Nuclear fuel is occasionally warranted to produce a stipulated average Mwd/ton for discharged fuel. Mwd/ton is defined as the megawatt days of heat produced per 2000 pounds of total fissionable and fertile isotopes initially present. In the history of nuclear power reactors, Mwd/ton has been a difficult number to measure accurately. Measurements performed in different laboratories are not always in agreement. A fuel burnup group is preparing tentative procedures which will help standardize the field of burnup analysis. The purpose of this report is to evaluate some of the existing methods for burnup analysis and to select, if possible, the one best suited for warranty purposes.