**1. Introduction**

230 Nuclear Reactors

Suzuki, M., 2000. Light Water Reactor Fuel Analysis Code FEMAXI-V (Ver.1). JAEA Report,

Suzuki, М., 2010. Моdelling of light-water reactor fuel element behaviour in different

Japan Atomic Energy Research Institute, 285 pp.

loading regimes, Аstroprint, Оdessа, 248 pp. (in Russian).

In this chapter, different methods for monitoring and controlling power in nuclear reactors are reviewed. At first, some primary concepts like neutron flux and reactor power are introduced. Then, some new researches about improvements on power-monitoring channels, which are instrument channels important to reactor safety and control, are reviewed. Furthermore, some new research trends and developed design in relation with power monitoring channel are discussed. Power monitoring channels are employed widely in fuel management techniques, optimization of fuel arrangement and reduction in consumption and depletion of fuel in reactor core. Power reactors are equipped with neutron flux detectors, as well as a number of other sensors (e.g. thermocouples, pressure and flow sensors, ex-vessel accelerometers). The main purpose of in-core flux detectors is to measure the neutron flux distribution and reactor power. The detectors are used for flux mapping for in-core fuel management purposes, for control actions and for initiating reactor protection functions in the case of an abnormal event (IAEA, 2008). Thus, optimization on power monitoring channel will result in a better reactor control and increase the safety parameters of reactor during operation.
