Development of a Simulation Program for the Pyroprocessing Material Flow and MUF Uncertainty

A simulation program, PYMUS has been developed for the simulation of the pyroprocessing material flow and MUF(material unaccounted for) uncertainty. The PYMUS was designed applicable to the reference engineering scaled (10 ton/yr) pyroprocessing facility(REPF), which was conceptually setup for a Republic of Korea(ROK) Member State Support Program(MSSP) to IAEA. The PYMUS simulation is started from the preprocessing input material information generation using ORIGEN code[1] and the pyroprocess progressing materials are generated through the PYMUS simulation of the unit process one by one. The nuclear material measurements are also simulated on the basis of the given measurement uncertainties in order to finally estimate the MUF uncertainty by the PYMUS. All simulation processes and results are real-timely displayed in the user interface(UI) environment. As a performance test of the PYMUS, the total Pu MUF uncertainty was calculated and as the result, the total Pu MUF uncertainty appeared to be less than 2.424 kg, the limitation at the typical condition of the 95 % detection probability and 5 % false alarm.