Further Discussion of Gaseous Diffusion Separative Work

3 Further Discussion of Gaseous Diffusion Separative Work 

In any uranium separation process the work of enrichment increases rapidly with 235U content in the product. Because the price of natural uranium varies widely with time and location (and fluctuating government subsidies) it is useful to distinguish between the price of the feed and the value added by the separative process. For example, the purchaser himself might provide the feed and then pay only for the separative work required to make the desired product. Separative work is defined in Equation 8.7. 

Here W, P and F are the amounts of waste, product, and feed, respectively, and the V(xi) s are the separation potentials of waste, product and feed, respectively. 

Most often W, P and F are chosen to have units of mass (x , as always, is isotope fraction), in which case separative work has the dimension of mass and can be thought of as the mass flow rate multiplied by the time required to yield a given quantity of product. The cost of isotope separation is then obtained by assigning a cost to one separative work mass unit (kgSW or SWU). 

---