Developing a Preliminary Design of Control and Monitoring Systems for Control Rods of RDNK (Sigit Santoso1, a), TJ Suryono1, b), Dian Fitri Atmoko2, c), Sudarno1, d) and Achmad Suntoro2, e)

Abstract. A non-commercial power reactor based on HTGR technology is being developed in Indonesia. Controlling the
power generated from such reactor can be conducted both by maneuvering control rod and helium circulation flow.
Inserting and retracting the control rods to achieve their intended position accurately required a control rod drive mechanism
and control system. This paper discusses the preliminary design of the control rod control and monitoring system developed
for a non-commercial power reactor or in Indonesian is called as Reaktor Daya Non-Komersial (RDNK). The design was
developed with considering RDNK operation characteristics, safety standards, and proven technology for control rod
control system design applied to other nuclear reactors. The preliminary design was based on a digital system which
comprises of three main parts that are Rod control system, reactor control system, and user interface system. The rod control
system includes logic cabinet and power cabinet which provide electric current to energize the coils of the control rod drive
mechanism. The designed system is used to control and monitor ten control rods of RDNK where each drive mechanism
was designed to drive a single control rod. The control rods are located at the reflector side instead of the core region.
Moreover, the operation characteristics of RDNK, such as high-temperature envelope was also considered in the design
and selection of control rod control systems component parts. The result achieved in this study would be used further to
develop detail design of control rod drive mechanism and control systems of RDNK.
Keywords. control rod, RDNK, monitoring and control system, shut down system