Comparative Study on the Impact of ENDF/B-VII.1 Nuclear Library Uncertainty on the CERCER and CERMET Fueled Accelerator-Driven System Calculation Results Using Monte Carlo Method Codes

A new design of a small power accelerator-driven system (ADS) using inert matrix fuel- ceramic-ceramic matrix (CERCER) and ceramic-metallic matrix (CERMET) was proposed in our previous work for high transmutation rate, small reactivity loss due to burnup, and enhanced safety features. The fast neutron spectrum in the ADS showed a benefit for reducing minor actinides inventories in the fuel cycle. However, the reliability of the nuclear cross section data of evaluated libraries, especially at high energy, needs to be investigated and its impact on CERCER and CERMET fueled ADS calculation results needs to be assessed. In this study, the impact of ENDF/B-VII.1 nuclear library uncertainty on the CERCER and CERMET fueled ADS reactivity calculation are evaluated using the Monte Carlo method (SCALE6.2 and WHISPER-1.1). The sensitivity coefficients and uncertainty obtained by the two codes show a good agreement. The results reveal the uncertainty of the ENDF/B-VII.1 nuclear data caused significant uncertainty in the reactivity calculations (about 1000 pcm) and it is particularly higher in the CERMET fueled core due to a harder neutron spectrum. The paper identifies the major contributes-isotopes and related cross sections-to the core reactivity uncertainty by suggesting the enhancement of these nuclear data.