[en] The different methods for treatment of RAW – cementation bituminization, vitrification and immobilization in ceramic matrix, as well as the requirements for matrix materials are discussed

[en] Plutonium metal exchange programs operated by the Rocky Flats Plant were conducted from 1956-1989 to ensure quality and to compare measurements in a plutonium metal matrix. Los Alamos National Laboratory (LANL) re-established the program in 2001 to assess the quality of analytical chemistry capabilities that support special nuclear material characterization. It is the only program of its kind for the preparation and distribution of plutonium metal reference materials with a range of impurity contents to multiple laboratories for destructive measurements of elemental concentration, isotopic abundance, and both metallic and non-metallic impurity levels. This program provides independent verification of analytical measurement capabilities for each of the seven currently participating laboratories, and allows any technical problems with analytical measurements to be identified and corrected. This paper focuses on basic program elements and presents a summary of methods and results for plutonium, uranium, neptunium, and americium, measurements. (author)

[en] A major matrix effect that hampers nuclear analysis with charged particles is the range difference in sample and comparator. It has been shown that spiking a sample with the element under investigation can cause appreciable errors as a result of range changes introduced by the spike. This effect may be assessed beforehand, and subsequently corrected for, if an element not present in the sample is used for spiking. With PIPPS the error caused by spiking can be eliminated$

[en] A method is described for manufacturing a superconductor comprised of a superconducting intermetallic compound of at least two elements. The method consists of producing a composite containing at least one filament of at least one of the elements, this filament being embedded in a matrix material comprising a support material and the remainder of the elements. This material is coated with a material having a low self diffusion coefficient and which is insoluble in the matrix material. The remainder of the elements are allowed to diffuse into the filament and react to form the intermetallic compound. Full details are given of the application of the method, and examples are given. (U.K.)

[en] This work presents a systematic theoretical study for the hyperfine field due to diluted s-p-and transition impurities in metallic gadolinium matrices. The peculiarities de a gadolinium matrix are shown, they are characterized by a semi-completed 4f-shell, which is far from (below) the energetic levels such as the type s-p and d-conduction bands. (author)

[en] We present a model system that might serve as a blueprint for the controlled layout of graphene based nanodevices. The systems consists of chains of B₇ clusters implanted in a graphene matrix, where the boron clusters are not directly connected. We show that the graphene matrix easily accepts these alternating B₇-C₆ chains and that the implanted boron components may dramatically modify the electronic properties of graphene based nanomaterials. This suggests a functionalization of graphene nanomaterials, where the semiconducting properties might be supplemented by parts of the graphene matrix itself, but the basic wiring will be provided by alternating chains of implanted boron clusters that connect these areas

[en] In the framework of generation IV reactors, the implementation of a closed cycle involves a grouped management of actinides, as well as their united insertion in a new fuel material. The researches carried out for the main variant of fuel cycle are then centred on the synthesis of a material allowing to immobilize these radioelements in an ordered way inside a solid phase of known composition and structure, and in which they have to be dispersed in an homogeneous way. In this work, is considered the study of the synthesis of innovating materials by a molecular engineering approach. The aim is to explore the properties of matrices based on complex mineral fluids for actinides immobilization, to study the confinement potential of these new mineral liquid crystal phases and to understand their interaction with the actinides. (O.M.)

[en] The shielding body is made as a plate-shaped section from an elastic support material such as polyurethane, silicone rubber etc. and has lead balls in it. Fins are formed on one flat side of the plate-shaped section which are parallel to each other and at an angle to the longitudinal axis of the section, which also contain lead balls. The section is wound around the cable taken through the wall or ceiling penetrations in such a way that the fins are turned towards the cable or pipe and are arranged spirally around it. (orig./HP)

No abstract available

No abstract available