The behavior of reactor power and flux resulting from changes in core-coolant temperature for a miniature neutron source reactor

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“…The control rod cannot shutdown the Reactor when it stuck in full "out" position. Since the reactivity of the reactor is linearly related with flux and power distribution, the position of the control rod in the core at any point in time need to be monitored to establish the density or relative strength of the reactor flux [1]. Since the reactivity of the reactor is linearly related to its flux distribution determination of the control rod behavior will give information on the reactor reactivity and flux distribution.…”

“…In water cooled reactor like Nigeria Research Reactor-1 (NIRR-1), which is a Miniature Neutron Source Reactor (MNSR) the predominantly reactivity changes are brought about by change in the moderator (coolant temperature) and power which result in decrease in reactivity. This property is called Temperature Coefficient of Reactivity [1]. The neutron flux distribution in the core fission reactor determines the power and dynamic behavior of the reactor.…”

“…The thermal neutron flux reached its peak value at the center of reactor and falls exponentially at the extreme ends of the reactor core which result to the very few thermal neutrons production in the area. Hence the flux distribution is strongest at the middle of the reactor's core [1]. However, the average flux of a reactor is a variable parameter that depends on the reactor's moderator and coolant temperature.…”

“…A major safety concern in operating a nuclear reactor is to prevent the fuel temperatures from reaching levels where they can lead to the release of fission products into the reactor vessel [8]. According to the [1] core region of NIRR-1 is located close to the bottom of reactor vessel under 4.7m of water. The 1.5m3 of water contained in the reactor vessel acts as moderator radiation shield and primary cooling medium.…”

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“…The results of the study show that all computed accident situation temperatures were below the melting point of the U-Al alloy satisfying regulatory requirements for safe operations of the GHARR-1 facility. Ahmed et al, 2008 carried an experimental study to investigate the effect of coolant temperature on reactor power using Nigeria Research Reactor-1 NINR-1. The experimental data obtained were in good agreement with the data obtained using a semi-empirical relationship between the reactor power, core inlet temperature and the coolant temperature rise.…”