The 235U content of a spent MTR fuel element enclosed in a lead transfer cask has been nondestructively measured by observing the delayed-neutron emissions following high energy neutron induced fission. Fourteen MeV neutrons from a (D,T) neutron generator moderated through 8 in. of lead were used as the interrogating radiation. A DTF-IV calculation was used to correct the data for the contributions due to other fissionable isotopes. The nondestructive measurement agreed to within 1.5% with the 235U content as predicted by reactor burnup calculations.