Two-dimensional fluid simulation of plasma reactors for the immobilizationof krypton

Direct current glow discharge plasma sources are being developed as reactor s for immobilization of radioactive krypton gas recovered from the off-gas stream of a nuclear fuel reprocessing plant. In order to design these react ors, two-dimensional simulations have been performed using a fluid model co upled with Poisson's equation. Nonlinear governing equations were expressed by a fully implicit scheme and the equations were solved using the Newton- Krylov method. Mr, investigated algorithm performance of two methods from t he Krylov projection techniques, namely the Bi-CGSTAB method and the transp ose-free quasi-minimal residual (TFQMR) method. The results showed that the Bi-CGSTAB method converged considerably faster than the TFQMR method. Dire ct current glow discharge plasmas in three types of krypton immobilization apparatus were simulated to study the differences in electrode geometry. Si mulation results agreed qualitatively with measurements of electron density . (C) 2000 Elsevier Science B.V. All rights reserved.