05000281/LER-2008-001, Pressurizer Safety Valves Fail as Found Setpoint
| ML081980059 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 06/30/2008 |
| From: | Jernigan D Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 08-0342 LER 08-001-00 | |
| Download: ML081980059 (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)(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 |
| 2812008001R00 - NRC Website | |
text
1 OCFR50.73 Virginia Electric and Power Company Surry Power Station 5570 Hog Island Road Surry, Virginia 23883 June 30, 2008 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555-0001 Serial No.:
SPS:
Docket No.:
License No.:
08-0342 PAK 50-281 DPR-37
Dear Sirs:
Pursuant to 10CFR50.73, Virginia Electric and Power Company hereby submits the following Licensee Event Report applicable to Surry Power Station Unit 2.
Report No. 50-281/2008-001-00 This report has been reviewed by the Facility Saf ty Review Committee and will be forwarded to the Management Safety Review Co mi tee for its review.
Ve truly yours, Don Id E. Je nigan, Site ictp sident Surry Power Station Enclosure Commitments contained in the LER:
The Pressurizer Safety Valve maintenance strategy will be revised prior to the next refueling outage to address aging issues.
AJ40
1 OCFR50.73 cc:
United States Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 NRC Senior Resident Inspector Surry Power Station
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSIO APPROVED BY OMB NO. 3150-0104 EXPIRES: 8/31/2010 (9-2007)
, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE SURRY POWER STATION, UNIT 2 05000 281 1 OF 3
- 4. TITLE Pressurizer Safety Valves Fail as Found Setpoint
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR I SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCUMENT NUMBER I NUMBER NO, 05000 05 02 2008 2008
- - 001 -
00 06 30 2008 FACILITY NAME DOCUMENT NUMBER 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
El 20.2201(b)
Ej 20.2203(a)(3)(i)
[]
50.73(a)(2)(i)(C)
LI 50.73(a)(2)(vii)
El 20,2201(d)
E] 20.2203(a)(3)(ii)
[]
50.73(a)(2)(ii)(A)
Ej 50.73(a)(2)(viii)(A)
N LI 20.2203(a)(1)
- - E] 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
[]
50.36(c)(1)(i)(A)
[]
50.73(a)(2)(iii)
El 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)
LI 20.2203(a)(2)(iii)
El 50.36(c)(2) 50.73(a)(2)(v)(A)
[] 73.71(a)(4)
El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B) 73.71(a)(5) 0L 20.2203(a)(2)(v)
[]
50.73(a)(2)(i)(A)
[
50.73(a)(2)(v)(C)
VOUOTHER 0%
E] 20.2203(a)(2)(vi)
[]_ 50.73(a)(2)(i)(g)
E]
50.73(a)(2)(v)(D)
VOLUNTARY LER
- 12. LICENSEE CONTACT FOR THIS LER NAME TELEPHONE NUMBER (Include Area Code)
B. L. Stanley, Director Station Safety and Licensing (757) 365-2003CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM OMPONENT MANU-REPORTABLE FACTURER TO EPIX.
FACTURER TO EPIX X
AB RV C710 N____
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR El YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
W]
NO DATESUBMIS ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On May 2, 2008 with Unit 2 shut down for a refueling outage, a pressurizer safety valve (PSV) 2-RC-SV-2551C as found lift setting was 2368 psig, which is 4.7% below the nominal value of 2485 psig.
Technical Specification (TS) 3.1.A.3.b specifies the as found tolerance shall not exceed +\\- 3% (2410-2510 psig).
On May 9, 2008, PSV 2-RC-SV-2551 B failed to lift within the as found set pressure requirement. The as found lift setting also did not meet the +/- 3% tolerance allowed by TS 3.1.A.3.b. This PSV exhibited an as found lift setpoint of 2399 psig which was 3.51% below the nominal value of 2485 psig.
The as found PSV lift settings were evaluated and it was determined that the PSVs were capable of performing their safety function and operation with the low as found lift setpoints was within the limits assumed in the accident analysis. Therefore, the health and safety of the public were not affected.
There were no significant safety consequences associated with this event. This report is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(B) "Any operation or Condition prohibited by the plant's Technical Specifications".
NRC FORM 366 (9-2007)
PRINTED ON RECYCLED PAPER (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17) was reassembled for the steam set pressure and steam seat tightness testing. PSV 2-RC-SV-2551C satisfactorily passed both steam set pressure and steam seat tightness testing.
In accordance with the requirements of ASME section XI, the remaining two PSVs were sent to Wyle labs for setpoint testing.
5.0 ADDITIONAL CORRECTIVE ACTIONS
The other two PSVs on Unit 2 were setpoint tested.
PSV 2-RC-SV-2551 B as found set pressure was 2399 psig which is 3.5% lower than the TS required range of 2410 - 2510 psig. PSV 2-RC-SV-2551B was completely disassembled and valve internals were VT-3 inspected and dimensions verified. The disk insert was replaced due to the disc seat step being near minimum tolerance. The spring assembly was replaced and the valve re-assembled and satisfactorily tested.
PSV 2-RC-SV-2551A was tested satisfactorily and subsequently re-installed.
6.0 ACTIONS TO PREVENT RECURRENCE The PSV test program is based on Section XI of the ASME Code. The EPRI Safety and Relief Valve Testing and Maintenance Guide lists several factors as potential causes of lift low. All but two of these factors, aging and spring relaxation, do not apply in this case. Failure rate of as found set pressure testing can be reduced if the valves are rebuilt prior to actual failure. The PSV maintenance strategy will be revised prior to the next refueling outage to address aging issues.
7.0
SIMILAR EVENTS
None.
8.0 MANUFACTURER/MODEL NUMBER Crosby, HB-BP-86EPRINTED ON RECYCLED PAPER