
Response
The materials of construction, pipe size, and schedule are shown on Table 3 below along with the wave modality and insonification angles.
ATTACHMENT Response to Request for Additional Information Page 6 Table 3 Shear mode, L =Longitudinal mode, SS =Stainless Steel, CS =Carbon Steel.
Weld Description Coverage Item Material Size I Sched I Angle Mode NE-5-0002 Elbow 50% 89.11 SS 10" 45S,60L NE-5-0022A Safe End to Elbow !so% 89.11 SS 10" I 80 45S,60L NG-D-0002 Elbow to Pipe 50% 89.11 SS 26" I 80 45S,60L NE-2-0061 Pipe to Valve V-14-0167 50% 89.11 SS 10" I 80 45S,60L NE-2-0256 Pipe to Valve V-14-0037 50%, 89.11 SS 10" / 80 45S,60L NE-2-0255 V-14-0036 to Pipe 50%~ SS 10" I 80 45S,60L NE-2-0257 V-14-0037 to Pipe 50% SS 10" / 80 45S,60L
~20 Valve to Pipe 50% 89.11 SS 10" / 80 45S,60L 40 Pipe 50% 89.11 SS 10" I 80 45S,60L NE-5-206 Valve to Pipe 50% 89.11 SS 10" / 80 45S,60L NE-5-214 Valve to Pipe 50% 89.11 SS 10" / 80 45S,60L
~~
NU-1-0001 Valve to Pipe SS 14" / 80 45S,60L ND-10-0005 I Pipe to Valve V-16-0063 SS 6" I 80 45S, 70S ND-10-0009 Pipe to Valve 50% 89.11 SS 6" I 80 45S, 70S
\JG-A-0007 Valve to Elbow 50% 89.11 SS 26" / 80 45S,60L
\JG-A-0006 Elbow to Valve 50% 89.11 SS 26" I 80 45S,60L
~G-A-0014 Elbow to Pump 50% 89.11 SS 26" / 80 45S,60L m-A-0018 Elbow to Valve 50% 89.11 SS 26" I 80 45S,60L NG-8-0006 Valve to Elbow 50% 89.11 SS 26" I 80 45S,60L NG-8-0012 Pump to Elbow 50% 89.11 SS 26" I 80 45S,60L NG-8-0005 Pipe to Valve V-37-20 50% 89.11 SS 26" I 80 45S,60L NG-8-0016 Elbow to Valve 50% 89.11 SS 26" / 80 45S,60L NG-C-0005 Valve to Elbow 50% 89.11 SS 26" I 80 45S,60L NG-C-0012 Pump to Elbow 50% 89.11 SS 26" / 80 45S,60L NG-C-0016 Elbow to Valve 50% 89.11 SS 26" / 80 45S,60L NG-C-0004 Pipe to Valve 50% 89.11 SS 26" / 80 45S,60L ND-10-0020 Valve V-16-0061 to Pipe 50% 89.11 SS 6" I 80 45S, 70S ND-1-0029 to Valve 50% 89.11 SS 6" I 80 45S, 70S NE-2-0124 '-* o Valve V-14-0170 50% 89.11 SS 10' I 80 45S,60L NE-2-0254 Pipe to Valve V-14-36 50% 89.11 SS 10' I 80 45S,60L NU-4-0002 Tee to Valve 50% 89.11 SS 10" I 80 45S,60L NG-8-0017 Valve to Pipe 50% 89.11 SS 26" I 80 45S,60L NG-A-0019 Valve to Pipe 50% 89.11 SS 26" I 80 45S,60L ND-1-0209 Valve V-16-0001 to Pipe 50% 89.11 I ;::,;::, 6" I 80 45S, 70S ND-1-0208 Elbow to Valve 50% 89.11 SS 6" I 80 45S, 70S MV-5-001 Flange to Tee 50% 89.11 SS 4" 45S, 70S ND-10-0008 Valve to Elbow 50% 89.11 SS 6" / 80 45S,60L, 70S NG-D-0004 Pipe to Valve 50% 89.11 SS 26" I 80 45S,60L
ATTACHMENT Response to Request for Additional Information Page 7 Weld Description Coverage I Item Material Size I Sched. Angle Mode NG-D-0005 Valve to Pipe 50% 89.11 SS= 26" I 80 45S,60L NG-D-0011 A1 Pump to Elbow WOL 52% 89.11 SS 26" I 80 60L, 25L, Weld Overlav) 70L,OL NG-D-0015 NG-D-0016 NG-D-0022A Elbow to Valve Valve to Pipe Pipe to Safe End 75%
75'%
75°/o illfil 89.11 SS SS SS 26" I 26" I 26" /
80 80 80 45S,60L 45S,60L 45S,60L NG-E-0006 Pipe to Valve 75% 89.11 SS 26" / 80 45S,60L NG-E-0007 Valve to Elbow 50% 89.11 SS 26" / 80 45S, 60L, 45L, 60S NG-E-0016A Elbow to Valve 50% 89.11 SS 26" I 80 45S,60L NG-E-0017 Valve to Pipe 50% 89.11 SS 26" / 80 45S,60L NU-2-0001 Pipe to Valve 50% 89.11 SS 14" / 80 45S,60L
~082 Valve to Elbow 75% 89.11 SS 8" / 80 45S, 70S 0021 Pipe to V-16-61 50% 89.11 SS 6" / 80 45S,60S, 70S NU-3-0006 Valve V-17-54 to Pipe
= 50% 89.11 SS 14" I 80 45S,60L NU-4-0003 NZ-3-0005 NZ-3-0023 NZ-3-0024 Tee to Valve Valve to Tee Pipe to V-20-0150 Valve to Tee 50%
39%
50%
48%
89.11 89.11 89.11 89.11 ff SS 14" I 80 8"/80 8" I 80 45S,60L 45S, 70L 45S, 70L 45S, 70L NZ-3-0028 Elbow to Valve 50% 89.11 SS 8" I 80 45S, 70L 50% .11 SS 8" I 80 45S, 70L B = l v e t o Elbow e to Valve 44% .11 SS 8" I 80 45S, 70L veto Elbow 50% B9.11 SS 8" / 80 45S, 70L veto Tee 43% B9.11 SS 8" / 80 45S, 70L NZ-3-0056 Valve to Elbow 50% B9.11 SS 8" / 80 45S, 70L NZ-3-0070 Valve to Tee 44% B9.11 SS 8" I 80 45S, 70L NZ-3-0076 Pipe to Valve 50% B9.11 SS 8" / 80 45S, 70L NZ-3-0077 Valve to Elbow 45% B9.11 SS 8" I 80 45S, 70L NZ-3-0081 Pipe to V-20-0023 50% B9.11 SS 8" I 80 45S, 70L RF-2-0115 Valve to Pipe 87% .11 cs 18" I 80 45S NZ-3-0004 Pipe to Valve V-20-0015 50% 11 SS 8" I 80 45S,60S, 70S V-1-173 Valve EMRV Valve Body Weld 82% B12.40 cs 6" Inlet 45S Body CD-14-001 B/ Hemi Head to Nozzle 50% C2.21 SS 8" /NA 45S,60L 211-C-6 Weld CD-14-001 B/ Hemi Head to Nozzle 50% C2.21 SS 12" I NA 45S,60L 211-S-6 Weld Question:
2.4.2 Please confirm that the required surface examinations were performed for the Category B-J, Item 89.11 welds, whether these surface examinations were full ASME Code examinations (>90% coverage per Code Case N-460), and describe any indications that were detected.
Response
ATTACHMENT Response to Request for Additional Information Page 8 Oyster Creek Nuclear Generating Station implemented Code Case N-663 during the fourth interval. Therefore, surface examinations were not required on these welds.
Question:
2.4.3 Fully clarify the wave modality and insonification angles used for all ultrasonic examinations, if not already provided. If applicable, state whether shear wave only techniques were used to examine any austenitic weld. The longitudinal wave method has been shown capable of detecting planar inside diameter {ID) surface-breaking flaws on the far-side of austenitic welds. If longitudinal examination methods were not employed, please justify why these techniques were not used as part of a best effort examination to maximize coverage.
Response
See Table 3 above.
Welds ND-10-0005, ND-10-0009, ND-1-0209, ND-1-0208, MV-5-001, ND-10-0020, ND 0021, ND-1-0029 and NZ-3-0004 were examined with only shear wave examination techniques due to the thickness being ::;;0.500". POI procedure demonstration has shown that the 70 degree shear wave technique is appropriate for opposite side flaw detection for thicknesses
- 0.500" when examination scanning is limited to one side of the weld.
Weld RF-2-0115 was examined with only shear waves due to the material being carbon steel.
Note that weld NQ-2-0215 has been withdrawn from this relief as discussed below.
Question:
2.5 Request for Relief R-45, Part E, Examination Category B-M-1, Item 812.40, Pressure Retaining Welds in Valve Bodies 2.5.1 Please state the materials of construction for all valve body welds in Category B-M-1.
Response
The material of construction for all valve body welds in Category B-M-1 is forged carbon steel.
Question:
2.5.2 Fully clarify the wave modality and insonification angles used for all ultrasonic examinations, if not already provided.
Response
The wave modality and insonification angle used for ultrasonic examinations was 45 shear for V-1-173 valve body weld.
Question:
2.6 Request for Relief R-45, Part F, Examination Category C-B. Item C2.21, Pressure
ATTACHMENT Response to Request for Additional Information Page 9 Retaining Nozzle Welds in Class 2 Vessels 2.6.1 The description associated with Category C-B component, Item C2.21, lists the ASME examination type (nozzle to head weld); however, it is not clear to what actual component the nozzle is welded to, or what system is involved. For request for relief Category C-B, Item C2.21 (nozzle-to-head welds), please state the actual component and to what system this weld is associated.
Response
The component is the Isolation Condenser which is part of the Emergency Condenser System.
Question:
2.6.2 Please state the materials of construction and the wall thicknesses for all welds in Examination Category C-B.
Response
The material of construction is stainless steel. Refer to Pages 74 and 75 of Relief Request R-45 for measured thickness.
Question:
2.6.3 Please confirm that the required surface examinations (liquid penetrant or magnetic particle) were performed for the subject welds, whether these surface examinations were full ASME Code examinations (>90% coverage per Code Case N-460), and describe any indications that were detected.
Response
Surface examintations (liquid penetrant) were performed on these Isolation Condenser welds.
No recordable indications were identified.
Question:
- 2. 7 Request for Relief R-45, Part G, Examination Category C-F-1, Item C5.11, Pressure Retaining Welds in Austenitic Stainless Steel or High Alloy Piping 2.7.1 Fully clarify the wave modality and insonification angles used for all ultrasonic examinations. State whether shear wave only techniques were used to examine any austenitic weld. The longitudinal wave method has been shown capable of detecting planar ID surface-breaking flaws on the far-side of austenitic welds. If longitudinal examination methods were not employed please justify why these techniques were not used as part of a best effort examination to maximize coverage.
Response
Refer to Table 3 above. POI procedure demonstration has shown that the 70 degree shear wave technique is appropriate for opposite side flaw detection for thicknesses ::;;0.500" when examination scanning is limited to one side of the wall.
ATTACHMENT Response to Request for Additional Information Page 10 Question:
2.7.2 Please confirm that the required surface examinations {liquid penetrant or magnetic particle) were performed for the subject welds, whether these surface examinations were full ASME Code examinations (>90% coverage per Code Case N-460), and describe any indications that were detected.
Response
Oyster Creek Nuclear Generating Station implemented Code Case N-663 during the fourth interval. Therefore, surface examinations were not required.
Question:
2.8 Request for Relief R-45, Part H, Examination Category C-F-2, Item C5.81, Pressure Retaining Welds in Carbon or Low Alloy Steel Piping For ASME Code Category C-F-2, Item C5.81, Weld NQ-2-0215, only a surface examination is required per IWC-2500. From the drawing and description provided by the licensee, it is unclear why a full surface examination could not be completed on this weld as there are no obstructions or access restrictions listed or shown that would prevent full access to the surface of the weld.
The licensee's drawing appears to indicate that an ultrasonic testing examination, not a surface examination, was performed.
Response
In addition to a surface exam, weld NQ-2-0215 was inadvertently examined with ultrasonic testing during the fourth interval. Accordingly, relief is no longer requested for this weld.
Question:
2.8.1 Please confirm that the required surface examination (liquid penetrant or magnetic particle) was performed for the subject weld, whether these surface examinations were full ASME Code examinations (>90% coverage per Code Case N-460), and describe any indications that were detected.
Response
A surface examination (magnetic particle) was performed on 100% of the required area of weld NQ-2-0215 during 1R20 (2004). No indications were recorded during examination.