Energy optimal control for reactor shutdown problems with maintenance time

Various types of terminal conditions in Reactor Shutdown Problem can be unified by a maintenance time parameter lambda sub(M), which represents a scheduled period after shutdown. Two types of energy optimization problems are analyzed by application of Pontryagin's Maximum Principle. Variation of lambda sub(M) changes the shape of target curve of these problems. We investigated how optimal trajectories are influenced by this parameter. Though optimal control law for problems of lambda sub(M)=0 can be always applied to ones of lambda sub(M)<0, specific control law, u=0 control, appears in lambda sub(M)<0 cases. The cost is decreased by increasing the parameter value. (author)