Westinghouse was contracted to design, develop, fabricate and test a Solid/liquid separation process system (SLSS) to safely and efficiently remove excess liquid and increase solids concentration in a waste storage tank.
Utilizing significant in-house process engineering & design experience, Westinghouse was able to define the required specification for the process system. Our engineering team then developed a solution incorporating all the necessary control elements in accordance with applicable nuclear codes and standards, including ASME Sec. VIII, B31.1 and NQA-1.
Engineering this system to meet nuclear industry standards required a complex and detailed knowledge of nuclear manufacturing as well as the in-house capability to perform; structural and seismic analysis, pressure vessel and piping design including analysis for code compliance, pressure drop calculations, detailed analysis of shielding requirements, and analysis of structural integrity under extreme wind loads.
The Westinghouse SLSS solution employs “cross-flow” filter technology for the efficient removal of clean filtrate and concentration of radioactive solids in a mixed supernatant using a continuous concentrating process, as opposed to the more conventional “once-through” filtration process. Working to the customer requirement for high efficiency and low maintenance, the solution incorporates a number of innovative design features including a filtration system with “backpulse” crud removal system, and an acid/base chemical injection system to provide periodic thorough cleaning and decontamination of the filters and process equipment.
The complete solution is integrated and mounted inside a weatherproof enclosure on a single 50-ton skid, which houses all of the piping and components required for the separation process. The skid is provided with significant radiation shielding to protect personnel from exposure in high radiation fields resulting from process concentration. Internally, the process equipment includes two filters, main circulation pump, filtrate storage tank, backpulse system, chemical tanks and pumps, and required process valves and piping. Complete PLC control, instrumentation and monitoring systems are also provided. Control is fully automated and is integrated with a human-machine interface.