[en] The purpose of incineration is to minimize the volumes of radioactive waste to be stored. Cleaning combustion gases from these incinerators requires prefilters to protect the very high efficiency filters (known by the French acronym THE). These prefilters should make it possible to recover products such as plutonium while at the same time presenting a very limited source of secondary waste. This document sets out the feasibility study for a granular bed prefilter. This bed should be made of a material which is itself combustible so that it can be recycled in the incinerator to minimize production of secondary waste. During an initial stage, a design study of a demonstration device was carried out using a calculation code constructed on the basis of existing physical models, and which makes it possible to forecast the performance of the support. This theoretical approach has been correlated against experimental results from the validation test. During a second stage, the study dealt with the selection of the material from which the bed was made as well as quantification of the release of radiation during incineration of the plutonium contamined material. In this way, the very low transfer of radioactivity into the gaseous phase was demonstrated. Finally, during a third stage, a study of the change in efficiency and the loss of charge of a granular bed filter was carried out during industrial operation using an incinerator. In conclusion, it was demonstrated that the granular bed represents a viable solution for prefiltering at 200 deg C. Research might develop along a different path and involve using the granular bed as a high temperature filter at 500 to 600 deg C

[en] During the past ten years, a large amount of experimental data has been accumulated which gives information with regard to the sizes of the nucleus and the distribution of nuclear matter. Some particularly relevant results are presented. From a theoretical point of view, the contribution of the microscopic models is shown and particularly the results obtained by Hartree-Fock (HF) and Hartree-Fock-Bogoliubov (HFB) methods using D1 effective interaction. The limitations of static calculations are also shown making necessary to take into account the dynamical effects, especially in shape transition regions. The densities obtained by the HF + RPA and HFB + Bohr hamiltonian theories are presented and compared to the experimental results

[en] The purpose of this note is to point out that a drastic under-estimation of nuclear level densities for both spherical and deformed nuclei could be rather a common feature of effective interactions, which generate too weak densities of single-particle states near the chemical potential corresponding to the Fermi energy in a Fermi gas model

[en] The charge distribution of the ⁵⁸Ni nucleus was calculated, taking into account collective oscillations associated with changes in the nucleus shape but conservation of the axial symmetry. The results seem to be in agreement with experimental results

No abstract available

[en] Pairing effects versus deformation have been carried out for the ¹⁵²Sm with the complete Hartree-Fock-Bogoliubov (H.F.B.) method using the effective D1 interaction. The results obtained are discussed and compared with approximations generally used to treat pairing, namely constant gap approximation and prescription of G proportional to the nucleus surface

[en] This theoretical study is intended to establish a preliminary selection of non fissible even-even nuclei with mass number A < 208 for which the potential energy surfaces V (β) display a secondary minimum along an elongation coordinate β. Our selection relies upon a joint use of the Hartree-Fock-Bogoliubov and Strutinsky methods. The occurrence of secondary minima in V (β) maps is of critical importance for the formation of long life excited states (i.e. shape isomers) which most likely would decay into the γ channel. Our study shows that more than seventy nuclei in the vicinity of the stability line might develop shape isomerism

[en] The purpose of the present work is first to investigate the capabilities of a semi-microscopic optical-model potential involving fewer adjustable parameters than phenomenological models and second, to test the sensitivity of this potential to various rotational band assumptions. Our analysis of the model capabilities is performed using experimental elastic, inelastic, and total cross sections from approx. 10 keV to 15 MeV as well as neutron strength functions, and our sensitivity study is performed for the first three bands of ²³⁹Pu: 1/2⁺(0.0), 5/2⁺(286 keV), and 7/2^-(392 keV)

[en] In this work we introduce new developments of our nucleon-nucleus optical model potential (OMP) built from the nuclear matter (NM) approach of Jeukenne, Lejeune and Mahaux (JLM). Having selected prescriptions for the local density approximation (LDA) and using nuclear densities obtained from Hartree-Fock-Bogoliubov (HFB) calculations, the normalizations of the potential depth are carefully optimized and given functional forms that represent their variations with projectile energy over a broad mass and energy range for incident protons an neutrons. These OMPs, used in the coupled channel framework, produce good predictions of neutron and proton scattering and reaction measurements available up to 200 MeV for deformed rigid nuclei in the range A=80-240

[en] The Hartree-Fock-Bogolyubov model and the effective interaction were used to study nuclear deformation properties of rare earth nuclei. The results obtained for ¹⁵⁰Nd are presented. It is shown that this nucleus has no permanent deformation