Output control and instrumentation of nuclear reactor

In reactor instrumentation, the requirements for safety and reliability are particularly serious as compared with the requirements in thermal power plants and general process instrumentation, besides, the requirements must be met in each instrument or system. Good regulating character of PWRs enables the operation following the requirement of turbogenerators together with its load follow-up character, and the reactor control system is constructed so as to supply necessary steam steadily. The reactor control system of PWRs is divided into such sub-systems as control rod control system, boric acid concentration control system, pressurizer control system, feed water control system (steam generator level control system) and steam dump control system. The operation of these systems is described briefly in view of safety and reliability. The functions peculiar to atomic power, required to individual instrument, are illustrated in case of the pressure or differential pressure transmitter installed in a containment vessel and an instrument rack and rack-mounted instruments. Complete redundancy or danger-dispersing multiplicity and severe quality control are needed. Of course, each system design must be performed from a standpoint of total system. (Wakatsuki, Y.)