Simulating Radiation Chemistry with Mathematica

Karen Colins

Atomic Energy of Canada Limited

Abstract

Computer models for calculating the radiation chemistry of water-cooled nuclear reactors must simulate radiolysis, chemical reactions, and transport — phenomena that occur within irradiated, aqueous environments.  The variables of foremost interest are the evolving concentrations of radiolysis products and radioactive species.  Existing computer models are usually programmed in a manner that requires the user to convert standard 2-dimensional symbolic representations of chemical reactions into 1-dimensional pseudocode that can be read as input.  For example,  " (Subscript[I, 2])(SuperMinus[OH]) + (Subscript[H, 2])(Subscript[O, 2]) ⇌ (Subscript[HIO, 2]) + (SuperMinus[I]) + (Subscript[H, 2])O " may have to be translated into a 1-dimensional character sequence such as " I2OH- + H2O2 = HIO2 + I- + H2O \!\(\*
StyleBox["\"",
FontFamily->"Arial"]\).  Inherent disadvantages of this process are that the pseudocode is significantly more difficult to read than the original, and errors of translation are likely to occur, especially when dealing with hundreds or thousands of chemical reactions.  Using Mathematica's ability to communicate 2-dimensional textual information, Atomic Energy of Canada Limited is overcoming these disadvantages by developing a special-purpose chemical-kinetics computer program that reads standard 2-dimensional chemical-reaction equations directly and uses them to generate sets of coupled ordinary differential equations suitable for numerical solution.