The purpose of this work is to define and verify the range of validity and limitations of correlations used for nuclear waste characterization and to scrutinize the dependencies and propagation of uncertainties that affect the waste inventory declarations and their independent verification. This is accomplished by numerical assessment and simulation of waste production using well accepted codes SCALE 6.0 and 6.1 to simulate the cooling time and burn up of a spent fuel element. The simulations are benchmarked against spent fuel from the pressurized water reactor Obrigheim in Germany for which sufficiently precise experimental reference data are available
