Preliminary optimization study for NGNP fuel block design

An advanced gas reactor fuels development and qualification program is being undertaken by the USDOE to address the need for data in support of the licensing operation of the Next Generation Nuclear Power Plant (NGNP). Reactor physics tasks have been defined and are being conducted to support this program. As part of this effort, a preliminary assessment of deterministic lattice codes (WIMS8 and DRAGON) was performed. It was found that the results from these deterministic codes generally agree well with the reference Monte Carlo results. Based on these results, parametric studies were performed with the WIMS8 code to develop an optimum design of the NGNP fuel block. The design goal is to discharge burnup greater than 100 GWd/t and a cycle length of about 18 to 24 months are targeted. As a first step, the effects of fuel kernel size, particle packing fraction, and uranium enrichment have been investigated, while using the NGNP reference design values for the other design parameters such as the fuel compact size and coating thicknesses