[en] A balance is made of nuclear data needed for studying FBR fuel cycle. From the accuracy of the obtained data, sensitivity calculations have enabled the future experimental measurements to be established

[en] The decay heat calculation code PROTEE has been checked against integral measurements and specific component measurement. Of particular relevance are the PHENIX measurements, which are presented here together with the calculation experiment value comparison. A reasonnable agreement is found and a slight tendency (approximately 10%) to over estimation of the PROTEE code is indicated

[en] When comparing the behaviors of a heterogeneous core configuration and a homogeneous core configuration of a large LMFBR subject to a LOF type HCDA, it is necessary to understand the influence of many different core parameters. We present the results of the comparative calculations made with the SURDYN code, up to the end of the primary power excursion. They show that, if sodium does boil, the energy yield is larger with the heterogeneous core, but the preboiling time is then longer. Parametric calculations, with gradual modifications from the homogeneous core to the heterogeneous core, show that the power and temperature distribution and, to a smaller extent, the fuel reactivity feedback, are the main contributors. Doppler and void coefficients (somewhat smaller in the heterogeneous core) have less influence

[en] Radioactive wastes are mixed with cement then with an epoxy resin additioned of a hardening agent

[en] A process is claimed for cleaning with a sublimable abrasive, especially carbon-dioxide ice particles, and equipment for the operation. Application is made for decontamination of radioactive materials

[en] This paper describes the process developed to decontaminate the CO₂ cooling system of the G2 gas-cooled reactor with the objective of recycling the majority of the scrap material as conventional waste. The process is first implemented before dismantling to facilitate pipe cutup operations. If necessary, a second application is performed in a sealed cell to meet the specified objective. (author)

[en] The main goal of the SPIN program developed by CEA is to improve the management of high activity waste containing minor actinides and long-lived fission products. In that field, americium has been pointed out as the main hazardous element to be firstly recovered. With the aim to extract more than 99% of the americium contained in high level liquid waste (HLLW), the SESAME process, which consists in the selective extraction of oxidised Am, is foreseen as a promising way to succeed in Am management. Dealing with the americium selective recovery from HLLW, many studies concerning the electrochemical oxidation of Am to its hexavalent state in the presence of lacunary poly-anionic ligands (LHPA) have been carried out. The main results of several laboratory scale tests of the SESAME process are presented and the further process development is discussed. (author)

[en] An evaluation is presented of those nuclear data which relate to fuel cycle studies of fast neutron reactors. Sensitivity calculations, based on precise values obtained from actual data, allow the definition of priorities for experimental measurements and for future evaluations. (Auth.)

[en] The decommissioning of nuclear installations requires decontamination techniques that are efficient, simple to apply and producing a small amount of wastes, which are easy to process. With a view to this, three decontamination methods, which appear to be particularly suited to decommissioning, have been studied. These three methods are: - spraying of gels carrying chemical decontaminating agents, - electropolishing with a swab device, - abrasives blasting. After parametric tests on non-radioactive and active samples, the industrial application of these methods in the dismantling of installations was studied. These industrial applications concern: - decontamination of pieces coming from the German BWR ISAR by immersion and gel spraying, - decontamination, mainly by gel spraying, and dismantling of the BRENNILIS bituminisation plant, - decontamination of part of the cooling circuit of the graphite gas reactor G2 by gel spraying, - decontamination of a component of the FBR SuperPhenix, using dry abrasives blasting. During the first three applications, generated secondary wastes volume and form were determined. 33 tabs., 16 figs., 12 refs

[en] The Act of the French Parliament passed on 30 December 1991 concerning the management of high activity, long-lived nuclear wastes identifies three main lines of research: the separation of long-lived elements for their transmutation, repository in deep geological formations and, third, conditioning and interim storage. In each of these fields, the research organisation involved are required to provide the necessary scientific and technical assessments before the year 2006 to enable the public authorities to make the appropriate strategic decisions. The French Atomic Energy Commission (CEA) drew up the SPIN programme as a response to the first axis of the Act: it essentially involves investigation on the separation and transmutation of the long-lived radionuclides present in spent nuclear fuel. (author)