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NRC approves transfer of Vallecitos to North Star for D&D
By an order dated April 25, the Nuclear Regulatory Commission has approved the transfer of ownership of Vallecitos Nuclear Center from GE Hitachi Nuclear Energy to NorthStar Group Services for nuclear decontamination, decommissioning, and environmental site restoration.
Bill K.-H. Sun, Seung Oh, Paul H. Rothe
Nuclear Technology | Volume 64 | Number 3 | March 1984 | Pages 290-299
Technical Paper | Heat Transfer and Fluid Flow | doi.org/10.13182/NT84-A33358
Articles are hosted by Taylor and Francis Online.
During an overcooling transient in a pressurized water reactor, cold water from the high pressure injection (HPI) mixes with the hot primary coolant in the cold leg. The transit time is a gauge for the assessment of the time and the velocity of the mixed flow that passes through the cold leg to the downcomer. Existing data from mixing tests at the Electric Power Research Institute (EPRI)ZCREARE and EPRI/ SAI facilities are analyzed. By means of models for HPI jet entrainment as well as the propagation of a gravity current, dimensionless correlations have been developed for the transit time and cold water front velocity at stagnant loop flow conditions. Based on this transit time correlation for stagnant loop flow and the limiting condition for large loop flow, a general correlation has been developed to account for the loop flow effect on transit time. These correlations unify a wide range of data obtained from five geometrically different test sections with two fluids (pure water and saline solution). In addition to the geometric factors, the governing dimensionless parameters for the transit time are the HPI jet Froude number, the Froude number for the cold-leg channel, and the ratio of loop flow to HPI flow.