Lightbridge and KAERI will explore collaborative opportunities in pre-irradiation examination of the Lightbridge-designed metallic fuel samples and other areas. As part of the planned loop irradiation experiments in the Advanced Test Reactor in the United States and MIR research reactor in Russia, Lightbridge plans to conduct pre-irradiation examination of metallic fuel samples prior to their insertion for irradiation testing.
KAERI is interested in Lightbridge-designed metallic fuel technology and its potential application to Korean OPR-1000 and APR-1400 reactors.
Nextbigfuture has covered Lightbridge technology. They are developing larger surface area fuel and all metal nuclear fuels for uprating Pressure Water Reactors by 17 to 30%. Lightbridge is developing two fuel product families for power uprates in existing and new build reactors.
Earlier MIT studies have shown that internally and externally cooled annular fuel makes it possible to significantly increase (by up to 50%) power density in the standard Westinghouse PWR while maintaining or increasing safety margin. The present project has evaluated feasibility of 20% higher power density for the Korean OPR-1000 reactor having annular fuel assemblies of different dimensions and operating conditions than the standard Westinghouse PWR used in previous MIT analyses. The most important difference is keeping the coolant flow rate fixed at the reference value in this study.
Core physics parameters of an equilibrium core for an OPR-1000 type reactor with annular fuel were found to be similar to those of a solid pellet core, even with a 20% uprate. This suggests that reactor physics considerations peculiar to annular fuel do not provide any impediment to its use. The proposed annular fuel assemblies are composed of 7.5% and 6.5% U-235 enriched fuel rods, and burnable poisons with various Gd2O3 weight percentages ranging from 4% to 16%.
The annular fuel design given by KAERI exhibits a better performance than the solid rod because it is capable of achieving 70 MWd/kg burnup at both 100% and 120% power.
The largest possible power uprate that appears justifiable from the present study is 17.55% for the 12×12 annular fuel, close to but still less than the target of 20%. This limit arises largely from DNB considerations in the inner channel of the annular fuel. However, given that our analyses have applied conservative assumptions to cover the transient effects and uncertainties, and that our methods have not been calibrated as much for the Korean reference assembly designs (like grid effects, and power distribution factors), this 2.45% difference in the uprate level may simply amount to added conservatism.