Lessons Learned at Whitehorse Rapids: Repairing a Failed Runner Blade

摘要

After 30 years of operation, an 8-MW four-bladed propeller-style turbine at the 40-MW Whitehorse Rapids hydro site suffered a catastrophic runner failure. Analysis attributed the failure to fatigue cracks originating from locations hardened during repair welds completed after the casting process. The blade was repaired using a custom-designed weld repair and heat treatment procedure.