The Development of High Purity Tantalum and Alloys for Liquid Plutonium Containment in LAMPRE I

Abstract

By combining arc casting and electron beam melting, spectroscopically pure tantalum and alloys, suitable for containment of molten Pu-Fe alloys, were producedo The 0. 1% W alloy was used for the first LAMPRE loading.The effects of a large number of additives on the corrosion resistance of tantalum were tested^ Additions of up to 10% tungsten gave increasing endurance« Specimens of tantalum irradiated with neutrons until 3% converted to tungsten were still satisfactory in mechanical properties for reactor use.Either tungsten or the traces of yttrium remaining after arc melting can raise the one-hour recrystallization temperature of tantalum by 400'C, Effects of internal strain, critical strain and precipitation hardening in tantalum alloys were studied., High-temperature annealed tantalum had superior corrosion resistance, while impact extruded and ironed material was better than deep-drawn metal. Mechanical tests on tantalum with added interstitial elements showed that their presence to the extent expected in LAMPRE would be unlikely to weaken the tantalum. Evidence was found that oxygen promotes plutonium attack on tantalum. Small amounts of hydrogen, nitrogen and carbon had no effect on corrosion.

Chemical Solution Deposition of Protective Er2O3 and Y2O3 Coatings onto Stainless Steel for Molten Metal Casting using Metal-Nitrate Precursors

“…Casting of molten metals, including f-table elements, is important for nuclear metallurgical foundries, and it is common for thermally robust materials (e.g., carbides, oxides, refractory metals) to be used as molds and crucibles. To prevent their corrosion from molten metals, alloying has been used before as a method of protection, but even alloys are still susceptible to corrosion after repeated exposure. As a result, molds greatly suffer from short lifespans, drastically increasing the costs for replacements and the removal of generated waste.…”

Reaction of Tantalum with Molten Cerium-Cobalt Alloys

“…The Los Alamos Molten Plutonium Reactor Experiment (LAMPRE) was operated to determine the problems that might be encountered when these fuels are used under operating conditions. The core of the LAMPRE reactor consisted of an array of tantalum capsules containing plutonium fuel alloy (6)(7)(8). Tantalum and tungsten had been observed to be satisfactory materials for alloy containment, but tantalum was preferred because of the greater ease in its fabrication.…”