05000281/LER-2011-003, Regarding Isolation of Main Feedwater Pump Results in Auxiliary Feedwater Actuation
| ML11227A245 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 08/01/2011 |
| From: | Gerald Bichof Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 11-400 LER 11-003-00 | |
| Download: ML11227A245 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
| 2812011003R00 - NRC Website | |
text
1 OCFR50.73 Virginia Electric and Power Company Surry Power Station 5570 Hog Island Road Surry, Virginia 23883 August 1,2011 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555-0001 Serial No.:
SPS:
Docket No.:
License No.:
11-400 JSA 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. 50-281/2011-003-00 This report has been reviewed by the Station Facility Safety Review Committee and will be forwarded to the Management Safety Review Committee for its review.
Very truly yours, Gerald T. Bischof, Site Vice President Surry Power Station Enclosure Commitment contained in this letter: None
cc: U.S. Nuclear Regulatory Commission, Region II Marquis One Tower, Suite 1200 245 Peachtree Center Ave., NE Atlanta, GA 30303-1257 NRC Senior Resident Inspector Surry Power Station
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMI3SIOM APPROVED BY OMB: NO. 3150-0104 EXPIRES 10/31/2013 (10-2011)
, the NRC may 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 Isolation of Main Feedwater Pump Results in Auxiliary Feedwater Actuation
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO.
MONTH DAY YEAR 05000 FACILITY NAEDOCKET NUMBER 05 30 11 2011 -
003 -
00 08 01 11 FACILITY NAME 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
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- 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME TELEPHONE NUMBER (Include Area Code)
B. L. Stanley, Director Safety and Licensing (757) 365-2003MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT FACTURER TO EPIX FACTURER TO EPIX X
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B260 Y
- 14. SUPPLEMENTAL REPORT EXPECTED 15U EXPECTED MONTH DAY YEAR El YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
OX NO SUBMISSION I
DATE ABSTRACT (Limit to 1400 spaces, Le., approximately 15 single-spaced typewntten lines)
On May 30, 2011, at 0808 hours0.00935 days <br />0.224 hours <br />0.00134 weeks <br />3.07444e-4 months <br />, with Surry Power Station Unit 1 at 100% power and Unit 2 at intermediate shutdown, securing of a Unit 2 Main Feedwater pump resulted in the actuation of the Unit 2 motor driven Auxiliary Feedwater (AFW) pumps. The Unit 2 B Main Feedwater (MFW) pump was undergoing maintenance when the running Unit 2 A MFW pump outboard motor bearing experienced high temperature due to low oil flow. A decision was made to secure the Unit 2 A MFW pump to prevent bearing damage. The pump motor breakers for the Unit 2 A MFW pump were opened and the Unit 2 motor driven AFW pumps automatically started as expected and fed the Unit 2 steam generators until the plant was realigned to feed the steam generators with the condensate pumps. Plant equipment responded as designed and and the health and safety of the public were not affected. This report is being submitted pursuant to 10CFR50.73(a)(2)(iv)(A) for automatic actuation of the AFW system.
1.0 DESCRIPTION OF THE EVENT On May 30, 2011, at 0808 hours0.00935 days <br />0.224 hours <br />0.00134 weeks <br />3.07444e-4 months <br />, with Surry Power Station Unit 1 at 100% power and Unit 2 at intermediate shutdown (ISD) (- 405"F and - 823 psig) following a scheduled refueling, securing of Unit 2 A Main Feedwater (MFW) pump [EIIS-SJ-P]
resulted in Auxiliary Feedwater (AFW) [EIIS-BA] actuation. The Unit 2 B MFW pump was undergoing maintenance for seal replacement when the running A MFW pump outboard motor bearing experienced high temperature due to low oil flow.
Operators secured the A MFW pump and the Unit 2 motor driven AFW pumps automatically started, as expected.
A decision was made to secure the A MFW pump to prevent bearing damage with the knowledge that AFW would automatically start. The pump motor breakers for the A MFW pump were opened at 0808 hours0.00935 days <br />0.224 hours <br />0.00134 weeks <br />3.07444e-4 months <br /> and the Unit 2 motor driven AFW pumps automatically started as expected and fed the Unit 2 steam generators (SGs). The plant was subsequently realigned to feed the SGs with the condensate pumps [EIIS-SD-P] and the motor driven AFW pumps were secured at 0821 hours0.0095 days <br />0.228 hours <br />0.00136 weeks <br />3.123905e-4 months <br />.
Alternative actions that were considered to avoid AFW pump start would have taken additional time and would have extended operation of the A MFW pump at high temperatures. An 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> notification for the automatic actuation of AFW was made pursuant to 1 OCFR50.72(b)(3)(iv)(A).
This report is being submitted pursuant to 1 OCFR50.73(a)(2)(iv)(A) for automatic actuation of the AFW system.
2.0
SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS
Plant equipment responded as designed and there was no challenge to normal plant operation. An evaluation determined this event to be of very low safety significance. The unit was maintained stable at ISD. There were no radiation releases due to these events. Therefore, the health and safety of the public were not affected at any time during this event.
3.0
CAUSE
When the Unit 2 A MFW pump outboard bearing increasing temperature was identified, Operations personnel made a decision to secure the MFW pump and allow the AFW actuation. The action was taken to protect plant equipment when the rapid increase in bearing temperature was noted. A cause evaluation determined debris was present in the Unit 2 A MFW pump lube oil system and caused the low oil flow to the A MFW pump outboard motor bearing.U. S. NUCLEAR REGULATORY COMMISSION (10-2011)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE YEAR SEQUENTIAL REV Surry Power Station 05000- 281 NUMBER NO.
3 of 3 2011 003 00 4.0 IMMEDIATE CORRECTIVE ACTION(S)
When AFW actuated, operators realigned condensate pumps to feed the SGs. The AFW pumps were then secured.
5.0
ADDITIONAL CORRECTIVE ACTIONS
The lube oil system for the Unit 2 A MFW pump was disassembled, cleaned, flushed, tested and placed back into service at 0817 hours0.00946 days <br />0.227 hours <br />0.00135 weeks <br />3.108685e-4 months <br /> on June 11, 2011.
6.0 ACTIONS TO PREVENT RECURRENCE The action to secure the A MFW pump and the resulting AFW pump actuation was needed to prevent further damage to the pump.
7.0
SIMILAR EVENTS
None 8.0 MANUFACTURER/MODEL NUMBER Main Feedwater Pump: Sulzer Bingham Pumps, Inc./CD 9.0
ADDITIONAL INFORMATION
Unit 1 was at 100% power and remained unaffected by the Unit 2 AFW actuation.
Unit 2 continued with the scheduled refueling outage.