Oscillations have been observed in a magnetically supported cylindrical rod of plasma. This rod of plasma can be the discharge occurring in the defining aperture of a Mode II, pressure gradient arc. Similar oscillations can also occur in the column of a Mode I arc. These oscillations appear to be the mechanism that drives the Mode II blowup phenomena.

The General Electric Company is proceeding with an irradiation program to proof test a representative array of Savannah I fuel rods. Irradiation of a test assembly containing Savannah I fuel rods has begun and it is proposed that the results of this irradiation will permit an advance evaluation of the fuel performance and fuel burnup in the Savannah I reactor. This report covers the first two quarters of the reporting period. All aspects of the subject program have been consolidated and applicable portions are discussed in some detail.

Preliminary results from experiments on the dissolution of beryllium metal and sintered UO2-BeO fuel pellets are reported. In all cases the pellets were fired in hydrogen at 1650-1800°C. Uranium, from UO2-BeO pellets containing more than 60% UO2, is readily leached with boiling 6-13 M HNO3 in about 6 hr. The BeO in these pellets dissolves only slowly in nitric acid; however, in 8 M HNO3-0.2M NaF, it dissolves at about the same rate as the UO2. Sintered pellets containing less than 10% UO2 do not dissolve rapidly in common aqueous reagents. The highest rates are obtained in boiling acidic fluoride solutions; e.g., sintered BeO and BeO-8% UO2 are dissolved initially at a rate of about 1.7 mg min-1cm-2 (13 mils/hr) in boiling 5.8 M NH4HF2.