Computational investigation of the lifetime characteristics of IGR neutrons

It is shown computationally that the IGR neutron lifetime depends on the neutron creation location in the core and that the absorbing material of the control rods strongly affects its value. It is shown that the neutron lifetime at the bottom of the core can be approximately 30% longer than at core center. The influence of the reflector, the water tank, and the temperature on the neutron lifetime is investigated.