COMIDA: a radionuclide food chain model for acute fallout deposition

Area of Science:

• Environmental Science
• Radiological Assessment
• Computational Modeling

Background:

• Accurate estimation of radionuclide concentrations in food is crucial for assessing risks following radioactive fallout events.
• Existing models may have limitations in dynamic simulation of seasonal transport and progeny ingrowth.

Purpose of the Study:

• To develop and validate a dynamic food chain model, COMIDA, for estimating radionuclide concentrations in agricultural products.
• To assess the model's performance against established models like PATHWAY and international steady-state models.

Main Methods:

• Developed the COMIDA (Computerized Model for Investigating Dietary transfer of radionuclides) dynamic food chain model.
• Incorporated seasonal transport processes, discrete events for soil/vegetation, and simpler equilibrium models for animal assimilation.
• Evaluated differential transport and ingrowth of radioactive progeny.

Main Results:

• COMIDA demonstrates very similar seasonal agreement to the PATHWAY model for integrated concentrations in milk and beef.
• Benchmark results show good agreement with international steady-state models for mid-growing season deposition events.
• The model successfully estimates yearly harvest and integrated concentrations for crops and animal products.

Conclusions:

• COMIDA provides a robust tool for estimating radionuclide concentrations in food following acute fallout.
• The model's dynamic capabilities and validation against other models enhance its reliability for nuclear accident consequence assessment.
• COMIDA will be integrated into the MELCOR Accident Consequence Code System for evaluating accidental releases.