coefficient de ralentissement

CONT: Les résultats préliminaires laissent croire que le coefficient de ralentissement de la migration des contaminants est élevé en raison de l'échange entre les contaminants dans les fractures du substratum rocheux et les contaminants dans la matrice non fracturée.
OBS: De la migration des radionucléides.

CONT: ... seepage pits which were used for dilute aqueous wastes have resulted in a contaminant plume of considerable volume. This leads to the fundamental decision that only solidified wastes will be considered for disposal. Experience with an early trench with a nonreinforced concrete cap, which collapsed and led to its flooding, illustrated the need for a strong, self-supporting cap as well as a permeable floor. Contaminant plumes have provided the opportunity to measure groundwater flow and radionuclide transport and to determine retardation coefficients for the different radionuclides under field conditions. This provides valuable data for safety assessments.