05000331/LER-2010-004, Regarding Linear Indication Found During Examination of Safe-End to Nozzle Welds
| ML103540234 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 12/16/2010 |
| From: | Costanzo C NextEra Energy Duane Arnold |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NG-10-0626 LER 10-004-00 | |
| Download: ML103540234 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3312010004R00 - NRC Website | |
text
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ý;ý~A R NO LD December 16, 2010 NG-1 0-0626 10 CFR 50.73 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001 Duane Arnold Energy Center Docket 50-331 License No. DPR-49 Licensee Event Report #2010-004-00 Please find attached the subject report submitted in accordance with 10 CFR 50.73. This letter makes no new commitments or changes to any existing
commitments
Christopher R. Costanzo Vice President, Duane Arnold Energy Center NextEra Energy Duane Arnold, LLC NextEra Energy Duane Arnold, LLC, 3277 DAEC Road, Palo, IA 52324
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010)
Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the Records and FOIA/Privacy Service Branch (T-5 F52), U.S. Nuclear Regulatory Commission, LICENSEE EVENT REPORT (LER)
Washington, DC 20555-0001, or by internet e-mail to infocollects@nrc.gov. and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202 (3150-0104), Office of Management and Budget, Washington, DC 20503. Ifa means used to impose an information collection does not display a currently valid OMB control (See reverse for required number of number, the NRC may not conduct or sponsor, and a person is not required to respond digits/characters for each block) to, the information collection.
- 3. PAGE Duane Arnold Energy Center 05000331 1 OF 3
- 4. TITLE Linear Indication Found During Examination of Safe-End to Nozzle Welds
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCUMENT NUMBER NUMBER NO.
N/A 05000 10 29 10 2010 004 0
12 16 10 FACILITY NAME DOCUMENT NUMBER N/A 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
Dj 20.2201(b)
[
20.2203(a)(3)(i)
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50.73(a)(2)(i)(C)
E] 50.73(a)(2)(vii) 5 20.2201(d)
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20.2203(a)(3)(ii)
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50.73(a)(2)(ii)(A)
Fj 50.73(a)(2)(viii)(A) 20.2203(a)(1)
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El 50.73(a)(2)(ii)(B)
[0 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
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50.36(c)(1)(i)(A)
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E] 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
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50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A) 73.71(a)(4) 0%
El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B) 73.71(a)(5)
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El 50.73(a)(2)(i)(A) 0 50.73(a)(2)(v)(C)
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OTHER El 20.2203(a)(2)(vi)
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50.73(a)(2)(v)(D)
VOLUNTARY LER
- 12. LICENSEE CONTACT FOR THIS LER NAME TELEPHONE NUMBER (Include Area Code)
Robert J. Murrell, Engineering Analyst (319) 851-7900CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX FACTURER TO EPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR rn
~~~SUBMISSION 0
2 I21 L[
YES (If yes, complete 15. EXPECTED SUBMISSION DA TES)
El NO DATE 01BMIS20ON ABSTRACT (Linit to 1400 spaces, i.e., approxintiely 15 single-spaced typewritten lines)
Safe-end to nozzle weld RRA-FO02A was scheduled in Refuel Outage (RFO) 22 as an examination under BWRVIP-75 and as a successive examination under ASME Section XI. On October 29, 2010, UT examination of the N2A reactor recirculation riser safe-end to nozzle weld, RRA-F002A, identified a circumferential flaw. The RRA-FO02A circumferential weld indication was approximately 6.5" and 71% through-wall (TW), and identified as Inner Diameter (ID) surface connected. As part of the BWRVIP and ASME Section XI Inspection Programs, the inspection population was expanded to determine the extent of condition. There were three additional welds that required examination in accordance with guidance BWRVIP-75. The welds were RRG-F002A, RRF-F002A, and RRH-F002A. The UT examinations for all three welds were completed with no indications of flaws noted.
RRA-F002A was subsequently overlaid following verbal approval on November 15, 2010 of the relief request dated November 10, 2010 (ML103160155).
The root cause and safety consequences of this event will be documented in a supplement to this Licensee Event Report.
There were no Systems, Structures, or Components inoperable at the time of the event that contributed to the event.
There were no actual safety consequences and no effect on public health and safety as a result of this event.
N RC FORM 366 (10-2010)
PRINTED ON RECYCLED PAPER (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
IV. Corrective Actions
A modification was planned to perform repairs of the safe-end to nozzle welds. The repair was to overlay the flawed weld with material (Alloy 52) resistant to Stress Corrosion Cracking (SCC). The implementation of the overlay required a relief request from the NRC to approve the use of a non-NRC approved code case (N-504-4). The overlay was successfully applied and the ultrasonic examination results were found to be acceptable.
Any additional corrective actionsinitiated from the RCE for this event will be documented in the supplement to this LER.
V. Additional Information
Previous Similar Occurrences:
Previous Similar Occurrences:
- 1. LER 1999-006, "Indications in Recirculation Riser Nozzle-to-Safe End Welds."
In 1999, stress corrosion cracking was found in two safe-end to nozzle welds (RRB-F002 and RRD-F002). Both of these welds were overlaid using an approved relief request from the NRC.
In 2007, stress corrosion cracking was found in two safe-end to nozzle welds (RRF-F002 and RRC-F002). Both of these welds were overlaid using an approved relief request from the NRC.
EIIS System and Component Codes:
AD - Reactor Recirculation System
Reporting Requirements
This report is being submitted under 10 CFR 50.73(a)(2)(ii)(A)