Abstracts and Available Papers Presented at the
2005 International RERTR Meeting

IRRADIATION TESTING OF HIGH DENSITY U-MO FUELS IN THE ATR

D. M. Wachs, R. G. Ambrosek, G. S. Chang, and M. K. Meyer
Nuclear Fuels and Materials Department
Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID, 83415-1688, USA

ABSTRACT

A variety of high uranium density (uranium molybdenum alloy based) research reactor fuels are being irradiated in the Advanced Test Reactor at the Idaho National Laboratory. The RERTR-7A, -7B, and -8 experiments will consist of three test trains containing 66 miniplates of various fuel meat compositions that will be subjected to  near prototypical reactor environment. The RERTR-7A and –7B experiments will explore the influence of modified matrix materials (RERTR-7A) and fuel alloys (RERTR-7B) on fuel/matrix chemical interaction. The three experiments will also contain a number of monolithic type fuel plates that will substantially expand their irradiation performance database. The modified matrix materials include 6061-Al, 4043-Al, Al-0.5 Si, Al-2.0Si, and Mg. The modified fuel alloys used in RERTR-7B will include small amounts of Zr or Ti alloyed with the U-Mo fuel. The plates in RERTR-7A and –7B will be operated with peak surface heat flux, surface temperature, centerline temperature, and burnup of approximately 350 W/cm², 200ºC, 250ºC, and 70% LEU equivalent, respectively. The RERTR-8 experiment will expose 16 plates to a short (15 day) high power irradiation cycle. The RERTR-8 test train will consist of one capsule (eight miniplates) removed from the RERTR-7B experiment following one irradiation cycle and one fresh capsule (eight miniplates). The capsules will be irradiated for one additional ATR cycle (~50 days) prior to the high power cycle. The peak surface heat flux in the RERTR-8 experiment will be on the order of 550 W/cm².

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