Flushing Efficiency of Steam-Generator Tube-Tubesheet Assemblies with Restricted Crevices. Final Report (PWR)

摘要

The objective of this project was to determine the effectiveness of steam generator tubesheet crevice flushing operations when access to the crevice is restricted by particulate matter within the crevice or by a hard sludge pile on top of the tubesheet. The methodology for forming a hard, stable sludge pile was also developed. The testing indicated that the most effective flushing procedures were similar to those found to be most effective in testing of unrestricted crevices. However, the effectiveness of a given depressurization cycle was generally lower than in the unrestricted crevice testing and more cycles were required to obtain an equivalent extent of dilution. The testing produced some hideout return directly from the hard sludge and was successful in partially breaking up a sludge pile composed entirely of magnetite. (ERA citation 08:038908)