The 14MeV neutron emission from JET deuterium discharges is analyzed on the basis of all neutron diagnostics information available on JET. This emission is due to the t + d → α + n reaction, mainly the triton burn-up process and is used to determine the fast triton confinement. A simplified model for triton burn-up neutron emission has been used and provides an adequate description of the 14MeV emission. First orbit triton losses are found to amount to 50, 20 and 10% at Ip = 1, 2 and 3MA, respectively. Neutron emission spectroscopy measurements with the Magnetic Proton Recoil Neutron spectrometer have detected a contribution to the 14MeV emission due to residual tritium. For the selected (low impurity) discharges analyzed in this paper 15% of the 14MeV emission comes from the residual tritium reactions. It is also found that residual tritium concentration tends to increase with increasing impurity content.