The consequences of a severe nuclear accident on the agricultural environment, releasing 137Cs and 90Sr-enriched aerosols, have been studied within an original lysimetric facility driven in controlled conditions. Focal point of a research scope widely open to European collaborations, this facility has hosted several scientific programmes spread over about a decade (RESSAC and PEACE, notably), the principal achievements of which are provided in the form of a synthetic overview. After a brief reminder of the historical context strongly challenged by the Chernobyl accident within which this project has evolved, the originality of the instrumental set up used for simulating a nuclear accident at a small scale is presented. The addressed scientific aspects concern the clarification of radioecological mechanisms governing the behaviour of these two radionuclides in the soil-plant system. A particular focus is placed on foliar transfers and the resulting translocation, soil in-depth migration, chemical composition of the soil interstitial water, the influence of the later on root absorption which determines the soil-to-plant transfer, all aspects being stressed over a representative spectrum of plants, soil and climates. Based on a strategy of synergy between experiments and modelling developments, the achievements obtained are used to improve the predictive radioprotection tools.