The Advanced Test Reactor National Scientific User Facility Overview

Frances_Marshall
SPEAKER:
FRANCES MARSHALL
DATE/TIME:
MON, 05/02/2011 – 4:00PM TO 5:00PM
LOCATION:
3105 ETCHEVERRY HALL
Spring 2011 Colloquium Series
Abstract:

This presentation provides an overview of the research and irradiation capabilities of the Advanced Test Reactor (ATR) located at the U.S. Department of Energy Idaho National Laboratory (INL). The ATR which has been designated by DOE as a National Scientific User Facility (NSUF) is operated by Battelle Energy Alliance, LLC. This paper will describe the ATR and discuss the research opportunities for university (faculty and students) and industry researchers to use this unique facility for nuclear fuels and materials experiments in support of advanced reactor development and life extension issues for currently operating nuclear reactors.

About the Speaker:

Ms. Marshall is currently the manager of the Advanced Test Reactor (ATR) National Scientific User Facility (NSUF) Program at the Idaho National Laboratory (INL), with responsibility for managing the NSUF irradiation experiments performed in the ATR. Ms Marshall earned a bachelor’s degree in nuclear engineering from the University of Virginia, a master’s degree in chemical engineering from the University of Idaho, and is a registered Professional Engineer. She held a reactor operator license on the UVA Reactor and worked in the commercial nuclear power industry as a startup and plant system engineer prior to coming to the INL in 1991. At the INL, Ms Marshall has supported and led projects in the areas of irradiation experiments, nuclear power plant engineering, and regulatory support.

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Origins, Visions, Plans & Wave Reactors

Teichert
SPEAKER:
CHRISTIAN TEICHERT
DATE/TIME:
MON, 04/25/2011 – 4:00PM TO 5:00PM
LOCATION:
3105 ETCHEVERRY HALL
Spring 2011 Colloquium Series
Abstract:

Low-energy ion irradiation of semiconductor surfaces [1] opens an elegant and efficient route towards fabrication of large-scale arrays of uniform semiconductor nanostructures. Using power spectral density analysis of atomic force microscopy (AFM) images, the degree of pattern uniformity can be quantified as is demonstrated for ion- bombardment induced GaSb dot arrays [2]. Attempts to obtain similar pattern formation by ion-bombardment of clean silicon substrates fail [3], unless there is a supply of metal impurities [4].

Since the ion-bombardment induced nanostructure arrays cover the entire sample surface, they can be used as large-area nanopatterned templates for subsequent deposition of magnetic thin films. This will be illustrated for the shadow deposition of cobalt onto ion-bombardment induced GaSb dot patterns. It will further be demonstrated how pre-ion bombardment can influence the resulting growth mode of organic semiconductor films [6]. Finally, it is shown that friction force microscopy and atomic-force microscopy can be employed to study single impacts of highly charged ions.

[1] S. Facsko, et. al., Science 285 (1999) 1551;
[2] T. Bobek, et al., Phys. Rev. B 68 (2003) 085324.
[3] C. Hofer, et al., Nucl. Instrum. Meth. B 216 (2004) 178.
[4] C. Teichert, et al., Adv. Eng. Mat. 8 (2006) 1057-1065.
[5] C. Teichert, et al., J. Cond. Mat. Phys. 21 (2009) 224025.
[6] G. Hlawacek, et al., Science. 321 (2008) 108.

This research has been supported in the framework of the European Project NAMASOS (Nanomagnets by Self-Organisation, Grant No. STRP 505854-1) and by Austrian Science Fund within NFN “Organic Thin Films” project S9707.

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Treatment of Epistemic Uncertainty in Risk Analysis: Implications for Risk-Informed Decision-Making

Dana_Kelly SPEAKER: DANA KELLY DATE/TIME: MON, 04/18/2011 – 4:00PM TO 5:00PM LOCATION: 3105 ETCHEVERRY HALL Spring 2011 Colloquium Series Abstract:

Quantitative risk assessments are an integral part of risk-informed regulation of current and future nuclear plants in the U.S. The Bayesian approach to uncertainty, in which both stochastic and epistemic uncertainties are represented with precise probability distributions, is the standard approach to modeling uncertainties in such quantitative risk assessments. However, there are long-standing criticisms of the Bayesian approach to epistemic uncertainty from many perspectives, and a number of alternative approaches have been proposed. Among these alternatives, the most promising (and most rapidly developing) would appear to be the concept of imprecise probability (Walley, 1991). In this colloquium, I will employ a performance indicatory example to focus the discussion. I will first give a short overview of the traditional Bayesian paradigm and review some its controversial aspects, for example, issues with so-called noninformative prior distributions. I then discuss how the imprecise probability approach handles these issues and compare it with two other approaches: sensitivity analysis and hierarchical Bayes modeling. I conclude with some practical implications for risk-informed decision making and an overview of ongoing research.

About the Speaker:

Dana Kelly is a Distinguished Staff Scientist in the Nuclear Risk and Reliability group at the Idaho National Laboratory. His current research focuses primarily on Bayesian and non-Bayesian approaches to uncertainty quantification, decision analysis, and simulation of complex systems. He has worked in the field of risk assessment for over 20 years and has numerous peer-reviewed publications in technical journals.

The Spent Nuclear Fuel and Non-Proliferation

Bekhzod_Yuldashev
SPEAKER:
BEKHZOD YULDASHEV
DATE/TIME:
MON, 04/04/2011 – 4:00PM TO 5:00PM
LOCATION:
3105 ETCHEVERRY HALL
Spring 2011 Colloquium Series
Abstract:

The review of the activities on repatriation of highly enriched spent fuel from research reactors as well as data on the conversion of research reactors to low enriched fuel will be presented.

About the Speaker:

Professor Bekhzod Yuldashev is presently working as professor consultant at the Center for International Security and Cooperation ( CISAC) of Stanford University. From June 2006 till December 2009 he served as scientific consultant at International Atomic Energy Agency in Vienna (Austria). From 1990 till 2006 he was director general of the Institute of Nuclear Physics in Tashkent, Uzbekistan. He also served as president of Uzbekistan Academy of Sciences in 2000-2005.
He is a full member of Uzbekistan Academy of Sciences, Foreign Member of National Academy of Sciences of Kazakhstan, a Fellow of the World Academy of Sciences of Islamic Countries and some other scientific academies and societies. He is Honorary Doctor of the Joint Institute for Nuclear Research-JINR (Dubna, Russia), the Honorary Professor of Samarkand State University, was Visiting Fellow of Indiana University (Bloomington, USA) and Cambridge University (UK). He has been elected as a member of International Scientific Council of JINR (1992-2002), member of the Standing Advisory Group on Nuclear Applications, SAGNA (IAEA, Vienna, 2002-2006), the Chairman of Uzbekistan Scientific Council on Awarding doctoral ranks in nuclear sciences (1991-2006), head of Nuclear Department of Tashkent State University (1994-2000).

He is awarded by the State Prize in Science and Technology (1983), the Science and Technology ECO International Prize (2004), the order “For Glorious Work” (Uzbekistan, 2003) etc.

Professor Bekhzod Yuldashev graduated from Tashkent and Moscow universities (1968) and got his Candidate Degree ( PhD) in 1971 at JINR and Full Professor degree (Doctor of Physics and Mathematics) in 1981. He was spokesman of two experiments performed at Fermi National Laboratory (Batavia, US) and at Canadian nuclear center “TRIUMF” (Vancouver BC) by two international teams involving physicists from Uzbekistan, Russia, US and Canada. In 1977-1978, 1980-1981 and 1989-1990 he was visiting professor at Physics Department of University of Washington (Seattle, USA) and in 2007 at CISAC, Stanford University (Stanford, USA).

His research covered particle and nuclear physics and nuclear applications. He published more than 200 papers and has more than 20 patents. He was scientific supervisor of 27 PhD and 6 Full Professor theses.

In last 15 years Professor Yuldashev is deeply involved in non-proliferation and nuclear applications projects. In particular, he led projects on upgrading physical protection of research reactors, on utilization of highly radioactive sources, development of systems to prevent illicit trafficking of nuclear and radioactive materials, the conversion of research reactors to low enriched fuel, the return of highly enriched spent fuel from research reactors to country-origin. Being consultant at IAEA Professor Yuldashev was working on performance of Russian Research Reactor Spent Fuel Return Program and wrote the IAEA technical book on lessons learned from shipments of highly enriched spent fuel from research reactors to country-origin.

Nuclear Nonproliferation Research at Los Alamos National Laboratory

Dan_Holden
SPEAKER:
DAN HOLDEN
DATE/TIME:
THU, 03/31/2011 – 4:00PM TO 5:00PM
LOCATION:
3105 ETCHEVERRY HALL
Spring 2011 Colloquium Series
Abstract:

The topic of nuclear nonproliferation (both cooperative and non-cooperative) is broad, drawing upon interdisciplinary scientific, political and social sciences. At Los Alamos National Lab, as well as across the entire National Nuclear Security Administration complex, virtually all aspects of this urgent problem are being addressed. Research is ongoing in the safeguarding special nuclear materials (SNM), remote and in situ sensing of nuclear facilities, producing proliferation-resistant nuclear fuels and medical targets, technical forensics and in policy. Tracking and accounting for SNM involves not only the direct physics measurements of neutron and gamma emissions, but also the attendant accounting methodologies, much like tracking banking transactions. State-of-the-art micro-calorimeter and X-ray fluorescence techniques are improving our ability to assay plutonium. Remotely inferring reactor core burn up rates might be possible via an anti-neutrino technique that uses the containment structure itself as the sensor. New polymer ligand films are being developed that will selectively pre-concentrate plutonium into thin film geometry to increase selectivity and sensitivity for assaying actinides and their isotopes. Remote sensing can range from space-borne sensors looking at gamma, X-ray, optical and radio frequency signals to spectroscopic returns from laser induced breakdown spectroscopy inside a building. Powering reactors and manufacturing medical targets using low enriched uranium (LEU) and designing efficient fuels with taggants to identify their source all lower the proliferation risk. Social and political science play equally important roles in understanding both the problems and the solution.

About the Speaker:

Dan Holden currently serves as the program manager for nuclear nonproliferation verification science and technology at Los Alamos National Lab, a broad research portfolio that funds approximately one hundred staff members. His research interests are in radio frequency remote sensing of both natural and manmade phenomena. After earning his Bachelors’ Degree at UC Berkeley in Astronomy, he switched to physics where he earned graduate degrees at the New Mexico Institute of Mining and Technology and Clemson University specializing in lightning and thunderstorm research. He enjoys whale watching along the coast of Northern California from a sailboat that he keeps on San Francisco Bay.

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Chemical separation processes for advanced nuclear fuel cycles: Challenges and possibilities

Mikael_Nilsson
SPEAKER:
MIKAEL NILSSON
DATE/TIME:
MON, 03/14/2011 – 4:00PM TO 5:00PM
LOCATION:
3105 ETCHEVERRY HALL
Spring 2011 Colloquium Series
Abstract:

In the world today, nuclear energy comprises ~15% of the total electricity mix. This power source produces no CO2 during the operation of the plants and can provide bulk power to industry and households 24/7. Concerns about CO2 emissions from burning fossil fuels (coal, oil and natural gas) have caused the world demand of nuclear power to rise. With increasing interest in nuclear energy, we are facing a problem of sharing the readily available uranium resources. To increase the energy utilization and decrease the radiotoxicity of the waste advanced concepts for fuel reprocessing are being investigated on a global scale. This is a multi disciplinary research field spanning from organic synthesis to particle physics, and no single research group can hope to cover all aspects. Collaboration is crucial to the success of these projects. For a successful advanced nuclear fuel cycle, one or several chemical separations steps are required to fractionate the different elements in spent fuel. These separations processes are of varying complexity and use a range of different chemicals making it challenging to implement them on industrial scale. Furthermore, some of the processes under development are still in the experimental stage and require supporting fundamental studies to succeed. In this presentation, similarities and differences between the different separation schemes are discussed, emphasizing the challenges that will be faced before an advanced nuclear fuel cycle can be implemented in industry. Current projects carried out by the UC Irvine nuclear group that address some of these challenges will be presented and discussed.

About the Speaker:

Mikael (Micke) Nilsson joined the department of Chemical Engineering and Materials Science at University of California – Irvine in January 2009. His expertise is in the field of nuclear energy and nuclear waste treatment, and encompasses both the fundamental and applied aspects of the field. Dr. Nilsson is a specialist in separations technology as it applies to the reprocessing of spent fuel from nuclear reactors. He also studies the effects of radioactive decay on solvents and chemicals used for nuclear waste management. Dr. Nilsson received an M.S. degree in chemical engineering in 2000 and a Ph.D. in nuclear chemistry in 2005 from Chalmers University of Technology, Sweden. Between 2006 and 2008 he was a post-doc in the chemistry department at Washington State University. At UC Irvine, Dr. Nilsson teaches courses in chemical engineering thermodynamics and unit operations, nuclear chemistry, and the nuclear fuel cycle. Dr. Nilsson recently (October 2010) passed the Nuclear Regulatory Commission exam and became a qualified senior reactor operator on the UC Irvine TRIGA reactor. The research group of Dr. Nilsson currently comprises 5 graduate student researchers and 4 undergraduate students.

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Trivalent Actinide and Lanthanide Interactions with Phosphate Materials

Kiel_Holliday
SPEAKER:
KIEL HOLLIDAY
DATE/TIME:
WED, 03/09/2011 – 4:00PM TO 5:00PM
LOCATION:
3105 ETCHEVERRY HALL
Spring 2011 Colloquium Series
Abstract:

The incorporation of Eu and Cm into the LaPO4 monazite structure is presented as a model phosphate system, relevant as a nuclear waste form. Site selective time resolved laser fluorescence spectroscopy of Eu and Cm was used as a structural probe. This revealed “satellite” species previously seen in LuPO4 [1]. These species are now clearly resolved and their origin is discussed. Apatite is considered to be a barrier to radionuclide migration due to its ability to incorporate a wide range of elements and the low solubility of actinides in phosphate media. Little is known about the incorporation mechanism of trivalent actinides and lanthanides in apatite at temperatures and conditions relevant to the environment. Previous work identifies Eu3+ incorporated into apatite at room temperature by TRLFS and describes the species as incorporated into the Ca(I) site with C3 symmetry. All published TRLFS emission spectra show a splitting of the F1 transition that is greater than expected for C3 symmetry and is attributed to impurities from natural apatite [2] or multiple site excitations [3]. The presented study eliminates these possibilities and produces similar spectra. The explanation proposed is that Eu3+ incorporates into amorphous grain boundaries producing a range of related species with low symmetry. Possibilities for charge compensation before and after heat treatment are also discussed [4, 5]. The mechanistic understanding of uptake in apatite is expanded to studies on biologically produced apatite. In this case, the mechanism proposed by the current study explains observed trends of uptake in apatite produced by Serratia bacteria. By tailoring the microstructure of the apatite produced one can design a material suited for various applications, such as filter material for decontaminating ground water or as a coating for surgical implants. These studies illustrate the value in attaining an atomic scale mechanistic understanding of the sorption and incorporation mechanisms that dictate actinide behavior. References [1] Murdoch, K.M., Edelstein, N.M., Boatner, L.A., Abraham, M.M.: Excited state absorption and fluorescence line narrowing studies of Cm3+ in LuPO4. J. Chem. Phys. 105, 2539 (1996). [2] M Gaft, R Reisfeld, G Panczer, G Boulon, S Shoval, B Champagnon, Optical Materials, 1997, 8, 149-156. [3] M Karbowiak, S Hubert, Journal of Alloys and Compounds, 2000, 302, 87-93. [4] R. Ternane, M. Trabelsi-Ayedi, N. Kbir-Ariguib, B. Pirou, Journal of Luminescence, 1999, 81, 165-170. [5] R. Sahoo, S.K. Bhattacharya, R. Debnath, Journal of solid state chemistry, 2003, 175, 218-225.

About the Speaker:

Kiel Holliday is a post doctoral scholar in the group of Thorsten Stumpf at the Institut für Nukleare Entsorgung at the Karlsruhe Institut für Technologie were he specializes in time resolved laser fluorescence spectroscopy and radionuclide migration. He received his Ph.D. in Radiochemistry from the University of Nevada, Las Vegas under Ken Czerwinski studying the synthesis, characterization and dissolution behavior of advanced nuclear fuel. Kiel Holliday has also performed investigations on materials for various applications such as waste forms, target materials, and exotic phase compositions for radiation damage studies.

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Delayed Gamma Assay for Nuclear Safeguards

Vladimir_Mozin
SPEAKER:
VLADIMIR MOZIN
DATE/TIME:
MON, 03/07/2011 – 4:00PM TO 5:00PM
LOCATION:
3105 ETCHEVERRY HALL
Spring 2011 Colloquium Series
Abstract:

The UC Berkeley Nuclear Engineering Department in collaboration with Los Alamos National Laboratory and Lawrence Berkeley National Laboratory participates in the US DOE Next Generation Safeguards Initiative with a focus on developing advanced instruments and methods in nuclear material control and accountancy. Within this context, a delayed gamma non-destructive assay (NDA) technique is being investigated as a means to directly quantify both the fissile and fertile content of spent nuclear fuel, and as a general safeguards tool that can be easily integrated with other active interrogation instruments. In support of this research, a newly developed modeling technique was introduced, offering a versatile capability for time- and spatially-dependent, prompt and delayed discrete gamma source term and detector response calculations. The new modeling approach was validated in a series of experiments involving accelerator-driven neutron sources and samples of fissile and fertile materials and their combinations with varying parameters for interrogation setups.

About the Speaker:

Vladimir Mozin graduated from the Moscow Engineering Physical Institute in 2002 with an M.S. in Radiochemistry. He spent several years working as an engineer at a nuclear fuel reprocessing facility. Currently, he is a Ph.D. candidate participating in a collaborative research effort between the UC Berkeley Nuclear Engineering Department, Los Alamos National Laboratory, and Lawrence Berkeley National Laboratory.

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An Innovative Neutron Transport Method for Whole Reactor Core Criticality Analysis

Farzad_Rahnema
SPEAKER:
FARZAD RAHNEMA
DATE/TIME:
MON, 02/28/2011 – 4:00PM TO 5:00PM
LOCATION:
3105 ETCHEVERRY HALL
Spring 2011 Colloquium Series
Abstract:

A new coarse-mesh radiation transport (COMET) method for modeling and simulation of realistic reactor cores (e.g., operating water reactors) is presented at this colloquium. This innovative method has Monte Carlo accuracy while having computational efficiency that is several orders of magnitude better than achievable by stochastic and fine-mesh deterministic transport methods. Benchmark results in several whole-core problems typical of operating reactors are presented to demonstrate the accuracy and efficient of the method. The new method overcomes many of the limitations inherent in current whole-core (loosely coupled transport/diffusion theory) methods used in the industry. Notable limitations/approximations are single lattice transport theory calculations with approximate boundary conditions (e.g., full specular reflection), cross section homogenization, ad hoc de-homogenization (fuel pin reconstruction) and whole-core homogenized diffusion theory calculations. These approximations breakdown with increasing assembly and core heterogeneities, features encountered in advanced and next generation reactor designs. We first present an overview of current industry methods, research directions and critical gaps in the context of advanced and Generation IV nuclear reactors. The limitations of current methods and reactor design trends are highlighted as motivation for the developments of the advanced radiation transport methods by the Computational Reactor and Medical Physics Group (CRMPG) at Georgia Tech.

About the Speaker:

Dr. Farzad Rahnema received his PhD from the University of California in Los Angeles in 1981. He joined Georgia Institute of Technology in October 1992 and is currently Professor and Chair of the Georgia Tech Nuclear and Radiological Engineering and Medical Physics Programs. He also holds an adjunct Professor appointment at the Emory University Radiation Oncology Department. From 1981 to 1992, Dr. Rahnema was at General Electric Nuclear Energy and was responsible for Monte Carlo Benchmark Methods and GE’s 3-D Nuclear/Thermal Hydraulics BWR Core Simulator PANACEA used for core design and monitoring. He led the development of three versions (8-10) of the simulator.

Dr. Rahnema’s recent research activity and interest have been in the areas of reactor and medical physics methods development, transport theory, perturbation theory and variational methods. He is a Fellow of the American Nuclear Society (ANS) and Chair of the ANS Mathematics and Computation Division.

Reduced-Order Physics Models For Computationally Efficient Charged Particle Transport

Anil_Prinja
SPEAKER:
ANIL PRINJA
DATE/TIME:
MON, 02/14/2011 – 4:00PM TO 5:00PM
LOCATION:
3105 ETCHEVERRY HALL
Spring 2011 Colloquium Series
Abstract:

High-energy charged particles (electrons, light and heavy ions, from 10’s keV to GeV and above) are ubiquitous in nuclear science and engineering, medical physics, space science, and advanced materials applications, but the computational complexity associated with the transport of charged particles can greatly exceed that of neutrons, photons and other neutral particles. The primary reason is that long range, Coulomb-field mediated elastic and inelastic collisions of energetic charged particles with target nuclei and electrons are characterized by extremely small collision mean free paths and near-singular differential cross sections. This extreme physics renders the computational modeling of the analog or true problem prohibitively expensive in both stochastic (Monte Carlo) and deterministic numerical settings. The condensed history (CH) Monte Carlo method, widely employed in electromagnetic and hadronic shower codes, attempts to circumvent this practical difficulty by advancing the particle in fixed large steps but inherent flaws limit the ultimate accuracy possible with this method.

In this talk, a new approach will be presented that obviates the need for CH-like approximations for computational expediency yet retains the “look and feel” of the single-event or event-by-event analog simulation. The essence of this method is the construction of a pseudo-transport problem with de-singularized collision operators, which are constrained to preserve certain moments of the corresponding analog collision operators. This moment-preserving or reduced-order physics model is developed through a variety of projection-based strategies that include stabilizing asymptotic higher order Fokker-Planck expansions by renormalization methods and using purely discrete as well as hybrid discrete-continuous kernel representations. The result is a systematic and robust, particle species independent methodology, which can achieve high accuracy and computational efficiency for energy straggling, angular spreading, and dose calculations. After some background material, the new formalism will be described in detail, followed by a presentation of several illustrative numerical results from a Monte Carlo implementation, and concluding with a discussion of some outstanding challenges.

About the Speaker:

Dr. Anil K. Prinja is currently Professor and Associate Chair of the Chemical and Nuclear Engineering Department at the University of New Mexico. He also holds the positions of Co-Director (former Director) of the Center for Nuclear Nonproliferation Science and Technology, and Co-Director of the interdisciplinary Medical Physics Program at UNM. Dr. Prinja obtained his Ph.D. (1980) and B.Sc. (1st Class Honors, 1976) in Nuclear Engineering from the University of London, UK, and was a Research Engineer at UCLA (1980-1987) prior to joining UNM. Dr. Prinja is a Fellow of the American Nuclear Society, and a recent recipient of the NNSA Defense Programs “Award of Excellence”.

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