Evaluation of the impact of cadmium poison and cadmium line channel on the dynamic behavior of miniature neutron source reactor (MNSR)

Abstract

Nigerian Research Reactor-1 (NIRR-1) undergo different installation such as permanent
Cadmium line due to high demand for epithermal neutrons activation analysis (ENAA)
irradiation by the clients and cadmium poison to regulate the reactivity of the reactor with
a range value 4.0mk to 3.7mk. Safety and flux stability. Simulations were carried out via
Monte Carlo Transport Code MCNP5 for these installations but very few experimental
calculation were done. The results of all these research work revealed that the effect of
cadmium-line on safety and flux stability is very small. But in the case of cadmium poison,
the reactivity of the reactor after 10 years of operation was observe to be decreasing. The
results obtained for excess core reactivity after (2.96 and 2.95) mk, and predicted power of
14.65 kW for the two experiment with coolant temperature (12.10 and 12.08) °C
respectively. These show that the change in power of the reactor is very small. The outcome
of the research will help sample handling capabilities of NIRR-1 and provide useful data to
the MNSR.

Key words: Epithermal neutron, ENAA Irradiation, NIRR-1.