05000219/LER-2004-006, Regarding Local Leak Rate Test Results in Excess of Technical Specifications
| ML050120114 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 01/04/2005 |
| From: | Swenson C AmerGen Energy Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 2130-04-20328 LER 04-006-00 | |
| Download: ML050120114 (5) | |
| 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) 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)(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 |
| 2192004006R00 - NRC Website | |
text
AmerGen SM AmerGen Energy Company www.exeloncorp.com An Exelon Company Oyster Creek US Route 9 South, P.O. Box 388 Forked River, NJ 08731-0388 10 CFR 50.73 January 4, 2005 2130-04-20328 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 - 0001 Oyster Creek Generating Station Facility Operating License No. DPR-16 NRC Docket No. 50-219
Subject:
Licensee Event Report 2004-006-00, Local Leak Rate Test Results in Excess of Technical Specifications Enclosed is Licensee Event Report 2004-006, Revision 0. This event did not affect the health and safety of the public or plant personnel. There was no safety system functional failure associated with this event.
If any further information or assistance is needed, please contact David Fawcett at 609-971-4284.
Sincr C. N. Swenson Vice President, Oyster Creek Generating Station CNS/DIF : List of Regulatory Commitments cc:
S. J. Collins, Administrator, USNRC Region I P. S. Tam, USNRC Senior Project Manager, Oyster Creek R. J. Summers, USNRC Senior Resident Inspector, Oyster Creek File No. 04116 Lee
ATTACHMENT 1 SUMMARY OF AMERGEN ENERGY CO. LLC COMMITMENTS The following table identifies commitments made in the document by AmerGen Energy Co. LLC (AmerGen). Any other actions discussed in this submittal represent intended or planned actions by AmerGen. They are described to the NRC for the NRC's information and are not regulatory commitments.
COMMITMENT
COMMITTED DATE OR "OUTAGE" The MSIV Overhaul Procedure will be revised to include a documented 04/30/2005 management review prior to eliminating seat lapping even if a successful blue check has been obtained.
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BYOMS: NO. 3150-0104 EXPIRES: 0600/2007 (6-2004)
, the NRC may not conduct or digits/characters for each block) sponsor, and a person Is not required to respond t0. the information collection.
- 3. PAGE O sterCreek, U it1 05000 F
1 j3
- 4. TITLE Loa L e t T
- -F
.- L~cal-L-e-a-kR~a-t-e,T-est R-e~s~ulit~s !-n Etx-c-e~s's o
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- -;I
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILmES INVOLVED l SEQUENTIAL REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO MONTH DAY YEAR 05000 11 05-2004 2004 006 -
00
-.01 104 2005 P~ctrYNAME DOCKETNUMBER 05000
- 9. OPERATING MODE
- 1. THIS REPORT IS SUBMrrlED PURSUANT TOTHE REQUIREMENTS OF 1 OCFR §: (Check thatapply)
N 20.2201 (b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(li)(A) 50.73(a)(2)(viii)(A) 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B)
_20.2203(a)(2)(i)
_50.36(C)(1)(i)(A)
_50.73(a)(2)Ciii)
_50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 20.2203(a)(2)(ii) 50.36(c)(1)(Ii)(A) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 0 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71 (a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 73.71 (a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)
OTHER 20.2203(a)(2)(vi)
_ 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)
Specity in Abstract below
- 12.
I I
or I NRC Form 3C6A
- 12. LICENSEE CONTACT FOR THIS LER FAL.U I Y NAME=
IELEPHUNE NUMBER (rideudeArea Code)
David Fawc'ett, Licensing Engineer,, :-:
i 1
(609) 971-28 4 -
, -CAUSE SYSTEM COMPONENT MANU.
REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX PACTURER TO EPIX X
SB ISV A585 Y.- X; i,--
- 14. SUPPLEMENTAL REPORT EXPECTED 15.EXPECTED MONTH DAY YEAR SUBMISSION I il
_JYES (IfyescompleteEXPECTEDSUBMISSIONDATE) m~ NO DATE l -_-_-___
ABSTRACT (ktto 1400spacese.,e aOp enaey s 15sispacedtypewrten nes)
- On Frriday, November 5, 2004, with the plant in Cold Shutdown for refueling outage 1 R20, th at-f Local Leak Rate Test (LLRT) of Main Steam Isolation Valve (MSIV) NS04A failed to meet the':,
acceptance criteria of Technical Specification 4.5.D.2. The acceptance criteria was revised just prior to' i1 R20 and is now less than or equal to 11.9'SCFH and the actual measured leakage was 24.3 SCFH at
' 20.6 psig. The valve was last refurbished during forced outage 1 FO7 in September 2004 and found to..:;-'
be acceptable after maintenance that replaced the valve poppet. The valve was successfully repaired in 1 R20 and subsequently passed the as-left LLRT.
- r;
.:,The apparent cause of the as-found LLRTlfailure in 1 R20 was irreguiarity of the mating surfaces between' the poppet seating surface and the valve body seating surfaces.
Previous similar events of LLRT failures have occurred in each of the' last two refueling outages:
LER 2000-01 0, Local Leak Rate Test Results in Excess of Technical Specifications, NS04B:-
LER 2002-002, Local Leak Rate Test Results in Excess of Technical Specifications,NSO3A.
NRC FORM 366 (6-2004)
NRC ORM366AU.S NULEARREGLATRY CMMISIO (if more space Is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A)
Analysis of Event (cont'd)
A review of industry Operating Experience (OE) for MSIV LLRT revealed numerous cases where there were leak rates significantly in excess of their limits that were unexplained and when the valve seat was lapped successful LLRTs were performed. One reported incident at another BWR plant during 1987 had an original LLRT failure on July 5th and then failed another LLRT on September 6th. The cause of the second failure was determined to be deformation of the lower seating surface that had not been removed by lapping during the prior maintenance outage in July.
Cause of Event
The apparent cause of the as-found LLRT failure was the irregularity of the mating surfaces between the poppet seating surface and the valve body seating surfaces. These minor irregularities may have caused the valve to seat differently when the valve was stroked entering the 1 R20 refueling outage causing the LLRT failure. The decision to proceed with valve re-assembly in 1 F07 without lapping was made based on an acceptable blue check indicating a complete seat contact.
Corrective Actions
The valve was disassembled in 1 R20 and the valve body seat was lapped. A satisfactory blue check was achieved and the valve was reassembled.
The MSIV Overhaul Procedure will be revised to include a documented management review prior to eliminating seat lapping even if a successful blue check has been obtained.
Additional Information
A. Failed Components:
Main Steam Isolation Valve (MSIV) NS04A (V-1-009)
B. Previous similar events
LER 2000-010, Local Leak Rate Test Results in Excess of Technical Specifications, NS04B LER 2002-002, Local Leak Rate Test Results in Excess of Technical Specifications, NS03A C. Identification of components referred to in this Licensee Event Report:
Components IEEE 805 System ID IEEE 803A Function MSIV SB ISV