Can gravel augmentation restore thermal functions in gravel‐bed rivers? A need to assess success within a trajectory‐based before–after control–impact framework

International audienc

Can gravel augmentation restore thermal functions in gravel‐bed rivers? A need to assess success within a trajectory‐based before–after control–impact framework

International audienc

Riparian shading mitigates warming but cannot revert thermal alteration by impoundments in lowland rivers

International audienc

High-precision measurements of reflectance

International audienc

The CIRENE loop: a tool to study ACP deposits and to validate the PACTOLE code

International audienceThe understanding of Activated Corrosion Product (ACP) transfers in the primary circuit is of great importance for the PWR industry. For this purpose, the CEA, in collaboration with EDF and AREVA NP, has launched an R&D program for many years involving specific experiments related to the development and validation of the PACTOLE code. Among them, the CIRENE out-of-pile loop is dedicated to the study of ACP deposits on fuel rods and on steam generator tubes. The first results were presented at the Jeju Island International Conference. This paper presents the experimental results of a new CIRENE test and compares the numerical simulations obtained with the PACTOLE V3.2 code. This test has been carried out with thermal-hydraulic parameters corresponding to a subcooled boiling regime at the outlet of the core section, and chemical conditions representative of a French PWR primary circuit. A radioactive tracing methodology have been applied, using gamma spectrometry measurements with the injection of specific radiotracers, 58 Co and 59 Fe: in-situ gamma spectrometry measurements are performed at the outlet of the core section and the SG tubes, while frequent radiochemical analyses of the primary fluid are carried out for checking the instantaneous mass balances. The comparison between the experimental results and simulations with the PACTOLE V3.2 code has led to the main following comments: • deposited activity variations in operation : for the core section as well as for the SG tube section, the calculated variations reproduce the experimental ones; • residual deposited activities after shutdown : the calculated activities are coherent with the experimental measurements. Consequently, the modelling developed in the PACTOLE code is globally validated for the CIRENE loop, and the differences between simulation and experimental results point out some remaining issues in the modelling of ACP behaviour in PWRs

High-accuracy measurements of the normal specular reflectance

International audienc

Détection précoce du stress hydrique des forêts alluviales : de l’individu au peuplement, del’écophysiologie à la télédétection (DéPréSHyF)

National audienceEtat de santé des forêts alluviales, des individus au peuplement de l'écophysiologie à la télédétectio

Détection précoce du stress hydrique des forêts alluviales : de l’individu au peuplement, del’écophysiologie à la télédétection (DéPréSHyF)

National audienceEtat de santé des forêts alluviales, des individus au peuplement de l'écophysiologie à la télédétectio

Détection précoce du stress hydrique des forêts alluviales : de l’individu au peuplement, del’écophysiologie à la télédétection (DéPréSHyF)

National audienceEtat de santé des forêts alluviales, des individus au peuplement de l'écophysiologie à la télédétectio