Korean Radiation Exposure Assessment Model for aviation route dose

KREAM is a cosmic radiation calculation model developed by the Korea Astronomy and Space Science Institute and Korea Meteorological Administration-National Meteorological Satellite Center for the management of cosmic radiation exposure at aviation altitude.

Cosmic radiation at aircraft altitude comes from the sun and outside the solar system blowing towards the earth. Most of these are made up of protons, of which only relatively high-energy particles (i.e. high-energy protons) penetrate the Earth's atmosphere without being completely shielded by the Earth's magnetic field. In the process of penetrating into the atmosphere, high-energy protons collide with the neutral molecules constituting the atmosphere and produce various secondary particles such as protons, electrons, photons, neutrons, and muons. As a result, all of these particles cause cosmic radiation at aircraft altitude.

KREAM reflects all these physical processes to reasonably calculate the radiation dose at the aircraft altitude. The KREAM is mainly composed of three parts. In first part, the program calculates the spectra of the cosmic rays blowing towards Earth. To this end, spectra of cosmic rays, galactic cosmic radiation and solar high-energy particles, which are obtained from the prediction model and measured in geostationary orbit respectively, are integrated into single spectrum. And the proton spectrum becomes the input value of the second part.

The second part uses a particle transport model that tracks the path of protons entering the atmosphere and collisions with atmospheric molecules. As a result, the energy spectra of secondary particles such as protons, electrons, photons, and neutrons per unit cell of altitude, latitude, and longitude is obtained. In the third part, dose equivalent and effective dose are obtained by applying the conversion coefficient recommended by the International Commission on Radiological Protection (ICRP) to the secondary particle spectra.

When air route information is given as altitude, latitude, and longitude, KREAM calculates the radiation dose according to the GPS route of the flights by performing the above process.