Open AccessMODELLING OF COUPLED GROUNDWATER FLOW AND RADIONUCLIDE TRANSPORT IN CRYSTALLINE BASEMENT USING FEFLOW 5.0
Author(s) -
Vaidotė Jakimavičiūtė-Maselienė,
Jonas Mažeika,
Rimantas Petrošius
Publication year - 2006
Publication title -
journal of environmental engineering and landscape management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.514
H-Index - 28
eISSN - 1822-4199
pISSN - 1648-6897
DOI - 10.3846/16486897.2006.9636886
Subject(s) - radionuclide , groundwater , radioactive waste , groundwater flow , geology , tectonics , basement , hydrology (agriculture) , environmental science , mining engineering , geochemistry , aquifer , geotechnical engineering , seismology , waste management , civil engineering , engineering , nuclear physics , physics
The strategy of radioactive waste management of Lithuania provides for evaluating the possibilities of disposal of spent nuclear fuel and long‐lived radioactive waste originated from Ignalina NPP in deep geological formations. The initial studies performed in Lithuania during 2001–2004 focused on screening of all potentially prospective geological formations as host formations. Since most information is available on crystalline basement, this formation was selected for the model case studies. Taking into account the assumptions (canister defect scenario proposed by Swedish experts and evaluated by LEI experts), groundwater flow and radionuclide (iodine‐129 as mobile and long‐lived one) transport modelling using computer code FEFLOW was performed according to geosphere conditions and parameters characteristic of the southern part of Lithuania (0,8×0,6×0,52 km far‐field block). The upward groundwater flow through defected canister located in tectonically damaged zone was simulated. The main results of calculations are the following: in the case of upward groundwater flow, the maximum I‐129 volumetric activity in single tectonic fracture above defected canister will not exceed 1 Bq/1, and in the active water exchange zone, it is close to 10−2 Bq/l. These figures show that doses obtained by human recipient via aquatic pathway should be below the dose constraint (0,2 mSv/y). More complicated scenarios and assumptions should be investigated in future studies.