MUF Calculation of Indonesian 10-MWt RDE Experimental HTGR Using Combined Uncertainty Approach

Abstract

Abstract A safeguards assessment for the 10-MWt RDE Experimental HTGR needs to be established in order to fulfill the requirements needed to construct it. Methods and instruments used for the RDE’s nuclear material accounting and safeguards system are reviewed in this paper. Material unaccounted for (MUF) is calculated using the uncertainty of each method and instrument. The effectiveness of the safeguards system is examined by comparing the resulting MUF with the number of SQ ( = significant quantity, i.e. the approximate amount of nuclear material for which the possibility of manufacturing of a nuclear explosive device cannot be excluded). The total uncertainty from each KMP showed a number less than 10%. The number of MUF in each KMP according to total uncertainty showed a number below 1 kg of U-235 in one inventory period (~12 months). According to the number of MUF counted, it is impossible to reach 1 SQ if the diversion done is only by taking the advantage of MUF in the measurement. The result of total uncertainty and MUF calculation showed that the safeguards system and the material measurement designed for RDE is amendable. The sets of instruments and measurements designed will give a comprehensive data of each nuclear material in the RDE. The low number of MUF in comparison with the SQ showed that the RDE has a high proliferation resistance.