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[en] Considerable uranium-plutonium mixed-oxide (MOX) experience was developed by U.S. companies from 1960 to 1975. Most of the work involved plutonium with high 239 isotopic content. This material is therefore similar to the isotopic concentration of current weapons-grade plutonium under consideration for MOX production. A summary of some of the activities performed within the United States is provided in this paper
[en] In order to ensure that the mass of Pu present in the workstation is always below the criticality safety limit, it is necessary to define an internal threshold taking into account weighing uncertainties. These uncertainties must be reasonably overestimated in order to allow normal operation of the workstation. The statistical method presented in this paper makes it possible to define an uncertainty from which the internal threshold will be defined. This is a few hundred grams of Pu, instead of several kilograms if the usual method is used.
[en] When a nuclear installation is permanently shut down, it is crucial to completely dismantle and decontaminate it on account of radiological safety. The expertise that SCK-CEN has built up in the decommissioning operation of its own BR3 reactor is now available nationally and internationally. Last year SCK-CEN played an important role in the newly started dismantling and decontamination of the MOX plant (Mixed Oxide) of Belgonucleaire in Dessel, and the decommissioning of the university research reactor Thetis in Ghent.
[en] The purpose of this paper is to describe the organization of the relationship between the operator of the MELOX facility and the Euratom Safeguards Directorate in both the project definition and implementation phases of the safeguards scheme. Safeguards activities are discussed at each of the three major steps in the process, namely: (1) the input plutonium area, (2) the process area, and (3) the assembly area
[en] The Tokai-Mura accident has shocked the Japanese society and made it fully aware of important failures in the organization of nuclear safety. 3 technicians received lethally radiation doses, about 50 others were less irradiated, 300000 people living in the nearby area were panic stricken when they were told to stay at home, and insufficient or inefficient rescue operations were launched. An inquiry has revealed that the cause of the accident was human irresponsibility: botched job and not-followed safety regulations. In France 75% of about 500 yearly-listed incidents originated in human factors. (A.C.)
[en] Here are gathered 1)the decree (99-627) of the 22. of July 1999 authorizing the CEA to install a nuclear unit called 'Atalante' at Marcoule (Gard). 2)the decree (99-664) of the 30. of July 1999 authorizing the Cogema to extend the nuclear unit called 'Melox' at Chusclan (Gard). (O.M.)
[en] The present paper focuses on the criticality studies performed by the Engineering division of Belgonucleaire. These are one of the two pillars of the criticality prevention implemented for the Belgonucleaire MOX producing plant. (author)
[en] This work studied a way to reclaim uranium from contaminated UO2 oxide scraps as a sinterable UO2 powder for UO2 fuel pellet fabrication, which included a dissolution of the uranium oxide scraps in a carbonate solution with hydrogen peroxide and a UO4 precipitation step. Dissolution characteristics of reduced and oxidized uranium oxides were evaluated in a carbonate solution with hydrogen peroxide, and the UO4 precipitation were confirmed by acidification of uranyl peroxo-carbonate complex solution. An agglomerated UO4 powder obtained by the dissolution and precipitation of uranium in the carbonate solution could not be pulverized into fine UO2 powder by the OREOX process, because of submicron-sized individual UO4 particles forming the agglomerated UO4 precipitate. The UO2 powder prepared from the UO4 precipitate could meet the UO2 powder specifications for UO2 fuel pellet fabrication by a series of steps such as dehydration of UO4 precipitate, reduction, and milling. The sinterability of the reclaimed UO2 powder for fuel pellet fabrication was improved by adding virgin UO2 powder in the reclaimed UO2 powder. A process to reclaim the contaminated uranium scraps as UO2 fuel powder using a carbonate solution was finally suggested. (author)
[en] The microwave heating techniques have enormous potential to improve the processing conditions for many radiochemical and radio-metallurgical processes. An update review on the various aspects of development and fabrication of an indigenous microwave heating system and its adaptation to the glove box has been reported in this paper. (author)
[en] This article is a review of safeguards activities during the startup of the MELOX mixed-oxide fuel fabrication plant in France. The concepts applied in MELOX are based on the establishment and maintenance at different levels of independence, according to a structured hierarchy, of independent knowledge of the movements and dispositions of the nuclear material present in the installation. The initial testing/verification of the safeguards-related aspects of the facility is outlined