Validation of Modified ART Mod 2 Code through Comparison with Aerosol Deposition of Cesium Compound in Phébus FPT3 Containment Vessel

Abstract

Evaluation of aerosol deposition in the containment vessel is an important step for the assessment of radioactive material release to the environment. ART Mod 2 is a calculation code that is used for evaluation of aerosol deposition in the containment vessel. The authors modified aerosol deposition models of ART Mod 2, namely, gravitational settling model, Brownian diffusion model, diffusiophoresis model, and thermophoresis model in order to increase potential of capturing the deposition phenomena. This study aims to compare the simulated results of modified ART Mod 2 with aerosol deposition of cesium compounds in the containment vessel of Phébus FPT3 experiment, in order to validate modified ART Mod 2 code. It is found that aerosol deposition using modified ART Mod 2 agrees with Phébus FPT3. Prediction of Brownian diffusion is significantly improved due to the consideration of turbulent damping process. Cesium mass flow rate and aerosol size are factors that can significantly influence the uncertainty of the results. When conditions of single volumes are carefully selected to match those of the Phébus FPT3 experiment, modified ART Mod 2 can predict aerosol deposition in Phébus FPT3 with relative accuracy.

Assessment of Cesium Compound Behavior during Simultaneous Failure of Reactor Pressure Vessels and Spent Fuel Pools Using Modified ART Mod 2: Fukushima Daiichi Accident Simulation

“…As for the gaseous fission products, models for condensation and adsorption are considered to evaluate fission product behavior only at the wall surface [16], while the aerosol fission products consider deposition on both the wall and the floor [17]. Phenomena of Brownian diffusion, diffusiophoresis, and thermophoresis are used to illustrate the aerosol deposition on the wall.…”

“…ailand has been using the code of Analysis of Radioactive nuclide Transport and deposition/Modification 2 (ART Mod 2) [16] of the Japan Atomic Energy Agency (JAEA) to conduct the source term analysis since 2015. ART Mod 2 code was modified and validated for the evaluation of fission product behavior of cesium compounds from RPVs into Primary Containment Vessels (PCVs) [17]. Four models of aerosol deposition phenomena were validated in order to increase the accuracy of the calculation, namely, gravitational settling, Brownian diffusion, diffusiophoresis, and thermophoresis.…”