The Division's reactor physics activities are aimed at enhancing computational capabilities and execution of neutronics analyses in support of DOE's national and international nuclear energy initiatives.

Software Development

Software development efforts are focused on exploiting advances in modeling techniques, numerical methods, and computing technology to improve upon existing software capabilities used in optimizing the operation of existing reactors and designing future advanced reactors. These activities include:

Monte Carlo Library Quality Assurance: A set of software programs are being developed to provide complete and detailed comparison between cross section libraries in an accurate and efficient manner.

LWR Lattice Physics: An effort is underway, in cooperation with CEA (French nuclear energy research organization) and Ecolé Polytechnique de Montreal, to enhance and validate the DRAGON lattice physics code. The objective is to establish a leading-edge lattice physics code for assessing performance and safety issues associated with the use of advanced assembly designs (e.g., high-burnup fuel) and MOX fuel in LWRs. Current efforts include the implementation of enhanced self-shielding models and more explicit representation of heterogeneities in the assembly-level transport solution.

Nodal Transport Methods: The usefulness of the VARIANT code is being enhanced by adding a neutron kinetics capability. Additionally, faster running code options have been implemented and more efficient solution acceleration schemes are now available.

Nuclear Data Representation: Rigorous methods are being developed for generating the nuclear data parameters input to cross-section processing code systems and to codes that execute hyperfine- or continuous-energy neutronics computations. The objective is to preserve the rigor of modern nuclear data evaluations (e.g., Reich-Moore representation of resolved resonance data) and to accommodate new developments in resonance theory. This rigor is particularly important for high-precision, continuous-energy Monte Carlo analyses, used increasingly in lieu of experiments to benchmark design-oriented methods.

Analyses and Applications

Division personnel perform neutronics analyses that address a variety of issues of current national and international interest. These efforts include:

• Designing and evaluating reactors and accelerator-driven systems that can be used for burning transuranics and long-lived fission products in spent nuclear fuel. The transmutation systems include fast-spectrum and thermal reactor systems. These activities are being conducted under the Advanced Fuel Cycle Initiative.
• Characterizing the fuel and blanket assemblies previously irradiated in the EBR-II reactor, to support the demonstration of the electrometallurgical technology for spent fuel disposition. This spent-fuel treatment demonstration project is being conducted in the fuel conditioning facility (FCF) at Idaho National Laboratory.
• Evaluating the reactor performance and safety implications of using Russian and western reactors for disposition of excess weapons Pu. For example, an evaluation is being conducted of the safety implications of converting the Russian BN-600 reactor from uranium to mixed oxide fuel.
• Performing analyses to aid in the design and interpretation of nondestructive assay techniques applied to characterization of the fissile content of irradiated fuels and other nuclear materials. Currently, this effort is aimed at verifying the fissile content of fuel assemblies previously irradiated in the BN-350 fast reactor located in Kazakhstan.
• Optimizing reactor and shield/filter configurations for application of reactor-generated neutron beams to boron neutron capture therapy. The objective is to optimize the intensity and the energy spectrum of the neutron beam to maximize the therapeutic benefit of destroying cancerous cells while minimizing the collateral damage to surrounding, healthy tissue.
• Designing reactor cores for high temperature, gas-cooled fast reactor systems. These activities are aimed at evaluating the merits and feasibility of gas-cooled fast systems, and at assessing core designs utilizing fuel pebbles, fuel pins, and fuel blocks.