Impossible.
Upon seeing the 21 sieverts of neutron radiation, Roland's first reaction was nothing but this.
The exploration of deep space has been a complete blank for countries around the world. Either due to lack of funding or official bans, there are some amateur astronomers based on personal interest in the Republic, but it's just pure academic discussion derived from astrology. The understanding of the world above ten thousand meters largely remains in hypothesis and dialectic stages.
Yet no matter how you say it, this altitude shouldn't have intense neutron radiation.
In fact, the types of radiation detectable in near-Earth orbit include Galactic Cosmic Rays (GCR), Solar Energetic Particles (SEP), anomalous region radiation belt particles, and backscatter protons and neutrons caused by atmospheric scattering. Although there are neutrons in these, they could never reach the lethal level of 21 sieverts.