1 - Alaska Energy Data Inventory

"WHAMO" was used for the run and results were:Minimum surge tank WSEL = 764 ft.Minimum piezometer elevation at the unit = 598 ft.Plate B2 shows the location of the demand run and Plates B7 through B10illustrate the various transients occurring during demand. Figure 14 ofAppendix B2 is the WHAMO input file.(3) Emergency Closure of Spherical Valve - In the event of afailure of the wicket gates or penstock rupture downstream of the sphericalvalve, the spherical valve will be closed to stop the flow of water intothe powerhouse. Spherical valve specifications (by HEDB) call for a valveclosure time of 2 minutes. Straight line valve closure rates of 30, 60,and 120 seconds were simulated on the "WHAMO" program using the dischargecoefficient vs valve angle curve for the spherical valve provided by HEDB(figure 15 of Appendix B2). The water hammer resulting from the closurerate of 30 seconds was chosen for conservatism. The pressures on theupstream side of the valve resulting from these valve closure rates aretabulated as follows:Spherical Valve Closure RateSeconds3060120Maximum Pressure onUpstream Side of Valve (ft)1 , 1281,0791,047The various transient conditions occurring as a result of the 30 secondvalve closure are shown on Plates B16 and B17. The IWHAt-IO" run simulated asituation in which the wicket gates are frozen in the open position andconstant power generat i on ; s occurr; ng (generate mode on "WHAMO"). Th ismode produced a higher water hammer than a standard reject run. Figure 16of Appendix B2 shows the "WHAMO" input file for this run (30 secondclosure). The spherical valve closure runs were made with the same initialconditions as those assumed for the load rejection run in subparagraph 1.04K (1).Bl-35