Plutonium experiments with

The chemistry of plutonium is unique in the periodic table. This theme is exemplified throughout much of the research work that is described in this volume. Many of the properties of plutonium cannot be estimated accurately based on experiments with lighter elements, such as uranium and neptunium. Because massive amounts of plutonium have been and are being produced throughout the world, the need to define precisely its chemical and physical properties and to predict its chemical behavior under widely varying conditions will persist. In addition to these needs, there is an intrinsic fundamental interest in an element with so many unusual properties and with so many different oxidation states, each with its own chemistry. 

The early field studies revealed that elevated concentrations of fallout plutonium correlated with Increased concentrations of dissolved organic carbon. Experiments at Argonne National Laboratory corroborate this correlation the explanation Is probably that the organic compounds complex Pu(IV), and, hence, decrease the distribution ratio between water and sedlments(27). In these experiments the distribution ratio (Kj) between sediment and natural waters was measured as a function of DOC. Measurements of Kj In both field and laboratory experiments show an unmistakable effect of DOC upon the distribution ratio. Figure 4 shows the Inverse correlation between the K, of plutonium and concentration of DOC. 

Before starting the plutonium experiments, the influence of dissolved oxygen on the Ej, of each ground-water sample was determined by sparging separate samples with oxygen and nitrogen. 

Allhough Ihe ceramification and SYNROC lechnologies are being researched to develop a final waste form for plutonium-contaminated materials, no experiments with plutonium have been performed. The SMITE process is designed for the treatment of solid, inorganic materials. The final waste form will leach in acidic solutions so storage in a basic environment is recommended. 

Static Absorption Experiments with Plutonium and Americium Added Simultaneously to Each Solution at Ambient Temperature. The experiments were each run for 900 h or more. 

Initial experiments were performed to verify and demonstrate the feasibility of the electrolytic reduction method with uranium, followed by experiments with a mixture of uranium and plutonium. Experiments were conducted batchwise in a small electrolytic cell. Basic parameters, such as concentration of solutes and type of holding agents (in the aqueous phase) for removal of any nitrite which would reoxidize the reduced heavy metal, electrode material and geometry, off-gas composition and type of diaphragm, were also determined. These data were valuable in the conceptual design of the first continuously operating column for the electrolytic reduction process. 

Although the existence of a volatile higher fluoride of plutonium had been surmised from tracer experiments, positive evidence of the existence of PuF6 was obtained by Florin (31) who first prepared the compound. An investigation of the preparation and properties of PuF6 was also conducted by Mandleberg et al. (58). but in recent years the compound has been most intensively studied by Weinstock and his collaborators. Plutonium hexafluoride can be prepared by a variety of procedures similar to those used for the preparation of uranium hexafluoride. The most widely used method consists in the fluorination of plutonium tetrafluoride with elemental fluorine. Whereas uranium hexafluoride can be prepared by the analogous reaction at 300°, and neptunium hexafluoride at 500°, the preparation of plutonium hexafluoride by this reaction appears to require a... 

Experiments with Pu confirmed theoretical predictions that it would exhibit high fissibility with both thermal and fast neutrons. This meant that Pu in sufficient quantity would also experience an instantaneous nuclear explosion like If controlled nuclear fission could be accomplished in a nuclear reactor, it would be possible to produce large amounts of plutonium by neutron bombardment of U. The Pu could be isolated by chemical methods which were expected to be simpler than the isotopic separation required to obtain pure As a consequence, the production of Pu became a major project of the atomic bomb program of the United States during World War II see further Ch. 19. 

FIG. 18.14. Glove-box for plutonium experiments. A radiochemical fume hood with filler is seen in the background. Note that all connections are in the ceiling. 

The UK and France were the first countries to develop civil nuclear energy in Europe building upon their separate experiences with gas cooled reactors devoted to military plutonium production. In the 1960s France altered its technology policy to favor pressurized water reactors while the UK did not make an equivalent policy choice until 1979 with policy implementation spanning the 1980s. France and the UK are the only EU-15 countries ever to have been nuclear weapons states and both states continue to maintain nuclear weapons capacity. 

Distribution ratio experiments with Inorganic cation exchangers were performed by equilibrating 1.0 g of the exchanger with 10 ml of either 0.25M oxalic acid or water In a 14 ml vial on a rotating wheel for up to 72 hours. The aqueous pH was adjusted with 50Z NaOH or 7M HNO. The Initial and final americium and plutonium concentrations were determined radlometrlcally. The volume distribution ratio, D, Is defined as [Am]/g solid r [Am]/ml aqueous phase,and Is calculated from 10 x ([Am]aq - [Amjaq /[Am]aq... 

Oppenheimer acted quickly to maximize the laboratory s efforts to master implosion. Only if the implosion method could be perfected would the plutoniiun produced at Hanford come into play. Without either a plutonium gun bomb or implosion weapon, the burden would fall entirely on uranium and the less efficient gun method. Oppenheimer directed a major reorganization of Los Alamos in July 1944 that prepared the way for the final development of an implosion bomb. Robert Bacher took over G Division (for gadget) to experiment with implosion and design a bomb George Kistiakowsky led X Division (for explosives) in work on the explosive components Hans Bethe continued to head up theoretic studies and Deke Parsons now focused on overall bomb construction and... 

Homogeneous Critical Experiments with Plutonium/Plastic Mixtures in the lnterme> diate Energy Range, C. R. Richey, J. D. White, R. C. lAoyd, and E. D. Clayton (GE HAPO). 

A series of experiments with hydrogen-moderated plutonium systems has been performed in the Physical Constants Testing Reactor (PCTR). The boron concentration required to reduce the infinite multiplication factor, k , to unity was measured for various Pu-240 concentrations, fuel plate thicknesses, and moderator-to-fuel ratios. The measured values of the boron concentra-Uon were compared to theoretical predictions to check the accural of calculational methods and parameters. The principal components for these experiments were Pu-Al (M wt% Pu), pure polyethylene, and borated lyetlqrlene (0.90 wt% natural boron). All three materials were in the form of disks, 1.960-in. in diam and 0.020-in. thick. 

Critical Experiments with Highly Burned-up Plutonium in Heavy Water/A. L. Olson, W. E. Graves (duPont-SRE)... 

R. C. LLOYD et aL, Basic Criticality Experiments With Plutonium Nitrate Solutions in Slab Geometry, I%ysics Research Quarterly Report January, February, March 1967, BNWL-472, Battelie-Northwest Labs. (December 1967). 

Comparisons between calculations and experiments will be covered in greater detail in the paper. - Also, additional results from recent experiments with plutonium solutions in slab geometry will be presented. 

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