TVA, Purchasing, 1101 Market Street, Chattanooga, TN 37402

Z -- INVESTIGATIVE DRILLING AND GROUTING TO REPAIR LEAK SOL To be determined POC Contracting Officer, Bill Murray, 423-751-2346 The following information pertains to a job at TVA's Tims Ford Hydro Plant:Plans are being made to award a contract for investigation drilling and grouting ofthe right rim leakage. The drilling and grouting will be started during the normaldrawdown of the reservoir this winter. This will allow for a lower leakage flowthrough the rim and aid in the grouting. This contract will consist of the following:(1) Percussion holes approximately 100 feet deep will be drilled through the overburden (soil) and into rock to approximate elevation 840. These holes will beused to determine top of rock, locate any open cavities, etc. (2) Holes will bespaced 20 feet on center along the crest of the rim. (3) The rock will be groutedthrough these holes using a hydrophobic polyrethane grout instead of a cementiousmaterial. The hydrophobic polyurethane grout expands when it meets water or moisture. (4) Based on the grout take in these holes additional holes will be drilledsplitting the spacing and grout injected. (5) This procedure will be repeated inareas as required. (6) As the grouting proceeds, the effectiveness of the repair willbe evaluated, and a decision will be made whether to continue with the process. (0247)

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