The transfer of heat and force from UO2 pellets to

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We demonstrate parameter calibration in the contex

In this work, we used the phase field method to si

Parameter studies, design calculations and neutron

The 3D neutron transport and core analysis program

Tungsten samples (6 mm diameter, 0.2 mm thick) were irradiated to 0.025 and 0.3 dpa with neutrons in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Samples were then exposed to deuterium plasma in the tritium plasma experiment (TPE) at 100, 200 and 500ºC to a total fluence of 1 x 1026 m-2. Nuclear reaction analysis (NRA) and Doppler broadening positron annihilation spectroscopy (DB-PAS) were performed at various stages to characterize damage and retention. We present the first known results of neutron damaged tungsten characterized by DB-PAS in order to study defect concentration. Two positron sources, 22Na and 68Ge, probe ~58 µm and through the entire 200 µm thick samples, respectively. DB-PAS results reveal clear differences between the various irradiated samples. These results, and the calibration of DB-PAS to NRA data are presented.

The entropy viscosity method [4] has been successf

BISON is a modern finite-element based nuclear fue

The next generation of methodologies for nuclear reactor Probabilistic Risk Assessment (PRA) explicitly accounts for the time element in modeling the probabilistic system evolution and uses numerical simulation tools to account for possible dependencies between failure events. The Monte-Carlo (MC) and the Dynamic Event Tree (DET) approaches belong to this new class of dynamic PRA methodologies. A challenge of dynamic PRA algorithms is the large amount of data they produce which may be difficult to visualize and analyze in order to extract useful information. We present a software tool that is designed to address these goals. We model a large-scale nuclear simulation dataset as a high-dimensional scalar function defined over a discrete sample of the domain. First, we provide structural analysis of such a function at multiple scales and provide insight into the relationship between the input parameters and the output. Second, we enable exploratory analysis for users, where we help the users to differentiate features from noise through multi-scale analysis on an interactive platform, based on domain knowledge and data characterization. Our analysis is performed by exploiting the topological and geometric properties of the domain, building statistical models based on its topological segmentations and providing interactive visual interfaces to …

Sensitivity analysis and uncertainty quantificatio

The Idaho National Laboratory (INL) has been engag

Fire accidents pose a serious threat to nuclear facilities. It is imperative that transport casks or shielded containers designed to transport/contain radiological materials have the ability to withstand a hypothetical fire. A numerical simulation was performed for a shielded container constructed of stainless steel and lead engulfed in a hypothetical fire as outlined by 10 CFR §71.73. The purpose of this analysis was to determine the thermal response of the container during and after the fire. The thermal model shows that after 30 minutes of fire, the stainless steel will maintain its integrity and not melt. However, the lead shielding will melt since its temperature exceeds the melting point. Due to the method of construction of the container under consideration, ample void space must be provided to allow for thermal expansion of the lead upon heating and melting, so as to not overstress the weldment.

Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especially important for non-equilibrium beams in the LINACs. The measurements were made by means of simultaneous imaging with two CCD sensors with different exposure time. Two images are combined then numerically in to one HDR image. The system works as an online tool providing HDR images at 4 Hz. An optically polished YAG:Ce crystal with the thickness of 100 {micro}m was used for the measurements. When tested with a laser beam images with the DR of about 10{sup 5} were obtained. With the electron beam the DR was somewhat smaller due to the limitations in the time structure of the tune-up beam macro pulse.

This paper describes the use of MATLAB/Simulink to simulate the electrical and grid-related aspects of a WTG and the FAST aero-elastic wind turbine code to simulate the aerodynamic and mechanical aspects of the WTG. The combination of the two enables studies involving both electrical and mechanical aspects of the WTG.

Wind and solar power generations differ from conventional energy generation because of the variable and uncertain nature of their power output. This variability and uncertainty can have significant impacts on grid operations. Thus, short-term forecasting of wind and solar generation is uniquely helpful for power system operations to balance supply and demand in an electricity system. This paper investigates the correlation between wind and solar power forecasting errors.

Recently the JLAB FEL has demonstrated 150 W at 400 nm and 200 W at 700 nm using a 33mm period undulator designed and built by STI Optronics. This paper describes the undulator design and performance. Two key requirements were low phase error, zero steering and offset end fields and small rms trajectory errors. We will describe a new genetic algorithm that allowed phase error minimization to 1.8 degrees while exceeding specifications. The mechanical design, control system and EPICS interface will also be summarized.

A seven-step progression is given for the implemen

As hardware advances continue to modify the supercomputing landscape, traditional scientific software development practices will become more outdated, ineffective, and inefficient. The process of rewriting/retooling existing software for new architectures is a Sisyphean task, and results in substantial hours of development time, effort, and money. Software libraries which provide an abstraction of the resources provided by such architectures are therefore essential if the computational engineering and science communities are to continue to flourish in this modern computing environment. The Multiphysics Object Oriented Simulation Environment (MOOSE) framework enables complex multiphysics analysis tools to be built rapidly by scientists, engineers, and domain specialists, while also allowing them to both take advantage of current HPC architectures, and efficiently prepare for future supercomputer designs. MOOSE employs a hybrid shared-memory and distributed-memory parallel model and provides a complete and consistent interface for creating multiphysics analysis tools. In this paper, a brief discussion of the mathematical algorithms underlying the framework and the internal object-oriented hybrid parallel design are given. Representative massively parallel results from several applications areas are presented, and a brief discussion of future areas of research for the framework are provided.

RAVEN (Reactor Analysis and Virtual control Environment) is a software code under development at Idaho National Laboratory aimed at performing probabilistic risk assessment and uncertainty quantification using RELAP-7, for which it acts also as a simulation controller. In this paper we will present the equations characterizing a dynamic stochastic system and we will then discuss the behavior of each stochastic term and how it is accounted for in the RAVEN software design. Moreover we will present preliminary results of the implementation.

Detailed understanding between microstructure evolution and mechanical properties is important for designing new high burnup nuclear fuels. In this presentation we discuss the use of picosecond ultrasonics to measure localize changes in mechanical properties of fuel surrogates. We develop measurement techniques that can be applied to investigate heterogeneous elastic properties caused by localize changes in chemistry, grain microstructure caused by recrystallization, and mechanical properties of small samples prepared using focused ion beam sample preparation. Emphasis is placed on understanding the relationship between microstructure and mechanical properties

The Modular High Temperature Gas-Cooled Reactor (M

During the last year we have been benchmarking FEL oscillator simulation codes against the measured performance of the three Jefferson Lab oscillator FELs. While one might think that a full 4D simulation is de facto the best predictor of performance, the simulations are computationally intensive, even when analytical approximations to the electron bunch longitudinal distribution are used. In this presentation we compare the predictions of the 4D FEL interaction codes Genesis and Medusa, in combination with the optical code OPC, with those using a combination of the 2D & 3D versions of these codes, which can be run quickly on a single CPU core desktop computer.

Nonlinear diffusion acceleration (NDA) can improve