Boiling Experimental Reactor BER

The meat of the enriched uranium plates is an alloy of zirconium with 5% by weight of fully enriched uranium. Since this meat itself is highly corrosion resistant, only a cladding of 10 mils is specified. 

Twelve blade-type shim-safety rods move vertically through the core in the pattern shown in Fig. 7. The absorbing portion of each rod is about 7 in. wide and 42 in. long. The drive mechanisms for these rods are located in a room underneath the reactor (Fig. 9). 

Grid structures above and below the core hold the fuel assemblies and safety rods in a fixed geometry. The bottom grid has a slot for each assembly. The basic cell of the top grid encloses four assemblies. 

The eccentric shielding plugs in the top of the pressure vessel are for the purpose of allowing removal or insertion of individual fuel assemblies without removing the large plugs. Irradiated fuel is stored in a water-filled concrete well adjacent to the reactor (Fig. 9). 

The biological shield for the reactor will be ordinary concrete about 8 ft thick. This will be augmented by dense concrete or other material of increased shielding effectiveness in certain areas. Cooling coils will be provided in the biological shield to remove the heat generated due to absorption of nuclear radiation and the heat transferred by normal thermal processes from the insulated pressure vessel. 

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