ILT20 – an Upgraded Computer Program for Evaluation of Accelerated Leach Test Data of LLW in the Hungarian NPP Paks

Abstract

Computer Program ILT15 was earlier developed to accompany a new leach test for solidified radioactive waste forms in the Hungarian NPP Paks. The program was designed to be used as a tool for performing the calculations necessary to analyze leach test data, a modelling program to determine if diffusion is the operating leaching mechanism (and, if not, to indicate other possible mechanisms), and a means to make extrapolations using the diffusion models. The program uses computational algorithm of ASTM C1308 standard. Now we have developed another computational algorithm based on a Partial Differential Equation (PDE) of a cylindrical specimen, solved the PDE by a Crank-Nicolson Finite Difference Method (FDM) and calculated by integration the eluted amount of a given component in time. The new solution more accurate method was integrated into the existing ILT15 computer program and the resulting new ILT20 program is able to calculate the Incremental/Cumulative Fraction Leached IFL/CFL) either by ASTM or PDE numerical solution methods.ILT20 program is written in C++ in the Borland C++ Builder programming environment. A detailed description of application of this upgraded modelling computer program is given.

Research in Industrial Use of Ion Exchange and Simulation

“…At the Department of Chemical and Environmental Process Engineering (earlier Department of Chemical Technology) of BME we have developed several programs and models for industrial use. As we discussed earlier, we constructed models and computer programs for the simulation of scaling in multicomponent geothermal water (program GEOPROF [8]), a model for the simulation of leaching processes from solid radioactive waste samples (ILT15, ILT20) [9,10], and models for the simulation of multicomponent sorption processes in packed columns [11,12], and stirred bath [13]. We have also developed a simulation program to describe multicomponent ion exchange kinetics according to the Nernst-Planck model in columns [14].…”