@article{rak_o'brien_shin_andersson_stanek_brenner_2016, title={Theoretical assessment of bonaccordite formation in pressurized water reactors}, volume={474}, ISSN={["1873-4820"]}, DOI={10.1016/j.jnucmat.2016.02.016}, abstractNote={The free energy of formation of bonaccordite (Ni2FeBO5) as a function of temperature has been calculated using a technique that combines first principles calculations with experimental free energies of formation of aqueous species. The results suggest that bonaccordite formation from aqueous metal ions (Ni2+ andFe3+) and boric acid is thermodynamically favorable at elevated temperature and pH that have been predicted to exist at the CRUD-clad interface in deposits thicker than 60 μm.}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Rak, Zs and O'Brien, C. J. and Shin, D. and Andersson, A. D. and Stanek, C. R. and Brenner, D. W.}, year={2016}, month={Jun}, pages={62–64} }
 @article{rak_o'brien_brenner_andersson_stanek_2016, title={Understanding the Atomic-Level Chemistry and Structure of Oxide Deposits on Fuel Rods in Light Water Nuclear Reactors Using First Principles Methods}, volume={68}, ISSN={["1543-1851"]}, DOI={10.1007/s11837-016-2102-z}, number={11}, journal={JOM}, author={Rak, Zs. and O'Brien, C. J. and Brenner, D. W. and Andersson, D. A. and Stanek, C. R.}, year={2016}, month={Nov}, pages={2912–2921} }
 @article{brenner_lu_christopher j. o'brien_bucholz_rak_2015, title={A particle assembly/constrained expansion (PACE) model for the formation and structure of porous metal oxide deposits on nuclear fuel rods in pressurized light water reactors}, volume={457}, ISSN={["1873-4820"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84915820676&partnerID=MN8TOARS}, DOI={10.1016/j.jnucmat.2014.11.061}, abstractNote={A new model is proposed for the structure and properties of porous metal oxide scales (aka Chalk River Unidentified Deposits (CRUD)) observed on the nuclear fuel rod cladding in Pressurized Water Reactors (PWR). The model is based on the thermodynamically-driven expansion of agglomerated octahedral nickel ferrite particles in response to pH and temperature changes in the CRUD. The model predicts that porous nickel ferrite with internal {1 1 1} surfaces is a thermodynamically stable structure under PWR conditions even when the free energy of formation of bulk nickel ferrite is positive. This explains the pervasive presence of nickel ferrite in CRUD, observed CRUD microstructures, why CRUD maintains its porosity, and variations in porosity within the CRUD observed experimentally. This model is a stark departure from decades of conventional wisdom and detailed theoretical analysis of CRUD chemistry, and defines new research directions for model validation, and for understanding and ultimately controlling CRUD formation.}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Brenner, Donald W. and Lu, Shijing and Christopher J. O'Brien and Bucholz, Eric W. and Rak, Zsolt}, year={2015}, month={Feb}, pages={209–212} }
 @article{o'brien_rak_bucholz_brenner_2014, title={First principles calculations predict stable 50 nm nickel ferrite particles in PWR coolant}, volume={454}, ISSN={["1873-4820"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84906355696&partnerID=MN8TOARS}, DOI={10.1016/j.jnucmat.2014.07.049}, abstractNote={Thermodynamic calculations that combine experimental data with the results of first principles calculations yield negative free energies for {1 1 1} surfaces of nickel ferrite for the temperature, pressure and ion concentrations typical of Pressurized Light Water Reactor (PWR) coolant. When combined with a positive bulk free energy of formation, the negative surface energies predict that thermodynamically-stable octahedral nickel ferrite particles with diameters of ∼50 nm should be present in PWR coolant during operation. These particles would not be removed by mixed bed demineralizers and would be below the filter pore sizes typically used in Chemical and Volume Control Systems. The calculations also predict that these particles are not thermodynamically stable in coolant under ambient conditions. Based on these results it is proposed that solvated nickel ferrite particles, which are predicted to be stable and likely long-lived in PWR primary coolant, contribute to the nucleation of metal oxide scale on PWR fuel rod cladding and that conventional methods for purifying the primary coolant may be ineffective in removing these species.}, number={1-3}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={O'Brien, C. J. and Rak, Zs. and Bucholz, E. W. and Brenner, D. W.}, year={2014}, month={Nov}, pages={77–80} }