Two aluminum replicas of the fuel pins used in NRX reactor at CRNL for the production of molybdenum 99, a fission product from which technetium 99 is produced. The latter is widely used in medical diagnostics. The ribbed part of the full scale pencils is 15.9 cm and the overall length is 16.7 cm (nominal 6 ½ inches). The diameter measures 12.5 mm (nominal ½ inch).
