Results of experiments at the AVR reactor

Fission Product Transport and Source Terms in HTRs: Experience from AVR Pebble Bed Reactor

“…Accordingly, the corresponding core temperature is about 20 K higher than the recorded maximum temperature. The results for 144 monitor pebbles, extracted until end of AVR operation, are as follows [31][32][33]: except of about 1/3 of the pebbles fed into the radial inner core zone, all pebbles revealed core higher temperatures than the originally calculated maximum temperature of about 1100 • C, 1/3 of the pebbles fed into the radial outer zone even by more than 200 K, that is, all melt wires were molten. Whereas almost 90% of the fuel elements fed onto the inner core zone were evaluated, this holds for only about 55% of the monitor pebbles fed onto the outer core zone.…”

RANS modeling for particle transport and deposition in turbulent duct flows: Near wall model uncertainties

“…sizes of the dust particles are reported in the literature. For example, dust particle size measured at the end of the life cycle of the pebble-bed AVR reactor was found to be largely submicron with a geometric-mean diameter of 0.6 m (Gottaut and Kruger, 1990). Recent experiments for HTR-10 indicate a geometric-mean diameter of about 2.2 m (Luo et al, 2005).…”

Particle deposition and resuspension in gas-cooled reactors—Activity overview of the two European research projects THINS and ARCHER

“…During standard operation, the particle concentration in the primary circuit was in the range of C = 1-15 g/m 3 and increased by up to 3 orders of magnitude during cleaning transient flows which were caused by an increase in the blower speed. Scanning electron microscopy based size classification revealed a volume-averaged mean particle diameter of about 2 m to 3 m. Gottaut and Krüger (1990) described the formation of graphite deposits distributed in the recirculation areas of the primary circuit of the AVR after its decommission in 1988.…”