05000270/LER-2002-003, Re Steam Generator Tube Leak During In-Situ Pressure Test
| ML023600191 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 12/16/2002 |
| From: | Rosalyn Jones Duke Energy Corp, Duke Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| O-02-6118 LER 02-003-00 | |
| Download: ML023600191 (9) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(ix)(A) 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 |
| 2702002003R00 - NRC Website | |
text
^i Duke rPowere A Duke Energy Company R. A. JONES Vice President Duke Power 29672 1 Oconee Nuclear Site 7800 Rochester Highway Seneca, SC 29672 864 885 3158 864 885 3564 fax December 16, 2002 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C.
20555
Subject:
Oconee Nuclear Station Docket Nos. 50-270 Licensee Event Report 270/2002-03, Problem Investigation Process No.:
Revision 0 0-02-6118 Gentlemen:
Pursuant to 10 CFR 50.73 Sections (a)(1) and (d),
attached is Licensee Event Report 270/2002-03, Revision 0, concerning a Steam Generator tube which failed an in-situ pressure test.
This report is being submitted as a voluntary Licensee Event Report.
This event is considered to be of no significance with respect to the health and safety of the public.
Very/ ily yours, Attachment www duke-energy corn
Document Control Desk Date: December 16, 2002 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 FORM-366 U.S. NUCLEAR REGULATORY APPROVED BY OMB NO.
3150-0104 EXPIRES 7-31-2004 V7-2001)
COMMISSION
, the N C may not conduct or sponsor,
.- rn n nprmo I not rponirpri fo raonnnrl tn thp -f--rmnt-oo rlpr-t1inn 1 FACILITY NAME
- 2. DOCKETNUMBER
- 3. PAGE Oconee Nuclear Station, Unit 2 050-0270 1
OF 7
4 TITLE Steam Generator Tube Leak During In-Situ Pressure Test 5 EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED I
FACILITY NAME DOCKET NUMBER MO DAY YEAR YEAR NUMBER NO MO DAY YEAR None FACILITY NAME DOCKET NUMBER 10 31 2002 2002 -03 0
12 16 2002
- 9. OPERATING
- 11. THIS REPORT IS SUBMITTED PURSUANTTO TiHE REQUIREMENTS OF 10 CFR § (Check all that apply)
MODE None 120 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)(Ill) 150.73(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) 1
,_ 20 2203(a)(2)(i)
__ 50.36(c)(1)(fi)(A)
_ 50.73(a)(2)(v)(A) 73 71 (a)(5) v a _
20 2203(a)(2)(1i) 50.36(c)(2)
__ 50.73(a)(2)(v)(B)
X OTHER
{
20 2203(a)(2)(iii) 50 46(a)(3)(i1 50.73(a)(2)(v)(C) in Abstract below or in
Abstract
On 10-31-02, Unit 2 was defueled in No Mode for a Refueling outage.
During in-situ pressure testing, Steam Generator (SG) "B, Tube 37-27 began to leak at approximately 3900 psig.
This did not meet the "3 times normal operating delta-p pressure, (4250 psig) test criterion. The failure was at an axially oriented indication in a dent with manufacture burnish marks (MBM) superimposed over the dent.
The tube was removed from service by plugging.
Axial indications have been seen in dents in the past and are anticipated in the ONS SGs.
Existing test data was reviewed.
Unit 2 had 28 indications of dents and MBM that overlapped and were preventatively plugged.
Unit 3 had no similar indications.
Unit 1 found 13 such indications but had no indication of cracking.
The root cause of this event is human error (i.e. guidance document not followed correctly) due to a difficulty associated with interpreting eddy current test results.
During previous inspections, the combination of signals from the overlapping indications resulted in masking the defect.
Additional guidance for eddy current analysis will be provided so that this type of complex indication that potentially could mask degradation shall be considered for plugging.
This event is considered to have no significance with respect to the health and safety of the public.
NRC FORM 366 (7-2001)
NRC FORM S66A U.S. NUCLEAR REGULATORY COMMISSION (1-2001)
LICENSEE EVENT REPORT (LER)
DOCKET (2)
FACILITY NAME (1)
NUMBER (2)
LER NUMBER (6)
PAGE (3)
SEQUENTIAL REVISION YEAR NUMBER NUMBER Oconee Nuclear Station, Unit 2 0500270 2002 03 00 2
OF 7
NARRATIVE
(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 (if more space is required, use additonal copies of (If more space is required, use additional copies of NRC Form 366A) (17) indications have been in-situ pressure tested with no problems; though of these, only a few have been associated with a dent.
This indicates that there has not been a generic problem with detectability or growth rate of defects contained within dented locations.
There have not been any indications of volumetric flaws approaching structural limits and therefore the detectability of MBM indications is not in question.
There were no releases of radioactive materials, radiation exposures or personnel injuries associated with this event.