1. Lessons Learned from Guy Wire and Anchor Replacement at Sequoyah Nuclear Plant by Doyle Pittman 12th NUMUG Meeting - 2008

2. 2 Background 91-m tower erected in 1970 Advance 33 in. triangular, galvanized tower Instrumented at 3 levels 18, 3/8 in. guy wires 6 guy anchors 2003 and 2004 inspections: –Replace guy wires –Replace two guy anchors –Install new grounding Work order but no $$ 12th NUMUG Meeting - 2008

3. 3 Background Continued Guy wire tension checked every 3-years Self assessment in 2006 found no tolerance limit for tension Acceptable range = 1050 to 2250 pounds per square inch Six wires outside range Declared tower unsafe to climb March 2007 Investigated alternative ways to reach instruments – mobile crane with basket 12th NUMUG Meeting - 2008

4. 4 Lesson 1- Need Civil Engineer Support Maintain tower specifications Perform structural analysis –replace or repair tower –wind load less than design Guy anchor placement –slope –clearance –ground disturbance Tower condition 12th NUMUG Meeting - 2008

5. 5 Lesson 2 – Need for Workplan Training Forms/approvals –crane operation –digging permit –NEPA review –job safety analysis –rigging planning Pre-job brief –weather conditions Contingencies –concrete drying 12th NUMUG Meeting - 2008

6. 6 Lesson 3 – Regulatory Implications Degraded condition determination Calibration due dates –Tolerance –Tracking Data recoverability Limiting Condition for Operation –Moved to technical requirements manual –Any two of three wind levels –One of three temperature differences 12th NUMUG Meeting - 2008

7. 7 Getting Closer! 12th NUMUG Meeting - 2008

8. 8 New Guy Wire and Anchor 12th NUMUG Meeting - 2008

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10. 10 Success!!! 12th NUMUG Meeting - 2008