Application of K-Type Heated Junction Thermocouples for Water Level Measurement in PWR and BWR Reactors:A Comparative Study of 2-Wire vs. 3-Wire Connections

Accurate water level measurement in nuclear reactors, particularly in PWRs (pressurized water reactors) and BWRs (boiling water reactors), is essential for ensuring the safety and efficiency of reactor operations. K-type HJTCs (heated junction thermocouples) are widely used for this purpose due to their ability to withstand extreme temperatures and radiation conditions. This article explores the role of HJTCs in reactor water level measurement and compares the performance of 2-wire and 3-wire connections. While the 2-wire connection is simple and cost-effective, it can introduce measurement inaccuracies due to wire resistance. In contrast, the 3-wire connection compensates for lead resistance, offering more precise and reliable measurements, particularly in long-distance applications. This paper discusses the operational considerations of these wiring configurations in the context of nuclear reactors and highlights the importance of choosing the appropriate connection type to optimize safety and measurement accuracy in PWR and BWR reactors.