[en] The process for reducing 700 g ²³⁹PuO₂ to metal is a standard procedure at Los Alamos National Laboratory. This process is based on research for reducing 200 g ²³⁸PuO₂ to metal. This report describes in detail the experiments and development of the 200-g process. The procedure uses calcium metal as the reducing agent in a molten CaCl₂ solvent system. The process to convert impure plutonia to high-purity metal by oxide reduction followed by electrorefining is also described

No abstract available

No abstract available

[en] Letter-to-the-editor

No abstract available

[en] Pulmonary fragments from control rats (Wistar) of varying age and contaminated with PuO₂ were grafted in an immunodeficient medium onto mice or histocompatible rats. In both cases the authors observed lesions presenting the histological characteristics of pulmonary cancer in rats; proliferation, however, remained discrete. After grafting on the athymic mice, the lungs of the control animals exhibited a percentage of tumoral-type differentiations which increased with age. in the contaminated rats, for an initial pulmonary burden of 10 nCi and cumulative doses of between 6X10⁸ and 38X10⁹ α/g of lung, the grafts showed a clear-cut increase in lesions of this type. Their frequency increased with the total dose delivered. Conversely, if the dose delivered during a three-month period varied from 2X10⁸ to 50X10⁹ α/g of lung, the maximum proliferation was observed at the lowest doses. Furthermore, the histological nature of the proliferations varied with the dose delivered. This transplantation technique would appear to show the existence of lesions which are not yet overt and which are a consequence either of ageing or of α-irration. The authors discuss the meaning of these lesions and the immunological component of the phenonmenon. (author)

[en] Options for plutonium disposition require PuO₂ that can be used as feed material for mixed oxide (MOX) reactor fuel pellets, or glass and ceramic immobilization forms (cf. Federal Register Doc. 97-1355, Vol. 62, No. 13, January 2 1,1997). As part of a DOE-sponsored demonstration known as the Advanced Recovery and Integrated Extraction System (ARIES), conversion of plutonium to oxide by the Hydride/Oxidation (HYDOX) process will be used, along with other supporting technologies, to recover plutonium from the cores or *number sign 34;pits'' of nuclear weapons that have been determined to be surplus to national defense needs. This demonstration will be performed jointly by the Los Alamos and the Lawrence Livermore National Laboratories at the Los Alamos Plutonium Facility. The pyrochemical methods employed by HYDOX offer a simple and reliable process to recover plutonium in oxide form from various sources. This process will: Separate plutonium from other nuclear and non-nuclear materials, Convert massive metallic shapes into fine oxide particles, Produce oxide directly acceptable for MOX fuel fabrication, and Produce no solid or liquid waste. The paper describes the reactor module and operational sequences, provides up-to-date experimental results, identifies rate-controlling factors, and discusses their impact on the reactor design

[en] The packaging has been developed as a packaging for plutonium oxide to be recovered from light water reactor spent fuel and is designed for easy handling within a facility. As deformation and shock absorption data for balsa wood, the data obtained from various experiments carried out when developing the packaging were used. With this packaging, it is possible to transport almost all kinds of raw powder materials required to produce fuel as stated under Section 2 not only in the country but also from abroad. The packaging is expected to be frequently used in transporting plutonium oxide powder from England and/or France which are commissioned by domestic power companies to reprocess spent fuel and also in transporting highly enriched uranium oxide which is required at FBR experimental reactors. 14 references, 5 figures, 4 tables

No abstract available

[en] The main objective of this project is to improve capabilities for evaluating health risks to humans associated with inhaling plutonium (Pu). Two key DOE issues are being addressed: (1) the need to improve capabilities for evaluating plutonium dioxide (PuO2)-associated health risks for DOE workers involved in decommissioning/decontamination (D and D) activities; and (2) the need to improve capabilities for evaluating health risks for public exposures arising from residual PuO2 in soil at remediated (cleaned-up) DOE sites. The scientific goal of this project is to improve capabilities for assessing health risk distributions for DOE workers and the public associated with inhaling Pu. The focus of our work has been on DOE worker and public exposure scenarios related to the Rocky Flats Environmental Technology Site near Denver, Colorado, commonly called Rocky Flats