A Novel Method For Producing 15N Enriched NH3 For Manufacture of U15N Accident Tolerant Fuel

Particularly since the Fukushima accident in March 2011, there has been intense interest in the development accident tolerant fuels (ATF) for nuclear fission reactors. Uranium Nitride (UN) offers many compelling technical advantages as an accident tolerant fuel; for example its fissile density and thermal conductivity are higher than the current fuel of choice UO2 or other ATF alternatives such as U3Si2. However, when the nitride is composed of 14N atoms, UN produces radioactive 14C gas when burned. This problem can be eliminated by replacing the 14N with the most common isotope of nitrogen 15N; however, to date the lack of any reliable method to produce 15N enriched molecules in an economical and scalable fashion has proved a roadblock to the development of UN. Millikelvin Technologies (MKT) is developing a novel method for producing enriched 15NH3, the preferred precursor for manufacture of U15N. Unlike existing enrichment methods that focus on differences in isotopic mass, the MKT approach employs magnetic force to separate isotopes based on differences in their nuclear magnetic moments. The relative weakness of the nuclear magnetic moment is overcome by “hyperpolarizing” the nuclear spins in target isotopes, using techniques that have been developed for hyperpolarized magnetic resonant imaging. The MKT approach offers both relatively high isotopic enrichment factors and high production rates that, when realized on an industrial scale, will significantly outperform existing separation processes. We call our technique “Cryotopes”. In Phase I of this project we will prove the Cryotopes concept by accomplishing 3 principal Aims. First we will determine key magnetic parameters of NH3 and demonstrate 15N hyperpolarization of liquid and gaseous natural abundance NH3. Next, we will design, build and test a benchtop Cryotopes apparatus, and then use that apparatus to demonstrate collection of enriched 15NH3 in apparatus built in Aim II The overall definition of success for Phase I is to demonstrate collection of ~1% isotopic enrichment in collected samples of 15NH3/ 14NH3. In Phase II of this project we will build upon the data and knowledge obtained in Phase I to build a full scale prototype 15N separator. This will enable sales of 15NH3 to begin, at first on a relatively small scale into the existing biochemical research market, then on a larger scale as a precursor for manufacture of U15N. We expect that our entry into the 15N market will lower the overall price for 15N enriched molecules which, due to the very high cost for these molecules today, will be a significant benefit for biochemistry R+D programs. Furthermore, this will prepare us to meet the demand for U15N that is expected to increase significantly in 5 – 10 years. In Phase III we will work with larger industrial partners to scale up our production levels to meet their 15N needs. We also expect that the data and knowledge gained in Phase I will enable a version of Cryotopes that can produce enriched 13C molecules; there is a significant market for these molecules, in particular 13C enriched urea for urea breath test diagnosis of the h. Pylori bacteria that causes peptic ulcers.