1. 2012 Operating Experience for Feedwater and Related Systems
Discuss
WANO Indicator – Based on Auto only per 7000 hrs.
This data is ALL Unplanned While Critical
Mike Ballard – INPO ER Group
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7. General Comments on 2012 Scrams
Tied 2011 for fewest scrams
But equipment scrams significantly increased from 40 to 53 (fewer scrams by external causes and Hu error)
BWR scrams increased in 2012 from 20 to 29 
PWRs continued the 3 year decline from the peak in 2010 
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8. 2012 FW Scrams 13 FW in 2012 (compared to 9 in 2011 and 15 in 2010)
Five scrams were from SPVs not mitigated or with bridging strategies. Most were known SPVs.
Four attributed to problems with FRVs.
Nine occurred below 100 percent power.
Three Scrams attributed to gaps in maintenance and work instructions.
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9. 2012 FW Scrams Half the scrams had previous industry OE.
One scram attributed to operations error.
One scram caused by no PM strategy.
One scram from a longstanding problem not corrected in a timely manner.
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10. SPV FW Scrams
Contaminated shuttle valve in positioner housing for FRV (SPV? – some stations have dual positioners)
Three element circuit card and FWP control loop malfunction (SPV?)
7300 card failed. Digital FW control system project delayed with no mitigating strategy.
Degraded resistance film transducer on postioner feedback mechanism - replaced with noncontact positioner
FWPT control SPV not mitigated in timely manner - project delays
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11. Maintenance related FW Scrams
Three Scrams attributed to gaps in MA and work instructions
Instrument air to an AOV fitting failure
Inexperienced MA technicians performing ST and inadequate procedure
Inadequate FW pump turbine rebuild and gaps in work instructions
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12. Feed Reg Valve related scrams
Degraded instrument air quality
Actuator malfunction
Degraded resistance film transducer on postioner feedback mechanism - replaced with noncontact positioner
Maintenance related HU error
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13. PM related FW Scram
FRV malfunction caused by high contact resistance on FW control channel selector switch resulted in the loss of feed water flow signal for a short duration. This switch had been in service for over 40 years. The cause was the failure to recognize the need for PM for low voltage control switches based on the PM Basis template.
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14. Other Notable 2012 FW OE
The 2A and 2B Feedwater Heaters (FWH) shells were had through-wall failures during outage inspections. Trending of FWH levels and control valve position did not show any indications of an adverse trend in either FWH. No changes in thermal performance occurred in either FWH. Failures were found along the heater underside. Based on the wear profile along the internal surface of the FWH shells, the primary cause of failure has been attributed to Flow Accelerated Corrosion (FAC) wear.
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15. Other Notable 2012 FW OE
During surveillance testing, a feedwater check valve failed to stroke fully closed as evidenced by low differential pressure across the valve. The valve was declared inoperable and the required to be in Mode 4 within 18 hours was subsequently met. The cause was mechanical binding.
A  previous 8Y PM had been mistakenly retired and was not identified by engineering
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16. Other Notable 2012 FW OE
UNUSUAL EVENT DECLARED when a fire was detected at one of the running feedwater pumps. Reactor power was lowered to 62. The fire appeared to have started from oil soaked lagging.
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17. Other Notable 2012 FW OE BOP AOVs
High level in a feedwater heater caused the FWH string to isolate. Power was reduced to 89%. The cause was a faulty level indicating controller.
Min flow recirc valve spuriously opened causing low FW pump suction alarms and tripped a pump, and power reduction to 55%.
A rapid load reduction occurred when a heater drain tank level control valve began controlling erratically and failing closed. Severe internal damage was found from misalignment. PMs did not include replacement of the upper and lower stem bushings
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18. Equipment Reliability Process Top Level Diagram
Performance
Monitoring
Scoping &
Identification
of Critical
Components PM
Implementation
Corrective
Action
Life Cycle
Management
Continuing
Equipment Reliability
Improvement
Equipment Reliability Process Top Level Diagram
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19. Gaps in AP913 Implementation contributing to the events
Life cycle management – single point vulnerabilities not mitigated – Engineers can be advocates for identifying and driving resolution in assigned systems
PM implementation – system engineers ensure components are accurately classified and own the PM basis for critical components
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20. Gaps in AP913 Implementation contributing to the events
Corrective Action (CA) – Many of the FW events occurred previously. System engineer’s role is key to:
Learn from OE and implement timely CAs.
Find direct and underlying causes and implement solutions that address the causes [go beyond creating new PMs when possible]
Prioritize equipment problem resolution
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21. Gaps in AP913 Implementation contributing to the events
Performance monitoring – this includes
Effective system walkdowns
Long-term trending of important parameters [not just reviewing the current data against the action limit]
Trend equipment failures within the system, across system boundaries, and compared to other stations
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22. But I am only the system engineer…..
So was the engineer that knew about the Challenger problems.
If the issue is one that impacts nuclear safety or plant reliability then be an advocate and go to the next level.
System engineers need to overcome barriers and not stop at the first “no”
Use CAP, health reports, plant health committee
Find alternative solutions
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23. Questions?
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