05000287/LER-2003-001, From Oconee, Unit 3 Regarding Apparent Reactor Pressure Vessel Head Leakage from a Control Rod Drive Nozzle
| ML031490044 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 05/19/2003 |
| From: | Rosalyn Jones Duke Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 03-001-00 | |
| Download: ML031490044 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(B) |
| 2872003001R00 - NRC Website | |
text
.- Ph Duke
- rPower, A Duke Energy Company R. A. JONES Vice President Duke Power 29672 / Oconee Nuclear Site 7800 Rochester Highway Seneca, SC 29672 864 885 3158 864 885 3564 fax May 19, 2003 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555
Subject:
Oconee Nuclear Station Docket No. 50-287 Licensee Event Report 287/2003-01, Revision 0 Problem Investigation Process No.: 0-03-02557 Gentlemen:
Pursuant to 10 CFR 50.73 Sections (a)(1) and (d), attached is Licensee Event Report 287/2003-01, Revision 0, addressing the discovery of apparent reactor pressure vessel head leak from a control rod drive nozzle.
This report is being submitted in accordance with 10 CFR 50.73 (a)(2)(i)(B) and (a)(2)(ii)(A). For this event, the overall safety significance of this event was minimal and there was no actual impact on the health and safety of the public.
Vert
- urs, R.A.
nes Vice President Oconee Nuclear Site Attachment www. duke-energy. com 0-1
Document Control Desk Date: May 19, 2003 Page 2 cc:
Mr. Luis A. Reyes Administrator, Region II U.S. Nuclear Regulatory Commission 61 Forsyth Street, S. W., Suite 23T85 Atlanta, GA 30303 Mr. L. N. Olshan Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D.C. 20555 Mr. M. C. Shannon NRC Senior Resident Inspector Oconee Nuclear Station INPO (via E-mail)
NRC FOPM 366 U.S. NUCLEAR REGULATORY APPROVED BY OB NO.
3150-0104 EXPIRES 7-31-2004 (f-201)
COMMISSION
, the NRC may not conduct or sponsor,
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- 3. PAGE Oconee Nuclear Station, Unit 3 050- 0287 1 OF 5
- 4. TiTLE Apparent Reactor Pressure Vessel Head Leakage From A Control Rod Drive Nozzle
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEUENTI REV FACILITY NAME DOCKET NUMBER MO DAY YEAR YEAR NUER NO MO DAY YEAR None FACILITY NAME DOCKET NUMBER 05 02 03 2003 - 01 00 05 19 03
- 9. OPERATING
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 C:R §: (Check all that apply)
MODE 5
20.2201 (b) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(B) 50.73(a)(2)(ix)(A)
- 10. POWER 20.2201 (d) 20.2203(a)(4) 50.73(a)(2)(iii) 50.73(a)(2)(x)
LEVEL 0
20.2203(a)(1) 50.36(c)(1)(i)(A) 50.73(a)(2)(iv)(A) 73.71 (a)(4)
- _ 20.2203(a)(2)()
_ 50.36(c)(1)(ii)(A) 50.73(a)(2)(v)(A) 73.71 (a)(5) 20.2203(a)(2)(ii) 50.36(e)(2) 50.73(a)(2)(v)(B)
OTHER 20.2203(a)(2)(iii) 50.46(a)(3)(ii) 50.73(a)(2)(v)(C)
Specify in Abstract below or in Z
~~~~~~~~~~~~~~~~~~~~~~~NR F:orm 366A a, N 20.2203(a)(2)(iv) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(D) 20.2203(a)(2)(v)
X 50.73(a)(2)(i)(B) 50.73(a)(2)(vii) 20.2203(a)(2)(vi) 50.73(a)(2)(i)(C)
_ 50.73(a)(2)(viii)(A) 20.2203(a)(3)(i)
X 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(B)
- 12. LICENSEE CONTACT FOR THIS LER NAME TELEPHONE NUMBER (Include Area Code)
L.E. Nicholson, Regulatory Compliance Manager I
(864) 885-3292
[ 1 MANU-REPORTABLE J
MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT FACTURER TO EPIX
CAUSE
SYSTEM COMPONENT FA CTURER TO EPIX 136a RCS NZL B&W Y
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR YES (If yes, complete EXPECTED SUBMISSION DATE).
X INO DATE
ABSTRACT
Unit 3 entered its scheduled end-of-cycle 20 refueling outage on April 26, 2003. On May 2, 2003, a' visual inspection of the bare reactor vessel head (RVH) was performed. Results of the visual inspection revealed two (2) control rod drive (CRD) mechanism (CRDM) nozzles that were suspected of leakage.
Of these, CRDM No. 4 was observed to contain a very thin white coating on the nozzle and CRDM No. 7 appeared to have a small accumulation of boron on the head adjacent to the annulus region. In addition, approximately 6 to 8 CRDMs could not be visually inspected as they were masked by deposits from a Component Cooling (CC) system leak above the RV head.
Subsequent evaluation of the prior refueling outage RVH inspection videotape showed that the CRDM No. 7 deposits were not associated with a new leak but rather were remnants from a prior refueling outage leak and repair campaign where the boron residue had not been completely removed from the RVH during the wash down process. The CRDM No. 4 boron deposit appeared fresher, exhibited characteristics similar to prior RVH leaks and as such, was conservatively identified as a leak. The apparent root cause of the nozzle leak is primary water stress corrosion cracking.
This RVH will be retired from service and replaced with a new RVH prior to unit restart. For this event, the overall safety significance of this event was minimal and there was no actual impact on the health and safety of the public.
NRC FORM 366 (7-2001)
NRC-=
(If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
Figure 1 - Oconee Unit 3 RVH Map Service Structur Support Flange Themocouple Nozzles (8)
(Oconee Unit I Only)
Nozzles 3, 7, 11, 23, 28, 34, 50, 56, and 63 were repaired (maintenance outage)
Nozzles 2, 10, 26, 31, 39, 49 and 51 were repaired (EOC 19 refueling outage)
Nozzle 4 was not repaired since the RVH is being retired (EOC 20 refueling outage)