Evaluation of the model performance is one of important tasks of the development process. The atmospheric transport module of the GLEMOS modelling system was recently tested via simulation of a tracer transport corresponding to atmospheric dispersion of a radioisotope (I-131) from the accident at the Fukushima-1 nuclear power station. Details of the tracer conventional source is given below along with an example of the simulation results (animation).

 

Conventional source:
Source: Fukushima-1 (37°25-22.7N 141°01-58.5E)
Release: 2.5 · 1016 Bq/day
Tracer: I-131
Half-life: 8.02 days
Simulated atmospheric dispersion of I-131
from Fukushima-1 (Mar-Apr 2011)

 

Evaluation of model results vs. observations

The simulation results of the tracer long-term dispersion in the atmosphere were evaluated against observations. In particular, an episode of elevated concentrations of iodine-131 was detected by numerous measurement sites in Central and Northern Europe (see for example the EURDEP website). The measurement data for the model validation were provided by Swedish Radiation Safety Authority (SSM). Some results of the comparison of simulated and observed data are given below.