16  New Project HYDRONEWS No. 29 Lower Monumental  USA

By Yunfeng Gao [email protected]

The U.S. Army Corps of Engineers, At the hydro­ ANDRITZ HYDRO will also supply new Walla Walla District, awarded a contract power plant, the turbine unit #1 experi­ stator windings and a stator core for to ANDRITZ HYDRO in July 2015, for enced a runner hub linkage failure, unit #1. Replacing the stator core will be generator rewind and turbine cavitation prompting the customer to weld blocks dependent on the on-site inspection and repairs at HPP Lower Monumental Dam. to the hub to hold the blades in a fixed condition assessment of the existing With 810 MW it is one of the four major position. The work will replace internal core. hydro­power plants on the lower Snake hub linkage components requiring disas­ Just prior to this award, ANDRITZ River in State, USA. sembly of the main unit and turbine HYDRO successfully completed a gen­ runner, with a provision to inspect and erator rewind project on 10 of 14 units at HPP Lower Monumental Dam is a run- refurbish other turbine and generator the McNary hydropower plant, located of-river plant with six Kaplan turbines components. on the near Umatilla, installed. Construction began in 1961, Repairs also include cavitation repair Oregon. with three units completed in 1969 and to unit #1 blades, hub and discharge ring an additional three units finished in 1981. as well as repair of cavitation damage to The entire project is expected to be All six generators and three of the six the unit #2 runner. Following the repair, completed by May 2017.  turbines were originally provided by both runners will work as completely ANDRITZ HYDRO’s predecessor com­ functional double-regulated Kaplan run­ TECHNICAL DATA panies. ners. Some of the generator and turbine Output 810 MW units, after nearly a half century’s opera­ 900 MVA tion, have performed past or are nearing Voltage 13.8 kV the end of their design life. Major rehabil­ Head 30 m itations have been carried out or are Speed 90 rpm planned. ANDRITZ HYDRO will continue Runner diameter 7,925 mm to work very closely with the Walla Walla District on these rehabilitation activities awarded under this contract.

Lower Monumental Dam U.S. Army Corps of Engineers photograph ©