CONCEPTUAL DESIGN AND NEUTRONICS ANALYSIS OF A FLOWING LITHIUM/MOLTEN SALT BLANKET FUSION HYBRID BREEDER REACTO

The conceptual design of an Inertial Confinement Fusion (ICF) Hybrid Breeder reactor is presented. The primary design objectives were as follows, (1) identify a workable ICF hybrid system in which radiation damage to structural components is reduced to allow for extended operation between component replacement and (2) enhance fissile fuel production from the hybrid to provide as large a light water reactor (LWR) support ratio as possible.;Radiation damage to structural components is reduced by filling the fusion chamber with flowing lithium jets. These jets form a protective curtain which shields the first wall from x-ray and charged particle debris and reduces radiation damage to structural material by softening the neutron spectrum. This flowing lithium first wall protection scheme is adapted from that proposed for the High Yield Lithium Injected Fusion Energy (HYLIFE) fusion reactor design. Hybrid reactor configurations are presented in which radiation damage is reduced significantly. In some situations no component replacement may be necessary during the entire hybrid reactor operating life time.;In the designs presented here, fertile thorium is circulated through the hybrid blanket zone dissolved in a LiF-BeF(,2)-ThF(,4) molten salt. Considerable experience with the handling and processing of salts of this type has been gained as a result of the Molten Salt Breeder Reactor (MSBR) Program. Salts of these constituents have low parasitic neutron absorption cross sections, are capable of dissolving large amounts of fertile and fissile material and are chemically stable at very high temperatures and in intense radiation environments.;The fluidized blanket leads to unique operational characteristics for this hybrid. Fissile fuel production is enhanced since bred ('233)U can be extracted from the blanket zone on a continuous basis. Fissioning of bred fuel is minimized since the fissile concentration in the blanket zone is always low. This leads to a very low blanket zone power density (7.3 W/cm('3)). Fission products that do accumulate in the blanket fuel salt can also be removed as an on-line process so that radiological problems in accident situation are minimized.;For hybrid reactors investigated in this study, blanket energy multiplications (total blanket power/incident neutron power) are as low as 1.4 but large values of specific fuel production, 1.3-1.55 kg/MW(,th)-yr (0.75 capacity factor included), result. While the low power producing hybrids have large recirculating power fractions, large LWR support ratios are obtained. In this situation symbiotic system electricity costs are found to be much less sensitive to increases in hybrid reactor capital cost than they are for high energy multiplication hybrids with lower support ratios. This leads to more favorable economics for the suppressed fission, enhanced fuel production hybrid reactor designs presented here.