Document YD4e5nL7QXzo3greNo21dYBrN

October 31, 1975 CC: H. 7. MeCuatoer BCC: A. K. Roberta -- Constr. W. E. Ellis - ESD G. F. Moore - Design W. E. Cornelius - Design TO.- R. F. STEWART (3) FROM: K. S. 8CIMEITZER STAFF M8BTXEG KOTE Project 1772 - Old Hickory - EMT 7 Corrosion of Insulated c/S Pipe During the week of October 6, severe corrosion was found on a piece of carbon steel pipe from which insulation had been removed for pipe rework. The corrosion was to a depth of about a third of the wall thickness. The insulation was saturated with water. Additional pro-insulated pipe has been inspected. The following summarises tha current situation: 1. Corrosion has occurred only where the insulation haa become significantly wet (and not always even though wet). 2. The corrosion is most serious in SVT2V pipe (limited to 1" to 4" sise). Repair or replacement of pipe, if required, is limited to these sizes currently. 3. To date, insulated pipe for 2600 c/s isometrics (TPA and Dow not yet examined) has been checked. Approximately 150 have wet insulation. Current indication is that 2575 of the wet ones (or about 40) are severely corroded. Those will be checked by Design to datereins necessary action. 4. Construction plans to disseminata this information to other construction sites. 7 5. At this time, we see no significant dollar or schedule effect. DU 015246