Field testing and inter-comparison of advanced tritium transfer models

Korolevych, V.*; Le-Dizes-Maurel, S.*; Kwamena, N. O.*; Ota, Masakazu  ; Aulagnier, C.*; Patryl, L.*

Participants of the Tritium (T) Work Group of IAEA MODARIA conducted blind testing of four models, TOCATTA of IRSN, CTEM-CLASS of CNL and SOLVEG of JAEA and CERES of CEA, against three field scenarios. Two field experiments were conducted in Canada: one at the Chalk River site by CNL and the other near a T light facility in Pembroke by the CNSC. The third field experiment was conducted near the La Hague processing plant, France. The diversity provided by three field campaigns and the similarity of modeled processes allowed us to determine the minimal complexity requirements of advanced T models. For each model scenario, predictions deviated from observations and revealed not only natural spatiotemporal variability of processes relevant to T transfer, but also intrinsic uncertainty of prediction. It is difficult to analyze the latter and proceed with model development before the natural variability is quantified, which require well instrumented field experiments.