REPROCESSING OF POWER REACTOR FUELS. Tenth Quarterly Progress Report for JANUARY 1, 1960 to April 1, 1960

Electrolytic dissolution of unirradiated Fcrmi core elements and of Zircaloy-2 was successfully demonstrated on a laboratory scale. Tantalum and niobium are adequate as materials of construction for the inert anode basket of as electrolytic dissolver in a field of 10/sup 7/ rep/hr. The corrosion of 304L and 3O9SCb in boiling HNO/sub 3/ is increased by the presence of dissolved stainless steel, which promotes intergranular attack of these metals. Corrosion tests of both welded and wrought 309SCb indicated that a solution of 0.075M HF and 0.05 to 1M HNO/sub 3/ offers advantages over either the 0.075M HF or the 0.075M HF --3.0M HNO/sub 3/ solutions previously proposed for the chemical dissolution of Fermi core elements, Urirradiated Zr--low U alloy was dissolved in 1M HNO/sub 3/ by intermittent addition of HF at such a rate as to obtain an average penetration rate of 4.5 mils per hour. The average composition of the off-gas was 8% H/sub 2/, 18% N/sub 2/. 50% NO. 23% N/sub 2/O. and 1% miscellaneous trace gases. (For preceding period see DP-479.) (auth