Replacement of I&C System for the Four Main Pumps in the Fuel Channels Cooling Circuit of “Maria” Polish Research Reactor

In this work the replacement of the I&C connected with the four main pumps in a Polish research reactor called “Maria” is discussed. In particular, this paper focuses on the aspect of the whole system of pump parameters measurements (temperature, vibrations, power) and pump control system. The whole architecture of the I&C system (including power supply, redundancy of electrical and control system) will be showed. During the I&C replacement some problems arose, such as the change in the pump control system from analog to digital system; the link existing in the reactor part of the measurement made in analogue to a digital system, as part of the measurements, which were carried out in an old control system; the code for the PLC controller program dedicated exclusively to the requirements of control systems pumps. All of these problems will be discussed here, together with the proposed solutions. Moreover, I&C functional and operational tests carried out after the placement of the pumps will be described, such as loss of power and failure of one PLC controller.