Buffering of Uranium Monocarbide to Control Carbon Activity

The utilization of the theoretical principle that activities must remain constant at constant temperature and pressure if the number of phases present is equal to the number of elemental constituents present was described. The potential was outlined for use of this principle to achieve compatibility between uranium carbide and certain metals. A sample of UC alloyed with 5 at.% tungsten to control its carbon activity showed no embrittlement of stainless steel after being in positive contact for 3000 h at 800°C (1472°F).