Stored energy in the graphite stack of the IR reactor

Storage of Wigner energy and the nature of stored energy release were investigated in the graphite stacks of the IR reactor. The investigations were carried out on graphite bricks removed from the reactor stack as the latter was being dismantled. Other samples were cut out from the reactor stack with the aid of a special drill cutter during the two years after the stack was dismantled, when an additional integral flux of thermal neutrons 2.2 ·1021 neutrons/cm2 developed. The samples were so chosen that the pattern of stored-energy distribution throughout the stack might be obtained. Stored Wigner energy was determined by the technique of two successive heatings of the samples to temperatures of 600–650 ° C in vacuum calorimeters, making possible an energy release during the anneal. The total quantity of stored energy was determined by combustion of the graphite in a standard solid fuel testing calorimeter.