A5041315420- Nuclear reactor physics and engineering
- Nuclear and radioactivity studies
- Nuclear Materials and Properties
- Graphite, nuclear technology, radiation studies
- Nuclear Physics and Applications
- Risk and Safety Analysis
- Coding theory and cryptography
- Combustion and flame dynamics
- Nuclear Engineering Thermal-Hydraulics
- Radiative Heat Transfer Studies
- Magnetic confinement fusion research
- Radiation Shielding Materials Analysis
- Polynomial and algebraic computation
- Probabilistic and Robust Engineering Design
- Fusion materials and technologies
- Cryptography and Residue Arithmetic
- Superconducting Materials and Applications
- Radioactive contamination and transfer
- Fire dynamics and safety research
- Forest Biomass Utilization and Management
- Radiation Detection and Scintillator Technologies
- Combustion and Detonation Processes
- Gas Dynamics and Kinetic Theory
- Atmospheric and Environmental Gas Dynamics
- Radioactivity and Radon Measurements
Gas Technology Institute
2006-2019
Idaho National Laboratory
2017-2018
Oak Ridge National Laboratory
2007-2016
Argonne National Laboratory
2012-2015
Pacific Northwest National Laboratory
2015
Sandia National Laboratories
2015
UT-Battelle
2015
National Technical Information Service
2012-2013
Office of Scientific and Technical Information
2000-2013
Office of Nuclear Energy
2012
Although the Monte Carlo method is considered to be most accurate available for solving radiation transport problems, its applicability limited by computational expense. Thus, biasing techniques, which require intuition, guesswork, and iterations involving manual adjustments, are employed make reactor shielding calculations feasible. To overcome this difficulty, we have developed a using SN adjoint function automated variance reduction of through source consistent with weight window...
AbstractThis paper presents a hybrid (Monte Carlo/deterministic) method for increasing the efficiency of Monte Carlo calculations distributions, such as flux or dose rate distributions (e.g., mesh tallies), well responses at multiple localized detectors and spectra. This method, referred to Forward-Weighted CADIS (FW-CADIS), is an extension Consistent Adjoint Driven Importance Sampling (CADIS) which has been used more than decade very effectively improve quantities flux, dose, reaction...
This paper provides a review of the hybrid (Monte Carlo/deterministic) radiation transport methods and codes used at Oak Ridge National Laboratory examples their application for increasing efficiency real-world, fixed-source Monte Carlo analyses.The two principal are (1) Consistent Adjoint Driven Importance Sampling (CADIS) optimization localized detector (tally) region (e.g., flux, dose, or reaction rate particular location) (2) Forward Weighted CADIS (FW-CADIS) optimizing distributions...
AbstractThe use of a fusion component testing facility to study and establish, during the ITER era, remaining scientific technical knowledge needed by Demo is considered described in this paper. This aims test components an integrated nuclear environment, for first time, discover understand underpinning physical properties, develop improved further testing, time-efficient manner. It requires design with extensive modularization remote handling activated components, flexible hot-cell...
A study on the Fukushima Daiichi nuclear power station spent-fuel pool (SFP) at Unit 4 (SFP4) is presented in this paper. We discuss design characteristics of SFP4 and its decay heat load detail provide a model that we developed to estimate SFP evaporation rate based temperature. The level following March 11, 2011, accident predicted fundamental conservation laws mass energy. Our temperatures are good agreement with measured data consistent Tokyo Electric Power Company evaluation results.
This paper describes code and methods development at the Oak Ridge National Laboratory focused on enabling high-fidelity, large-scale reactor analyses with Monte Carlo (MC).Current state-of-the-art tools used to perform "real" commercial have several undesirable features, most significant of which is non-rigorous spatial decomposition scheme.Monte methods, allow detailed accurate modeling full geometry are considered "gold standard" for radiation transport solutions, playing an...
Summary The effectiveness of penicillin and sodium sulfadiazine against viruses in the psittacosis-lymphogranuloma venereum group has been tested chick embryos. Penicillin delayed death embryos infected with each ten tested. Sodium had a similar effect only two classical strains psittacosis virus, mouse pneumonitis virus (Greb strain), 12 XN strain, lymphogranuloma failed to delay Borg SF pigeon or ithosis (P 207 meningopneumonitis (Cal 10 feline virus.
The compact (R0~1.2-1.3m) Fusion Nuclear Science Facility (FNSF) is aimed at providing a fully integrated, continuously driven fusion nuclear environment of copious neutrons. This facility would be used to test, discover, and understand the complex challenges plasma material interactions, tritium fuel management, power extraction. Such properly designed provide, initially JET-level pressure (~30%T2) conditions (e.g., Hot-Ion H-Mode, Q<1)), an outboard neutron flux 0.25 MW/m2 while requiring...
Certain reactor transients cause a reduction in moderator temperature and, hence, increased attenuation of neutrons and decreased response excore detectors. This detector is concern because the credit assumed for detector-initiated trip to terminate transient. Explicit modeling this phenomenon presents analyst with difficult problem dense optically thick neutron absorption media, given constraint that precise characteristics must be known order account phenomenon. The solution study was...
AbstractAbstractMonte Carlo is quite useful for calculating specific quantities in complex transport problems. Many variance reduction strategies have been developed that accelerate Monte calculations tallies. However, when trying to calculate multiple tallies or a mesh tally, users had accept different levels of relative uncertainty among the run separate optimized each individual tally. To address this limitation, an extension Consistent Adjoint Driven Importance Sampling (CADIS) method,...
Simulating nuclear well-logging devices with Monte Carlo methods is computationally challenging and requires significant variance reduction to compute detector responses low statistical uncertainties in reasonable lengths of time. The consistent adjoint-driven importance sampling (CADIS) method, which provides source transport biasing parameters based on a deterministic adjoint (importance) function, has been demonstrated be very effective for simulations other deep-penetration problems. A...
This paper provides insights into the neutronic similarities between a representative high-capacity rail-transport cask containing typical pressurized water reactor (PWR) spent nuclear fuel assemblies and critical state-points, referred to as commercial (CRC) state-points. Forty CRC state-points from five PWRs were analyzed, characteristics of that may be applicable for validation burnup-credit criticality safety calculations transport/storage/disposal systems identified. The study employed...
Summary Penicillin showed a definite therapeutic effect when given by the subcutaneous route to mice infected with Gleason strain of psittacosis, Borg Strain, pigeon ornithosis virus (P 207), meningopneumonitis (Cal 10), and mouse pneumonitis (Nigg). Oral sulfadiazine was effective in two psittacosis strains virus, but not SF Pigeon Ornithosis Virus Meningo-pneumonitis feline virus. Results obtained drugs were, each instance, agreement those chick embryos.
The immense size and complex geometry of the ITER experimental fusion reactor require development special techniques that can accurately efficiently perform neutronics simulations with minimal human effort. This paper shows effect hybrid Monte Carlo (MC)/deterministic techniques—Consistent Adjoint Driven Importance Sampling (CADIS) Forward-Weighted CADIS (FW-CADIS)—in enhancing efficiency modeling demonstrates applicability coupling these methods computer-aided-design-based MC. Three...