The first irradiation testing and PIE or TRISO-coated particle fuel in Korea

The first irradiation testing of TRISO-coated particle fuel to demonstrate and qualify its use in a VHTR was finished at the beginning of 2014 in HANARO, Korea. A PIE (post-irradiation examination) of the irradiated TRISO-coated particle fuel was then performed. The irradiation device contained two kinds of test rods: one containing nine fuel compacts, and the other five compacts and eight graphite specimens between the fuel compacts. The irradiation testing was carried out under the condition of filled with an inert gas atmosphere and being sealed (no sweep gas). After irradiation testing, the maximum power of the fuel compact was estimated to be around 56 W at 25 EFPD, and the maximum power of the particle was calculated to be 215.4 mW. And, the maximum discharged burn-up was evaluated to be about 37,344 MWD/MTU (3.99% FIMA). The estimated maximum fast fluence of the graphite specimen was 2.99 × 1020 n/cm2 (E > 0.18 MeV). In this paper, the characteristics of TRISO-coated particle fuels, the estimated thermal power, fuel temperature, burnup, fluence, and some PIE results were described.