Development of Accident Tolerant Fuel Options for Near Term Applications: Fuel Performance Modeling under Transient / Severe Accidents by MELCOR: PART Ⅰ: Benchmark for SURRY: Short Term Station Black Out (STSBO)

摘要

While waiting for the materials' parameters from the experiments, a benchmark of MELCOR for SURRY is being done in the University of Wisconsin-Madison to provide an analyzing platform for further work. MELCOR version 1.8.6 was selected because materials edition is allowed. Based on the core of the SURRY plant, MELCOR codes are run under the STSBO conditions. SURRY nodalization scheme is described. After that, the thermal hydraulic safety parameters, such as event timing, variation of water level, temperature, pressure and mass of hydrogen are provided based on the calculation results. Uncertainty analysis was done using comparison between the SANDIA report and the UW-Madison calculation. The comparison results showed a good match between these two code versions, in most cases (difference of RPV down-comer water level is explained in detail in the text). It means there is an efficient modification of the codes. In the next step, an approach for Zr coatings will be developed and FeCrAl will be investigated as a potential accident tolerant cladding material.