Fail-safe reactivity compensation method for a nuclear reactor

A system for controlling a solution nuclear reactor comprising:

• (A) a solution nuclear reactor having a nuclear reactor vessel and a homogenous fissile solution disposed therein;
• (B) one or more standpipes located in at least one low worth area of the nuclear reactor vessel, the one or more standpipes having an open end located at a level below a solution level of the homogenous fissile solution contained in the nuclear reactor vessel of the solution nuclear reactor so that the homogenous fissile solution is free to move both into and out of the one or more standpipes;
• (C) at least one gas system, wherein the at least one gas system is in fluidic communication with the one or more of the standpipes and is configured to adjust a pressure within the one or more standpipes,
• wherein a fluid level of the homogeneous fissile solution in the one or more standpipes is controlled via the pressure exerted within the one or more standpipes by the at least one gas system.