Chernobyl-Born Radionuclides In Geological Environment - Groundwater Vulnerability: Chernobyl Nuclear Disaster - page 38

transport of radionuclides from the soil surface into the deeper geological envi-
ronment and groundwater significantly increases, facilitating the rehabilitation of
soils and self-cleaning of areas.
From the data presented above, a conclusion can be made about the
importance of studying PFMZ of different scales characterized by heterogeneities
of flow and transport parameters. These zones are of principal importance in
assessments of groundwater vulnerability to surface contamination as well as in
questions of postaccident autorehabilitation of areas contaminated with
radionuclides.
From the viewpoint of balance, physicochemical, and modeling consider-
ations, the revelation of measurable 137 Cs concentrations in liquid and solid phases
at significant depths is an interesting fact requiring the implementation of addi-
tional specially designed field and modeling studies. The only possible explanation
for these observation results is the existence of PFMZ of different dimensions
with preferential vertical pathways of downward radionuclide migration.