Emission rewards are credited to the staked pool within each validator component automatically by the Radix Protocol at the end of every epoch. The Liquid Stake Units (LSUs) that represent a proportional claim on the XRD in that pool can therefore claim slightly more XRD with the passing of each epoch.
As per the Radix Economic model, approximately 300m XRD will be emitted per year for 40 years after network genesis.
Further reading:
- Start Here! Radix Tokens and Tokenomics
- How do XRD emissions work?
- How long is an epoch on Radix?
- How XRD staking emissions rewards are calculated - general