Measurements Enhancement of the Instrumentation and Control for Research Reactors

The Research Reactor (RR) is a pool-type reactor with an open water surface and variable core arrangement, the core cooling by light water, moderated by water and with beryllium reflectors. It has plate-type fuel elements with aluminum clad. the core thermal power 22 MW. The Reactor Protection System (RPS) commands two diverse and independent reactor shutdown systems that extinguish the nuclear reaction. The Thermal power is measured by summation of the heat exchanger power of core cooling system with pool cooling system or the power of the secondary side (cooling tower power consumption). The transmitters of the temperature were recalibrating. Accurate measurements are fundamental to operation and power control of any Research Reactor. This paper is to propose and discuss methods for verifying accurate measurements in a typical open pool RR. The recalibration technique is proposed for verifying the calibration of temperature instrumentation. Most critical process temperatures in Nuclear Research Reactor are measured using resistance temperature detectors RTDs. In addition to excellent reliability and accident survivability, nuclear safety related RTDs are expected to have good calibration and fast dynamic response time, as these characteristics are important to plant safety and economy. The power measuring system base on ¹⁶N (Nitrogen-16) measurement can ensure accurate relationship between indicated power and actual core power. The reactor thermal power calibration is very important for precise neutron flux and fuel element burn up calculations. (author)