[en] In order to assess the optimum approach for extending the SUPERENERGY code to transient LMFBR analysis, it is necessary to consider the advantages and disadvantages of the various temporal differencing schemes that can be applied to the energy equation used by the code. These differencing schemes can be fully implicit or fully explicit, although differencing schemes consisting of a combination of temporally implicit and explicit parts may also be used. It is well recognized that temporally implicit differencing schemes tend to be more stable, but that this stability can be offset in practice by factors such as greater computer storage requirements and considerably longer running times