The GM2003 model extends the r(t) glass dissolution model with water diffusion through the diffusion layer. Boron and alkali diffusion through the diffusion layer is described by introducing a retention factor Kd,i between boron/alkali and water in the diffusion layer. Introducing a boron/alkali diffusion coefficient, the BRAG model describes boron/alkali diffusion in the diffusion layer as well. It is shown that both models are consistent with each other and an expression is derived for the boron/alkali diffusion coefficient (BRAG) as a function of both parameters of GM2003: the retention factor Kd,i and the water diffusion coefficient DH2O in the diffusion layer. From dissolution data only, it is possible to fit the value for the boron/alkali diffusion coefficient in the diffusion layer but due to correlations the individual values of both parameters Kd,i and DH2O of GM2003 cannot be determined. From theoretical considerations follows that the Kd,i value for boron/alkali should be slightly larger than 0.1 kg/liter. A user friendly code for the BRAG model allows automatic fits of glass dissolution data in water.
|Title of host publication||Scientific Basis for Nuclear Waste Management XXX, MRS Proceedings Volume 985|
|Place of Publication||Warrendale, Pennsylvania, United States|
|State||Published - Dec 2007|
|Event||Materials Research Society Scientific Basis for Nuclear Waste Management XXX - Materials Research Society, boston|
Duration: 27 Nov 2006 → 1 Dec 2006
|Conference||Materials Research Society Scientific Basis for Nuclear Waste Management XXX|
|Period||2006-11-27 → 2006-12-01|