Hello, A new project on the LCRC cluster has been requested. Please forward the information on to the LCRC Allocation sub-committee. Applicant's name: Nathaniel Hoyt Applicant's institution: ANL Applicant's division: NE Project Name: PuPrecipitation Project title: Plutonium Particle Precipitation Simulations for Use in the Development of Nuclear Forensic Signatures Associated funding: National Technical Nuclear Forensics Center (Dept. of Homeland Security) Other Systems: falcon (INL) Science: The science goal of the project is to understand how chemical engineering process conditions ultimately affect the particle size distribution and morphology of plutonium particles that are created from plutonium oxalate precipitation in production-scale reaction vessels. The knowledge of the pathway toward precipitation in these systems for a variety of reaction scenarios will allow for the development of nuclear forensic signatures for interdicted plutonium oxide powders. Project description: This work is being conducted as a part of the National Technical Nuclear Forensics Center’s (NTNFC) forensic signature development program. The program seeks to develop material signatures that can be used to attribute the origin of interdicted nuclear materials. This project specifically seeks to understand how chemical engineering process conditions ultimately affect the particle size distribution and morphology of plutonium particles that are created from plutonium oxalate precipitation. Through identification of the original production conditions, the country and processing facility of origin can potentially be ascertained. To provide this insight, in FY2017 we developed a full reactive precipitation solver taking into account multiphase flow, species transport, chemical reactions, particle nucleation, crystal growth, and rheological phenomena. This custom solver was created in OpenFOAM, an open-source, finite volume computational fluid dynamics (CFD) toolkit written in C++. Simulations of the reactive precipitation process are inherently multi-scale and include phenomena ranging from length scales of 100’s of centimeters down to 10’s of nanometers. Inasmuch, they are extremely computationally intensive. Up until now, parallel simulations of individual cases have generally been run on approximately 100 cores for typical cases that require around 3 million computational cells. In general, the parallel scaling of the code has been found to suffer below 30,000 cells per core. In general, individual simulations therefore require three weeks or more to be completed. The project requires the simulation of a wide variety of lab-scale and production-scale reaction vessels operating under a large parameter space of process conditions (different temperatures, concentrations, volumes, stirrer speeds etc.). At present, the speed at which the simulations can be run is therefore prohibitively slow. Therefore, for FY2018 we are pursuing a variety of avenues to increase the speed of the simulations, ranging from changes to the iterative linear solvers to changes to the coupling of the non-linear PDEs. Investigations into the bottlenecks inherent in the underlying OpenFOAM libraries will also be investigated (potentially with assistance from LCRC staff) to achieve improved performance of the code on HPCCs. With improvements to the speed of the solver combined with the LCRC computing resources, it is hoped that the precipitation simulations will start to provide the quantitative understanding of the reactive precipitation process that is necessary to enable the use of PSD and morphology as valid nuclear forensics signatures for PuO2. Industry partnership: N/A Project URL: Requested allocation: 475000 Q1: 0 Q2: 0 Q3: 225000 Q4: 250000 Justification: Storage requirements: 1 TB is sufficient The requester has used undetermined amount hours of their initial startup project. In addition to approving an initial amount, please specify a Category and Subcategory for this project. For a list of the current selection of approved categories, please see: https://wiki.lcrc.anl.gov/wiki/Processes/Categories Once the Allocation committee has approved the project, please go to the Project Management page to create it: https://accounts.lcrc.anl.gov/projects.php Thank You, The LCRC Accounts System