05000336/LER-2008-001, Re Failure of Eight Main Steam Safety Valves to Lift within the Acceptance Criteria
| ML081570348 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 05/30/2008 |
| From: | Price J Dominion Nuclear Connecticut |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 08-0266, MPS Lic/GWJ R0 LER 08-001-00 | |
| Download: ML081570348 (6) | |
| 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 |
| 3362008001R00 - NRC Website | |
text
Dominion Nuclear Connecticut, Inc.
Millstone Power Station Rope Ferry Road, Waterford, CT 06385 4
Dominion MAY 3 0 2008 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Serial No.
MPS Lic/GWJ Docket No.
License No.
08-0266 RO 50-336 DPR-65 DOMINION NUCLEAR CONNECTICUT, INC.
MILLSTONE POWER STATION UNIT 2 LICENSEE EVENT REPORT 2008-001-00 FAILURE OF EIGHT MAIN STEAM SAFETY VALVES TO LIFT WITHIN THE ACCEPTANCE CRITERIA This letter forwards Licensee Event Report (LER) 2008-001-00 documenting a condition discovered at Millstone Power Station (MPS) Unit 2, on April 3 and 4, 2008. This LER is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(B), as a condition prohibited by technical specifications.
If you have any questions or require additional information, please contact Mr. William D.
Bartron at (860) 444-4301.
Sincerely, J. Ala Price S eVice President - Millstone Attachments: 1 Commitments made in this letter: None A-t ak
Serial No. 08-0266 Docket No. 50-336 Licensee Event Report MP2-2008-001-00 Page 2 of 2 cc:
U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-1415 Mr. J. D. Hughey Project Manager Millstone Units 2 and 3 U.S. Nuclear Regulatory Commission, Mail Stop 08 B3 One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station
Serial No. 08-0266 Docket No. 50-336 Licensee Event Report MP2-2008-001-00 ATTACHMENT LICENSEE EVENT REPORT MP2-2008-001-00 FAILURE OF EIGHT MAIN STEAM SAFETY VALVES TO LIFT WITHIN THE ACCEPTANCE CRITERIA MILLSTONE POWER STATION UNIT 2 DOMINION NUCLEAR CONNECTICUT, INC.
I-NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES 08/31/2010 (9-2007)
, the RC may not conduct or sponsor, and a person is not required to respond to, the information collnotion.
(See reverse for required number of digits/characters for each block)
- 3. PAGE Millstone Power Station - Unit 2 05000336 1 OF 3
- 4. TITLE Failure of Eight Main Steam Safety Valves to Lift Within the Acceptance Criteria
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER MO DAY YEAR YEAR SEQUENTIAL REV MO DAY YEAR NUMBER NO.
05000 FACILITY NAME DOCKET NUMBER 04 03 2008 2008-001-00 05 30 2008 05000
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
.20.2201(b) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(B) 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 100 120.2201(d) 20.2203(a)(4) 50.73(a)(2)(iii) 50.73(a)(2)(x) 20.2203(a)(1) 50.36(c)(1)(i)(A) 50.73(a)(2)(iv)(A) 73.71(a)(4) 20.2203(a)(2)(i) 50.36(c)(1)(ii)(A) 50.73(a)(2)(v)(A) 73.71(a)(5)
K 20.2203(a)(2)(ii) 50.36(c)(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 20.2203(a)(2)(iv) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(D) in (If more space is required, use additional copies of NRC Form 366A) (17) design limit. The FSAR Chapter 14 single main steam isolation valve (MSIV) closure event reports a maximum main steam pressure of 1093 psia, which is 7 psi less than 110% of design pressure limit. This event relies on the opening of all eight MSSVs on the steam generator with the isolated MSIV to limit the main steam pressurization. Since valve 2-MS-248 would not have opened until the main steam system pressure exceeded 110% of design, the FSAR Chapter 14 acceptance criterion would have been exceeded for this event. Using the as-found MSSV settings, should the single MSIV closure event have occurred, it is expected that the maximum main steam system pressurization would have exceeded the 1100 psia design limit by less than 2% or 20 psi. Based on an engineering evaluation, DNC concludes that the integrity of the steam generator secondary side and main steam system would have been maintained.
- 4.
Corrective Action
The current as-left settings of the valves were performed using the Crosby SPVD method. Consistent use of the Crosby SPVD going forward, will eliminate the subjectivity associated with identifying the correct MSSV lift points.
After testing, all MSSVs were left within +/- 1% of TS acceptance criteria to account for future drift. Additional corrective actions to address micro bonding and the in-situ testing process will be evaluated in accordance with the station's Corrective Action Program.
- 5.
Previous Occurrences
Micro bonding has occurred previously during simmer testing at MPS2. Valve 2-MS-241 failed high (3.4%) during 2R16 simmer testing on April 07, 2005.
No previous similar events were identified related to test methodology, as this was the first time the Crosby SPVD has been used at MPS2.
Energy Industry Identification System (EIIS) codes are identified in the text as [XX].