ML23242A119

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(Vcsns), Unit 1 - Inservice Inspection (ISI) Owner'S Activity Report (OAR) for Refueling Outage 27
ML23242A119
Person / Time
Site: Summer South Carolina Electric & Gas Company icon.png
Issue date: 08/29/2023
From: Ryan Justice
Dominion Energy South Carolina
To:
Office of Nuclear Reactor Regulation, Document Control Desk
References
23-214
Download: ML23242A119 (1)


Text

Dominion Energy South Carolina V. C. Summer Nuclear Station ~ Dominion Bradham Boulevard & Highway 215, Jenkinsvil le, SC 29065 Mailing Address:

~ Energy P.O. Box 88, Jenkinsville, SC 29065 Dominion Energy.com August29,2023 Document Control Desk Serial No.23-214 U.S. Nuclear Regulatory Commission VCS UC/HK/Rev 0 Washington, DC 20555 Docket No. 50-395 License No. NPF-12 DOMINION ENERGY SOUTH CAROLINA (DESC)

VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT 1 INSERVICE INSPECTION (151) OWNER'S ACTIVITY REPORT (OAR) FOR REFUELING OUTAGE 27 Enclosed is the lnservice Inspection (ISi) Owner's Activity Report (OAR) covering ISi activities associated with the second outage of the third period of the fourth ISi interval (Enclosure 1).

Also enclosed is the Containment lnservice Inspection (CISI) Responsible Engineer Evaluation Report associated with the third outage of the second period of the third CISI interval (Enclosure 2).

This report is submitted pursuant to the American Society of Mechanical Engineers (ASME)

Boiler and Pressure Vessel Code (2007 Edition through 2008 Addenda),Section XI, Rules for lnservice Inspection of Nuclear Power Plant Components, Article IWA-6000, Records and Reports, ASME Code Case N-532-5, Repair/Replacement Activity Documentation Requirements and lnservice Summary Report Preparation and Submission ,Section XI, Division 1, and ASME Code Case N-892, Alternative Requirement for Form OAR-1, Owner's Activity Report, Completion Time Section XI, Division 1.

Should you have any questions, please call Mr. Michael Moore at (803) 345-4752.

V.C . Summer Nuclear Station

Enclosures:

1) lnservice Inspection Owner's Activity Report for Refueling Outage 27, Report Number 26
2) Containment lnservice Inspection - 2023 (RF-27), ASME Section XI, Subsections IWE and IWL, Responsible Engineer Evaluation Report Commitments contained in this letter: None cc: (Without Enclosures Unless Indicated)

G. J. Lindamood - Santee Cooper L. Dudes - NRC Region II G. Miller - NRC Project Mgr.

NRC Resident Inspector

Serial No.23-214 Enclosure 1 VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) Unit 1 DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 ENCLOSURE 1 INSERVICE INSPECTION OWNER'S ACTIVITY REPORT FOR REFUELING OUTAGE 27, REPORT NUMBER 26

Page 1 of 3 FORM OAR-1 OWNER'S ACTIVITY REPORT Report Number_ _ _ _ _ _ _ _ _ _ _ _ _ _l_N_S_E_R_V_IC_E_IN_S_P_E_C_T_IO_N_R_E_P_O_R_T_#_2_6_ _ _ _ _ _ _ _ _ _ _ __

Plant _ _ _ _ _ _ _ _v_._c_.s_U_M_M_E_R_N_U_C_L_EA_R_S_T_A_T_IO_N_,_P_.o_._B_o_x_a_a_,_JE_N_K_l_N_SVI_L_LE_,_s_c_z_g_o_ss_ _ _ _ _ _ _ __

Unit No, ______U_N_I_T_1______ Commercial service date ___J_A_N_U_A_R_Y_1_*_1_9_8_4_ _ Refueling outage no. _ _R_F_-2_7_ _

(if applicable)

Applicable inspection interval _ _ _ _ _ _ _ _ _ _ _ _ _ _ Is.,..,I_-...,In,....t...,.e_rv_a,....I4_;_C_I_S_J_-_ln_te_rv_a_l3_ _ _ _ _ _ _ _ _ _ _ _ __

(1st,. 2nd, 3rd, 4th, other)

Applicable inspection period _ _ _ _ _ _ _ _ _ _ _ _ _ _ _IS_I-_P_e_r_io_d_3_;C_IS_I_-_P_.e_r_io_d_2 _ _ _ _ _ _ _ _ _ _ _ _ _ __

(1st, 2nd, 3rd)

Edition and Addenda of Section XI applicable to the inspection plans _ _ _ _ _ _ _2_0_0_7_E_d_ili_*o_n_t_hr_o_u_g_h_2_00_B_A_dd_e_n_d_a_ _ _ _ __

Date and revision of inspection plans _ _ _ _ _ _ _ _IS_I_-_0_4_12_4_1_2_02_3_R_e_vi_s*_1o_n_3_D--';_C_I_S_I-_11_/_04_/_2_0_22_R_e_vl_si_o_n_3_F_ _ _ _ _ _ __

Edition and Addenda of Section XI applicable to repair/replacement activities, if different than the inspection plans NIA Code Cases used for inspection and evaluation: _ _ _ _ _ _ _ _ N_-5_3_2_-5_,_N_-_5_7_8-_1_,_N_-_58_6...,*_1_,N_-_7_6_5_,N_-7_7_0_-5_,_N_*-_89_2_ _ _ _ _ _ __

(if applicable)

CERTIFICATE OF CONFORMANCE I certify that (al the statements made in this report are correct; {bl the examinations and tests meet the Inspection Plan as required by the ASME Code,Section XI; and (cl the repair/replacement activities and evaluations supporting the completion of RF-27 conform (refueling ~utage number) to the requirements of the ASME Code,Section XI.

Signed,_..,~=--*-"'--*__,__~ __

  • _ _ _ _n, __s_u~pe_lVl~:s_o~r,_Nu_o_le_ar_En~gi_ne_e_rin~g~l~SI~*-nd_N~D_E_P_r~og~ra~_m_s_ Date _ _ _ _ _-=.0.::;8/c:2::21:.::2::.:0:;.::2:;.::3c___ _ _ _ _ _ _ __

(Owner or Owner's Designee, Title)

CERTIFICATE OF INSERVICE INSPECTION I, the undersigned,holding a valid commission issued by the National Board of Boiler and Pressure Vessel Inspectors and emplqyed by The Hartford Steam Boiler Inspection and Insurance Company of _ _ _..,H.:.;a:::rtc::i-=-o.:.:rd::.,,..:C::.:o::.:n.:cn.:.:e:.::cc::li-=-c=:cut::......_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

have inspected the items described in this Owner's Activity Report and state that, to the best of my knowledge and belief, the Owner has performed all activities represented by this report in accordance with the requirements of the ASME Code,Section XI.

By signing this certificate,. neither the Inspector nor his employer makes any warranty, expressed or implied, concerning the repair/replacement activities and evaluations described in this report. Furthermore, neither the Inspector nor his employer shall be liable in any manner for any personal injury or property damage or loss of any kind arising from or connected with this inspection.

---,~~.,,.~--'P,...,,,.._$.--:-~-,-A_-:s

/Ji:pector's Signature)

____ Comrnission _ _ _ _ _ _ _N_B_#_1_3_10_4_C_-_I-_N-_R_ _ _ _ _ _ _ _ _ _ _ __

(National Board Number and Endorsement)

(07/15)

Page 2of3 FORM OAR-1 OWNER' S ACTIVITY REPORT (Cont'd)

Table 1 Items With Flaws or Relevant Conditions That Required Evaluation for Continued Service Examination Category Item and Flaw or Relevant Evaluation Description and Item Number Condition Description F-A MK-SIH-0395 SIH-0395 support is a spring can with a 1/2" hanger rod, weldless F1.10C Spring Can Support, eye nut, and pipe strap. The maximum load on the support is a Loose jam nut downward 349 lb. load (normal case). The weldless eye nut requires the use of a jam nul During the inspection, this jam nut was noted to be loose. Adequate thread engagemen t {minimum 1 full thread beyond internal threaded member per 321-001 sh, 32) of the rod to the weldless eye nut was confinned.

Since proper thread engagement was confirmed, support will adequately support pipe loads. Recommend tightening jam nut in accordance with MMP-300.001.

F-A MK-SIH-0218 SIH-0218 support is a W4 beam spanning between two hanging F1.20A Rigid Support, rods with a maximum downward load of 1432 lb. {upset case). One Bent turnbuckle and rod rod is3/4" and the other is 5/8". The rod that is bent is the 5/8" rod.

It is a Bergen Paterson.133A. A welding clevis {BP part#S-216) is used for connection to the W4 beam. The 5/8" rod and welding clevis are rated for 1810 lbs. per BP catalog (1MS-94B-1154).

Review of the support calculation shows a load on this rod (rod farthest away from 6" pipe) is approximately 400 lbs.

Load on the rod and clevis are approximately 22% of the allowable capacity of the components. The bent portions of the rod and clevis have adequate structural capacity to support the pipe loads.

F-A MK-CSH-0120 The clevis acts as the load bearing piece on this tension only F1.20C Spring Can Support, support .and the support is still performing its design function. No Loose jam nut other issues were noted during the inspection and the variable spring load was as expected. The jam nut should be tightened to ensure that the clevis does not back out and result in loss of pre-load ofthe support.

R-A RHR Mixing Tee Welds The postulated circumferential and axial flaw size of 0.108 depth MRP-192 2-2522A-13, pipe to tee weld by 4.5" length h.ave been shown to meet the requirements of 2-2522A-14, tee to pipe weld ASME Section XI, Non-Mandatory Appendix C, Article C-5000 for

'A' RHR Mixing Tee locations for an additional 18 months of Weld 13 exhibited multiple operation after being placed back in service during the current liner indications with RFO (RF-27). The areas of possible craze cracking which are characteristics of thermal shallow with unquantifiable depth, were also shown to meet the fatigue crazing. acceptance standard.s of IWB-3514 when conservatively assumed to be one continuous flaw having a maximum depth equal to the Weld 14 has a prominent minimum detectible flaw size for1:he NDE technique used.

linear indication with planar Therefore, the piping remains fully capable of performing its characteristics. design basis function, with no challenges to structural integrity, and is acceptable for continued service until additional inspections/repairs cari be performed during the next scheduled refuelirn:i outaqe, per the provisions IWB-3640.

Page 3 of3 FORM OAR-1 OWNER'S ACTIVITY REPORT (Cont'd)

Table 1 (Cont'd)

Items With Flaws or Relevant Conditions That Required Evaluation for Continued Service Examination Category Item and Flaw or Relevant Evaluation Description and Item Number Condition Description F-A MK-EFH-0067 Issue 1: The inner nut is a full size nut and is structurally capable F1.30C Spring Can Support, of transferring load into the steel angle. The condition at present Loose nut on threaded rod, does not degrade the functionality of the support.

misalignment, Outside cold/hot settings Issue 2: The spring can assembly misalignment does not adversely impact the ability of the spring hanger to support the piping system. The spring can is tension only support and the tensile load in the rod/spring can is not impacted by the minor misalignment.

Issue 3: The spring cans are outside (high) of the hot load setting.

The spring can is supporting the piping in the current condition and has no adverse impact on the piping system.

Conclusion:

The support is a deadweight only support and is still supporting the deadweight of the piping system as designed. The spring support is not credited in the piping analysis for Upset/Emergency loading conditions arid therefore there is no impact on the capability of the EF system to withstand a seismic event or system transient.

EFH-067 remains capable of providing support function in the condition identified in CR1222779.

Table 2 Abstract of Repair/Replacement Activities Required for Continued Service Code Class Item Description Description of Work Date Repair/Replacement Completed Plan Number None None None None None

Serial No.23-214 Enclosure 2 VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) Unit 1 DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 ENCLOSURE2 CONTAINMENT INSERVICE INSPECTION-2023 (RF-27)

ASME SECTION XI, SUBSECTIONS IWE AND IWL RESPONSIBLE ENGINEER EVALUATION REPORT

CONTAINMENT INSERVICE INSPECTION-20 23 (RF-27)

ASME SECTION XI, SUBSECTIONS IWE AND IWL RESPONSIBLE ENGINEER EVALUATION REPORT CONTAINMENT INSERVICE INSPECTION - 2023 (RF-27)

ASME SECTION XI, SUBSECTIONS IWE AND IWL VIRGIL C. SUMMER NUCLEAR STATION RESPONSIBLE ENGINEER EVALUATION REPORT May 10, 2023 Prepared By:

Shawn P. Sweigart, P.E.

IWE/ IWL Responsible Engineer Page 1 of 10

CONTAINMENT INSERVICE INSPECTION -2023 (RF-27)

ASME SECTION XI, SUBSECTIONS IWE AND IWL RESPONSIBLE ENGINEER EVALUATION REPORT Table of Contents 1 INTRODUCTION ................................................................................................................3 2 SCOPE ................................................................................................................................3 3 INSPECTION PERSONNEL ..............................................................................................4 4 IWE / IWL INSPECTIONS ..................................................................................................4 5 INSPECTION PHILOSOPHY .............................................................................................4 6 RESPONSIBLE ENGINEER EVALUATION ......................................................................4 6.1 IWE Evaluation ........................................................................................................................4 6.1.1 IWE Augmented Examinations .............................................................................................. 5 6.1.2 Other IWE Inspection Results ............................................................................................... 7 6.1.3 IWE Reportable Conditions .................................................................................................... 7 6.1.4 IWE Reportable Conditions Requiring Augmented Examination ....................................... 7 6.2 IWL Evaluation ........................................................................................................................ 7 6.2.1 IWL Augmented Examination ................................................................................................ 8 6.2.2 IWL Prestress Tendon System Evaluation ........................................................................... 9 6.2.3 IWL Containment Exterior Concrete Surfaces ..................................................................... 9 6.2.4 IWL Reportable Conditions .................................................................................................... 9 6.2.5 IWL Reportable Conditions Requiring Augmented Examination ...................................... 9 7

SUMMARY

AND CONCLUSION S ..................................................................................... 9 Page 2 of 10

CONTAINMENT INSERVICE INSPECTION -2023 {RF-27)

ASME SECTION XI, SUBSECTIONS IWE AND IWL RESPONSIBLE ENGINEER EVALUATION REPORT 1 INTRODUCTION This report evaluates the Containment In-service Inspections which were conducted in accordance with the requirements of 10CFR50.55a paragraphs (g)(4), (b)(2)(viii), and (b)(2)(ix) at the Virgil C. Summer Nuclear Station (VCSNS) during the period of April through May 2023.

2 SCOPE The Containment In-service Inspection (CISI) Program Plan (ISE-4) details the requirements for the examination and testing of ASME Section XI Class MC and Class CC components at the VC Summer Nuclear Station (VCSNS). This Program Plan was developed in accordance with the requirements of the 2007 Edition (with Addenda through 2008) of the ASME Boiler and Pressure Vessel Code,Section XI, Division 1, Subsections IWE and IWL, as modified by NRC final rulemaking to 10 CFR 50.55a published in the Federal Register on November 5, 2014.

This Program Plan was developed using the guidance of "Containment Inspection Program Guide, (ASME Section XI, Subsections IWE and IWL)", EPRI document GC-110698.

The components subject to ASME Section XI, Subsection IWE and IWL requirements are those that make up the containment structure, its leak-tight barrier (including integral attachments),

and those that contribute to its structural integrity.

Specifically included are Class MC pressure retaining components and their integral attachments, (including metallic shell and penetration liners of Class CC pressure retaining components and their integral attachments), per IWE-1100; and Class CC reinforced concrete containments and post-tensioning systems, per IWL-1100.

The terms "Class MC" and "Class CC" are used in Section XI to identify components which meet the functional definitions in IWE-1100 and IWL-1100; however, these terms should not be equated with components and items that are designed per ASME Section Ill, Class MC and Class CC requirements. Typically, the scope of components and items subject to ASME Section Ill for Class MC containment vessels and Class CC pre-stressed and reinforced concrete containments extends beyond that of ASME Section XI, Subsections IWE and IWL.

This Program Plan is effective from January 1, 2017 to December 31, 2026 for Subsection IWE and Subsection IWL activities. IWE and IWL inspections will be performed according to the schedules shown on Table 4.1.2.4-1 and Table 4.2.2.4-1 of ISE-4, respectively.

This report includes Period 2 IWE and IWL Inspections performed during the planned refueling outage (RF-27) in the spring of 2023.

The scope of inspection was in accordance with the ISE-4 RF-27 Outage Plan for Interval 3, Period 2 and included the following component inspections identified in ISE-4 and shown on the ISi drawings listed in ISE-4, Appendix A:

  • Containment Liner, Penetrations, and Penetration Bolting
  • Hatches, Transfer Tube, and Airlocks
  • Valve Chambers and Guard Pipes for RHR and RB Spray at EL. 397' Auxiliary Building (Augmented)
  • Concrete Tendon Access Gallery (General and Augmented)

The Surveillance Test Procedure STP-803.006, "IWE and IWL Visual Examination" defines the Page 3 of 10

CONTAINMENT INSERVICE INSPECTION-20 23 (RF-27)

ASME SECTION XI, SUBSECTIONS IWE AND IWL RESPONSIBLE ENGINEER EVALUATION REPORT requirements for the Visual Examinations in accordance with ASME Section XI for IWE and IWL.

Design Guideline ST-07, "Containment In-service Inspection Evaluation Criteria", was also developed to support this program and provides Engineering Services personnel the inspection criteria used to identify degradation mechanisms requiring documentation as "Recordable Indications". Also included are descriptions of suspect conditions which require evaluation and resolution by the Responsible Engineer.

3 INSPECTION PERSONNEL IWE inspections were conducted by or under the supervision of the ISI-NDE Containment In-service Inspection (CISI) Coordinator, J. Hamilton. Each inspector has been qualified to the requirements of the VCSNS CISI Program Plan, ISE-4.

The IWE/ IWL Responsible Engineer, Shawn Sweigart has BS and MS Degrees in Civil Engineering, with 11 years of experience in the design/construction of nuclear fuel plants and nuclear power plants and four years at VC Summer Nuclear Power Station. The Responsible Engineer is qualified to DQR-PGM-ISI-VC-CTMT and is a Registered Professional Engineer in the State of South Carolina (License Number 31145).

4 IWE / IWL INSPECTIONS The 2023 IWE and IWL inspections were conducted as an ongoing assessment of the condition of the Reactor Building (i.e., containment) structure. The RF-27 IWE/ IWL inspections were started in April 2023 and completed in May 2023.

5 INSPECTION PHILOSOPHY The 2021 inspections are part of an ongoing assessment of VCSNS programs which ensure compliance with ASME Section XI Subsections IWE and IWL. Previous inspections have identified areas for augmented examination. The augmented examinations were conducted to determine whether continued degradation had occurred, the extent of the continued degradation, and/or if the degradation had stabilized relative to the results of the previous inspection.

6 RESPONSIBLE ENGINEER EVALUATION Based on the inspections and examinations performed during RF-27, no conditions have been identified by the Responsible Engineer evaluation which are considered to be abnormal degradation or of significance to structural function. Additionally, no new conditions which exceeded the STP-803.006 threshold criteria (i.e., likely to experience accelerated degradation or aging) were identified during this evaluation.

6.1 IWE Evaluation Visual examinations of scheduled IWE components are performed, either directly or remotely, by line of site from available permanent vantage points. Remote viewing equipment (binoculars, cameras, etc.) are utilized where appropriate.

RF-27 IWE inspections include both General Visual and VT-1 examinations performed by qualified inspectors under the direction of CISI Coordinator.

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ASME SECTION XI, SUBSECTION S IWE AND IWL RESPONSIBLE ENGINEER EVALUATION REPORT 6.1.1 IWE Augmented Examinations Augmented Examination of the following components have been conducted since damage/

degradation was identified during the IWE baseline inspections of 2000 (RF-12). The RF-27 Augmented Examinations included issues identified during previous IWE inspections, specifically:

  • RHR and Reactor Building Spray Penetration Guard Pipes Containment Moisture Barrier Integrity All accessible areas of the Containment Moisture Barrier, between the perimeter of the basement floor slab at Elevation 412' and the Containment Liner, were examined by VT-1 during RF-27. The moisture barrier seals the small gap between the perimeter of the concrete floor slab and the containment steel liner plate. This sealant joint has been subject to inspections and maintenance over the years because it has been observed that minor degradation has occurred at the sealant detail along with some light rusting in localized areas of the RB liner plate (typically where the sealant loses adhesion to the liner).

Additionally, the Containment Moisture Barrier has been the subject of NRC Information Notice 2004-09, "Corrosion of Steel Containment and Containment Liner", because typical minor degradation in the sealant and minor rusting on the adjacent liner has been identified at a number of operating nuclear facilities.

None of the inspection findings documented at VCSNS have reduced the capability of the RB liner plate to perform the required design basis function under required loads and conditions.

Containment Moisture Barrier examinations are performed in accordance with the ISE-4 plan and specifically the ASME Code for IWE, Table IWE- 2500-1.

The Augmented Examination of the Containment Moisture Barrier performed during RF-27 identified two (2) locations where the seal had separated from the liner. All examinations were performed under Work Order 88101049481, with degradation documented in CR1224039. The noted locations were reworked under Work Order 88201691476 .

Note that CER-04-1517, CR-08-01993, CR-09-04879, CR-12-05160, CR-14-02363, CR 04864, CR-17-01976, CR-18-04657, CR-20-01168, CR-20-01440, and CR-21-02689 have documented similar observations during previous IWE inspections of the Containment Moisture Barrier. In each case, necessary maintenance actions were taken to rework the seal and return the identified locations to design requirements.

Augmented Examinations will continue during future refueling outages to monitor the Containment Moisture Barrier integrity and ensure fulfillment of its design function; protecting the liner from potential corrosion in areas inaccessible to direct visual examination.

RHR and Reactor Building Spray Guard Pipes The Augmented Examination of the RHR and RB Spray Guard Pipes continues to monitor the issue first identified during the IWE baseline inspections of 2000 (RF-12). Groundwater leaks into the annulus space between the sump guard piping and the surrounding concrete wall pipe sleeve, resulting in degradation of the guard pipe coating and subsequently the exterior carbon steel surface.

The RF-27 Augmented Examination of the "A" Train RHR and RB Spray sump penetration (XRP0325 & XRP0329) guard pipes found continued signs ground water intrusion. Minor rust Page 5 of 10

CONTAINMENT INSERVICE INSPECTION -2023 {RF-27)

ASME SECTION XI, SUBSECTIONS IWE AND IWL RESPONSIBLE ENGINEER EVALUATION REPORT staining was observed on the coated surfaces as well as light rust on uncoated surfaces.

CR1226210 was written to document the observed conditions. Work order 88201695374 was created to re-coat the degraded and suspect areas.

The RF-27 Augmented Examination of the "B" Train RHR and RB Spray sump penetration (XRP0328 & XRP0425) guard pipes found continued ground water intrusion and degradation of the pipe coating and surface. Corrosion was observed on both guard pipes while areas of pitting were observed on XRP0425 at areas with missing coating. CR1225890 was created to document the observed conditions. An engineering evaluation was performed for CR assignment CA 11823284. The evaluation concluded that the pipe wall thickness would be sufficient through Cycle 28 and beyond. Additionally, CR assignment CA 11833626 was written to track re-coating of the degraded and suspect areas. CR1226992 was written to document the presence of degraded coatings and surface rust found on the "B" train spray guard piping during inspection of the XSM0004B isolation valve chamber. The recoating of this area will be tracked by the above referenced CA 11833626.

Note that CR-06-03337, CR-11-03206, CR-12-05536, CR-14-02439, CR-15-05594, CR 02004, CR-18-05192, and CR-20-01583 have documented similar observations during previous IWE inspections of the RHR and RB Spray guard piping.

Augmented Examinations will continue during future refueling outages to monitor the condition of the guard piping and ensure fulfillment of design function, providing containment integrity under required loads and conditions.

Historical Background on Guard Pipes The exterior surface of the four carbon steel guard pipes within each penetration sleeve were cleaned, prepared, and recoated during RF-20 (2012). The degraded surface of each guard pipe was visually inspected by borescope prior to and after recoating. Borescope inspections were performed during subsequent RF-21, RF-22, and RF-23 outages.

During RF-24, the Augmented Examination of the RHR and RB Spray guard pipes found that the "B" Train RHR and RB Spray sump penetrations (XRP0425, XRP0328) exhibited the greatest quantity of groundwater in-leakage and therefore an elevated degree of coating degradation and observable corrosion. Penetrations associated with the "A" Train RHR and RB Spray piping (XRP0329, XRP0327) were relatively dry with minimal areas of observable corrosion.

Condition Report CR-18-05192 was generated to document rust, pitting, and mineral deposits observed on inaccessible areas of the "B" RHR (XPR0425) guard pipe. Pipe wall thickness readings were obtained using Ultrasonic Testing on the subject carbon steel pipe to support the ES-120 Operability Recommendation. Reference Simpson/Rus sellTWR dated 11/17/2018 which evaluates the current XRP0425 guard pipe wall thickness and the projected thickness at the end of the next operating cycle.

During RF-25, the Augmented Examination of the RHR and RB Spray guard pipes found conditions similar to those found in RF-24. The "B" Train RHR and RB Spray sump penetrations (XRP0425, XRP0328) exhibited the greatest quantity of groundwater in-leakage and therefore an elevated degree of coating degradation and observable corrosion.

Penetrations associated with the "A" Train RHR and RB Spray piping (XRP0329, XRP0327) were relatively dry with minimal areas of observable corrosion. Condition report CR-20-01583 was generated to document the continued groundwater intrusions and subsequent coating degradation and corrosion. Calculations performed in Technical Work Record (TWR) JG40733 Page 6 of 10

CONTAINMENT INSERVICE INSPECTION - 2023 (RF-27)

ASME SECTION XI, SUBSECTI ONS IWE AND IWL RESPONSIBLE ENGINEER EVALUATI ON REPORT attached to this condition report (CR) show that the condition would not cause pipe wall thinning in excess of established acceptable limits during the next cycle (Cycle 26).

The exterior surface of the four carbon steel guard pipes within each penetration sleeve were cleaned, prepared, and recoated during and prior to RF-26 (fall 2021) under WO1605575. The augmented inspections of the guard pipes found areas that were missed during the recoating activities (documented in CR-21-02939). Some of these areas appeared to have intact coatings from previous coating applications. Other areas had been cleaned to the steel pipe surface.

The guard pipes, including the uncoated areas, did not show signs of corrosion or other degradation since the cleaning and recoating activities were performed. Maintenance worked with the remote visual NOE crew to recoat the identified areas. Upon completion of the touch up activities, complete coverage of the guard piping was confirmed via remote borescope inspection.

6.1.2 Other IWE Inspection Results Degraded Coatings No new coating degradation exceeding acceptance standards was identified during the RF-27 IWE examinations. The inspections for RB degraded coatings for the unquailed coatings program were tracked under CR1224444. Degraded coatings identified were documented under various conditions reports referenced in this tracking CR.

Pressure Test Connections to Liner Leak Chases No examinations for the Liner Leak Chase Pressure Test Connections closure plugs were scheduled or performed during RF-27. Examination of the closure plugs are scheduled for RF-28.

6.1.3 IWE Reportable Conditions In accordance with evaluation criteria provided in STP-803.006, no Recordable Indications of flaws or areas of abnormal degradation were identified during the RF-27 (2023) IWE Inspections.

6.1.4 IWE Reportable Conditions Requiring Augmented Examination None of the results of the IWE inspections were found to exceed the evaluation criteria of STP-803.006 or determined to be of concern that could potentially progress to an unacceptable structural condition prior to the next regularly scheduled IWE surveillance.

6.2 IWL Evaluation Visual examinations of scheduled IWL concrete components are performed directly or remotely, with adequate illumination, by qualified personnel with visual acuity sufficient to detect evidence of degradation. Remote viewing equipment (binoculars, borescopes, cameras, etc.) are utilized where appropriate.

The RF-27 IWL augmented examination of the tendon access gallery was performed by GISI Coordinator Julian Hamilton, with assistance from VCSNS GISI Responsible Engineer Shawn Sweigart.

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CONTAINMENT INSERVICE INSPECTION - 2023 (RF-27)

ASME SECTION XI, SUBSECTION S IWE AND IWL RESPONSIBLE ENGINEER EVALUATION REPORT 6.2.1 IWL Augmented Examination Augmented Examination of the Tendon Access Gallery (TAG) has been conducted since flaws/

degradation were identified during the IWL baseline inspections of 2000 (RF-12). The RF-27 Augmented Examinations included issues identified during previous IWL inspections, specifically:

  • Corrosion build-up and leaching on the outer TAG wall near the location of Tendon V-15 (Ref. WO 88101049980).

Corrosion Build-Up Corrosion build-up near Tendon V-15 was inspected and determined to be mostly unchanged and comparable with previous observations made during the RF-25 (2020) and RF-26 (2021) inspection. See Figures 2 and 3 in the TAG Inspection Report attached to WO 88101049980 for comparison. This type of corrosion remains limited to a single location. It is thought that the corrosion is due to groundwater in-leakage through a shrinkage crack in the tendon gallery exterior retaining wall causing corrosion of embedded metal (potentially a reinforcing bar).

The impact of this localized corrosion on the capability of the retaining wall to perform its structural design function is insignificant. It should be noted that the retaining wall is not a part of the containment structure but has been conservatively included in the IWL inspection scope boundary.

General Visual Examination During RF-27, the entire Tendon Access Gallery was inspected for groundwater in-leakage and concrete leaching. Water intrusion remains minimal with only a few areas exhibiting a wet surface. The extent of concrete leaching is comparable to previous inspections and evaluated as acceptable per CR-00-00988, CR-09-03667, and CR-21-04283.

Other observations from the TAG General Visual Examination included:

  • A small pile of grease estimated to be approximatel y 6 oz was observed on the floor below V-113. An additional amount of grease was observed at the interface between the grease can mounting plate and the tendon anchor head bearing plate.

This condition was documented in CR 1223243 and determined to be of negligible quantity in comparison to the total grease quantity in the tendon duct. A follow-up inspection (WO 88201691861) approximatel y 20 days from the original inspection confirmed that the leak is progressing at a slow rate and is of no immediate concern. Another inspection is planned for approximately 6 months from the original inspection under WO 88201694965 to monitor the leakage.

  • Only minor traces of grease seepage were observed from a few other vertical tendon end caps. Theses quantities were also insignificant and do not represent any degradation of the tendon corrosion protection system.
  • Housekeeping was found to be acceptable.
  • Floor sumps were clear of any debris which could impede drainage.
  • The accumulation of calcium deposits on the floor noted at several locations during the previous inspection in RF-26 appeared unchanged during the RF-27 inspections. See Figures 1-2 of TAG Inspection Report attached to WO Page 8 of 10

CONTAINMENT INSERVICE INSPECT ION - 2023 {RF-27)

ASME SECTION XI, SUBSEC TIONS IWE AND IWL RESPONSIBLE ENGINEE R EVALUA TION REPORT 8810105 0005 for comparison.

6.2.2 IWL Prestress Tendon System Evaluation No surveillances of the prestress tendon systems were scheduled or performed during RF-27.

The next tendon surveillance is scheduled for the Spring of 2026 (RF-29) for the 45-year examination.

6.2.3 IWL Containment Exterior Concrete Surfaces No surveillances of the containment exterior concrete surfaces were scheduled or performed during RF-27. The next concrete surface inspection is scheduled for the Spring of 2026 (RF-29) for the 45-year examination.

6.2.4 IWL Reportable Conditions In accordance with evaluation criteria provided in STP-803.006, no Recordable Indications of concrete deterioration or distress, such as described in ACI 201.1 and ACI 349.3R, were identified during the RF-27 (2023) IWL Inspections of the Tendon Access Gallery.

6.2.5 IWL Reportable Conditions Requiring Augment ed Examination None of the results of the IWL inspection were found to exceed the evaluation criteria of STP-803.006 or determined to be of concern that could potentially progress to an unacceptable structural condition prior to the next regularly scheduled IWL surveillance.

7

SUMMARY

AND CONCLUSIONS The ASME Section XI IWE/IWL inspections performed concurrent with RF-27 (April-May 2023) are the continuation of the ongoing required inspections of the containment structure. These inspections provide the necessary basis for comparison with future surveillance results.

There were no reportable findings during the IWE inspections. All minor findings relating to coatings and moisture barrier were reviewed by the Responsible Engineer and found to be acceptable with no impact on the capability of the Reactor Building to meet its required license basis design functions.

Localized concrete surfaces of the Tendon Access Gallery displayed evidence of groundwater in- leakage and efflorescence. These conditions were essentially unchanged, when compared to the previous RF-26 observations. Tendon grease accumulations at tendon V-113 were evaluated and determined to not represent tendon degradation. Additional monitoring of this leakage is planned during cycle 28. None of the IWL observed concrete conditions were judged to adversely impact performance or design function.

The RF-27 Augmented Examination of the Containment Moisture Barrier identified two (2) locations where the sealant had separated from the adjacent structure. CR 1224039 documen ts this degradation, which is similar to that found in previous barrier inspections. Localized sections of the sealant were reworked/inspected to restore the design function of the Containment Moisture Barrier.

Guard piping associated with the RHR and Reactor Building Spray sump penetrations continue to be susceptible to corrosion, exacerbated by the in-leakage of groundwater. The RF-27 Augmented Examination resulted in CR1226210 documenting rust staining, light surface rust, and continued water intrusion in the "A" train penetrations XRP0325 and XRP0329.

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CONTAINMENT INSERVICE INSPE CTION -2023 (RF-27)

ASME SECTION XI, SUBSECTIONS IWE AND IWL RESPONSIBLE ENGINEER EVALUATION REPORT CR1225890 was written to document and evaluated the rusting and pitting observed on the "B" train penetrations XRP0328 and XRP0425. Wall thickness calculations were performed to justify the structural integrity of the guard pipes through cycle 28. Repair of the degraded or deficient coating areas on guard pipes inside and outside of the penetra tions will be tracked via CA11833626 (CR1225890) and WO88201695374 (CR1226210).

The following areas shall remain on the STP-803.006 Augmented Examin ation list, for performance during subsequent refueling outages to ensure that any structur al degradation will continue to be examined and evaluated in compliance with the plant design basis.

  • IWE - Contain ment Moistu re Barrier Integrit y
  • IWE - Guard Pipes Corros ion
  • IWL - Tendon Access Gallery Corros ion In addition, the inspection of the Tendon Access Gallery for concrete leachin g and general housekeeping will continue as General Visual Examinations under the ASME Section XI IWE/IWL program to be performed along with the Augmented Examination during each Refueling Outage. Though the conditions inspected as part of the augme nted inspection of the Tendon Access Gallery were found to be essentially unchanged, these augmented inspections will conservatively continue during the next refueling outage.

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