Enough time for counter-measures

Radionuclides even in critical sand soils travel so slowly that in the case of a hypothetical reactor accident, there would still be enough time to take counter-measures to prevent a large area ground water contamination. One counter-measure would be to have protective wells. If the soil is cohesive at the source of contamination, then the soil forms such a strong transport barrier that the contamination front would merely travel 1 mm per year. This transport delay would mean a sufficient reduction of concentration merely via the radioactive decay of the critical radionuclide Sr 90 after a few meters of travelling. Radionuclide transport in clay soils is no problem as here the extremely low permeability and high sorption ability of clay would bring about confinement of the radioactive source. (orig./HP)