The time-dependent escape of neutrons and gamma rays from a nuclear explosion is of interest in Plowshare and nuclear weapons effects investigations, particularly with regard to generation of the electromagnetic pulse (EMP). In the present paper the neutron and gamma-ray leakage rates, spectra, and useful yield-related integral quantities are calculated for the 24kt S-device. EMP parameters and fields at 500 m from the explosion of the S-device on the ground are presented and discussed.