From preface: This report satisfies the quarterly progress report requirements for PL-1 and PL-2 plant design work for the period ending September 30, 1960 At present time a SL-1 Core 2 is under construction. This is a replacement core for SL-1 (ALPR) and will be identical to a PL-2 core; a PL condenser is under test at the SL-1 facility; final construction plans for PL components and modules which are not site sensitive will be completed in March 1961.

Abstract: "Sound, fabricable ingots of thorium were produced by triple are melting of electrolytic thorium. Consumable electrodes were fabricated by tack welding of cold-pressed and vacuum-sintered bars of the granular thorium electrodeposited from a molten-salt bath. The hydrogen content of the electrodeposited material was reduced from 80 to 4 ppm by vacuum sintering at 1250 C at pressures below 1 x 10-(-3) mm of mercury. Both sodium and chlorine content were reduced during melting; sodium from 250 to 25 ppm and chlorine from 1000 to 30 ppm. Oxygen and HCl acid-insoluble contents increased during sintering and melting. Oxygen content increased from 0.35 to 0.50 w/o and HCl acid-insoluble content from 0.8 to 4.0 w/o. A starlike includion revealed by metallographic examination of the as-cast thorium was identified as ThO2."

This report documents the study of the recovery of thorium by solvent extraction in pilot plant pulse columns, using a filtered liquor from nitric acid digestions of the raffinate cake produced by the ethyl ether extraction of uranium from pitchblende.

The development of a high heat flux heater for use in corrosion rate and stress-rupture tests of fuel cladding materials in a sodium environment is described.