Zirconium molybdate gel as a generator for technetium-99m.

A new (99m)Tc generator based on zirconium molybdate gel is described. Essentially the gel is a cation ion exchanger which permits the elution of the pertechnetate ion. The high molybdenum content of this gel its stability under self-irradiation and the absence of organic materials during preparation provide a generator concept that eliminates high processing costs active waste storage costs and stability problems in other types of generator

Interaction of erythrocytes and hexavalent uranium compounds - an autoanalytical study.

An automated analytical system was devised to measure the kinetics of hemolysis by uranyl compounds. Accurate plots of percentage hemolysis v. time were obtained; these together with the corresponding differential curves show that hemolysis of plasma-free erythrocytes is a two-stage process. The first stage of hemolysis is particularly affected by pH and anion content of uranyl solutions and also by incubation of cell suspensions at 37 deg. before mixing with lysing solution. Complementary studies involving Coulter counting and microscopic observation established the general pattern of hemolysis and showed that cell agglutination is a prominent feature of the interaction of cells with uranyl solutions

Laboratory development of the grind-leach process for the H.T.G.C.R. fuel cycle, Part II - dissolution of beryllia in nitric acid solutions.

the development of the grind—leach process for the processing of beryllia—based fuels requires a knowledge of the dissolution of beryllia in nitric acid. A kinetic study using powdered specimens has proved suitable for the investigation of this system. The parameters studied include particle size, agitation, temperature, acid concentration, the effect of the addition of fluoride and aluminium, and the effect of neutron irradiation of the beryllia. The dissolution of beryllia in nitric acid is controlled by a chemical reaction at the surface of the solid and has an apparent activation energy of 18 kcal/mole

Laboratory development of the grind-leach process for the H.T.G.C.R. fuel cycle, Part 4 - leaching and dissolution of beryllia-based fuels.

This report covers the chemical development of an acid-leach head-end process for the separation of (U,Th)02 from a beryllia matrix. The work is related to a feasibility study of the H.G.T.C.R. fuel cycle. Although more than 99 per cent of the actinides can be recovered in a single batch nitric acid leach, more than 30 per cent of the beryllia is dissolved. When it was found that sulphuric acid selectively dissolved the beryllia, a two-step process using nitric and sulphuric acids in sequence was developed, with recycling of the actinide-rich heel to the next batch. Preliminary results from multi-batch experiments indicate that it might be possible to decrease the beryllia loss to the nitrate stream to 10 per cent and still recover 99 per cent of the actinides. Further development of the process would involve the use of proven reactor material irradiated to high burn-up. Suggestions for further research are given