Demonstration of fluidic pulse jet mixing for a horizontal waste storage tank

摘要

A fluidic pulse jet mixing system, designed and fabricated by AEA Technology of the United Kingdom, was successfully demonstrated for mobilization and retrieval of remote handled transuranic (RH-TRU) sludge from a 50,000-gal horizontal waste storage tank at Oak Ridge National Laboratory (ORNL). The pulse jet system, consisting of seven modular equipment skids, was installed and commissioned in about 7 weeks and operated remotely for 52 days to remove about 88% of the sludge in the tank. The system used specially designed fluidic jet pumps and pulse vessels, along with existing submerged nozzles for mixing the settled sludges with existing supernate in the tank. The operation also used existing piping and progressive cavity pumps for retrieval and transfer of the mixture. A total of 64,000 gal of liquid was required to transfer 6300 gal of sludge to the Melton Valley Storage Tanks (MVSTs) designated for consolidation of all ORNL RH-TRU sludges. Of the liquid used for the retrieval, 88% was existing or recycled tank supernate and only 7770 gal of additional process water was added to the system. Minimizing the addition of process water is extremely important at ORNL, where tank system storage capacity is limited. A simple manual sluicer was used periodically to wash down and aid the removal of localized sludge heels.