Core inventory model for fuel trajectory analysis in fusion-fission symbiotic systems

The dynamic behaviors of fissile and fusile fuel inventories in fusion reactors, fission reactors, and external fuel stockpiles are analyzed for a fusion-fission symbiotic system with a newly developed inventory model denoted as the core inventory model. In this method, the reactor core and fuel stockpile inventories are treated separately with the growth rate of reactor core inventories treated explicitly. The expansion rate of the core inventories are assumed to be proportional to the respective fuel stockpile inventories. Processing and fabrication delay times as well as fuel losses during reprocessing are also considered. Special emphasis is placed on the expansion rates of the fission and fusion reactor economies required to meet rapid demand growth. The system to which the model is applied consists of a Tandem Mirror Hybrid Reactor with either a molten salt or a beryllium blanket, and high-temperature gas-cooled fission reactors with high conversion ratios. Six different operating scenarios are used to test the model. The dynamic thermal power support ratio, the system doubling time, minimum initial fusile and fissile stockpile inventories as well as the critical tritium breeding ratio were the parameters selected for comparison of the six scenarios and analyzed based on the core inventory model