Parametric test and measurements after shimming of a beryllium reflector in a miniature neuron source reactor (MNSR)

摘要

After 10 years operation of Pakistan research reactor-2 (PARR-2), a miniature neutron source reactor (MNSR), a beryllium reflector was added to compensate the loss of reactivity due to burn up of fuel. Beryllium shim plates have been placed at the top of the core in a tray provided for this purpose. The control rod was dismantled and withdrawn from the core and the reactor was made subcritical with cadmium shimming. To monitor the neutron popula- tion during this experiment, two additional neutron monitoring channels based on BF_3 were installed around the core.