05000219/LER-2012-003-01, Regarding Control Rod Drive Return Nozzle Weld NC-4-1A PT Indications at N9
| ML13128A068 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 04/30/2013 |
| From: | Peak R Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RA-13-046 LER 12-003-01 | |
| Download: ML13128A068 (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 |
| 2192012003R01 - NRC Website | |
text
A Exelon Generation, Oyster Creek Generating Station www.exeloncorp.com Route 9 South PO Box 388 Forked River, NJ 08731 RA-13-046 10 CFR 50.73 April 30, 2013 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 - 0001 Oyster Creek Nuclear Generating Station Renewed Facility Operating License No. DPR-16 NRC Docket No. 50-219
Subject:
Licensee Event Report (LER) 2012-003-01, Control Rod Drive Return Nozzle Weld NC-4-1A PT Indications at N9 Enclosed is LER 2012-003-01, Control Rod Drive Return Nozzle Weld NC-4-1A PT Indications at N9, Revision 1. The LER was revised to add supplemental information as required by Revision 0. This event did not affect the health and safety of the public or plant personnel. This event did not result in a safety system functional failure. There are no regulatory commitments made in this LER submittal.
Should you have any questions concerning this letter, please contact Jim Barstow, Regulatory Assurance Manager, at (609) 971-4947.
Respectfully, l/za'- 72ý/2 Russell R. Peak Plant Manager Oyster Creek Nuclear Generating Station Enclosure: NRC Form 366, LER 2012-003-01 cc:
Administrator, NRC Region 1 NRC Senior Resident Inspector - Oyster Creek Nuclear Generating Station NRC Project Manager - Oyster Creek Nuclear Generating Station
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 t licensing process and fed back to industry. Send comments regarding burde estimate to the FOIA/Pivacy Section (T-5 F63), U.S. Nuclear RegiLatory Commission, Washington, DC 20555-0001, or by lkteet *-mall to infocollects.resource@nrc.gov, and to the Desk Officer. Office of Inform LICENSEE EVENT REPORT (LER) and Regulatory Affairs, NEOB-10202, (3150-0104), OfficeofManefint ad Budget, Washington, DC 20503. If a means used to Impose an Information (See reverse for required number of collection does not display a currently valid OMB control nunber, the NRC may not conduct or sponsor, and a person is not required to respond to, fte digits/characters for each block) information collection.
- 3. PAGE Oyster Creek, Unit 1 05000219 1 OF 3 I Control Rod Drive Return Nozzle Weld NC-4-1A PT Indications at N9
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED I SEUNIL E
ACILITY NAME DOCKET NUMBFR_
MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR N/A N/A INUMBER NO.
FACILITY NAME DOCKET NUMBER 11 07 2012 2012
- - 003 01 04 30 2013 N/A N/A
- 91. OPTRATING MODE
- 11. THIS REPORT is SUBMITI'ED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
[1 20.2201(b) 0l 20.2203(a)(3)(i) 0l 50.73(a)(2)(i)(C)
[I 50.73(a)(2)(vii)
N [1 20.2201(d)
[I 20.2203(a)(3)(ii) 0 50.73(a)(2)(ii)(A)
[E 50.73(a)(2)(viii)(A) 20.2203(a)(1) 0l 20.2203(a)(4)
C] 50.73(a)(2)(ii)(B)
E] 50.73(a)(2)(viii)(B)
[] 20.2203(a)(2)(i)
[I 50.36(c)(1)(i)(A)
[I 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL [1 20.2203(a)(2)(ii)
[I 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(iv)(A) 0l 50.73(a)(2)(x)'
[o 20.2203(a)(2)(iii) 0l 50.36(c)(2) 0l 50.73(a)(2)(v)(A)
[I 73.71(a)(4) 0 E0 20.2203(a)(2)(iv)
[] 50.46(a)(3)(ii)
[I 50.73(a)(2)(v)(B) 0l 73.71 (a)(5)
[I 20.2203(a)(2)(v)
[I 50.73(a)(2)(i)(A)
[I 50.73(a)(2)(v)(C) 0l OTHER O 20.2203(a)(2)(vi)
[I 50.73(a)(2)(i)(B)
[I 50.73(a)(2)(v)(D)
Specify in Abstract below or in
Corrective Actions
The design of the OCNGS safe end, pipe, and elbow weld overlay was performed in accordance with requirements of ASME Code Case N-504-4 [2] and ASME Code,Section XI, Non-mandatory Appendix Q [3]. The weld overlay Is demonstrated to be acceptable for one operating cycle of 24 months based on the following:
- 1. In accordance with ASME Code Case N-504-4, structural design of the overlay was performed to meet the requirements of ASME Code,Section XI, IWB-3640 based on an assumed circumferential flaw 100% through-wall, and 3600 around the original weld. The resulting full structural weld overlay thus restores the original safety margins of the original weld, with no credit taken for the underlying flawed material.
- 2. A qualitative assessment was performed by assuming a conservative thermal transient and using other weld overlaid nozzle results with similar dimensions and transients to demonstrate that over one operating cycle of 24 months, ASME Code,Section III fatigue and fatigue crack growth criteria will be satisfied.
- 3. After completion of the WOL application, measurements of the weld overlay showed that all WOL dimensions exceeded the design minimums, and final PT and UT examinations were completed satisfactory.
- 4. A walk down of the affected line following the WOL application indicated that all hangers and other supports were either within or reset to design dimensional tolerances.
Based on the above observations and the fact that similar weld overlays have been applied to other plants since 1986 with no subsequent problems identified, it is concluded that the N9 nozzle weld overlay can safely operate for one operating cycle of 24 months. Subsequent analysis is being performed to support safe operation for continued operating cycles.
Previous Occurrences
There have been no similar Licensee Event Reports associated with this component failure submitted at OCNGS in the last three years.