Analysis of the steady-state and reactivity insertion accident is very
important for the safety of reactor operations. In this study, steady-state
and reactivity insertion accident analysis when the low enriched uranium foil
target is irradiated in the reactor core has been carried out. The analysis
is carried out by the best estimate method by using a coupled neutronic,
kinetic, and thermal-hydraulic code, MTR-DYN. The MTR-DYN code is based on
the 3-D multigroup neutron diffusion method. The cell calculations for the
target are carried out by the WIMSD/5 and MTR-DYN code. After reactivity
insertion, the coolant, fuel, and clad temperature are observed. The
calculation results for the initial power of 1 W showed that the maximum
temperature of the coolant, clad, and fuel are 49.76?C, 65.01?C, and
65.26?C, respectively. Meanwhile, when the reactivity insertion at the
initial power of 1 MW, the maximum temperature of the coolant, clad, and fuel
are 72.23?C, 140.79?C, and 141.97?C, respectively. Based on those calculation
results during irradiation low enriched uranium foil target, the temperature
in the steady-state and reactivity insertion accident does not exceed the
allowable safety limit.