Spillway concrete moving “slightly”

A spokeswoman for Duke Energy says a naturally-occurring reaction in the concrete of the Keowee spillway is causing the concrete to swell or to move, as she put it, “just slightly.”  That is enough for Duke and “FERC”–the Federal Energy Regulatory Commission–to agree there should be annual full–open tests of the gates.  Duke’s Mikayla Kreuzberger says tests on two of the spillway gates are partially done each year; full-open gate tests, every five years.  Now, however, there is to be full-open gate tests every year.  Spillways allow dams to safely pass large storm flows that exceed the discharge capacity of the hydro-electric units in the powerhouses.