| Title | Lifetime Prediction of a Recirculating Geothermal Cooling Water Pipeline |
|---|---|
| Authors | Keith A. Lichti, Rolan P. Vera Cruz and Melchor A. Ballestero |
| Year | 2005 |
| Conference | World Geothermal Congress |
| Keywords | Geothermal, cooling water, carbon steel, corrosion, Life Cycle Analysis |
| Abstract | A carbon steel recirculating cooling water pipeline in a geothermal power station experienced an increasing number of leaks after 17 years of operation. A risk based inspection internal and external survey of surface corrosion and remaining wall thickness measurements by Non-Destructive Ultrasonic Testing (UT) identified specific areas of continuing high risk of perforation while other areas exhibited low and acceptable rates of damage accumulation. A Life Cycle Analysis (LCA) approach was used to identify options for repair / replacement, comparing new coated steel vs. new stainless steel or relining of existing pipeline. Replacement with Type 316L stainless steel was the most economic option with a pay back period of 7 to 10 years for the additional capital investment. |