EBR-II Reference Fuel Element

A program has been initiated to investigate methods of fabricating the reference fuel element subassembly for EBR-II (Fig. 59). 

The fuel pin and fluid are sealed into the tube by means of end plugs silver soldered into place. The tube is rnade of AISI Type 347 stainless steel of 0.188 in. OD and 0.008 in. wall thickness. The helical rib outside the fuel tube is made of low-carbon steel for these tests, although stainless steel or other material will ultimately be used. The rib (cross section 0.065 in. by 0.025 in.), is made of flattened wire. The stock is edge wound on a 1-in. diameter arbor, set, and finally pulled out lengthwise to form a helix of the proper diameter and a 4-inch right hand pitch. The helix is slipped over the fuel tube and soldered into place. One hundred and sixty-nine fuel tubes are required for each subassembly. 

The hexagonal container has been made by bending 0.048 in. thick steel plate over a hexagonal form on a brake. Two halves are made, clamped over a hexagonal mandrel, and welded together. A simulated fuel pin, a complete fuel element, and the hexagonal container are shown in Fig. 60. 

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