Certain Aspects of Using 15N-Enriched Mixed Uranium-Plutonium Nitride Fuel in a Fast-Reactor Fuel Cycle

The production of 14C and tritium can be greatly diminished by substituting in mixed uranium-plutonium nitride fuel highly concentrated 15N for naturally occurring nitrogen with the natural isotopic composition. Neutronics calculations show that this gives an advantage in the form of a 14% fuel savings. To supply isotopically modified mixed uranium-plutonium nitride fuel [modified MUPN fuel] for the developed fast reactors, assessments were made of the well-known and promising methods of concentrating 15N. The boundary conditions in terms of the cost of production, price, and required production capacity supporting the use of 15N in closed NFC are formulated.