[en] An important program is currently in progress at several laboratories over the world for the development of sensitive, practical non-destructive assay techniques for the quantification of low level transuranics (TRU) in solid wastes. The wide variety of materials and contaminants, the low concentrations and large volumes involve, all make this kind of assay a complicated affair. Over the last few years, considerable progress has been made in the field of assay techniques for low level contaminated wastes. This report describes the methods being developed at French Atomic Energy Commission (C.E.A.) in Cadarache to assay high density TRU waste packages by using photon, neutron or both photon and neutron as interrogating particles. All of these particles are produced by using a pulsed electron linear accelerator from which the photons are produced following Bremsstrahlung phenomena on a heavy metallic converter and the neutrons are generated in appropriate low level photoneutron threshold target (e.g. Beryllium). The dynamic of photonuclear interactions and photoneutron production, use of an electron linear accelerator as a particle source, experimental and electronics details, experimental results, simulation to experiment performances and future experimental and theoretical studies are discussed. (authors)