LR-N21-0076, Updated Steam Generator Tube Inspection Report - Twenty-second Refueling Outage (2R22) to Reflect TSTF-577 Reporting Requirements
| ML21305A003 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 11/01/2021 |
| From: | Desanctis R Public Service Enterprise Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LR-N21-0076 | |
| Download: ML21305A003 (16) | |
Text
PSEG Nuclear LLC P.O. Box 236, Hancocks Bridge, NJ 08038-0236 LR-N21-0076 November 1, 2021 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington DC 20555-001 Salem Nuclear Generating Station Unit 2 Renewed Facility Operating License No. DPR-75 NRC Docket No. 50-311 0 PSEG Nudear LLC Technical Specification 6.9.1.1 O
Subject:
Updated Steam Generator Tube Inspection Report - Twenty-second Refueling Outage (2R22) to Reflect TSTF-577 Reporting Requirements
References:
- 1. PSEG letter LR-N21-0036, "Application to Revise Technical Specifications to Adopt TSTF-577, 'Revised Frequencies for Steam Generator Tube Inspections,"' dated April 28, 2021 (ADAMS Accession No. ML21118B060)
- 2. NRC Letter, "Salem Nuclear Generating Station, Unit Nos. 1 and 2 -
Issuance of Amendment Nos. 338 and 320 Re: Revise Technical Specifications to Adopt TSTF-577, 'Revised Frequencies for Steam Generator Tube Inspection' (EPID L-2021-LLA-0077)," dated September 3, 2021 (ADAMS Accession No. ML21202A078)
- 3. PSEG Letter LR-N17-0174, "Steam Generator Tube Inspection Report -
Twenty-second Refueling Outage (2R22)," dated November 21, 2017 (ADAMS Accession No. ML17325B055)
- 4. NRC Letter, "Salem Nuclear Generating Station, Unit No. 2 - Review of Steam Generator Tube Inspection Report for the Spring 2017 Refueling Outage 22 (EPID L-2018-LRO-0062)," dated June 1, 2018 (ADAMS Accession No. ML18144A911)
- 5. PSEG Letter LR-N15-0118, "Response to Salem Nuclear Generating Station, Unit 2, Request for Additional Information Re: Spring 2014 Steam Generator Tube Inspections", dated May 21, 2015 (ADAMS Accession No. ML15141A117)
PSEG Nuclear, LLC (PSEG) hereby submits an updated Steam Generator (SG) Tube Inspection Report consistent with the requirements of Technical Specification (TS) 6.9.1.10 as updated by Unit 2 TS Amendment 320 (Reference 2). As documented in Reference 1, an updated SG Tube Inspection Report is required to be submitted within 30 days of implementing the Reference 2 TS amendment. The TS amendment was implemented on October 1, 2021.
LR-N21-0076 Page 2 November 1, 2021 TS6.9.10 The original SG Tube Inspection Report was provided in Reference 3 and reviewed by the NRC as documented in Reference 4.
The following attachments are included in this letter:
Updated Steam Generator Tube Inspection Report TS 6.9.1.1 O 2R22 Service Induced Indications (AVB Wear) 2R22 Service Induced Indications (TSP Wear)
Summary of Condition Monitoring There are no regulatory commitments contained in this letter.
Should you have any questions regarding this submittal, please contact Mr. Brian J. Thomas at (856) 339-2022.
Sincerely, Richard Desanctis Plant Manager - Salem Generating Station Attachments (4) cc:
Mr. D. Lew, Administrator, Region I, NRC Mr. J. Kim, Project Manager, NRC NRC Senior Resident Inspector, Salem Ms. A. Pfaff, Manager IV, NJBNE Corporate Commitment Tracking Coordinator Site Commitment Tracking Coordinator Mr. M. Washington, Chief Inspector - Occupational Safety and Health Bureau of Boiler and Pressure Vessel Compliance
LR-N21-0076 Updated Steam Generator Tube Inspection Report TS 6.9.1.10 LR-N21-0076 UPDATED STEAM GENERATOR TUBE INSPECTION REPORT TS 6.9.1.10 Page 1 of 4 PSEG Nuclear LLC Salem Unit 2 DESIGN AND OPERATING PARAMETERS Salem Unit 2 is a four (4) loop Westinghouse Pressurized Water Reactor (PWR) with AREVA (also known as Framatome) Model 61/19T SGs that incorporate thermally treated Inconel 690 U-tubes. These replacement SGs (RSGs) were placed into service in 2008 which was the start of operating cycle 17. The 61 indicates approximately 6,100 square meters of heat transfer surface area per steam generator, the 19 indicates the approximate tube outside diameter (OD) in millimeters, and the T corresponds to a triangular tube pitch. The RSGs incorporate state-of-the-art features designed to improve reliability and minimize degradation. The thermally treated Inconel Alloy 690 tubing has a nominal OD of 0.750 inch and nominal wall thickness of 0.043 inch.
Industry experience and laboratory testing has shown thermally treated Inconel Alloy 690 to be far more resistant to cracking than the Inconel Alloy 600 tubing found in the original SGs. There are 5048 tubes within each SG fabricated in a triangular pitch. The tubes are hydraulically expanded the full tubesheet depth and seal welded at the tubesheet primary face. Lateral tube bundle support is accomplished using eight, 410 stainless steel (SS) broached tube support plates (TSP). The TSP holes are of a trefoil design with flat lands. The U-bends are supported with 3 sets of anti-vibration bars (AVBs) bent into a V shape. Since a given tube will intersect the same AVB at two separate locations, the AVBs are labeled AV1 through AV6 to segregate the separate hot-leg (HL) and cold-leg (CL) intersections. AV1 is near the upper hot leg TSP, and AV6 is near the upper cold leg TSP. The first 16 rows of tubes have been thermally stress relieved after the bending process to further reduce residual stresses in the U-bend region. A loose parts trapping screen system in installed in each of the SG upper secondary side internals, near the top of the downcomer. See Attachment 2 of Reference 3, for a general summary of the Tube Support Arrangement and Terminology.
At the time of the 2R22 SG inspection outage, the SGs accumulated a total of approximately 8 Effective Full Power Years (EFPY) of operation. Prior to 2R22, all 4 SGs were also inspected in refueling outage 2R20 (April 2014). Between refueling outage 2R20 and 2R22 the SGs were operated approximately 29.8 Effective Full Power Months (EFPM), with a reactor coolant hot leg temperature of approximately 607 degrees Fahrenheit.
PSEG Nuclear LLC has no deviations for Salem Unit 2 of Mandatory or Needed (shall) requirements important to tube integrity from the EPRI Guidelines referenced by NEI 97-06.
SG inspections were performed in accordance with TS 6.8.4.i, Steam Generator Program, during refueling outage 2R22. Each reporting requirement of TS 6.9.1.10 is addressed below (items a through f).
Refer to Attachment 1 of Reference 3 for list of terms (acronyms).
- a. Technical Specification 6.9.1.10.a, The scope of inspections performed on each SG Please refer to response provided in Reference 3 for item 6.9.1.10.a.
LR-N21-0076 UPDATED STEAM GENERATOR TUBE INSPECTION REPORT TS 6.9.1.10 Page 2 of 4
- b. Technical Specification 6.9.1.10.b, The nondestructive examination techniques utilized for tubes with increased degradation susceptibility Please refer to response provided in Reference 3 for item 6.9.1.10.a and 6.9.1.10.c.
- c. Technical Specification 6.9.1.10.c, For each degradation mechanism found:
- 1.
The nondestructive examination techniques utilized; Please refer to response provided in Reference 3 for item 6.9.1.10.a and 6.9.1.10.c.
- 2.
The location, orientation (if linear), measured size (if available), and voltage response for each indication. For tube wear at support structures less than 20 percent through-wall, only the total number of indications needs to be reported; Please refer to response provided in Reference 3 for item 6.9.1.10.d, which provides information including those indications less than 20% through-wall for AVB and TSP wear. Attachments 2 and 3 below provides supplemental voltage response information for AVB and TSP wear, equal to or greater than 20% through-wall.
- 3.
A description of the condition monitoring assessment and results, including the margin to the tube integrity performance criteria and comparison with the margin predicted to exist at the inspection by the previous forward-looking tube integrity assessment; Please refer to response provided in Reference 3 for item 6.9.1.10.g, and supplemental information provided in Attachment 4 below.
- 4.
The number of tubes plugged during the inspection outage; and Please refer to response provided in Reference 3 for item 6.9.1.10.e.
- d. Technical Specification 6.9.1.10.d, An analysis summary of the tube integrity conditions predicted to exist at the next scheduled inspection (the forward-looking tube integrity assessment) relative to the applicable performance criteria, including the analysis methodology, inputs, and results.
The Operational Assessment from the 2R22 outage tube inspections allows continued operation up to refueling outage 2R26 (Spring 2023), conservatively assuming 5.5 EFPY of plant operation (2R22 to 2R26, 66 EFPM). A full bundle probabilistic model for AVB Wear results in a Probability of Burst (POB) of 2.9% or less, and well less than the requirement of 5%. A deterministic analysis was provided for TSP and SPT wear. For TSP wear, a conservative beginning of service (Return to service) flaw size of 23.5%TW with assumed LR-N21-0076 UPDATED STEAM GENERATOR TUBE INSPECTION REPORT TS 6.9.1.10 Page 3 of 4 growth/wear rate of 5%TW per EFPY (for 5.5 EFPY), results in a bounding projected flaw size of 51%TW which is below a conservative structural depth of 52%TW. Similarly for SPT, a conservative beginning of service (Return to service) flaw size of 22.6%TW with assumed growth/wear rate of 5%TW per EFPY (for 5.5 EFPY), results in a bounding projected flaw size of 50.1%TW which is below a conservative structural depth of 53.6%TW. The maximum growth/wear rates for TSP and SPT are 4.01%TW/EFPY and 4.16%TW/EFPY, respectively and the estimated EFPY between start of cycle 23 to outage 2R26 is closer to 5.4 EFPY. In summary, these results provide reasonable assurance the performance criteria will not be challenged.
- e. Technical Specification 6.9.1.10.e, The number and percentage of tubes plugged to date, and the effective plugging percentage in each SG.
Please refer to response provided in Reference 3 for item 6.9.1.10.f.
- f. Technical Specification 6.9.1.10.f, The results of any SG secondary side inspections In each SG, following top of tubesheet (TTS) water lancing (sludge lancing), visual inspections and Foreign Object Search and Retrieval (FOSAR) were performed at the top of tubesheet. These inspections included the full length of the no tube lane (area between row 1 tubes), some inner bundle inspections (both HL and CL), and around the annulus tube areas (shell-to-tube bundle region, including periphery tubes). The annulus / periphery tubes inspection included view into the bundle (from the annulus region) allowing inspection between the periphery tubes into the bundle. The purpose of these inspections was to identify and remove foreign material and to assess the effectiveness of the water lancing. Visual inspections of the SGs TTS showed that water lancing was successful in removing most of the TTS deposits (sludge, hard deposits, and foreign material). Approximately 255 pounds of TTS deposits were removed from all four SGs (total). No eddy current possible loose parts (PLPs) were reported in outage 2R22 and there were no loose parts wear identified on any tube.
The upper steam drums, in all four SGs, were also inspected and FOSAR was performed for objects located on the loose part trapping screens. All steam drum components including internal fasteners for the internal manways and camera ports, various feedring locations, inside the feedring (J-nozzles), moisture separator equipment, flow restrictor/steam outlet nozzles, and other internal supports were visually inspected during 2R22 in all four SGs. No conditions adverse to quality were identified (also see discussions below for camera port nuts). Some foreign material was located on the internal SG loose part trapping screens, and removed. Foreign material removed from the loose parts trapping screens are summarized as few pieces of flexitallic material, graphite gasket material, foil like pieces, weld material, feedwater heater plug parts (bolt, washer, nut).
During the upper internals inspections all the fasteners of the internal manway hatches and camera ports were inspected. As discussed in item 5 of Reference 5, there are 2 inaccessible nuts evaluated for use-as is. During outage 2R22, PSEG conservatively attempted to use a new specialized tool to torque two inaccessible nuts (one nut in SG21 and one nut in SG22) on the camera inspection ports. The nut in SG22 was accessible with the new specialized tool, and torqued accordingly. The nut on the camera port in SG21 was still inaccessible, and remains LR-N21-0076 UPDATED STEAM GENERATOR TUBE INSPECTION REPORT TS 6.9.1.10 Page 4 of 4 acceptable for use-as is. A loose camera port nut was found identified in SG23, and was evaluated which determined the prior attempt in outage 2R18 to apply the proper torque was likely complicated by an interface which provided inaccurate torque reading for the nut. This nut was re-torqued accordingly during 2R22, and all other nuts for these closures in the SGs were inspected and remain secure.
LR-N21-0076 2R22 SERVICE INDUCED INDICATIONS (AVB WEAR)
%TW SUPPORT Voltage 21 58 76 21 AV4 0.52 21 58 76 21 AV5 0.50 21 66 48 22 AV4 0.55 21 66 68 23 AV4 0.58 21 67 53 21 AV3 0.49 21 67 53 21 AV4 0.50 21 68 64 21 AV4 0.49 21 69 61 22 AV4 0.54 21 69 61 20 AV5 0.45 21 69 63 28 AV3 0.91 21 69 63 25 AV4 0.69 21 70 56 20 AV3 0.46 21 70 56 20 AV4 0.47 21 70 56 25 AV5 0.68 21 71 65 21 AV3 0.50 21 72 64 24 AV3 0.65 21 72 64 22 AV4 0.54 21 72 70 20 AV3 0.49 21 72 70 23 AV4 0.62 21 73 65 22 AV3 0.57 21 75 67 22 AV4 0.54 21 75 69 20 AV5 0.47 21 76 60 25 AV3 0.69 21 77 57 20 AV3 0.48 21 77 57 23 AV5 0.62 21 78 62 20 AV2 0.48 21 78 62 23 AV3 0.59 21 78 62 21 AV4 0.51 21 80 60 24 AV3 0.67 21 82 68 22 AV4 0.55 21 82 74 24 AV5 0.65 21 83 67 20 AV4 0.45 21 84 58 21 AV4 0.52 21 84 58 25 AV5 0.69 21 84 80 21 AV5 0.51 21 87 65 23 AV4 0.60 21 89 57 25 AV4 0.73 21 90 56 23 AV4 0.61 LR-N21-0076 2R22 SERVICE INDUCED INDICATIONS (AVB WEAR)
%TW SUPPORT Voltage 21 91 59 21 AV2 0.52 21 91 59 21 AV4 0.51 21 92 58 21 AV3 0.52 21 92 58 24 AV4 0.63 21 94 62 22 AV2 0.56 21 94 62 28 AV3 0.85 21 94 62 24 AV5 0.64 21 96 60 27 AV4 0.84 21 96 60 25 AV5 0.69 21 99 59 31 AV4 1.10 21 99 65 21 AV3 0.52 21 101 59 22 AV3 0.54 21 101 59 23 AV4 0.60 22 60 74 20 AV2 0.48 22 62 52 29 AV4 0.96 22 62 52 27 AV5 0.80 22 62 62 24 AV4 0.64 22 62 62 22 AV5 0.56 22 64 64 21 AV2 0.53 22 64 64 23 AV5 0.60 22 65 67 25 AV4 0.70 22 65 67 20 AV5 0.48 22 66 60 25 AV3 0.67 22 66 60 21 AV4 0.52 22 67 61 25 AV3 0.72 22 67 61 20 AV4 0.49 22 67 61 24 AV5 0.62 22 68 60 23 AV3 0.58 22 70 64 21 AV2 0.52 22 71 63 22 AV3 0.55 22 71 63 24 AV4 0.64 22 71 65 24 AV4 0.65 22 72 58 27 AV4 0.81 22 73 77 20 AV5 0.45 22 76 54 25 AV4 0.71 22 77 63 22 AV3 0.56 22 77 63 21 AV4 0.53 22 79 59 23 AV5 0.62 22 79 63 21 AV3 0.49 22 79 63 21 AV4 0.52 LR-N21-0076 2R22 SERVICE INDUCED INDICATIONS (AVB WEAR)
%TW SUPPORT Voltage 22 81 57 20 AV3 0.47 22 81 57 20 AV4 0.47 22 81 69 23 AV3 0.58 22 82 74 22 AV2 0.55 22 89 53 22 AV4 0.54 22 89 59 23 AV2 0.59 22 91 59 20 AV4 0.49 22 91 59 25 AV5 0.68 22 92 50 23 AV4 0.62 22 92 54 26 AV4 0.73 22 92 54 29 AV5 0.94 22 93 57 20 AV4 0.46 22 93 65 23 AV5 0.61 22 95 55 29 AV3 0.96 22 95 57 22 AV4 0.54 22 95 57 24 AV5 0.64 22 95 61 30 AV3 1.03 22 95 61 26 AV4 0.75 22 98 58 21 AV3 0.50 22 98 58 20 AV4 0.46 22 98 78 26 AV2 0.75 23 67 61 23 AV3 0.61 23 67 61 22 AV4 0.54 23 75 73 21 AV5 0.53 23 77 73 25 AV4 0.69 23 83 67 27 AV5 0.82 23 88 64 21 AV3 0.52 23 88 64 33 AV4 1.29 23 91 63 29 AV5 0.97 23 91 73 21 AV2 0.52 23 92 56 21 AV4 0.50 23 92 56 20 AV5 0.48 23 92 62 30 AV4 1.04 23 95 51 22 AV5 0.54 23 102 64 33 AV5 1.31 24 53 53 24 AV4 0.66 24 53 53 21 AV5 0.51 24 59 73 20 AV4 0.47 24 70 68 22 AV3 0.56 24 70 68 25 AV4 0.67 LR-N21-0076 2R22 SERVICE INDUCED INDICATIONS (AVB WEAR)
%TW SUPPORT Voltage 24 73 61 22 AV3 0.56 24 76 62 22 AV3 0.55 24 76 62 23 AV4 0.59 24 77 73 30 AV4 1.07 24 77 73 30 AV5 1.03 24 79 65 25 AV4 0.72 24 80 60 20 AV5 0.49 24 81 67 22 AV2 0.55 24 81 67 21 AV4 0.50 24 81 67 21 AV5 0.52 24 82 64 20 AV5 0.48 24 85 57 20 AV4 0.45 24 92 76 22 AV2 0.56 24 96 64 21 AV4 0.50 24 98 52 24 AV2 0.66 24 100 76 22 AV2 0.55 24 101 53 22 AV5 0.54 24 101 69 21 AV2 0.50 24 101 69 26 AV4 0.77 24 102 70 29 AV2 0.94 21 58 76 21 AV4 0.52 21 58 76 21 AV5 0.50 21 66 48 22 AV4 0.55 21 66 68 23 AV4 0.58 21 67 53 21 AV3 0.49 21 67 53 21 AV4 0.50 21 68 64 21 AV4 0.49 21 69 61 22 AV4 0.54 21 69 61 20 AV5 0.45 21 69 63 28 AV3 0.91 21 69 63 25 AV4 0.69 21 70 56 20 AV3 0.46 21 70 56 20 AV4 0.47 21 70 56 25 AV5 0.68 21 71 65 21 AV3 0.50 21 72 64 24 AV3 0.65 21 72 64 22 AV4 0.54 21 72 70 20 AV3 0.49 21 72 70 23 AV4 0.62 21 73 65 22 AV3 0.57 LR-N21-0076 2R22 SERVICE INDUCED INDICATIONS (AVB WEAR)
%TW SUPPORT Voltage 21 75 67 22 AV4 0.54 21 75 69 20 AV5 0.47 21 76 60 25 AV3 0.69 21 77 57 20 AV3 0.48 21 77 57 23 AV5 0.62 21 78 62 20 AV2 0.48 21 78 62 23 AV3 0.59 21 78 62 21 AV4 0.51 21 80 60 24 AV3 0.67 21 82 68 22 AV4 0.55 21 82 74 24 AV5 0.65 21 83 67 20 AV4 0.45 21 84 58 21 AV4 0.52 21 84 58 25 AV5 0.69 21 84 80 21 AV5 0.51 21 87 65 23 AV4 0.60 21 89 57 25 AV4 0.73 21 90 56 23 AV4 0.61 21 91 59 21 AV2 0.52 21 91 59 21 AV4 0.51 21 92 58 21 AV3 0.52 21 92 58 24 AV4 0.63 21 94 62 22 AV2 0.56 21 94 62 28 AV3 0.85 21 94 62 24 AV5 0.64 21 96 60 27 AV4 0.84 21 96 60 25 AV5 0.69 21 99 59 31 AV4 1.10 21 99 65 21 AV3 0.52 21 101 59 22 AV3 0.54 21 101 59 23 AV4 0.60 22 60 74 20 AV2 0.48 22 62 52 29 AV4 0.96 22 62 52 27 AV5 0.80 22 62 62 24 AV4 0.64 22 62 62 22 AV5 0.56 22 64 64 21 AV2 0.53 22 64 64 23 AV5 0.60 22 65 67 25 AV4 0.70 22 65 67 20 AV5 0.48 LR-N21-0076 2R22 SERVICE INDUCED INDICATIONS (AVB WEAR)
%TW SUPPORT Voltage 22 66 60 25 AV3 0.67 22 66 60 21 AV4 0.52 22 67 61 25 AV3 0.72 22 67 61 20 AV4 0.49 22 67 61 24 AV5 0.62 22 68 60 23 AV3 0.58 22 70 64 21 AV2 0.52 22 71 63 22 AV3 0.55 22 71 63 24 AV4 0.64 22 71 65 24 AV4 0.65 22 72 58 27 AV4 0.81 22 73 77 20 AV5 0.45 22 76 54 25 AV4 0.71 22 77 63 22 AV3 0.56 22 77 63 21 AV4 0.53 22 79 59 23 AV5 0.62 22 79 63 21 AV3 0.49 22 79 63 21 AV4 0.52 22 81 57 20 AV3 0.47 22 81 57 20 AV4 0.47 22 81 69 23 AV3 0.58 22 82 74 22 AV2 0.55 22 89 53 22 AV4 0.54 22 89 59 23 AV2 0.59 22 91 59 20 AV4 0.49 22 91 59 25 AV5 0.68 22 92 50 23 AV4 0.62 22 92 54 26 AV4 0.73 22 92 54 29 AV5 0.94 22 93 57 20 AV4 0.46 22 93 65 23 AV5 0.61 22 95 55 29 AV3 0.96 22 95 57 22 AV4 0.54 22 95 57 24 AV5 0.64 22 95 61 30 AV3 1.03 22 95 61 26 AV4 0.75 22 98 58 21 AV3 0.50 22 98 58 20 AV4 0.46 22 98 78 26 AV2 0.75 23 67 61 23 AV3 0.61 LR-N21-0076 2R22 SERVICE INDUCED INDICATIONS (AVB WEAR)
%TW SUPPORT Voltage 23 67 61 22 AV4 0.54 23 75 73 21 AV5 0.53 23 77 73 25 AV4 0.69 23 83 67 27 AV5 0.82 23 88 64 21 AV3 0.52 23 88 64 33 AV4 1.29 23 91 63 29 AV5 0.97 23 91 73 21 AV2 0.52 23 92 56 21 AV4 0.50 23 92 56 20 AV5 0.48 23 92 62 30 AV4 1.04 23 95 51 22 AV5 0.54 23 102 64 33 AV5 1.31 23 1
65 20 04C 0.26 23 1
85 23 05C 0.32 LR-N21-0076 2R22 SERVICE INDUCED INDICATIONS (TSP WEAR)
%TW SUPPORT Voltage 23 1
65 20 04C -0.13 0.26 23 1
85 23 05C -0.71 0.32 LR-N21-0076
SUMMARY
OF CONDITION MONITORING Page 1 of 1 Degradation Mechanism Max Depth
%TW Outage 2R22 CM Limit 1
%TW Outage 2R22 Projected 2 Depth %TW From 2R20 to 2R22 AVB Wear 33 46 Note 3 TSP Wear 23 46 35 SPT Wear None 52 51 Note 1 - Conservative limit based on eddy current technique and flaw geometry/model.
Note 2 - Conservative deterministic projection provided by Operational Assessment from prior inspection outage (2R20) assuming 2 cycles of plant operation. Operational Assessment for AVB wear is a Probabilistic methodology.
Note 3 - AVB Wear Full Bundle Probabilistic model for 2 cycles of operation (starting from 2R20) provides probability of survival (POS) of 0.969, 0.976, 0.992, and 0.981 for SG 21 to 24, respectively. Meaning the probability of burst (POB) was projected to be 3.1% or less (i.e. - POB = (1 - POS) x 100), which is well below the requirement of 5%.