In search for an optimum plutonium density measurement fluid

Abstract Density measurements of plutonium metal and its alloys are performed at Los Alamos National Laboratory (LANL) using a technique based on the Archimedes principle. The goal is to find and characterize a fluid for density determination of large objects made of plutonium to replace the currently used monobromobenzene. Physical and chemical properties must be considered while selecting the fluid. Chemical properties of the fluid must ensure low corrosion rates and good resistance to radiological decomposition. The study was carried on to evaluate the corrosion rates of Pu metal cause by FC-43 and the FC-43 decomposition products of radiolysis. The results of these studies proved favourable for this application. The evaluation of the surface reactions between FC-43 and Pu metal will be conducted in the near future.