Energy
Researchers at PNNL are addressing our nation's most critical energy challenges to enable clean, secure, efficient, and affordable energy systems. The Energy application area includes modeling and simulation in electric power, nuclear power, fuel cells, energy efficiency, and projects that overlap with the Environment application area, such as carbon sequestration.
Energy Systems Modeling
Understanding the responses of the national electric power grid to the many stresses on the system is important to running the grid with highest efficiency while preventing failures that could have wide economic impacts. Modeling and simulation play a significant role in PNNL's diverse program for monitoring, modeling, and controlling the nation's electric power grid, with the general goal of improving the stability and efficiency of the grid through real time situational awareness.
To research, develop, and test next-generation tools and concepts for operating the energy infrastructure, PNNL established the Electricity Infrastructure Operations Center (EIOC). This capability can monitor, and potentially control, the power grid for the western U.S. To clarify the dynamics of the western electrical power grid, the EIOC gathers data from the existing power grid monitoring systems. PNNL has developed a suite of data access, analysis, modeling, and decision software tools and has analyzed grid transient events over seven years to establish an understanding of dynamic grid events and response.
Improved analytical tools are needed to assess the impact of key factors on electrical grid stability and system behavior. PNNL has developed superior analytical tools that enable identification of major system operating characteristics and a better understanding of system behavior and subsystem effects, using inputs from measurements and power system simulation software. To support secure, stable operation of the electrical grid with reduced (minimal) reserve margins, power system modeling and simulation is used to help evaluate distributed load control to help minimize frequency excursions.
Nuclear Power Modeling
As a part of the Global Nuclear Energy Partnership program, the nuclear community is considering the development of a model for the impact of nuclear energy on the economy, from source to disposition. PNNL conducts a diverse modeling and simulation program that supports such a model by addressing nuclear power generation, reactor design, fuel design and processing, materials impacts, and related non-proliferation issues. A comprehensive nuclear fuel cycle model is needed to consider the impact of new fuel processing methods. The fuel cycle model needs to include economic effects along the path from ore to fuel to reprocessing to fuel reuse to ultimate disposition. Such modeling is central to the design of proliferation-resistant fuel cycles.
With experience in core thermal hydraulics since the 1980s, PNNL is a leader in subchannel thermal hydraulic analysis of nuclear reactor cores and thermal performance of spent fuel storage and transportation casks.
- Water reactor core thermal-hydraulic modeling using subchannel analysis is a strength that PNNL staff applied in developing the COBRA-IV code for the Nuclear Regulatory Commission. A code version called VIPRE, created for the Electric Power Research Institute, has become the mainline core thermal hydraulic analysis code for nuclear utilities.
- PNNL participated in developing the multi-field models for gas/liquid flows in a loss of coolant accident.
- PNNL staff authored COBRA-SFS, a subchannel model for thermal performance of fuel storage and transportation casks. PNNL is currently the Nuclear Regulatory Commission's primary resource for evaluating thermal cask performance and an important contributor to fuel damage prediction during transportation accidents.
- PNNL staff members have also performed thermal-hydraulic subchannel analyses for a liquid metal reactor core (the Fast Flux Test Facility) using the COBRA-SFS (with wire wrap diversion cross flow model).
PNNL staff are also leaders in developing and applying the unique new Lattice-Boltzmann computational technique for fine-scale multi-phase fluid dynamic simulations. This method is extremely well suited to massively parallel machines and would be a very useful tool for Grand Challenge computations on tera-flop machines.
PNNL staff have unique experience in applying computational fluid dynamics modeling to non-Newtonian slurry flows, such as in re-suspension of settled/compacted solids by a fluid jet in nuclear waste tanks using a modified version of the TEMPEST code. TEMPEST was also uniquely applied to simultaneously computing heat transfer, natural convection, and electric fields in joule-heated glass melters. Other applications of computational thermal-hydraulic modeling include coolant systems in nuclear power plants, containments in nuclear power plants, and spent nuclear fuel in a fuel repository.
PNNL maintains a broad range of capabilities associated with nuclear safety design and analysis, including substantial capabilities in the areas of reactor core physics and neutronics analysis. These capabilities have been employed to evaluate nuclear materials production concepts in support of Department of Energy missions and proliferation assessments for the intelligence community.
PNNL has years of experience in nuclear criticality safety analyses. Criticality safety analysis is required to prevent or terminate an inadvertent nuclear criticality, to mitigate the consequences of a criticality, and to protect against injury or damage caused by a criticality.
PNNL applies extensive experience in addressing safety issues concerning the storage and chemical processing of nuclear materials. Analysts at PNNL played a major role in supporting DOE efforts to resolve Hanford tank waste safety issues (ferrocyanide, organic salt and flammable gas, toxic vapors) and have worked with the Waste Treatment and Immobilization Plant (WTP) Research & Technology Department to set design criteria for mixing and ventilation of process vessels/streams to control hydrogen gas levels.
Structures and Mechanics
Much of the structures work at PNNL focuses on issues of energy conservation. Heating, cooling and lighting are modeled to assess the impacts of structure design on energy savings. Evaluation of imaging to gauge heat emissions from buildings is one aspect of this work. Other notable applications in this area:
- To identify bottlenecks and improve throughput of logistics/supply systems for Department of Defense clients, PNNL performed modeling and predictive science R&D in logistics/maintenance process modeling.
- In support of innovative technologies for predictive maintenance, PNNL developed and deployed model-based health monitoring systems for power plan facilities and combat platforms.
- To support cost-effective facility operating decisions, the Decision Support for Operations and Maintenance (DSOM) system is a model-based operations and management tool that integrates plant operations, fuel management, and maintenance processes.
- To provide technical leadership and insight on predictive maintenance for military/logistics operations, PNNL developed a proof-of-concept prototype onboard, real-time system for monitoring, diagnosing, and predicting potential faults in the AGT1500 gas-turbine engine for the M1 Abrams tank.