[en] This paper assumes that there will be a requirement to store several tonnes of separated plutonium over the normal operational life of the associated industrial nuclear plant (i.e. 10-20 years) and that it must be capable of being used for both long and short-term storage. The paper includes the following main topics: packaging of plutonium, basic design of storage, general handling principles, criticality, maintenance and physical protection principles, and an analysis of safety and impact on the environment

[en] The numerical value of the first hydrolysis constant of tetravalent plutonium is uncertain by a factor of about ten. This article illustrates the estimation of that constant by a least squares method applied to simultaneous equations involving all of the Pu oxidation states. (author)

[en] It is stated that the cost of long-term storage of large quantities of Pu oxide is about $100/kg p.a. and a rough breakdown is given

[en] Savannah River National Laboratory (SRNL) started a multi-year project, the PreCalc Project, to develop a computational simulation of a plutonium oxide (PuO₂) production facility with the objective to study the fundamental relationships between morphological and physicochemical properties. This report provides a detailed baseline process description to be used by SRNL personnel and collaborators to facilitate the initial design and construction of the simulation. The PreCalc Project team selected the HB-Line Plutonium Finishing Facility as the basis for a nominal baseline process since the facility is operational and significant model validation data can be obtained. The process boundary as well as process and facility design details necessary for multi-scale, multi-physics models are provided.

[en] As part of international agreement between the United States and Russia, a significant amount of plutonium requires disposition. One of the disposition paths is to immobilize it and dispose of it in a geological repository. The two favored immobilization forms are glass and ceramic. The plutonium, as an oxide, would be reacted with the glass or ceramic to form a homogeneous material. The resulting solid product would then be encased in High-Level Waste (1-ILW)glass for the can-in-canister option. The HLW glass gives a radiation barrier to increase proliferation resistance. The glass canister would then be disposed of by geological emplacement. This paper discusses how glass meets two criteria: the condition of significant actinide volubility, and That the PuO₂ feed should be incorporated into the matrix without significant amount of unreacted material

No abstract available

[en] The oxidation of plutonium to the octovalent state and the preparation of PuO₃ were studied. The behaviour of volatile compounds formed under heating of trace quantities of ²³⁸Pu and ²³⁹Pu in a stream of He and O₂ mixture was investigated thermochromatographically (TC) using quartz TC columns. The concentration of the reagent c(O₂) was varied between 50 and ≤ 10^-7%. The deposition zones were measured alpha spectrometrically. It was found that under certain conditions, plutonium forms four adsorption zones with centers at 450±25 deg C, 250±25 deg C, 130±50 deg C and -105±25 deg C. A series of model experiments with carrier-free radioisotopes of Os, Re, Ru and Tc were carried out for the interpretation of the results. In a He stream with a negligible touch of O₂ they were adsorbed at 450-500 deg C and at 250-300 deg C in the form of dioxides and trioxides, respectively. The results of TC separation of volatile products of U(nat) and ²⁴⁹Cf oxidation are also presented. We assume that the first adsorption zone (450±25 deg C) is due to the formation of PuO₂, the second is due to the formation of PuO₃ and the third is presumably due to the formation of a plutonium acid. Comparison of OsO₄ and RuO₄ adsorption zones with the last deposition zone indicates their similarity. Only lower plutonium oxides form at low concentrations of O₂; this is also characteristic of Ru and Os. We can conclude that octovalent plutonium was produced which in a form of very volatile PuO₄ deposited at negative temperature

[en] The first empirical method for preparing a plutonium predominance-region diagram used horizontal lines to locate the boundaries of the regions of forbidden, unique, and ambiguous oxidation-state distributions. A second approach changes the procedure by using vertical lines to illustrate these regions. In both cases, the boundary lines are determined by the Pu oxidation number and the equilibrium fraction of one oxidation state. (author)

No abstract available

[en] Throughout the DOE complex, laboratories are performing calorimetric assays on items containing high burnup plutonium. These materials contain higher isotopic range and higher wattages than materials previously encountered in vault holdings. Currently, measurement control standards have been limited to utilizing 6% ²⁴⁰Pu standards. The lower isotopic and wattage value standards do not complement the measurement of the higher burnup material. Participants of the Calorimetry Exchange (CALEX) Program have identified the need for new calorimetric assay standards with a higher wattage and isotopic range. This paper describes the fabrication and verification measurements of the new CALEX standard containing 12% ²⁴⁰Pu oxide with a wattage of about 6 to 8 watts