ML13218A021

Licensee Slides, 08/07/13 Preapplication Meeting with Wolf Creek Nuclear Operating Corporation to Discuss Long-Term Corrective Actions for Water Hammer Events in the Essential Service Water System at Wolf Creek (TAC No. MF2457)

ML13218A021
Person / Time
Site:	Wolf Creek
Issue date:	08/07/2013
From:	Wolf Creek
To:	Office of Nuclear Reactor Regulation
Lyon C F
References
TAC MF2457
Download: ML13218A021 (13)

Text

1Modification to Essential Service Water SystemAugust 7, 2013WCNOC-NRC Pre-submittal Meeting 2Meeting Agenda*Introduction of the team*State the objectives of the meeting*Describe the waterhammer phenomena*Explain how this modification will address the issue*Describe the approach to the modification2 3Presentation ObjectiveDiscuss the Wolf Creek Waterhammer Mitigation Modification3 4Project Team*Rich ClemensVice President -Strategic Projects*Russell BowieESW Project Director*TomSydnorWater Hammer Mitigation PM

• Kamran DerakhshandeganESW Project Engineer

• Larry StevensLicensing Engineer

• RichKokeshSargent& Lundy -Project Manager

• Tony RyanSargent& Lundy -Lead Engineer*Donald GrafMPR Associates -Consultant4 55Description of the Total ESW Initiative*Buried Piping Replacement Project (BPRP)*Above Ground Replacement Project (AGRP)*Waterhammer Mitigation Project*ESW System Inspection and Repair Program5 66Description of the Waterhammer Mitigation Modification*The use of a bypass line around the ESW Pump discharge valve*The closure of the ESW Pump discharge valve for a fixed time period to force flow through the bypass*The locking shut of ESW cross-tie valves

• A time-delay relay in-line to ESW Pump discharge valve open signal6 Waterhammer Phenomena*Present design results in a pressure transient (waterhammer) when ESW flow is initiated upon shutdown of the normal Service Water (SW) system77 System Operation1.Initiating event2.Service water shutdown, system begins to drain down3.EDG start 4.Sequencer operation5.Cross-tie valve operation6.Start ESW pumps 7.ESW flow in bypass mode8.Main ESW Valves open, full flow of ESW88 99Effects of this Modification1.Reduces system column closure effects2.Reduction in pressure pulse3.Reduction in piping loads4.Remains within design specifications 9 1010Analytical Methods UsedComputer modeling (vice hand calculation) using the same calculation methods as existing plant license*Hydraulic network evaluation*Void closure pressure -JoukowskyEquation10 1111Conclusion*The 50.59 process has concluded that prior NRC approval not required*WCNOC intends to implement the proposed modifications to the ESW by completion of mid-cycle outage during spring of 2014.11 1212Schedule for Implementation*Complete design Oct. 29, 2013*Receive valves & materials Jan. 6, 2014

• Fabrication of sub-assemblies Jan. 17, 2014

• Start outageFeb. 1, 2014

• Start-upApril 2, 201412 1313Any questions or comments?13