The phenomena of runaway breakdown (RB) is based on specific features of the interaction between fast particles and matter. In the atmosphere RB is stimulated by cosmic-ray secondary electrons. A high-energy cosmic ray interacting with molecules in the atmosphere generates an extensive atmospheric shower (EAS) that consists of a large number of different elementary particles. The existence of high-energy emissions indicates that relativistic electrons play a significant role in thunder cloud discharge. The RB-EAS theory predicts a strong growth of the radio-pulse power with the cosmic-ray particle energy. Detailed studies of this phenomena could lead to a new method for radio detection of very high-energy cosmic-ray particles.