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At least 1,675 records · Page 93
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Data Evaluation of Actinide Cross Sections: 238 Pu, 237 Pu, and 236 Pu

This report documents the recent evaluation of the 236 Pu, 237 Pu, and 238 Pu cross section sets. Nuclear data evaluation is the fundamental interface that takes measured nuclear cross section data and turns them into a continuous curve that 1) is consistent with other measurements and nuclear reaction theory/models, and 2) is required by down-stream users. All experiments that generate nuclear data need to include an evaluation step for their data to be broadly useful to the end users.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2018

The 12 C(d,n) 13 N Diagnostic and the Need to Re-measure the Cross Section

We discuss the importance of the 12 C(d,n) 13 N mix diagnostics at NIF and show how this reaction can be used to determine the fraction of the 79 Kr signal produced by knock-on deuterons in bromine doped CH ablator capsules. We point out that current cross section measurements are discrepant with one another, by about a factor of two. We propose a new method for measuring this cross section, including a technique for uncovering the possible source of the current discrepancy.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

US Sections Prepared for Future NEA Crystalline Club (CRC) Report on Status of R&D in CRC Countries Investigating Deep Geologic Disposal in Crystalline Rock

U.S. knowledge in deep geologic disposal in crystalline rock is advanced and growing. U.S. status and recent advances related to crystalline rock are discussed throughout this report. Brief discussions of the history of U.S. disposal R&D and the accumulating U.S. waste inventory are presented in Sections 3.x.2 and 3.x.3. The U.S. repository concept for crystalline rock is presented in Section 3.x.4. In Chapters 4 and 5, relevant U.S. research related to site characterization and repository safety functions are discussed. U.S. capabilities for modelling fractured crystalline rock and performing probabilistic total system performance assessments are presented in Chapter 6.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

MC 2 -3: Multigroup Cross Section Generation Code for Fast Reactor Analysis Nuclear

The MC 2 -3 code is a Multigroup Cross section generation Code for fast reactor analysis, developed by improving the resonance self-shielding and spectrum calculation methods of MC 2 -2 and integrating the one-dimensional cell calculation capabilities of SDX. The code solves the consistent P1 multigroup transport equation using basic neutron data from ENDF/B data files to determine the fundamental mode spectra for use in generating multigroup neutron cross sections.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2018

Measurement of Neutrino Absolute Deep Inelastic Scattering Cross Section in Iron, Lead, Carbon, and Plastic Using MINERvA Detector at $E_{\nu} = 6$ \GeV

A deep inelastic sample is selected from the nuclear charged current inclusive analysis, by requiring reconstructed $Q^{2} \geq 1.0$ (GeV/c)$^{2}$ and $W \geq 2.0$ GeV/c$^{2}$. The neutrino energy range of $5 < E_{\nu} < 50$ previously applied to this analysis in the Low Energy (LE) analysis is removed and the energy range cut is imposed on the muon energy from $2 < E_{\mu} < 50$ GeV. Machine learning vertexing is used to improve the track-based vertexing resulting in higher purity and efficiency of the sample. A local sideband method is utilized to remove the plastic background for the events reconstructed in the target. After plastic backgrounds and non-DIS backgrounds are subtracted, the reconstructed neutrino energy and Bjorken-x are unsmeared to their true quantities via Bayesian unfolding. The unfolded distributions of carbon, iron, lead, and plastic are efficiency corrected and then divided by the flux and the number of nucleons in the target to produce the absolute cr oss section as a function of $E_{\nu}$ and differential cross section as function of $x_{bj}$. The results of the analysis show good agreement between data and MC for $E_{\nu}$ and $x_{bj}$ (see Figures \ref{fig:xsecEnuC} through \ref{fig:xsecXCH}). None of the distributions displayed significant differences with the theoretical models underlying MINERvAs MC.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

First Muon-Neutrino Charged-Current Inclusive Differential Cross Section Measurement for MicroBooNE Run 1 Data

This note presents MicroBooNE’s first ν µ charged-current (CC) inclusive measurement using 6 months of Run 1 data (~ 1.6 × 10 20 POT). The measurement is presented as a function of reconstructed muon kinematics, including a first assessment of systematic uncertainties. The signal topology for a ν µ CC inclusive measurement is the presence of a neutrino-induced muon track with or without other accompanying particles. It is therefore the most inclusive cross section measurement that can be made, and due to the very clear signal definition allows straight-forward comparisons to theory models and other experiments. Additionally, this analysis selection can be used for more exclusive-channel cross section measurements, and be used to further develop reconstruction and event selection techniques. The note also discusses the techniques developed to distinguish neutrino-induced from cosmic muons for a sample with full angular coverage.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

A Section 106 Evaluation of Building CP-1, Area 6, Nevada National Security Site, Nye County, Nevada

On December 17, 2015, the National Nuclear Security Administration Nevada Field Office (NNSA/NFO) vacated Building CP-1 (Building 06-CP-1) on the Nevada National Security Site (NNSS) in Nye County, Nevada. Starting in 1951, nearly all nuclear tests during the Cold War were controlled from this building on the facility, known as the Nevada Test Site for most of its years of operation. The test site was renamed the NNSS in 2010. CP-1 was the command and control center where decisions about NNSS activities were sought and made; where authorization for movements about the areas forward (north) of Mercury base camp were coordinated, granted or declined, and monitored; and where problems and emergencies in the forward areas were communicated and relayed to the appropriate agencies for solution. Some of the testing duties for the Control Point included the timing and firing of nuclear tests, air operations, security, communications, weather monitoring, and radiation safety. During tests, communications were maintained through various channels to receive and pass instructions or information to the numerous testing operations, to Washington, D.C., the national laboratories, and overhead aircraft monitoring the tests. At one time, the Security Control Center, a Class A Weather Station, and the Radiation Safety Headquarters were located in CP-1, which also contained a cafeteria, a dining area, and bunk rooms. This survey was prompted by recognition that closure of the building in place creates a situation where CP-1 is vulnerable to decay in its present and unused condition. Activities at CP-1 have been reduced gradually over time since the end of nuclear testing in 1992. The Area of Potential Effects (APE) was determined by NNSA/NFO to be a two-acre area historically considered the space directly associated with CP-1 and available to CP-1 personnel for use. The APE is bounded on the south by an unnamed main paved road into the guarded Control Point area, on the west by the edge of the parking lot for adjacent Building CP-9, on the east by the edge of the bladed cut-and-fill terrace for CP-1, and on the north by a barbed wire security fence (Figure 2). All of this lot is either bladed or covered with asphalt. Contained within the lot are eight Accessary Resources (AR) which are much more closely aligned with CP-1 than with adjacent buildings. AR are defined by the Nevada State Historic Preservation Office (SHPO) (2013) as “…related but subordinate to the principal building. Accessory resources would not exist were it not for the principal resource.” The Visual APE was determined by NNSA/NFO to be the same as the APE used for intensive survey because no exterior modifications to the resource are anticipated. The APE is located in Section 34 T11S R53E MDBM (projected) within the NNSS base called the Control Point in Area 6. It is on the 1986 Yucca Lake USGS 7.5 min. series topographic quadrangle. The Desert Research Institute (DRI) surveyed the APE with the assistance of National Security Technologies, LLC (NSTec), resulting in recordation and evaluation of CP-1 (SHPO Resource Number B14490) and eight accessory resources (AR1-AR8). This recording of CP-1 was done in three sessions. Copies of the building form and report are on file at Nevada Cultural Resources Information System (NVCRIS), DRI, and with the NNSA/NFO, Las Vegas, Nevada. Control Point refers to the support facilities of which Building CP-1, with its 126 rooms, is the most important part (Campbell et al. 1983:165). CP-1 refers to the entire building but it also is the designation for the first phase of construction, i.e. the original building. There were three major subsequent phases of additions to the building. The first two were called CP-1A (the east wing) and CP-1B (the west wing with the new War Room). A final phase filled in the hyphen between CP-1 and CP-1B with a Field Office. For convenience this last phase is called CP-1C in this report. Hence, CP-1 can refer either the entire building or to the first phase of the building exclusive of additions. The context makes clear which of the two meanings is intended in the various sections of this report. There were also two minor expansions consisting of a small battery room and a shelter for an emergency exit.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Prospects of Neutrino Cross Section Measurements Using the NuMI off axis at ICARUS [Poster]

ICARUS, a Liquid Argon Time Projection Chamber, will serve as the Far Detector of the short-baseline neutrino program using the Booster beamline at Fermilab. It is 103 mrad off-axis of the NuMI beamline. Prospects for cross-section measurements and the status of the trigger system using the PMT system to collect electron and muon neutrinos from NuMI will be shown. Accurate neutrino cross-section measurements on argon are required for precise measurements of neutrino oscillation physics such as CP- violation and the ordering of the neutrino masses.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Cross section measurements of deuteron electro-disintegration at very high recoil momenta and large 4-momentum transfers (Q^2)

The 2H(e,e'p)n cross sections have been measured at negative 4-momentum transfers of Q^2 = 4.5 +/- 0.5 (GeV/c)^2 and Q^2 = 3.5 +/- 0.5 (GeV/c)^2 reaching neutron recoil (missing) momenta up to p_r ?1.0 GeV/c. The data have been obtained at fixed neutron recoil angles 5 <= theta_nq <= 95 degrees with respect to the 3-momentum transfer q. The new data agree well with the previous data which reached p_r ?550 MeV/c. At theta_nq = 35 and 45 degrees, final state interactions (FSI), meson exchange currents (MEC) and isobar configurations (IC) are suppressed and the plane wave impulse approximation (PWIA) provides the dominant cross section contribution. The new data are compared to recent theoretical calculations, and a significant disagreement for recoil momenta p_r > 700 MeV/c is observed. The experiment was carried out in experimental Hall C at the Thomas Jefferson National Accelerator Facility (TJNAF) and formed part of a group of four experiments that were used to commission the new Super High Momentum Spectrometer (SHMS). The experiment consisted of a 10.6 GeV electron beam incident on a liquid deuterium target which resulted in the break-up of the deuteron into a proton and neutron. The scattered electrons were detected by the SHMS in coincidence with the knocked-out protons detected in the previously existing High Momentum Spectrometer (HMS) and the recoiling neutrons were reconstructed from energy-momentum conservation laws. To ensure that the 2H(e,e'p)n reaction channel was selected, we required the missing energy of the system to be the binding energy of the deuteron (?2.22 MeV). The spectrometers? central angles and momenta were set to measure three central missing momentum settings of the neutron corresponding to p_r = 80, 580 and 750 MeV/c, which required the SHMS central angle and momentum to be fixed and the HMS to be rotated from smaller to larger angles corresponding to the lower and higher missing momentum settings, respectively. The experiment was carried out in a time period of six days with typical electron beam currents of 45-60 uA at about 50% beam efficiency.

Yero, Carlos↗
DOE OSTI2020

Sample problems for Section III, Division 5 design by inelastic analysis of Grade 91 components

This report works through two sample design analyses of representative Grade 91 components using the ASME Boiler & Pressure Vessel Code Section III, Division 5, Appendix HBB-T rules for the strain and deformation and creep-fatigue design criteria using a design by inelastic analysis approach. The component geometries and loadings were selected to span a wide variety of potential applications. The sample components are an endplate geometry, which is fairly representative of typical pressure vessel construction, and a core block, representing a critical component in a heat pipe microreactor, which has a complicated geometry and complex thermal stress history. These sample problems serve several functions. First, they are complete worked examples of how to apply the current design by inelastic analysis rules. Second, they serve as test cases to evaluate the current rules and provide feedback on how they could be optimized to deal with complicated component geometries or to be better automated in modern finite element analysis software. Finally, the analysis here uses an inelastic constitutive model for Grade 91 developed by Argonne National Laboratory and proposed for inclusion in the ASME Boiler & Pressure Vessel Code Section III, Division 5 rules as a reference constitutive model. Using this constitutive model in the sample problem analyses tests the model in the context of the ASME Code rules. The final conclusions of this report are that the material model and the current Code rules are satisfactory, but that the Code rules could be optimized to simplify automation and reduce over conservatism. Future work should address the specific optimization topics discussed in this report.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2020

Oak Ridge National Laboratory Technical Input for the Nuclear Regulatory Commission Review of the 2017 Edition of ASME Section III, Division 5, ‘High Temperature Reactors’

To assist the Nuclear Regulatory Commission in its decision making on endorsement of the American Society for Mechanical Engineers Boiler and Pressure Vessel Code Section III, Division 5 (2017 Edition) for development of advanced non-light water reactors, the following Division 5 portions were reviewed: Article HBB-2000 Material; Article HCB-2000 Material; Article HGB-2000 Material; Mandatory Appendix HBB-I-14 Tables and Figures; and, Nonmandatory Appendix HBB-U Guidelines for Restricted Material Specifications to Improve Performance in Certain Service Applications. In addition to the 2017 Edition, the same parts of the 2019 Edition have also been reviewed as indicated in various sections of the report. This review was conducted by a collaboration of national laboratory and private sector participants with significant industrial experience, including some heavy lifting and deep diving from Clarus Consulting, LLC., all intended to achieve an objective, independent, and practical perspective. The report provides recommendations, descriptions of the evaluation methods, and the source references for the data used. To build confidence required for endorsement of the Code, this review was conducted as a verification and validation of the above Code contents. The objective of verification is to ensure that the Code is free of error – direct or implied; contains the information needed for its use, including proper coverage of the Code-specified materials for the intended application, and completeness and adequacy of references to other portions of the Code. The objective of validation is to authenticate that the Code tabulations and graphs represent design inputs consistent with what are determined using rules and methods specified by the Code. The authentication process used data that were assembled and/or generated independent of Code development, while the methods of analysis followed Code-specified methods where appropriate. The designated portions for this review cover the five alloys codified for high temperature reactor applications in Division 5, i.e. 316 SS, 304 SS, 800H, 2¼Cr-1Mo, and 9Cr-1Mo-V, regarding their general requirements, permitted specifications and design stress intensity values for pressure-retaining applications, deterioration in service, fatigue acceptance test, permissible weld materials, tensile and yield strength, expected minimum stress-to-rupture values (including for Alloy 718), weld stress rupture factors, permissible materials for bolting use, and restricted specifications in certain service applications. Additionally, stress intensity values for bolting materials including 316 SS, 304 SS and alloy 718 were reviewed. Analysis and discussion are also provided on contents outside of these designated Code portions where it was deemed relevant and necessary to develop a technically sound understanding of issues relating to the designated portions. Due to unavailability of sufficient test data on welds during the review period, the weld stress rupture factors in Tables HBB-I-10.14A to E, which cover a total of ten tables for the five alloys welded with twenty-eight different weld metals (some with similar properties), have been deferred to a future review effort. The review identified mainly two types of issues. The first type includes instances where the Code is found factually incomplete or incorrect, such as obsolete materials specifications listings, missing tabulation of stresses for bolting. Changes to the Code are recommended in these cases. The second type of issue includes instances where the Code tabulations and graphs are found to be less conservative than the review analysis results. In these cases, recommendations are made for further review and consideration where the difference in conservatism exceeds 10%, which is our threshold for questioning technical adequacy, meriting a risk assessment by the Nuclear Regulatory Commission and/or reactor designers. It is noted that this effort has been executed using all available data and established methods of analysis, including methods and criteria specified and used by the Code. As such, the findings that are presented in quantitative detail, in a format for convenient comparison with the Code, and with identification of where further review is recommended, should provide a sound technical basis for decisions about quantifying the implications of the reduced design margins and technical adequacy/inadequacy to form a basis for conditioning specific Code tabulation values on endorsement. Recommendations for specific changes to the Code, however, entail design conservatism considerations beyond the scope of this review effort, and are not made in this report.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2021

Fission TPC FY2020 Report (Mid Q2 FY2021): Preliminary 235 U(n,f)/ 6 Li(n,t)α Cross Section Ratio Analysis & Update on the 239 Pu(n,f) Data Collection

Fission TPC L2 Milestone Description: The fission TPC experimental campaign is in its final stages of collecting high precision (n,f) cross section data aimed at improving our understanding of the 239 Pu fission process. During FY 2019 235 U(n,f)/ 6 Li(n,t) ratio data collection began at WNR/LANSCE. This data is the first step in demonstrating the efficacy of 6 Li(n,t) as a diagnostic standard for a 239 Pu(n,f) ratio measurement. In FY 2020 and FY2021, the NIFFTE Collaboration will analyze 235 U(n,f)/ 6 Li(n,t) data already collected to establish this technique in preparation for 239 Pu(n,f)/ 6 Li(n,t) ratio data. Additionally, the ability to vapor deposit 239 Pu was developed in 2019, greatly improving target quality. As access to experimental facilities allows, 239 Pu/ 235 U and 239 Pu/ 6 Li data will be collected to provide new inputs for evaluation of the 239 Pu(n,f) cross section.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

Statistical Hauser-Feshbach model calculation for (α, n) reaction cross section and discrete level population

We calculate the α-particle induced reactions on 17,18 O, 19 F, and 23 Na, in the energy range 0 ≤ E α ≤ 10 MeV, with a particular attention to the branching ratios of populated discrete levels in the (α,n) channels. Since there are too many open channels to employ the R-matrix theory, we apply the statistical Hauser-Feshbach model to calculate these reaction cross sections and branching ratios. The branching ratio is defined as b n = $\frac{σ_n}{Σ_iσ_i + σ_c}$ , where σ n is the n-th level production cross section after the neutron emission, and σ c is the production of the continuum state. In the cases of our target nuclei and the energy range of interest, the residual nuclei of the neutron emission channel are always in their discrete states, so that σ c can be negligible.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Improved Cross Sections From Group T-2 For 11 B, 151 Eu, 153 Eu, and 165 Ho

Group T-2 has recently completed neutron-induced cross-section evaluations for 11 B, 151 Eu, 153 Eu, and 165 Ho. Evaluations for the latter three isotopes are described in Ref. 1. We have prepared cross-section tables based on the new evaluations for use in C-Division deterministic and Monte Carlo codes. Before describing how to access the new data for your calculations, we will compare some characteristics of the new data with previously available data. ZAID identifiers for the new and old data are listed in Table I, along with the source of the old data.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2021

Beam Coupling Impedances of Inter-cell Section in Scorpius Linac

The following technical note is prepared for distribution to external project collaborators. An inter-cell pumping section in the Scorpius linac contains a pumping grid with slots, bellows, and vacuum plenum. The beam coupling impedances of the inter-cell section are calculated with CST Studio. Important to note that all impedance values in the tech note below should be divided by a factor of 2 to obtain the beam coupling impedances in their standard definition; see reference for details.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Benchmark and Assessment of the Surrogate Reaction Method for Determining Unknown (n,n') and (n,2n) Reaction Cross Sections

A new approach for determining (n,n' ) and (n,2n) cross sections from a combination of indirect measurements and theory is presented. The method builds on and significantly extends the surrogate reactions framework developed at LLNL. Multiple theory advances are described and the overall approach is demonstrated through an application to benchmark cross sections. The work addresses nuclear data needs of the Stockpile Stewardship Program (SSP) and this report comprises multiple completion criteria for an ASC/PEM Level-2 milestone.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗