Reactor Parameters II

Interacting Arrays of Containers with Solution, R. C. Lloyd, E. D. Clayton 

Subcritical neutron Interaction experiments were performed with bare and Lucite-reflected arrays of bottles of U solution. The effect on criticality of adding Lucfte moderator between the bottles was also studied. These experiments provide data for nuclear safety guidance in handling, storage, and shipment of this material, and for checking interaction calculations. 

The u was in the form Of uranyl nitrate hekahydrate ( 2(NOj)2 6H2OJ at a concentration of about 330 g U/liter the uranium was contained in three-liter polyethylene bottles. The molarity of the solution was about 0.S3. The bottles were 17.75-in. high, 4.7-ih. o.d., with a wall thickness of 0.100 in. The average solution height was about 11.5 in.—960 g U/bottie. 

The bottles were placed in arrays on a remotely operated split-table device, using neutron multiplication techniques to estimate the number of bottles for criticality. Extrapolations were also made on spacing to determine the critical spacing for fixed-number square arrays of the bottles. Arrays were single tier, except in one experiment where a double-tier array was used. 

In the reflected arrays, the Lucite was placed touching the outside surface of the bottles, i.e., boxing in, the array. The thickness of the top and bottom Luciie reflector was 4.5 in., and the side reflectors were 6 in. A 

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