ML24176A113

American Society of Mechanical Engineers,Section XI, Fourth 10 Year Inspection Interval, Inservice Inspection, System Pressure Test, Containment Inspection, and Repair and Replacement Programs, Owner’S Activity Report Cycle 21 Oper

ML24176A113
Person / Time
Site:	Browns Ferry
Issue date:	06/23/2024
From:	Sivaraman M Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
Download: ML24176A113 (1)

Text

10 CFR 50.55a Post Office Box 2000, Decatur, Alabama 35609-2000 June 23, 2024 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 3 Renewed Facility Operating License No. DPR-68 NRC Docket No. 50-296

Subject:

American Society of Mechanical Engineers,Section XI, Fourth 10 Year Inspection Interval, Inservice Inspection, System Pressure Test, Containment Inspection, and Repair and Replacement Programs, Owners Activity Report for Browns Ferry Nuclear Plant, Unit 3, Cycle 21 Operation The Tennessee Valley Authority is submitting the Browns Ferry Nuclear Plant (BFN), American Society of Mechanical Engineers (ASME),Section XI, Owners Activity Report for BFN, Unit 3, Cycle 21 Operation. The report is contained in the enclosure to this letter and is in accordance with the requirements of ASME Code Case N-532-5, Repair/Replacement Documentation Requirements and Inservice Summary Report Preparation and Submission,Section XI, Division 1.

The report is an overview of the inservice examination results that were performed on components within the ASME Section XI boundary, up to and including the BFN, Unit 3, Cycle 21 refueling outage, during the third inspection period of the Fourth 10 Year Inspection Interval. The applicable provisions of the ASME Code Case N-532-5 require that this report be submitted within 90 calendar days of the completion of each refueling outage. The BFN, Unit 3, Cycle 21 refueling outage ended on March 24, 2024. Accordingly, this submittal is due by June 22, 2024.

1\\14 TENNESSEE VALLEY AUTHORITY

U.S. Nuclear Regulatory Commission Page 2 June 23, 2024 There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal, please contact David Renn, Site Licensing Manager, at (256) 729-2636.

Respectfully, Manu Sivaraman Site Vice President

Enclosure:

American Society of Mechanical Engineers,Section XI, Fourth 10 Year Inspection Interval, Inservice Inspection, System Pressure Test, Containment Inspection, and Repair and Replacement Programs, Owners Activity Report for Browns Ferry Nuclear Plant, Unit 3, Cycle 21 Operation cc (Enclosure): NRC Regional Administrator - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant NRC Project Manager - Browns Ferry Nuclear Plant

Enclosure Tennessee Valley Authority Browns Ferry Nuclear Plant Unit 3 American Society of Mechanical Engineers,Section XI, Fourth 10 Year Inspection Interval, Inservice Inspection, System Pressure Test, Containment Inspection, and Repair and Replacement Programs, Owners Activity Report for Browns Ferry Nuclear Plant, Unit 3, Cycle 21 Operation See Enclosed

FORM OAR-1 OWNER'S ACTIVITY REPORT Report Number _,B""F'--'N'--'----'U"--'3"-'R--"2=-1.,__ ___________________________________ _

Plant Browns Ferry Nuclear Plant P 0. Box 2000 Decatur. AL 35609 Unit No. --~3~--

{if applicable)

Commercial service date March 1 1977 Refueling Outage no. Refueling Outage 21 Current Inspection Interval FOL![(h Ten Year lnspectio~n~ ln=t~e~rv~a~I _________________________ _

(1st, 2nd, 3rd, other)

Current Inspection Period

~T~h=ir~d~P_e=r~io~d~----------------------------------

(1st. 2nd. 3rd) 2007 Edition, 2008 Addenda (ISi)

Edition and Addenda of Section XI applicable to the inspection plans ~2=0-'-1=3_,E=-d=i=ti=o~n__,_(=C~IS"'-'-'1)-----------------~

0-TPP-ENG-376. Revision 0006, 02/07/2024 0-Tl-364, Revision 0026, 11 /28/2023 Date and Revision of inspection plan 0-TPP-ENG-467 Revision 0002 02/05/2024 Edition and Addenda of Section XI applicable to repairs and replacements, if different than the inspection plan ~N~/A~--

Code Cases used for inspection and evaluation N-508-4 N-532--5 N-613-2 N-648-1 N-702 and N-716-1 N-747 N-864.

(if applicable, including cases modified by Case N-532 and later revisions)

CERTIFICATE OF CONFORMANCE I certify tl1at (a) the statempntq made in this report are correct; (b) the examinations and tests meet the Inspection Plan as required by the ASME' Code,Section XI; and (c) the repai,/replacement activities and evaluations supporting the completion of --~U~3~R~2~1 __ _

conform to 11,e requireme

• ' -,ection XI.

(refueling outage number)

Signed ______________________ Date _______________ _

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 employed by The Hartford Steam Boiler Inspection and Insurance Company of Hartford Connecticut 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 Section XI.

By signing this certificate neither the Inspector nor his employer makes any warranty, expressed or implied, concerning the repair/replacement activities and evaluation described in this report. Furthermore, neither the Inspector nor his employer shall be liable in any manner for any personal injury or property damage *r lo s of an r connected with this Inspection.

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/'1*1"11 Commissions N ;3 i '19 '7 1

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--'--""'Na'-ti-on-al~B.,_oa~,d=-N-u-'-m-be-r a-n~d ~En-do-rs_e_m-en-, --'-'--'---J/'---

/,/l o/ 1 vt Date __ l;)'--lif----+,-"=--------

FORM OAR-1 OWNER'S ACTIVITY REPORT TABLES Report Number BFN U3R21 PI ant Browns Ferry Unit No.

3 Commercial service date 03/01/1977 Refueling outage no.

21 Current inspection interval 4th Current inspection period 3rd Examination Category and Item Number F-A / F1.10D F-A / F1.20C TABLE 1 ITEMS WITH FLAWS OR RELEVANT CONDITIONS THAT REQUIRE EVALUATIONS FOR CONTINUED SERVICE Item Description Evaluation Description CR 1911989, NOi U3R21-001 During VT-3 examination of Mechanical Snubber Support, 3-47B400-75, examiners identified the pin was displaced, not fully engaged with the support bracket, resulting in examination failure.

Civil Engineering evaluated the condition and Main Steam System Snubber, concluded that the snubber in the "as found" 3-4 7B400-75 condition would still be able to perform its intended design function and sustain the imposed design seismic loads. The design loads would have been transferred from the main steam piping to the EL 584' floor steel features. The snubber pin was reinstalled and a new cotter pin was installed topside of the support bracket. The support was then re examined with no recordable indication.

CR 1914074, WO 124338851, NOi U3R21-003 During Owner Elected VT-3 examination of 3-47B455-628 the variable spring support was observed at an as found setting of 1650 lbs. The High Pressure Coolant Injection affected support nominal range setting is 1663 -

System Support, 3-47B455-628 1738 lbs. The as found setting was roughly 1 %

outside of the acceptable nominal range, constituting a relevant condition as defined in IWF-3410(a)(4), "Improper hot or cold settings of spring supports". The spring can was reset to 1700 lbs.

and an as left examination was performed with no relevant indications identified.

FORM OAR-1 OWNER'S ACTIVITY REPORT TABLES Report Number BFN U3R21 PI ant Browns Ferry Unit No.

3 Commercial service date 03/01/1977 Refueling outage no.

21 Current inspection interval 4th Current inspection period 3rd TABLE 2 ABSTRACT OF REPAIR/REPLACEMENT ACTIVITIES REQUIRED FOR CONTINUED SERVICE Code Item Description Description of Work Date Repair/Replacement Class Completed Plan Number During a pre-shutdown walk down a defect was revealed when a 1/2" drain pipe sheared at the heat affected zone at the Tee-to-Pipe interface due to cyclic fatigue cracking. (The valve at the end of the pipe was not supported and created a catalever at the pipe-to-tee joint.)

The defect was removed and 21,

Replace reducing Pipe Engineering Change (BFN Tee upstream of valve 010 (AWA-TVA-2024-0438)) t~

2 BFN-3-VTV-074-0683A was performed to replace a c-o-03/25/2024 124312449 with a 90-degree elbow degree elbow joint removing the and reducing insert catalever design issue with the drain valve.

The cause of the unacceptability is being documented in the BFN corrective action program CR 1911200 with an engineering evaluation shown in the Prompt Determination of Operability (PDQ) 1911200. An ECP was created to address the issue to prevent reoccurance.

FORM OAR-1 OWNER'S ACTIVITY REPORT TABLES Report Number BFN U3R21 PI ant Browns Ferry Unit No.

3 Commercial service date 03/01/1977 Refueling outage no.

21 Current inspection interval 4th Current inspection period 3rd REPORTING REQUIRED BY 10 CFR 50.55a(b)(2)(ix)(A)

ASME Section XI, Subsection IWE Steel Containment Vessel Inspection program 10 CFR 50.55a(b )(2)(ix)(A) requires reporting of the degradation assessment for inaccessible areas when conditions are identified in accessible areas during the performance of the ASME Section XI, Subsection IWE Steel Containment Vessel (SCV)

Inspection Program that could indicate the presence of or result in degradation to such inaccessible areas.

During BFN U3R21, isolated locations of the Moisture Seal Barrier (MSB) of the SCV was identified to have disbonding conditions requiring excavations and examination of inaccessi le areas beneath the barrier. The inaccessible areas of the SCV Leneath the MSB we rP-. determined to be acceptable by General Visual examination. The P.Xamination irlGntifa:.d

• 1:J evidence of complete separation from the drywell liner that wou;~1 ailow moistu1 *~: to enter the area below the seal. Conditions were corrected by cleaning and replacing damaged areas of the MSB with no Repair/ Replacement Activity required.