Sample records for orela
-
Proceedings of the Oak Ridge Electron Linear Accelerator (ORELA) Workshop
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dunn, M.E.
2006-02-27
The Oak Ridge National Laboratory (ORNL) organized a workshop at ORNL July 14-15, 2005, to highlight the unique measurement capabilities of the Oak Ridge Electron Linear Accelerator (ORELA) facility and to emphasize the important role of ORELA for performing differential cross-section measurements in the low-energy resonance region that is important for nuclear applications such as nuclear criticality safety, nuclear reactor and fuel cycle analysis, stockpile stewardship, weapons research, medical diagnosis, and nuclear astrophysics. The ORELA workshop (hereafter referred to as the Workshop) provided the opportunity to exchange ideas and information pertaining to nuclear cross-section measurements and their importance for nuclearmore » applications from a variety of perspectives throughout the U.S. Department of Energy (DOE). Approximately 50 people, representing DOE, universities, and seven U.S. national laboratories, attended the Workshop. The objective of the Workshop was to emphasize the technical community endorsement for ORELA in meeting nuclear data challenges in the years to come. The Workshop further emphasized the need for a better understanding of the gaps in basic differential nuclear measurements and identified the efforts needed to return ORELA to a reliable functional measurement facility. To accomplish the Workshop objective, nuclear data experts from national laboratories and universities were invited to provide talks emphasizing the unique and vital role of the ORELA facility for addressing nuclear data needs. ORELA is operated on a full cost-recovery basis with no single sponsor providing complete base funding for the facility. Consequently, different programmatic sponsors benefit by receiving accurate cross-section data measurements at a reduced cost to their respective programs; however, leveraging support for a complex facility such as ORELA has a distinct disadvantage in that the programmatic funds are only used to support program-specific measurements. As a result, ORELA has not received base funding to support major upgrades and significant maintenance operations that are essential to keep the facility in a state of readiness over the long term. As a result, ORELA has operated on a ''sub-bare-minimum'' budget for the past 10 to 15 years, and the facility has not been maintained at a level for continued reliable operation for the long term. During the Workshop, Jerry McKamy (NNSA/NA-117) used a hospital patient metaphor that accurately depicts the facility status. ORELA is currently in the intensive care unit (ICU) on life support, and refurbishment efforts are needed to get the ''patient'' off life support and out to an ordinary hospital room. McKamy further noted that the DOE NCSP is planning to fund immediate refurbishment tasks ($1.5 M over three years) to help reestablish reliable ORELA operation (i.e., move ORELA from ICU to an ordinary hospital room). Furthermore, the NCSP will work to identify and carry out the actions needed to discharge ORELA from the ''hospital'' over the next five to seven years. In accordance with the Workshop objectives, the technical community publicly endorsed the need for a reliable ORELA facility that can meet current and future nuclear data needs. These Workshop proceedings provide the formal documentation of the technical community endorsement for ORELA. Furthermore, the proceedings highlight the past and current contributions that ORELA has made to the nuclear industry. The Workshop further emphasized the operational and funding problems that currently plague the facility, thereby limiting ORELA's operational reliability. Despite the recent operational problems, ORELA is a uniquely capable measurement facility that must be part of the overall U.S. nuclear data measurement portfolio in order to support current and emerging nuclear applications. The Workshop proceedings further emphasize that ORNL, the technical community, and programmatic sponsors are eager to see ORELA reestablish reliable measurement operation and be readily available to address nuclear data challenges in the United States.« less
-
NASA Astrophysics Data System (ADS)
Valentine, Timothy E.; Leal, Luiz C.; Guber, Klaus H.
2002-12-01
The Department of Energy established the Nuclear Criticality Safety Program (NCSP) in response to the Recommendation 97-2 by the Defense Nuclear Facilities Safety Board. The NCSP consists of seven elements of which nuclear data measurements and evaluations is a key component. The intent of the nuclear data activities is to provide high resolution nuclear data measurements that are evaluated, validated, and formatted for use by the nuclear criticality safety community to provide improved and reliable calculations for nuclear criticality safety evaluations. High resolution capture, fission, and transmission measurements are performed at the Oak Ridge Electron Linear Accelerator (ORELA) to address the needs of the criticality safety community and to address known deficiencies in nuclear data evaluations. The activities at ORELA include measurements on both light and heavy nuclei and have been used to identify improvements in measurement techniques that greatly improve the measurement of small capture cross sections. The measurement activities at ORELA provide precise and reliable high-resolution nuclear data for the nuclear criticality safety community.
-
New Neutron Cross-Section Measurements at ORELA for Improved Nuclear Data Calculations
NASA Astrophysics Data System (ADS)
Guber, K. H.; Leal, L. C.; Sayer, R. O.; Koehler, P. E.; Valentine, T. E.; Derrien, H.; Harvey, J. A.
2005-05-01
Many older neutron cross-section evaluations from libraries such as ENDF/B-VI or JENDL-3.2 exhibit deficiencies or do not cover energy ranges that are important for criticality safety applications. These deficiencies may occur in the resolved and unresolved-resonance regions. Consequently, these evaluated data may not be adequate for nuclear criticality calculations where effects such as self-shielding, multiple scattering, or Doppler broadening are important. To support the Nuclear Criticality Predictability Program, neutron cross-section measurements have been initiated at the Oak Ridge Electron Linear Accelerator (ORELA). ORELA is the only high-power white neutron source with excellent time resolution still operating in the United States. It is ideally suited to measure fission, neutron total, and capture cross sections in the energy range from 1 eV to ˜600 keV, which is important for many nuclear criticality safety applications.
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Larson, N.M.
1984-02-01
This report describes a computer code (ALEX) developed to assist in AnaLysis of EXperimental data at the Oak Ridge Electron Linear Accelerator (ORELA). Reduction of data from raw numbers (counts per channel) to physically meaningful quantities (such as cross sections) is in itself a complicated procedure; propagation of experimental uncertainties through that reduction procedure has in the past been viewed as even more difficult - if not impossible. The purpose of the code ALEX is to correctly propagate all experimental uncertainties through the entire reduction procedure, yielding the complete covariance matrix for the reduced data, while requiring little additional inputmore » from the eperimentalist beyond that which is required for the data reduction itself. This report describes ALEX in detail, with special attention given to the case of transmission measurements (the code itself is applicable, with few changes, to any type of data). Application to the natural iron measurements of D.C. Larson et al. is described in some detail.« less
-
ORELA data acquisition system hardware. Vol. 5. SEL 810B/PDP-4/PDP-9 intercomputer link
DOE Office of Scientific and Technical Information (OSTI.GOV)
Reynolds, J.W.; Holladay, J.H.
1977-01-01
A report is given describing the IOT assignments and programming for the PDP-4 and PDP-9, the ground isolation wiring, the connector pin assignments, a simplified theory of operation for the SEL 810B link interface, a detailed theory of operation for the link interfaces at the PDP-4 and the PDP-9, and the use of the PDP-4 and PDP-9 link interfaces as an input to the SEL 810B Four-Channel Priority Multiplexer.
-
Engineering physics and mathematics division
NASA Astrophysics Data System (ADS)
Sincovec, R. F.
1995-07-01
This report provides a record of the research activities of the Engineering Physics and Mathematics Division for the period 1 Jan. 1993 - 31 Dec. 1994. This report is the final archival record of the EPM Division. On 1 Oct. 1994, ORELA was transferred to Physics Division and on 1 Jan. 1995, the Engineering Physics and Mathematics Division and the Computer Applications Division reorganized to form the Computer Science and Mathematics Division and the Computational Physics and Engineering Division. Earlier reports in this series are identified on the previous pages, along with the progress reports describing ORNL's research in the mathematical sciences prior to 1984 when those activities moved into the Engineering Physics and Mathematics Division.
-
Aluminum Data Measurements and Evaluation for Criticality Safety Applications
NASA Astrophysics Data System (ADS)
Leal, L. C.; Guber, K. H.; Spencer, R. R.; Derrien, H.; Wright, R. Q.
2002-12-01
The Defense Nuclear Facility Safety Board (DNFSB) Recommendation 93-2 motivated the US Department of Energy (DOE) to develop a comprehensive criticality safety program to maintain and to predict the criticality of systems throughout the DOE complex. To implement the response to the DNFSB Recommendation 93-2, a Nuclear Criticality Safety Program (NCSP) was created including the following tasks: Critical Experiments, Criticality Benchmarks, Training, Analytical Methods, and Nuclear Data. The Nuclear Data portion of the NCSP consists of a variety of differential measurements performed at the Oak Ridge Electron Linear Accelerator (ORELA) at the Oak Ridge National Laboratory (ORNL), data analysis and evaluation using the generalized least-squares fitting code SAMMY in the resolved, unresolved, and high energy ranges, and the development and benchmark testing of complete evaluations for a nuclide for inclusion into the Evaluated Nuclear Data File (ENDF/B). This paper outlines the work performed at ORNL to measure, evaluate, and test the nuclear data for aluminum for applications in criticality safety problems.
-
Working group summary report on effects of pulsed operation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gabriel, T.A.; Ni, L.
1996-06-01
In a short pulsed spallation neutron source, extremely high energy ({approx_gt}1 GeV) proton beam pulses are injected into a liquid metal target in a very short period of time ({approximately}1 {mu}sec) at a high repetition rate ({approximately}50 Hertz). The beam energy will be deposited in the target materials (such as mercury or lead) and converted into heat. It causes a sudden temperature rise and resulting pressure wave. This pressure wave travels through the liquid, reaches the steel container wall and may possibly lead to material damage due to induced stress. Almost all participants agreed that the shock problem due tomore » the short pulse operation in the liquid metal target could be serious and could present a challenging problem. It was determined that the following points need to be addressed: (1) equation of state for mercury (2) code validation and benchmark experiments (3) shock effects on the entire target system (4) two phase flow by gas injection. All these investigations should be carried out in the framework of international cooperation. Two small scaled Hg pressure pulse tests are planned at ORNL to provide insight into the pressure wave propagation and thermal shock effects. One experiment will use exploding wires to generate the pulse pressure, the other the electron beam at ORELA. Also PSI, LANL, CERN (ISOLDE facility), INR and IPPE could contribute to the experimental methods for producing shock. The necessary R&D for bubble injection might be performed at PSI, RIGA, ORNL or Ben-Gurion University. All of the above experiments can possibly yield benchmarking data which is absolutely necessary for code validation.« less