DEVELOPMENT AND MANUFACTURE OF FUEL, BLANKET, AND THERMOCOUPLE RODS FOR THE EXPERIMENTAL BREEDER REACTOR I, CORE IV

A description is given of the development and manufacture of Core IV for the Experimental Breeder Reactor I (EBR-I). A total of 420 rods and 10 thermocouple fuel rods containing plutonium-1.25 wt% aluminum fuel slugs were made. In addition, 120 blanket rods and 5 thermocouple A description is given of the developrnent and manufacture of Core IV for the Experimental Breeder Reactor I (EBR-I). A total of 420 rods and 10 thermocouple fuel rods containing plutonium-1.25 wt% aluminum fuel slugs were made. In addition, 120 blanket rods and 5 thermocouple rods were assembled with depleted uranium slugs. Both the fissile and fertile slugs were NaK bonded in Zircaloy-2 jacket tubes. The fuel alloy was made by induction melting plutonium and aluminum. The centrifugal casting technique developed for EBR-I, Core-II was tried without success with this alloy. The gas pressure injection casting method developed for the EBR-II fuel cycle was used to cast the Core-IV rods. These were parted into rough slugs which were roll-sized and coined to final shape. After coining, the slugs were heat-treated and inspected. A loading technique was developed to protect the outside of the jacket tube and the weld zone from plutonium contamination. A connector fitting, with an integral tube for NaK filling, was welded to the top of the jacket tube. A measured quantity of NaK was injected through the fill opening by a hypodermic needle and syringe. The filling tube was then welded closed by the capacitor-discharge technique. The rods were then heat treated, leak detected, eddy-current bond inspected, x-rayed for NaK level, and gaged. All rods were surveyed for alpha contamination of the external surfaces and were shipped in approved birdcages to the reactor site. (auth