This report presents the cold shakedown run for the UO{sub 3} plan. One complete batch conversion will be made in each of the eighteen Calcining Pots using unirradiated uranium food solution. The objectives of this series of conversions are as follows. A mechanical test of the conversion units; a shakedown of the unloading, pulverizing and material handling equipment; a functional test of the Nitro Acid Absorber system operating at approximately 5 to 20% of its design capacity; the determination of the optimum temperature and time cycle conditions for 60% UNH feed solution. These conditions may be based upon calcination of the initial charge of 60% UNH solution to form UO{sub 3}, in one pot; a confirmation of the calibration of instruments; and to provide operating experience and process know-how.

Simultaneous reduction of coolant to several or all reactor tubes raises concern not only for the adequacy of protection in the individual process tube but also the reactor as a whole. In event of such flow reduction, the heat generation does not decrease until at least 1.4 seconds have elapsed following the accident. Thus, the water temperature from each tube will rise, and result in an increase in the bulk water temperature. If the increase in bulk water temperature is such that saturation temperature at the top of downcomer is reached, pressurization may occur at that point and exceed the maximum recommended working pressure limit (approximately 1 to 2 psig). The purpose of this report is to present experimental data on a series of tests which were made to simulate flow reductions to a K type process tube by simulated front header pressure decreases.

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Small particles of zirconinm formed during mechancal operations have caused serious industrial explosions. Particles of this type will not be encountered during aqueous chemical reprocessing. However, small panticles of metallic phases rich in zirconium or niobium, produced by selective leaching of a more reactive uranium-rich phase, can enter into violently explosive reactions. The conditions under which explosions with zirconium-bearing alloys may be expected during chemical reprocessing have been defined in the literatare. The uranium-zirconiaum alloys containing less than 30 wt.% zirconium are hazardous when they contact nitric acid. Laboratory work has shown that potentially explosive zirconium alloys may be safely dissolved in nitric acid if enough fluoride ion is added to maintain a mole ratio of fluoride to dissolved zirconium of four. Niobium-bearing fuel alloys can also explode after contacting nitric acid, but the conditions which produce explosions have not yet been studied thoroughly. Dissolution studies with the EBWR alloy (93.5% U, 5% Zr, 1.5% Nb) indicate that hazardous niobium alloys can also be processed safely in nitric acid by addition of enough fluoride to prevent formation of surface deposits. The ternary phase diagram for zirconium -uranium -oxygen shows that the epsilon phase is unstable at the interface between a …

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Brillouin polyhedra for the intermetallic compounds of lithium and lead were determined using the zone theory. From these determinations, predictions and explanations of some electromagmetic and structural properties of the intermetallic compounds were made. (For Part IV see UCRL-4973.) (C.J.G.)

A study was made of the effects of temperature, impurities in the hydrogen chloride, flow rates, and niobium content on both the reaction rates and insoluble uranium losses in the Zircex Process is presented. (W.L.H.)

A Monte Carlo calculation for computing the diffusion coefficient and diffusion length in a linear system, with alternate solid and void segments is described. The program code is for the IBM 704. (auth)