[en] The phenomenon of nuclear-coupled density-wave oscillations in Boiling Water Nuclear Reactors (BWR) must be analyzed to demonstrate acceptable operational characteristics. Specifically, the stability margin required for acceptable system performance must be quantified. This is important not only from the design viewpoint but also from the requirement of establishing licensing acceptance criteria for a BWR. In this report the currently used licensing criterion based on the so called decay ratio of the system is analyzed. This criterion is based on a single-input single-output (SISO) analysis of the system and thus does not take into account the multi-input, multi-output (MIMO) nature of a BWR system. The deficiencies of the current criterion are discussed, and an interim acceptance criterion is purposed. MIMO-related problems are identified and not how the proposed interim criteria can evolve to deal with these concerns