ML121850006
| ML121850006 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 06/29/2012 |
| From: | James Shea Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML121850006 (8) | |
Text
Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 June 29, 2012 10 CFR 50.4 10 CFR50.55a ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Sequoyah Nuclear Plant, Unit 1 Facility Operating License No. DPR-77 NRC Docket No. 50-327
Subject:
Unit I Refueling Outage 18 Day Inservice Inspection Summary Report In accordance with the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section Xl, Article IWA-6230 and Code Case N-532-4, the Tennessee Valley Authority is providing the Sequoyah Nuclear Plant (SQN), Unit 1, Inservice Inspection (ISI) Summary Report within 90 days from completion of the Unit 1 Refueling Outage 18 (U1R18). The U1R18 ended on March 31, 2012. Accordingly, this report is required to be submitted by June 29, 2012.
The enclosure to this letter contains the Owner's Activity Report provides a list of items with flaws or relevant conditions that required evaluation for continued service (Table 1), an abstract of repairs, replacements, or corrective measures required for continued service (Table 2), and the evaluation of acceptability of inaccessible areas of the steel containment vessel in accordance with 10 CFR 50.55a(b)(2)(ix)(A).
There are no regulatory commitments associated with this submittal. Should you have any questions, please contact Rusty Proffitt (423) 843-6651.
- illy, Nuclear Licensing
Enclosure:
ASME Section Xl Inservice Inspection Summary Report, Unit 1 Refueling Outage 18 cc: See page 2 Printed on recycled paper
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U.S. Nuclear Regulatory Commission Page 2 June 29, 2012 Enclosure cc (Enclosure):
NRC Regional Administrator-Region II NRC Senior Resident Inspector - Sequoyah Nuclear Plant
ENCLOSURE TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT, UNIT I ASME SECTION XI INSERVICE INSPECTION
SUMMARY
REPORT UNIT 1 REFUELING OUTAGE 18
FORM OAR-I OWNER'S ACTIVITY REPORT Report Number UIRI 8 Plant SEQUOYAH NUCLEAR PLANT, P.O. Box 2000, Soddy-Daisy, TN 37384-2000 Unit No.
1 Commercial service date (if applicable)
July 1, 1981 Refueling outage no.
18 Current inspection interval Current inspection period Third lscion Interval
("2' (APVCoffer)
Second Inspection Period (1". 2",3'-
Edition and Addenda of Section XA applicable to the inspection plans Date and revision of inspection plans August 15, 2001 Edition, 2003 Addenda
?011 SI-DXI-000.114.3, Revision 17 Edition and Addenda of Section XI applicable to repair/replacement activities, if different than the inspection plans Not Applicable Code Cases used:
N-460, N-513-3, N-532-4, N-566-2, N-586-1. N-686-1, N-706-1. N-722-1, N-729-1. N-770-1 CERTIFICATE OF CONFORMANCE I certify that (a) the statements made in this report are correct; (b) the examinations and tests meet the Inspection Plan required by the ASME Code Xl and (c) the repair/replacement activities and evaluations supporting the completion of U1CI1 conform to there irements of Sectio t.(re'fueling Outage nrumbeo Signed 4
Date
?
Owner or Owfie'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 the State or Province of Tennessee and employed by H.S.B. CT of 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 make any warranty, expressed or implied. concerning the repair/replacement a.tivitles and evaluation described In this report. Furthermore, neither the Inspector nor his employer shall be A15 fofpsonal injury or property damage or a loss of any kind arising from or connected with this inspection.
Inspector's- -
ioCommissions qStre'o t
ISO Inspector's Signature Narionar ecard; State, Proviince, and Endorsements Date
(
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ASME SECTION XI INSERVICE INSPECTION
SUMMARY
REPORT SEQUOYAH NUCLEAR PLANT UNIT I REFUELING OUTAGE 18 TABLE I ITEMS WITH FLAWS OR RELEVANT CONDITIONS THAT REQUIRED EVALUATION FOR CONTINUED SERVICE Examination Category and Item Description Evaluation Description Item Number None N/A N/A E-2
ASME SECTION XI INSERVICE INSPECTION
SUMMARY
REPORT SEQUOYAH NUCLEAR PLANT UNIT I REFUELING OUTAGE 18 TABLE 2 ABSTRACT OF REPAIRS, REPLACEMENTS, OR CORRECTIVE MEASURES REQUIRED FOR CONTINUED SERVICE Code Item Description Date Repair/Replacement Class Description of Work Completed Plan Number Replace 0-VLV-067-0889B and -
Essential Raw 0889A with stainless steel ball 3
Cooling Water valves and replace the carbon 11/22/2011 110835785 (ERCW) Vent steel piping and fittings with Valves stainless steel. Small items replacement)
Control Rod Drive 3
Mechanism Cooler Braze repair of cooler coil socket 3/16/2012 113272203 Coil 1B-B fitting.
Centrifugal Replace the cooler coil due to 3
Charging Pump leakage from a socket weld 3/24/2012 112261016 Room Cooler 11B-B connection.
Repair welds on two of the integral attachment welds to the Seal Water Filter Ul seal water return filter 2
Housing Integral housing. Flaws exceed the 3/27/2012 113325859 Attachment Weld acceptance criteria of ASME Section III and were removed and repaired by welding.
Steel Containment Sealant was removed and Vessel (SCV) reinstalled to support SCV base MC Moisture Barrier metal inspection (Note this is not 3/27/2012 113339250 Sealant: Category an ASME Section Xl E-A, Item E1.30 repair/replacement activity)
Replace ERCW B-train emergency supply piping to the 3
Unit 1 Turbine Driven Auxiliary 3/29/2012 112358403 ERCW Piping Feedwater pump due to leakage from microbiologically influenced corrosion (MIC).
Replace ERCW return piping 3
ERCW Piping from the 1 B electric board room 8/14/2011 112565958 chiller due to leakage from (MIC).
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ASME SECTION XI INSERVICE INSPECTION
SUMMARY
REPORT SEQUOYAH NUCLEAR PLANT UNIT 1 REFUELING OUTAGE 18 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 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 the Unit 1 Cycle 18 refueling outage inspection of the steel containment moisture barrier (Item Number E1.30) four indications were identified in the SCV moisture barrier sealant (caulk) at the interface of the SCV and the Raceway floor in which the sealant was un-bonded from the SCV and/or concrete surfaces. The majority of the un-bonded area was along the concrete interface, not the SCV interface. However, failure of the moisture barrier sealant could potentially create a condition in which moisture would be allowed to penetrate the seal, and cause corrosion damage to the underlying SCV surface. Because of this potential, the sealant has been removed at the four locations to perform inspections of the otherwise inaccessible SCV surfaces. These visual inspections were performed to evaluate the acceptability of the inaccessible areas in accordance with 10CFR50.55a (b)(2)(ix)(A).
Results of the visual inspections, described below, show all inaccessible areas are acceptable for continued operation with no corrective action required. Since no additional corrosion is expected after the sealant is reinstalled, an evaluation of future corrosion rates and wall thickness effects is not required. The damaged areas of the moisture barrier sealant were repaired, and do not require an engineering evaluation. Future inspections of the SCV moisture barrier will continue to be performed in accordance with the ASME Code, Section Xl, IWE-2500-1 schedule.
- 1.
Azimuth 165 degrees - lack of bonding between the sealant and the concrete and SCV surfaces: Sealant was removed at the location of the flaw. Visual inspection of the underlying SCV and concrete surfaces identified no degradation or corrosion damage. No additional corrective action was required. The sealant has been reinstalled per IWE-3510.4 to prevent future moisture intrusion and reexamined to verify adequate sealing.
- 2.
Azimuth 85 degrees - lack of bonding between the sealant and the concrete and SCV surfaces: Sealant was removed at the location of the flaw. Visual inspection of the underlying SCV and concrete surfaces identified no degradation or corrosion damage.
No additional corrective action was required. The sealant has been reinstalled per IWE-3510.4 to prevent future moisture intrusion and reexamined to verify adequate sealing.
- 3.
Azimuth 39 degrees - lack of bonding between the sealant and the concrete and SCV surfaces: Sealant was removed at the location of the flaw. Visual inspection of the underlying SCV and concrete surfaces identified no degradation or corrosion damage.
No additional corrective action was required. The sealant has been reinstalled per IWE-3510.4 to prevent future moisture intrusion and reexamined to verify adequate sealing.
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- 4.
Azimuth 34 degrees - lack of bonding between the sealant and the concrete and SCV surfaces: Sealant was removed at the location of the flaw. Visual inspection of the underlying SCV and concrete surfaces identified no degradation or corrosion damage.
No additional corrective action was required. The sealant has been reinstalled per IWE-3510.4 to prevent future moisture intrusion and reexamined to verify adequate sealing.
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