ADDENDUM C-3 

 Xenon-133 Tagging Furnace 



The 133 Xe- tagging furnace, shown in Fig.C-9, was designed to tag 

 kO liters of sand. The basic unit is constructed of mild steel, contains 

 eight heating elements (23O-V, 1500-W Calrods) and eight cooling loops, 

 and is insulated with fire brick and sheet asbestos.. Two 30-amp 210- V 

 Variacs are used to furnish power to the heating elements. These are 

 enclosed in stainless steel to prevent corrosion and failure. Two cali- 

 brated thermocouples are used to monitor temperature in the center and 

 side of the furnace . The maximum operating temperature for the furnace 

 is 900°C. 



A typical heating cycle with U0 liters of sand is as follows. The 

 Variacs are set at 10 amp for 1 hr and are then raised to 20 amp for 3 

 hr. The final temperature is 850°C on the center thermocouple and 750°C 

 on the outside thermocouple. The cooling cycle is started immediately, 

 first with cooled N 2 gas (bubbled through liquid N2) at a flow rate of 

 5 cfm for 1 l/2 hr and then with water cooling to reduce the temperature 

 to 80°C (~2 hr). 



C-26 



