## 2 Experimental Section
### Automated Module  
An automated module was designed and built to perform Zr-Y separation protocol remotely inside a lead hot cell. The frame for this module (\(h\times w\times d=21\times 18\times 11\) in. = 0.53 \(\times\) 0.46 \(\times\) 0.28 m) was constructed of extruded Al modular framing, to which walls were attached that were made of ultra high-molecular weight polyethylene. Various system components were mounted on these plastic walls, as pictured in Figure 2. The front panel of the module was hinged to allow easy access to the components and wiring inside the module. All liquids were pushed through the system by  
Figure 2: **(A)** A flowchart describing the process for production and chemical separation of \({}^{89}\)Zr from an irradiated Y foil. Bold text indicates automated steps; dashed line, steps that are currently performed manually; **(B)** A photograph of the automated module. compressed air through C-Flex(r) flexible tubing and through needles made of polyetheretherketone (PEEK(tm)) tubing. The compressed air was delivered to various parts of the system through polytetrafluoroethylene (PTFE) tubing. All liquid and most gas connections were assembled using non-metallic connectors, which reduced exposure to metals that may have compromised ESA. Many of the liquid connection pieces were designed for high pressure liquid chromatography (HPLC) systems and were made of ethylene-tetrafluoroethylene (ETFE, Tefzel(r)); gas connections were made using stainless steel Swagelok(r) tube fittings (Swagelok, Solon, OH, USA). The path of fluids (liquids and air) through the system was controlled by solenoid-actuated isolation valves, and, as a fail-safe, solenoid-actuated pinch valves prevented liquids from flowing through the flexible tubing at inappropriate times or in the opposite direction. Solenoid valves were manufactured by NResearch (West Caldwell, NJ, USA). Solvents only came in contact with polymers and glass in the system. The compressed air was adjusted by a pressure regulator (Swagelok). The flow of compressed air was precisely controlled by a hot wire anemometer mass flow controller (Pneumtics) that received commands from the computer. Before each separation, all liquid solvents were pre-loaded into the system by hand in glass vials capped with silicone rubber septa that allowed for insertion of two PEEK needles--one connected to compressed air and one for transporting the liquid. The vials were then clipped onto the front of the module, and during the separation each liquid was extracted from its vial using positive pressure from the PEEK needle that was connected to compressed air. The general schematic of the entire system is shown in Figure 3.  
Figure 3: Process flow diagram for the automated module used for chemical separation of \({}^{89}\)Zr from irradiated Y foils. CAP: compressed air pump; CV: check valve; HV: hand valve; MFC: mass flow controller; NC: normally closed; NO: normally open; R: radiation detector; RV: regulator valve; SI: solenoid isolation; SP: solenoid pinch; V: valve; VP: Venturi pump; double line: PTFE tubing for compressed air or vented air only; solid line: flexible tubing for liquids and compressed air. Valves enclosed by a dashed box are part of a gradient manifold. Valves V14, V18, and V19 do not exist in the actual system, so they are not displayed here. (Illustration made using _Edraw Max_ software [51]). A computer located outside of the hot cell was used to control the entire chemical separation process. A program was created on the LabVIEW platform that featured a graphical user interface (GUI) that provides instructions and controls for production personnel. Users could follow a step-by-step procedure with a pre-programmed control scheme and, if necessary, intervene by controlling individual valves in the event of a problem in the system. Using the GUI, the user can easily and precisely change the flow through the mass flow controller and thereby the speed at which liquids were pushed through the system, most importantly the speed of solvents through the column.