05000280/LER-2012-001, Regarding Oil Foaming in Speed Increaser Results in Inoperable Charging Pump
| ML12102A017 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 04/02/2012 |
| From: | Lane N Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 12-227 LER 12-001-00 | |
| Download: ML12102A017 (6) | |
| 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)(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 |
| 2802012001R00 - NRC Website | |
text
1 OCFR50.73 Virginia Electric and Power Company Surry Power Station 5570 Hog Island Road Surry, Virginia 23883 April 2, 2012 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555-0001 Serial No.:
SPS:
Docket No.:
License No.:
12-227 JSA 50-280 DPR-32
Dear Sirs:
Pursuant to 10CFR50.73, Virginia Electric and Power Company hereby submits the following Licensee Event Report applicable to Surry Power Station Unit 1.
Report No. 50-280/2012-001-00 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, N. L. La" 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 COMMISSION 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 1 05000- 280 1 OF 4
- 4. TITLE Oil Foaming in Speed Increaser Results in Inoperable Charging Pump
- 5. EVENT DATE
- 6. LER NUMBER
[
- 7. REPORT DATE 1
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR SEQUENTIAL REV I DFACII-TY NAME OOCKFT NI IMRFR YEAR NUMBER NO.
MONTH DAY YEAR 05000 02 01 12 2012 -
001 -
00 I 04 02 12 0FACILITY NAME DCKETNuMBER0
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 4: (Check all that apply) 1:I 20.2201(b)
I]
20.2203(a)(3)(i)
IJ 50.73(a)(2)(i)(C) 50.73(a)(2)(vii)
N E] 20.2201(d)
I]
20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A)
I]
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)
EJ 20.2203(a)(2)(i)
EJ 50.36(c)(1)(i)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL C 20.2203(a)(2)(ii)
[] 50.36(c)(1)(ii)(A)
ED 50.73(a)(2)(iv)(A)
I]
50.73(a)(2)(x)
[] 20.2203(a)(2)(iii)
[]
50.36(c)(2)
[]
50,73(a)(2)(v)(A)
[]
73.71(a)(4) 100%
[]20.2203(a)(2)(iv)
[]
50.46(a)(3)(ii)
[]
50,73(a)(2)(v)(B)
[]73.71(a)(5)
IZ 20.2203(a)(2)(v)
[Z 50.73(a)(2)(i)(A)
[] 50.73(a)(2)(v)(C)
EJ OTHER 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B)
F 50.73(a)(2)(v)(D)
Specify in Abstract below l
22or in NRC Form 366A
- 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME TELEPHONE NUMBER (include Area Code)
F3. L. Stanley, Director Safety and Licensing (757) 365-2003SYTM CMOET MANU-REPORTABLE CAS YTM CMOET MANU-REPORTABLE
CAUSE
FACTURER TO EPIX SYSTEM COMPONENT FACTURER TO EPIX X
CH P
N402 Y
- 14. SUPPLEMENTAL REPORT EXPECTED I
- 15. EXPECTED MONTH DAY YEAR MW YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
El NO DATE 06 0
2012 ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On January 25, 2012 at 0033 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br />, with Surry Power Station Units 1 and 2 at 100% power, oil foaming was observed in the Unit 1 B Charging (CH) pump gearbox sight glass. The pump was secured and oil level verified. On January 31, 2012, the 1 B CH pump was started and within 30 seconds, foaming was again observed. On February 1, 2012 at 1410 hours0.0163 days <br />0.392 hours <br />0.00233 weeks <br />5.36505e-4 months <br />, the 1B CH pump was declared inoperable. Air ingress was considered to be the cause and oil pump suction line fittings were tightened and sealed.
The pump was started on February 4, 2012 with no foaming observed. Technical Specifications (TS) require one flow path of charging to be in operation with an additional CH pump to be operable when the reactor is critical. The TS limiting condition for operation (LCO) for one of the two CH pumps being inoperable is 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Without supporting information about the foaming, CH pump 1 B was considered inoperable from January 25, 2012, when oil could not be defined in the sight glass due to foaming, until the charging pump was declared inoperable on February 1, 2012, exceeding the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> LCO.
Therefore, 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. This event was determined to be of very low safety significance and the inoperable pump did not affect the health and safety of the public.
1.0 DESCRIPTION OF THE EVENT On January 25, 2012, at 0033 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br />, with Surry Power Station Units 1 and 2 at 100% power, oil was reported to be foaming in the gearbox sightglass for the Unit 1 Charging (CH) pump [EIIS:CB/BQ-P] 1 B speed increaser gear box. The speed increaser and CH pump have a common lubrication system. The oil reservoir with sightglass is located in the speed increaser. Engineering noted that there was no increase in bearing temperature or vibration and concluded that the foaming was not detrimental to the operation of the pump. At 1630 hours0.0189 days <br />0.453 hours <br />0.0027 weeks <br />6.20215e-4 months <br />, Operations reported bearing flow from the bearings to the sump was normal; however, the gearbox sightglass was covered in foam. A gallon of oil was added with no visable change in oil level. The CH pump was secured and the oil level was observed to be above the top of the sightglass. At 2015 hours0.0233 days <br />0.56 hours <br />0.00333 weeks <br />7.667075e-4 months <br />, one half gallon of oil was drained from the speed increaser and the oil level was observed to be at approximately the midpoint of the sightglass. The oil was tested and no water or excessive wear particles were found. Testing also verified there was no degradation of anti-foaming agent. With adequate oil level and quality, no observed increase in bearing temperature, no increase in vibrations, and no aeration in the return oil flow to the sump, CH pump 1B was considered operational and was placed in automatic. CH pump 1A remained the operating charging pump.
On January 31, 2012, at 1148 hours0.0133 days <br />0.319 hours <br />0.0019 weeks <br />4.36814e-4 months <br />, CH pump 1B was started and foaming was observed in the sightglass within 30 seconds. The foaming continued to increase and the pump was secured 3 minutes after the the pump was started. Based on the rate of foaming, it was concluded that air ingress on the oil pump suction line was the likely source of inleakage. On February 1, 2012, at 1410 hours0.0163 days <br />0.392 hours <br />0.00233 weeks <br />5.36505e-4 months <br />, CH pump 1 B was declared inoperable and a plan was initiated to stop the air ingress. On February 2, 2012, at 0200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br />, oil pump suction line fittings were tightened and sealant was applied to the mechanical fittings. The oil was changed and the pump was started on February 4, 2012, at 0013 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> with no oil foaming observed.
Although foam was present in the oil for CH pump 1 B, oil level was adequate with no leaks and no increase in bearing temperature or vibration trends. Also, the foaming was not considered excessive since none was coming out of any vents.
However, test data could not be provided to prove that the foaming would reach an equilibrium such that it would not continue foaming and deplete the oil to the point of threatening operation of the pump design basis mission time of 30 days.
Technical Specifications (TS) 3.2 and 3.3 require one flow path of charging to be in operation with an additional CH pump to be operable when the reactor is critical.
The TS limiting condition for operation (LCO) for one of the two CH pumps being inoperable is 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Without supporting information about the foaming, CH pump 1B was considered inoperable from January 25, 2012, when oil level could not be defined in the sightglass due to foaming, until the charging pump was declared inoperable on February 1, 2012, exceeding the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> LCO. Therefore,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 05000-280 NUMBER N
3 of 4 2012 001 00 this report is being submitted pursuant to 1 OCFR50.73(a)(2)(i)(B), any operation or condition prohibited by the plant's Technical Specifications.
In addition, on January 27, 2012 at 0001 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, CH pumps 1A and 1C were declared inoperable during return to service testing of CH pump 1A following maintenance activities. CH pump 1 B was also considered inoperable due to foaming during this time. CH pump 1C was returned to operable status within 32 minutes at 0033 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br />.
2.0
SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS
When foaming of the oil continued and the design basis 30 day mission time was in question, the appropriate number of charging pumps were either available or there was charging capability available from Unit 2 to provide charging to Unit 1 through a charging crosstie. Therefore, this event was determined to be of very low safety significance and the health and safety of the public was not affected.
3.0
CAUSE
A preliminary cause evaluation determined loose fittings resulted in air inleakage in the suction line of the speed increaser gear box oil pump.
4.0 IMMEDIATE CORRECTIVE ACTION(S)
When foaming of the oil continued and the design basis 30 day mission time was in question, CH pump 1 B was removed from service and a standby pump was placed in operation.
5.0
ADDITIONAL CORRECTIVE ACTIONS
Oil pump suction line fittings were tightened and sealed to prevent air ingress.
6.0 ACTIONS TO PREVENT RECURRENCE Maintenance procedures for removal and installation of the oil line fittings will be revised to ensure fittings are tightened appropriately.
7.0
SIMILAR EVENTS
None NRC Form 356A (10-2011)U. S. NUCLEAR REGULATORY COMMISSION (10-2011)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE YER SEQUENTIAL I REV 1YEAR NUMBER NO, o
Surry Power Station 05000 -280 UBR N.4 of 4 2012 001 00 8.0 MANUFACTURER/MODEL NUMBER Nuttall Gear Corporation & Chevron Al 68 9.0
ADDITIONAL INFORMATION
Unit 2 was at 100% power and remained unaffected by the Unit 1 B charging pump speed increaser gear box oil foaming. Unit 2B charging pump lube oil was also observed to be foaming; however, the oil level was observed to be adequate.
Testing and research will continue to gather additional information to better understand the effect of foaming on the operation of the CH pump.
N RC Form 366A (10-2011)