HBK project high temperature reactor fuel cycle. Testplan for Capsule R2-K13

This report describes the scope and the justification, the fuel, the irradiation facilities, and the plans for postirradiation examination for R2-K13, a cooperative irradiation experiment between General Atomic Company and Kernforschungsanlage Jülich under the auspices of the US/FRG Umbrella Agreement for cooperation in gas-cooled reactor development. The R2-K13 began irradiation in April 1980 in the R2 reactor in Studsvik, Sweden. Of the four instrumented cells, the two central ones contain GA fuel. Each of the GA cells irradiates TRISO coated low-enriched uranium (19.3 % enriched) UO_O.5O_1.5 and ThO₂ particles in fuel rods cured-in- place in H-451 multi-hole graphite bodies. These integral bodies were tested at centerline fuel temperatures of 1000 or 1200 °C to a peak fluence of 7.6 x 10²⁵ n/m² (E>29 fJ) HTGR. The maximum burnup for the fissile and fertile fuel will be 21.5 and 4.1 % FIMA, respectively. The upper and lower outer cells contain KFA fuel consisting of HEU LTI-TRISO (Th, U)O₂ particles in molded spheres. Centerline fuel temperatures were 1200°C in capsule 1 and 1000°C in capsule 4. Maximum burnup is expected to be 9 % FIMA. Irradiation time was 2 1/2 calender year, or about 525 full power days.