Determination of krypton-85 release temperatures of rods G-1, G-2, G-3, and G-6 of the F-1 (X094) irradiation experiment

The report describes Kr-85 annealing technique as a means of determining in-reactor fuel cladding temperature on non-instrumented GCFR fuel rod irradiation experiments. Experimental results show that clad temperatures may indeed be measured using this technique if the integrity of the inner surface has not been destroyed. Where minimal or no fuel-clad interaction has occurred, reliable data should be obtainable; where moderate to extreme cladding attack has occurred, the data indicate a possible significant lower operating temperature. Experimental applicability and limitations of the method are described.