ML093451502
ML093451502 | |
Person / Time | |
---|---|
Site: | Ginna |
Issue date: | 12/09/2009 |
From: | John Carlin Constellation Energy Nuclear Group, Ginna |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
EA-09-249, IR-09-008 | |
Download: ML093451502 (6) | |
Text
John Carlin R.E. Ginna Nuclear Power Plant, LLC Site Vice President 1503 Lake Road Ontario, New York 14519-9364 585.771.5200 585.771.3943 Fax John.Carlin@cengllc.com CENG
..a joint venture of Energy Constellation. It-nDF December 9, 2009 U. S. Nuclear Regulatory Commission Washington, DC 20555 - 0001 ATTENTION: Document Control Desk
SUBJECT:
R.E. Ginna Nuclear Power Plant Docket No. 50-244 Reply to a Notice of Violation; EA-09-249
REFERENCE:
Letter from Mr. S. J. Collins (NRC) to Mr. J. T. Carlin (Ginna) dated November 12, 2009, FINAL SIGNIFICANCE DETERMINATION OF WHITE FINDING, WITH ASSESSMENT FOLLOW-UP, AND NOTICE OF VIOLATION - R.E. GINNA NUCLEAR POWER PLANT (NRC Inspection Report No. 05000244/2009008).
This letter provides the R.E. Ginna Nuclear Power Plant, LLC (Ginna LLC) response to the referenced letter, which identified a Notice of Violation associated with a failure to preclude recurrence of a significant condition adverse to quality associated with the turbine driven auxiliary feedwater pump governor control valve, that led to a failure of the TDAFW pump to operate on July 2, 2009. Ginna LLC agrees with the violation and has taken corrective steps to prevent further violations.
The attachment to this letter provides the Ginna LLC detailed response to the violation. In accordance with 10 CFR 2.20 1, this response describes the reason for the violation, the corrective steps that have been taken and results achieved, the corrective steps that will be taken to avoid further violations, and the date when full compliance will be achieved.
If you should have any questions regarding this submittal, please contact Mr. Thomas Harding at (585) 771-5219, or via email at Thomas.HardingJrgcengllc.com.
Very truly yours, John T. Carlin
Attachment:
REPLY TO A NOTICE OF VIOLATION; EA-09-249
cc: S. J. Collins, NRC D. V. Pickett, NRC Ginna Resident Inspector, NRC P. D. Eddy, NYSDPS
ATTACHMENT REPLY TO A NOTICE OF VIOLATION; EA-09-249 R.E. Ginna Nuclear Power Plant, LLC December 9, 2009
ATTACHMENT REPLY TO A NOTICE OF VIOLATION; EA-09-249 NOTICE OF VIOLATION 10 CFR 50, Appendix B, CriterionXVI, "CorrectiveActions, "states, in part, "Measuresshall be establishedto assure that conditions adverse to quality,such asfailures, malfunctions, deficiencies, deviations, defective material andequipment, and nonconformnances arepromptly identified and corrected In the case of significant conditions adverse to quality, the measures shall assure that the cause of the condition is determinedand corrective action taken to preclude repetition."
Contrary to the above, after identifying corrosionon the turbine-drivenauxilialyfeed water (TDAFW) pump governor controlvalve stem on April 11, 2005, a significantcondition adverse to quality, R.E. Ginna Nuclear Power Plant,LLC did not take adequate measures to determine the cause and prevent recurrence. The cause of the condition was left uncorrectedand resulted in additionalstem corrosionthat led to binding of the governor control valve and the failure of the TDAFW pump on July 2, 2009.
This violation is associatedwith a White SDPfinding.
REASON FOR THE VIOLATION After identifying corrosion on the Turbine Driven Auxiliary Feedwater (TDAFW) Pump Governor Control Valve (V-9519E) stem during the 2005 Refueling Outage (RFO), adequate measures were not taken to determine the cause of the corrosion and prevent recurrence. The cause of the corrosion was left uncorrected and resulted in stem corrosion that led to binding of V-9519E, which caused the failure of the TDAFW Pump on July 2, 2009.
The failure occurred while the plant was in Mode 1, with reactor power at approximately 100%
and Main Steam header pressure at approximately 770 PSIG. While testing was being performed per STP-O- I6-COMP-T (flow into the Steam Generators), the TDAFW Pump tripped on overspeed. Videos and UDS valve traces indicated the cause of the problem was a degraded Oil Relay Valve (OP/RLYVLV) or V-9519E. Troubleshooting Plans were developed and resulted in testing of the OP/RLYVLV and V-9519E response to simulate changes in demand from the TDAFW Pump Governor (SAF03). Upon disassembly of V-9519E per Work Order (WO)
C20900344, the stem was found seized within the bushings. Visual inspectionshowed pitting on the surface of the stem where it contacts the upper valve bushing. The corrosion caused the stem to bind within the bushings, causing the control of steam to the turbine to be lost, and resulted in the overspeed trip.
During the Root Cause Analysis (RCA) of the overspeed trip, it was discovered that the stem was pitted during performance of the last major inspection of V-9519E per Work Order (WO)
C20401907 performed in 2005. Per a Vendor Representative recommendation, a replacement stem was installed. The stem replacement was the corrective action to the noted degradation.
However, the condition was not entered into the Corrective Action Process (CAP) to document R.E. Ginna Nuclear Power Plant, LLC December 9, 2009 Page 1
ATTACHMENT REPLY TO A NOTICE OF VIOLATION; EA-09-249 the condition or to take other action to determine the cause of the pitting, and no corrective actions to prevent recurrence were identified and instituted. Based on interviews, if this condition was identified today, current site practices would result in the condition being entered into the CAP to document the problem and initiate corrective actions as appropriate.
III. CORRECTIVE STEPS THAT HAVE BEEN TAKEN AND THE RESULTS ACHIEVED The following is a summary of the actions immediately taken following the July 2009 failure:
- 1. The stem of V-9519E was replaced with a spare.
- 2. The Relay valve (OP/RLYVLV) was removed, inspected, and re-assembled with no anomalies and no foreign material found per WO C90471610.
- 3. The TDAFW Pump steam traps were inspected using a boroscope, compressed air, and other visual methods of inspection. No anomalies were found per WO C90471684.
- 4. A slow speed start of the pump was performed by manually opening the Trip and Throttle Valve (V-3652) while monitoring turbine speed. Speed was increased in 500 RPM increments until SAF03 took control of turbine speed. No anomalies were noted during this slow speed start and all equipment behaved as expected.
- 5. The pump was tested using both PT-I 6Q-T (recirculation flow) and STP-O- I 6-COMP-T (flow into the Steam Generators) with no abnormalities noted.
- 7. Compensatory measures of increased test frequency coupled with video and UDS monitoring of SAF03 and V-9519E has continued since the July 2009 failure.
The following is a summary of the actions taken during the 2009 Refueling Outage (RFO) following the July 2009 failure:
- 1. The stem and bushings of V-9519E were inspected. The stem and bushings were replaced due to minor pitting and to allow for destructive testing of the components to aid in the validation of the corrosion rate correlation. Additional inspections of the valve internals will be conducted until enhanced materials are installed that are less susceptible to the corrosion that caused the stem binding in July 2009.
- 2. The Steam Admission Motor Operated Valves (MOV's), MOV-3504A and MOV-3505A, were overhauled to reduce the amount of steam leakage into the system during standby operation.
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ATTACHMENT REPLY TO A NOTICE OF VIOLATION; EA-09-249
- 3. A detailed inspection of the control linkage was conducted with no abnormalities noted.
- 4. Increased frequency testing of the pump and control valve have continued.
The adequacy of the before mentioned corrective actions discussed above with respect to equipment reliability of the TDAFW Pump is demonstrated by the seventeen (17) successful pump starts since the July 2009 failure.
IV. Corrective Steps That Will be Taken To Avoid Further Violations The following is a summary of the action that will be taken to prevent recurrence:
- 1. The stem and bushings of V-9519E will be replaced with enhanced materials that are less susceptible to the corrosion that caused the original stem binding.
- 2. The Preventative Maintenance (PM) frequency of the inspection of V-9519E will be revised to an optimum frequency based on further inspections and the replacement design.
- 3. MOV-3504A and MOV-3505A will be replaced to minimize the amount of steam leakage into the system during standby operation.
- 4. The maintenance procedure for V-9519E, CMM-37-19-9519E, will be revised to include the addition of verification of stem inspection results, specifically looking for pitting or any other surface degradation. The procedure will direct any condition be entered into the corrective action program if pitting is observed.
- 5. A series of High Performance Team-Building Workshops will be developed and implemented to focus on the use of formality and rigor in making decisions that affect equipment that is relied on for the safe operation of the plant.
V. Date When Full Compliance Will Be Achieved All the before mentioned correction actions are planned for completion by June 2011.
R.E. Ginna Nuclear Power Plant, LLC December 9, 2009 Page 3