Cosmic rays (CR) can be divided into two categories: primary species, which arrive at us
directly from their acceleration sites, and secondary species, which originate from reactions of
heavy primaries (C,N,O) with the interstellar medium (ISM). In this work, a new high precision measurement of an unusual primary/secondary couple specie of CR, 10Be/9Be, is presented, performed thanks to the AMS-02 data during 9 years of data-taking. This is a special measurement since 10Be has important radioactive clock properties, allowing it to be crucial for independent and new constraints on the parameters of the propagation of the CRs in the Galaxy, like the diffusion coefficient D and the thickness of the Dark Matter halo H.