Quantification of inhaled soot mass using Pathfinder coupled results

To be able to handle the fire risks present at CERN, the HSE unit needs to assess the risks relating to fire involving radioactive substances. Smoke consists of a multiphase flow, containing combustion gases and solid particles in suspension, what we commonly call soot.

The possible effect of radioactive smoke is quantified using an in-house developed methodology, based on Pursers model for toxicity, which is compatible with the output generated by a coupled FDS-Pathfinder simulation. The methodology has been specifically developed to be able to import Pathfinder output files and based on visibility and CO concentration, calculate the mass of inhaled radioactive soot particles and gases. The difference between the phases has been made to consider effects as soot deposition, which would not occur for radioactive gases. This methodology has been verified in several case studies.

This approach allows the evaluation of the incurred Fractional Effective Dose, which is a built-in function of Pathfinder, as well as the related inhaled mass of soot and radioactive gases, which in turn give us the amount of incurred radioactivity.

A case study will be presented showcasing the integrated FDS-Pathfinder approach with the developed methodology added on.