TY  - CONF
AU  - Altmaier, Marcus
AU  - Bischofer, Barbara
AU  - Bosbach, Dirk
AU  - Brendler, Vinzenz
AU  - Daniels, Natalia
AU  - Geckeis, Horst
AU  - Hagemann, Sven
AU  - Müller, Katharina
TI  - VESPA II Project: Behavior of Long-Lived Fission and Activation Products in the Near-Field of a Repository for Nuclear Waste and Possibilities of their Retention
M1  - FZJ-2019-04397
PY  - 2019
AB  - The German project VESPA II (www.vespa2.grs.de) aims at studying  the chemical  properties of  fission(FPs) and activation products (APs), 137Cs, 129I, 99Tc, and 79Se, as well as their transport behavior under conditions of near-field of a nuclear waste repository. This knowledge is mandatory for a safe and  reliable long-term  assessment  of  high-level radioactive   waste disposal avoiding conservative assumptions. The  work  performed  within VESPA II provides for the necessary links between important aspects of the management of FPs and APs in deep geological repositories. In particular, we  investigate: (1) the  source  term, evaluating e.g. 129I inventory  together  with  the  instant  release  fraction  and  its speciation; (2) the effect  of geochemical  conditions in the near-field, i.e. T, p, Eh and pH, on  the processes of surface redox-mediation and secondary mineral phases formation; (3) the solution chemistry, determining stable solubility products, complex  formation  and  activity  coefficients  of  Tc(IV)  in presence  of  anions,  Tc(VII)  in  presence  of  cations,  Se(-II) under  acidic  conditions  and  Se(IV),  Se(0),  Cs(I),  I(-I)  at elevated temperature; and (4) the retention behavior of I, Se and  Tc  on  layered  double  hydroxides  (LDH),  Fe-corrosion phases  and  on  calcite.  Finally, safety  analysis calculations will link obtained results and  provide for  an improved confidence in the risk assessment predictions.
T2  - Goldschmidt 2019
CY  - 18 Aug 2019 - 23 Aug 2019, Barcelona (Spain)
Y2  - 18 Aug 2019 - 23 Aug 2019
M2  - Barcelona, Spain
LB  - PUB:(DE-HGF)24
UR  - https://juser.fz-juelich.de/record/864726
ER  -