Initial cathode processing experiences and results for the treatment of spent fuel

As part of the spent fuel treatment demonstration at Argonne National Laboratory, a vacuum distillation process is being employed for the recovery of uranium following an electrorefining process. Distillation of a salt electrolyte, primarily consisting of a eutectic mixture of lithium and potassium chlorides, from uranium is achieved by a batch operation termed ``cathode processing.`` Cathode processing is performed in a retort furnace which enables the production of a stable uranium product that can be isotopically diluted and stored. To date, experiments have been performed with two distillation units; one for prototypical testing and the other for actual spent fuel treatment operations. The results and experiences from these initial experiments with both units will be discussed as well as problems encountered and their resolution

Production of metal waste forms from spent fuel treatment

Treatment of spent nuclear fuel at Argonne National Laboratory consists of a pyroprocessing scheme in which the development of suitable waste forms is being advanced. Of the two waste forms being proposed, metal and mineral, the production of the metal waste form utilizes induction melting to stabilize the waste product. Alloying of metallic nuclear materials by induction melting has long been an Argonne strength and thus, the transition to metallic waste processing seems compatible. A test program is being initiated to coalesce the production of the metal waste forms with current induction melting capabilities

Recent developments at the cathode processor for spent fuel treatment.

As part of the spent fuel treatment program at Argonne National Laboratory, a vacuum distillation process is being employed for the recovery of uranium following an electrorefining process. Distillation of a molten salt electrolyte, primarily consisting of a eutectic mixture of lithium and potassium chlorides with minor amounts of fission product chlorides, from uranium is achieved by a batch operation called cathode processing. Described in this paper are recent developments, both equipment and process-related, at the cathode processor during the treatment of blanket-type spent fuel. For the equipment developments, the installation of a new induction heating coil has produced significant improvements in equipment performance. The process developments include the elimination of a process step and the study of plutonium in the uranium product

Experimental observations on electrorefining spent nuclear fuel in molten LiCl-KCl/liquid cadmium system.

Argonne National Laboratory (ANL) is currently performing a demonstration program for the Department of Energy (DOE) which processes spent nuclear fuel from the Experimental Breeder Reactor (EBR-II). One of the key steps in this demonstration program is electrorefining of the spent fuel in a molten LiCl-KCl/liquid cadmium system using a pilot scale electrorefiner (Mk-IV ER). This article summarizes experimental observations and engineering aspects for electrorefining spent fuel in the molten LiCl-KCl/liquid cadmium system. It was found that the liquid cadmium pool acted as an intermediate electrode during the electrorefining process in the ER. The cadmium level was gradually decreased due to its high vapor pressure and vaporization rate at the ER operational temperature. The low cadmium level caused the anode assembly momentarily to touch the ER vessel hardware, which generated a periodic current change at the salt/cathode interface and improved uranium recovery efficiency for the process. The primary current distributions calculated by numerical simulations were used in interpreting the experimental results

Communication par crossbar optique dans une architecture informatique massivement parallèle

Computer with centralized organization generate the « Von Neumam Bottleneck » effect. The task sharing can be a solution to avoid this problem. The ability for optics to achieve crossbar networks with an important number of lines allows to design new and realistic architectures. C.E.R.T. presents an experiment on such a system as well as parallel architectures based on it. An optical crossbar network needs lines, switches as well as a controller. We take advantage of free space : high data rate, non interference, no material support for lines, and « fan-out » function. We present and analyse the characteristics and limitations of such a system depending on the components and the operation mode.Les machines informatiques à structure centralisée présentent de façon intrinsèque des problèmes « d'embouteillage » sur les lignes de transmission de données. La répartition des tâches sur plusieurs modules indépendants est un palliatif à cet état de fait. La possible mise en oeuvre, par des moyens optiques, de réseaux parallèles possédant un grand nombre d'abonnés permet de concevoir des architectures nouvelles et réalistes. Le C.E.R.T. présente une expérience sur un tel moyen de communication ainsi que les architectures parallèles auxquelles il peut servir de base. Un réseau se compose de lignes de transport de données, de commutateurs et d'un gestionnaire. Nous utilisons les avantages de la communication en espace libre : grande bande passante, non-interactivité des faisceaux, absence de support matériel et facile réalisation de la fonction « fan-out » (communication de 1 vers N). Nous exposons et commentons les performances et les limitations qui dépendent des composants utilisés et des contraintes spécifiques liées au principe même de l'expérience

Animaps

Unzip the file and open the html page in a browser window.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60258/1/Animaps.zi

Neutron irradiation and compatibility testing of Li/sub 2/O

A study was made of the neutron-irradiation behavior of /sup 6/Li-enriched Li/sub 2/O material in EBR-II. In addition, a stress-corrosion study was performed ex-reactor to test compatibility of Li/sub 2/O materials with a variety of stainless steels. Results of the irradiation testing showed that tritium and helium retention in the Li/sub 2/O (approx. 89% dense) lessened with neutron exposure. Helium and tritium retention appear to approach steady-state after approx. 1% /sup 6/Li burnup. The stress-corrosion studies, using 316 stainless steel (Ti-modified) and a 35% Ni alloy, showed that stress does not enhance the corrosion, and that dry Li/sub 2/O is not significantly corrosive, the LiOH content producing the corrosive effects. Corrosion, in general, was not severe as a passivation in sealed capsules seemed to occur after a time, greatly reducing corrosion rates