Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Tachi, Yukio; Ochs, M.*; Suyama, Tadahiro; Trudel, D.*
Materials Research Society Symposium Proceedings, Vol.1665, p.149 - 155, 2014/09
Sorption of radionuclides (K) in host rocks depends critically on relevant geochemical conditions, need to correspond to the specific performance assessment (PA) conditions. The integrated approaches for site-specific K setting have been developed focusing two transferring procedures, semi-quantitative estimation procedures and thermodynamic sorption models. The present paper focused on illustrating the derivation of K values and their uncertainties of Cs, Ni, Am and Th for geochemical conditions from the Horonobe URL. These K-setting results were compared with the measured K values, indicating that the magnitude of sorption can be quantitatively evaluated when adequate data and models were available. These comparative discussions between transferring procedures and measured data are effective to enhance the reliability of K setting, and the careful selections from transferred results are needed according to the situation in the existing data and process understanding.
Ochs, M.*; Tachi, Yukio; Trudel, D.*; Suyama, Tadahiro*
JAEA-Research 2012-044, 130 Pages, 2013/03
JAEA has developed the setting approaches of sorption parameter (Kd) for site-specific conditions, to derive reliable parameter for performance assessment (PA) of geological disposal. These approaches include any transferring procedures from experimental conditions to PA conditions through expert judgments, semi-quantitative estimation procedures and thermodynamic sorption models (TSMs). The present report focused on illustrating a range of example calculations regarding the derivation of Kd values and their uncertainties based on semi-quantitative estimation procedures and TSMs. The Kd values of four key radionuclides, Cs, Ni, Am and Th were derived for Horonobe mudstone systems. These Kd-setting exercises allowed to estimate the magnitude of sorption under the site-specific conditions, and to identify some critical gaps in the existing data and process understanding. The possibilities of extending such approaches to further rock types including granitic rocks were also discussed.