This report discusses the study of a modification in the structure of a boiler representative of the type used aboard nuclear-powered ships. The modification involves the relocation of the feed water injection point from the steam drum to the boiling region. On the basis of a simple mathematical model, the study is intended to be a first step in deciding the feasibility of this modification. The mathematical model is developed, and solutions of the system equations are compared with earlier work describing the original boiler configuration. Within the limitations of the model, the modification in boiler structure is seen to produce no essential alteration of system response to changes in steam flow. However, a substantial alteration is produced in system response to changes in feed water flows This is in such a direction as to suggest that the modification may make possible an improvement in boiler dynamics for control purposes, or at the very least, that no degradation of dynamics is produced.