[en] Full text of publication follows: The physical modeling of the Critical Heat Flux phenomenon (CHF) relevant to LWR core conditions has been attempted with various degrees of success in the past. The modeling of dryout-type CHF (relevant to BWR) is considered more 'mature' since the two-phase flow pattern is known (annular flow) and the dryout event can be linked (at the macroscopic level) to the liquid film thinning and disappearance. The modeling of DNB-type CHF (relevant to PWR) has always been much more speculative since the most basic information, the two-phase flow pattern, is not well known under high heat flux (near-DNB) conditions. In addition, both CHF types are affected by near-wall small-scale effects. With the advance of numerical tools for two-phase flow simulation, the mechanistic modeling of CHF has recently evolved from 1-D to 3-D simulations where near-wall information, relevant to the CHF phenomena, are expected to be better captured, hence improving the accuracy of the simulations. However, this evolution does not resolve the modeling issues mentioned above and the need for experimental investigations should be a primary focus. In the view of the author, the main current needs for experimental investigations are listed below: In a first step, at the meso-scale, it is necessary to systematically identify (e.g. through direct visualizations) the two-phase flow pattern(s), and the corresponding high resolution wall thermal response, occurring near and during the DNB-type CHF phenomena under PWR conditions. Even though past investigations are numerous, they are often limited to low pressure and restricted to narrow range of conditions. In these experiments, use of the latest technological tools in high time resolution video imaging, void fraction measurement and wall temperature measurement will be beneficial. Investigation of a wide range of condition is necessary since the two-phase flow pattern may change, thereby potentially modifying the mechanism leading to DNB. In a second step, it is equally important to investigate small and micro-scale phenomena, such as the detailed behavior of a boiling wall or of a thin liquid film (in annular flow and underneath a vapor slug or a near-wall vapor clot) under high heat flux convective flow conditions in order to identify the physical events leading to the CHF and investigate innovative and practical solutions to provide margin to both dryout and DNB-type CHF (e.g. by modifying the fluid or wall properties). In addition to the need for experimental investigations, the numerical simulation of the phenomena needs to proceed carefully. Leaping ahead to 3-D numerical simulations without careful considerations of the physics of two-phase flow near CHF is quite hazardous. In some situations, 1-D tool and proper consideration of the phenomena (e.g. through the use of adequate constitutive relations) can be as accurate (and much more practical and computational efficient) as the use of 3-D tool due the high degree of uncertainty in the measurement and modeling of local parameters. (author)