PM Task Report6/16/2010Component Type:Heat Exchanger - Feedwater HeaterTask Name:Internal InspectionCriticalityCriticalMinorDuty CycleHighLowHighLowHighLowHighLowService ConditionsSevereMildSevereMildCHSCLSCHMCLMMHSMLSMHMMLM5YNA10YNANANANANATask ObjectiveThis inspection detects the extent of internal tube erosion, corrosion, and scaling. There is discretion in the choice of interval, which is part of a sampling scheme, to be predictive of future deterioration.Task ContentInternal inspection should include the following: Inspect for evidence of erosion or corrosion. Measure selected tubes for evidence of wall thinning. Inspect the gaskets and channel heads for evidence of leakage. Inspect for loose, missing or damaged fasteners. If performance monitoring or other inspections indicate the need, perform a borescope inspection on a representative sample of tubes, and inspect the shell side, if possible. Visually inspect for the presence, amount , and type of fouling. Inspect condition of passive cathodic protection devices, if present. If appropriate, determine the degree of fouling for the heater, in order to adjust the cleaning interval. Verify that previously plugged tubes are still plugged (i.e. use the tube plug map). Inspect welds between the pass partition and channel for evidence of failures. Perform tube and shell pressure test to detect leaks in tubes or at the tube joints.Principle Failure Location And Causes:This inspection is focused on detecting the extent of internal tube erosion, corrosion, and scaling.Progression Of Degradation In Time:The above failure causes are random in nature with a wide range of possible development times, depending on condition. The occurrence of these events might influence the frequency of Internal Inspection.Support For The Task Interval And Relation To Other Tasks:EPRI PM Basis Database - PM Program ReportPage 1 of 2

PM Task Report6/16/2010Component Type:Heat Exchanger - Feedwater HeaterTask Name:Internal InspectionCriticalityCriticalMinorDuty CycleHighLowHighLowHighLowHighLowService ConditionsSevereMildSevereMildCHSCLSCHMCLMMHSMLSMHMMLM5YNA10YNANANANANAThe information this task provides is a material condition assessment but is also predictive of future deterioration. For this reason, even though the suggested interval is 5 to 10 years, this is best interpreted as an average interval, with a sampling scheme that provides a more or less continuous assessment of condition. To achieve this it is beneficial to perform the task each outage on a portion of the heaters. As an example, consider a set of 18 high pressure heaters, of which 3 are examined each outage, starting with the first outage in a continuing cycle. Over the first 9 years of plant experience the average interval is then close to 5 years; over the first 18 years the average moves out to 7 years, and then to over 8 years in the third decade. Low pressure heaters would be examined every second outage so that the average intervals would be 10 years, then 14 years, then 16 years. This kind of sampling scheme is very stable, provides continuous feedback on equipment condition, starts close to the average intervals shown in the Template, provides early feedback early in the life of the equipment, and provides a significant degree of interval extension over the life of the heaters provided experience remains good.EPRI PM Basis Database - PM Program ReportPage 2 of 2