Showing papers in "Nuclear Science and Engineering in 1981"
TL;DR: In this paper, numerical heat transfer and fluid flow are used to transfer heat from a nuclear power plant to a nuclear fluid flow system, and the resulting fluid flow is used for nuclear power plants.
Abstract: (1981). Numerical Heat Transfer and Fluid Flow. Nuclear Science and Engineering: Vol. 78, No. 2, pp. 196-197.
3,386 citations
TL;DR: In this paper, a method for using standard discrete ordinates neutron transport codes to perform Fokker-Planck calculations in one-dimensional slab and spherical geometries was developed.
Abstract: A method is developed for using standard discrete ordinates neutron transport codes to perform Fokker-Planck calculations in one-dimensional slab and spherical geometries. No modification of the co...
93 citations
TL;DR: The total neutron cross sections of the heavy and actinide nuclei 181Ta, 197Au, 232Th, 233U, 235U, 238U, 239Pu, and 240Pu were measured from 30 keV to 4.8 MeV.
Abstract: Total neutron cross sections of the heavy and actinide nuclei 181Ta, 197Au, 232Th, 233U, 235U, 238U, 239Pu, and 240Pu were measured from 30 keV to 4.8 MeV. The experimental procedures emphasized a ...
65 citations
TL;DR: Potential-pH diagrams for uranium and plutonium in water containing carbonate, chloride, fluoride, phosphate, sodium, and sulfate ions at 25, 100, and 200/degree/C complexation was considered in deriving the diagrams and the potential pH relationships were calculated for various total dissolved ion concentrations.
Abstract: Potential-pH diagrams are reported for uranium and plutonium in water containing carbonate, chloride, fluoride, phosphate, sodium, and sulfate ions at 25, 100, and 200/degree/C Complexation was considered in deriving the diagrams and the potential-pH relationships were calculated for various total dissolved ion concentrations The diagrams are used to analyze the general features of the thermodynamic behavior of uranium and plutonium in geological systems and to help identify processes that might be expected to occur in the vicinity of a deep underground vault for nuclear fuel waste 44 refs
55 citations
TL;DR: In this paper, the authors obtained nuclear plus interference elastic cross sections for all 25 particle combinations of the particles p, d, t, 3He, and α by subtracting Coulomb con...
Abstract: We consider all 25 projectile-target combinations of the particles p, d, t, 3He, and α. We obtained nuclear plus interference elastic cross sections for such interactions by subtracting Coulomb con...
52 citations
TL;DR: The capture cross section of 238U was measured using the activation technique and 235U and 197Au(n, f) as reference cross sections Capture events were measured by detection of two prominent landmarks as mentioned in this paper.
Abstract: The capture cross section of 238U was measured using the activation technique and 235U(n, f) and 197Au(n, γ) as reference cross sections Capture events were measured by detection of two prominent
50 citations
TL;DR: In this article, a new general methodology called Event Sequences and Consequence Spectrum is presented, which is the result of the synthesis between the Response Surface Methodology for the simulation of sys...
Abstract: This work presents a new general methodology called Event Sequences and Consequence Spectrum, which is the result of the synthesis between the Response Surface Methodology for the simulation of sys...
50 citations
TL;DR: In this article, a method of monitoring stability of boiling water reactors (BWRs) has been developed based on empirical discrete-time modeling of process noise signals and neutro.
Abstract: A method of monitoring stability of boiling water reactors (BWRs) has been developed The stability parameters were derived from empirical discrete-time modeling of process noise signals and neutro
42 citations
TL;DR: In this paper, the ratio of deuterium-tritium (D-T) to neutron-producing D-D reactions (RDT/RDD) was used as a diagnostic of the fuel density-radius product (ρR) for ini...
Abstract: It is proposed that the ratio of deuterium-tritium (D-T) to neutron producing deuterium-deuterium (D-D) reactions (RDT/RDD) be used as a diagnostic of the fuel density-radius product (〈ρR〉) for ini...
40 citations
TL;DR: A review of the various methods that have been developed for dealing with this important effect within the framework of numerical neutron transport theory is given in this paper, where some criteria for their applicability to practical problems are given.
Abstract: In many practical areas of neutron transport, anisotropic scattering of neutrons plays an important role. This study gives a review of the various methods that have been developed for dealing with this important effect within the framework of numerical neutron transport theory. On the basis of numerous examples of application, the different anisotropic scattering methods are discussed and some criteria for their applicability to practical problems are given.
36 citations
TL;DR: In the past few years, over 300 small-scale experiments have been performed by Nelson at Sandia National Laboratories, investigating the triggering of steam explosions over a variety of initial stages as discussed by the authors.
Abstract: During the past few years, over 300 small-scale experiments have been performed by Nelson at Sandia National Laboratories, investigating the triggering of steam explosions over a variety of initial...
TL;DR: In this article, absolute fission product decay energy-release rates have been measured for thermal-neutron fission of 239Pu and 241Pu Spectral data were obtained using scintillation spectrometers for beta and gam
Abstract: Absolute fission-product decay energy-release rates have been measured for thermal-neutron fission of 239Pu and 241Pu Spectral data were obtained using scintillation spectrometers for beta and gam
TL;DR: In this article, the F/sub N/ method is used to establish particularly accurate solutions, at modest cost, for the emerging angular fluxes basic to a class of multigroup particle-transport problems.
Abstract: The F/sub N/ method is used to establish particularly accurate solutions, at modest cost, for the emerging angular fluxes basic to a class of multigroup particle-transport problems. A study of the fundamental computational aspects of the established solution is reported, and numerical results are given, accurate to five significant figures, for the reflected and transmitted angular fluxes relevant to a 16-group albedo problem and to a 19-group albedo problem. 10 refs.
TL;DR: A measuring program has been carried out at the Van de Graaff accelerator facility of the Central Bureau for Nuclear Measurements for the determination of (n, α) cross sections on the main constitu....
Abstract: A measuring program has been carried out at the Van de Graaff accelerator facility of the Central Bureau for Nuclear Measurements for the determination of (n, α) cross sections on the main constitu...
TL;DR: In this paper, a particle transport theory method was developed for particle streaming and shielding calculations, which is similar to the SN technique in that discrete directions are assumed to follow the same path.
Abstract: A new particle transport theory method has been developed for application in particle streaming and shielding calculations. The method is similar to the SN technique in that discrete directions are...
TL;DR: In this paper, the mass distribution in the reactor-neutron-induced fission of /sup 232/Th was studied using radiochemical techniques and direct gamma-ray measurements.
Abstract: This investigation was undertaken to improve the data on product yields in the reactor-neutron-induced fission of /sup 232/Th. The mass distribution in the reactor-neutron-induced fission of /sup 232/Th was studied using radiochemical techniques and direct gamma-ray measurements. Absolute fission yields of the standard nuclides /sup 99/Mo and /sup 132/Te were obtained from /sup 232/Th sources irradiated in a fission counter. The yields of 36 mass chains, including three that have been measured for the first time, were determined both from measurements relative to /sup 235/U(n/sub th/, f) nth,f) yields and from /sup 232/Th data alone. 39 refs.
TL;DR: In this paper, a perturbation formalism is developed for the first-order change in keff due to a small perturbations in the exterior shape of a reactive system.
Abstract: A perturbation formalism is developed for the first-order change in keff due to a small perturbation in the exterior shape of a reactive system. The analysis is developed for both diffusion and tra...
TL;DR: In this paper, a time-dependent generalized perturbation theory for nonlinear fields is developed to any order of approximation required by simple heuristics based on the importance conservation principle.
Abstract: On the basis of the importance conservation principle, a time-dependent generalized perturbation theory for nonlinear fields is developed to any order of approximation required by simple heuristic ...
TL;DR: Stable Isotope Capture Cross Sections from the Oak Ridge Electron Linear Accelerator (OILA) as discussed by the authors were used to construct cross sections from stable isotope capture cross sections.
Abstract: (1982) Stable Isotope Capture Cross Sections from the Oak Ridge Electron Linear Accelerator—Part II Nuclear Science and Engineering: Vol 82, No 2, pp 230-231
TL;DR: In this article, a standard method by which the perturbed neutron flux is expanded in terms of eigenfunctions is proposed, and a formulation of more general scope is proposed.
Abstract: In relation to the proposed “standard method” by which the perturbed neutron flux is expanded in terms of eigenfunctions, a comment is made and a formulation of more general scope is proposed.
TL;DR: In this article, the total feed rate under equilibrium refueling is minimized by adjusting the exit irradiation of the fuel in specified burnup zones while obeying constraints on excess reactivity and on th...
Abstract: The total reactor feed rate under equilibrium refueling is minimized by adjusting the exit irradiation of the fuel in specified burnup zones while obeying constraints on excess reactivity and on th...
TL;DR: For the transport calculation of gamma rays including bremsstrahlung, an improvement was made in the PALLAS-PL, SP discrete ordinates direct-integration code.
Abstract: For the transport calculation of gamma rays including bremsstrahlung, an improvement is made in the PALLAS-PL, SP discrete ordinates direct-integration code to enable evaluation of bremsstrahlung. ...
TL;DR: In this article, the authors measured the neutron capture cross section of /sup 237/Np from 0.01 eV to 200 keV, covering the neutron energy range important to both thermal and fast reactors.
Abstract: The neutron capture cross section of /sup 237/Np was measured from 0.01 eV to 200 keV. These measurements cover the neutron energy range important to both thermal and fast reactors. 26 refs.
TL;DR: In this article, a benchmark gamma-ray skyshine experiment is descibed in which /sup 60/Co sources were either collimated into an upward 150-deg conical beam or shielded vertically by two different thicknesses of concrete.
Abstract: A benchmark gamma-ray skyshine experiment is descibed in which /sup 60/Co sources were either collimated into an upward 150-deg conical beam or shielded vertically by two different thicknesses of concrete. A NaI(Tl) spectrometer and a high pressure ion chamber were used to measure, respectively, the energy spectrum and the 4..pi..-exposure rate of the air-reflected gamma photons up to 700 m from the source. Analyses of the data and comparison to DOT discrete ordinates calculations are presented.
TL;DR: The neutron-induced fission cross section of /sup 240/Pu was measured in the neutron energy range from 10 keV to 10MeV using the 7-MV Van de Graaff and the electron linear accelerator of the Central Bureau for Nuclear Measurements as pulsed neutron sources as discussed by the authors.
Abstract: The neutron-induced fission cross section of /sup 240/Pu was measured in the neutron energy range from 10 keV to 10MeV using the 7-MV Van de Graaff and the electron linear accelerator of the Central Bureau for Nuclear Measurements as pulsed neutron sources, which delivered monoenergetic and continuous neutron spectra, respectively The neutron-induced fission events were detected with a parallel plate ionization chamber that provided a fast and narrow output signal allowing nanosecond timing, but where the time integral of the pulse contained, at the same time, the energy information of the ionizing particle This detector permitted a high discrimination between alpha particles and fission fragments 22 refs
TL;DR: The authors measured the transport of ∼14-MeV deuterium-tritium (D-T) neutrons through laminated slabs of proposed fusion reactor shield materials.
Abstract: Integral experiments that measure the transport of ∼14-MeV deuterium-tritium (D-T) neutrons through laminated slabs of proposed fusion reactor shield materials have been carried out at the Oak Ridg...
TL;DR: In this paper, an adjoint Monte Carlo technique is described for the solution of neutron transport problems, and the optimum biasing function for a zero-variance collision estimator is derived.
Abstract: An adjoint Monte Carlo technique is described for the solution of neutron transport problems. The optimum biasing function for a zero-variance collision estimator is derived. The optimum treatment of an analog of a non-velocity thermal group has also been derived. The method is extended to multiplying systems, especially for eigenfunction problems to enable the estimate of averages over the unknown fundamental neutron flux distribution. A versatile computer code, FOCUS, has been written, based on the described theory. Numerical examples are given for a shielding problem and a critical assembly, illustrating the performance of the FOCUS code. 19 refs.