MODELING WATER CHEMISTRY, ELECTROCHEMICAL CORROSION POTENTIAL, AND CRACK-GROWTH RATE IN THE BOILING WATER-REACTOR HEAT-TRANSPORT CIRCUITS .1. THE DAMAGE-PREDICTOR ALGORITHM

A computer code with the capability of simultaneously estimating the c oncentrations of radiolysis species, the electrochemical corrosion pot ential, and the kinetics of growth of a reference crack in sensitized Type 304 stainless steel is developed for the heat transport circuits of boiling water reactors (BWRs). The primary objective of this code, DAMAGE-PREDICTOR, is to theoretically evaluate the effectiveness of hy drogen water chemistry (HWC) in the BWRs as a function of feedwater hy drogen concentration and reactor power level. The power level determin es various important thermal-hydraulic parameters and the neutron and gamma energy deposition rate in the core and near-core regions. These input parameters are estimated using well-established algorithms, and the simulations are carried out for full-power conditions for two reac tors that differ markedly in their responses to HWC. The DAMAGE-PREDIC TOR code is found to successfully account for plant data from both rea ctors using a single set of model parameter values.