“…Common to these materials is that they generally contain minerals, which selectively and strongly fix and retain caesium cations (De Preter, 1990;Andersson, 1991). Other radionuclide ions would be expected to be less strongly held (Andersson, 2009;Brown, 2016), although it has been demonstrated that ruthenium in representative ionic forms is not very easily removed from a roof clay or concrete tile surface (Andersson, 1991). ERMIN uses weathering data based on the Chernobyl time series caesium measurements (Andersson, 2009) for all radionuclides in ionic form for these types of roof materials.…”