[en] To simulate the release of both the decay heat and the stored energy within the nuclear fuel rods, an appropriate power versus time curve has to be applied to the LOBI directly heated rod bundle. To obtain this power curve, a blowdown calculation for the LOBI test facility was performed with the RELAP4/MOD6 code, using a nuclear fuel rod model with the same axial power profile as the electrically heated bundle. The resulting surface heat fluxes and surface temperatures are then used as boundary conditions for the thermal analysis of the electrically heated rods. This leads to the required power versus time curves for the different axial sections of the test bundle. Since the heater rod bundle can be controlled only as a whole, a power fraction weighted average is determined from the calculated power curves for the different axial sections of the bundle. A stepwise approximation of this curve has been applied as the final power versus time curve for the LOBI heater rod bundle