Showing papers in "Annals of Nuclear Energy in 1982"

TL;DR: In this article, high-precision measurements of thick target yields from (α, n) reactions on Be, BeO, BN, C, UC, UO 2, Mg, Al, Si, Fe and stainless steel are described.

TL;DR: In this paper, a simple 1-D, one-energy group deep-penetration problem was solved by using angular biasing for both the space-transition part and the collision part of the transport kernel.

TL;DR: In this article, an approximate method to study the monokinetic linear transport equation is outlined, starting from its integral form, rather than the integro-differential one, and the approximate solution may be deduced either analytically, in simple cases, or numerically by means of typical space discretization techniques, associated to proper boundary conditions.

TL;DR: In this paper, a new approach for solving multigroup integral transport equation in cylindricalized cells containing fuel in the form of clusters was discussed, based on a combination of interface currents formalism and first-flight collision probabilities.

TL;DR: In this article, the use of the An approximate method in solving the monokinetic neutron transport equation has been studied and it has been shown that the system of space second-order differential equations which constitute the method may be cast into a form perfectly equivalent to the PN model, for any geometry.

TL;DR: In this paper, the boundary-free maximum and minimum variational principles for even-parity neutron transport are reviewed and the corresponding principles for odd-Parity transport are derived by a simple method to show why the essential boundary conditions associated with these maximum principles have to be imposed.

TL;DR: In this paper, the problem of the neutron response to an infinite frequency-dependent plane unit source in the moderator of an infinite regular heterogeneous lattice of cylindrical fuel elements is analyzed in the one-group diffusion approximation with a two-group slowing-down kernel, within the framework of the source-sink method of Feinberg and Galanin.

TL;DR: In this article, the energy and angular distribution of the α-particles from the reaction 93Nb+n for 14.1-MeV incident neutron energy was measured by means of a multitelescope system.

TL;DR: It is shown that the finite element method also shares with Monte Carlo the capability to bracket local characteristics of a solution, such as the reaction rate for a small locality.

TL;DR: In this paper, a solution of the two-group Feinberg-Galanin kinetic adjoint equations for a 2D heterogeneous lattice of a finite number of cylindrical fuel rods is presented and the terms corresponding to the local component of the detector response are identified in the solution.

TL;DR: In this article, the authors considered the anisotropy in the angular flux by expanding it in spherical harmonics in two half-spaces (double-PN or DPN approximation) and compared the results with the exact collision probability (Pij) method for clusters by using the same mesh-spacing in the moderator for both methods.

TL;DR: In this paper, a three-group theory of neutron noise is developed and it is shown that the neutron-noise field in homogeneous multiplying media can be separated into a component with a long attenuation length (global component) and two local components whose attenuation lengths in water-moderated reactors are very small and of the order of the diffusion length of thermal neutrons in the medium.

TL;DR: In this paper, the frequency-dependent source-sink formalism of Feinberg and Galanin in one-group diffusion theory with a two-group slowing-down kernel is used for the investigation of the frequency response of the neutron field to a localized frequencydependent perturbation in a 3D heterogeneous lattice of a finite number of fuel and control rods embedded in an infinite moderator with no upper or lower reflectors.

TL;DR: In this article, a previous treatment of the behaviour of radioactive aerosols is extended to take condensation into account and to cope more accurately with a general multicomponent aerosol.

TL;DR: In this article, the authors review several problems related to the measurement, analysis and evaluation of the neutron cross sections of the main fertile and fissile nuclides in the resonance region and recommend the validation of the unresolved resonance range evaluations with appropriate transmission and self-indication measurements.

TL;DR: In this paper, an effective homogenization method for heterogeneous assemblies such as fuel assemblies with and without control blades in BWR and control-rod channels in FBR was developed for rod-worth calculation for pin rods in the fast critical assembly ZPPR-10 and to the power-density calculation of a test BWR core.

TL;DR: The purpose of this report is to summarize and explain current requirements in cross section data that are essential to nuclear energy programs and to provide some insight into how these data might be obtained.

TL;DR: In this paper, the quasistatic method used in reactor-physics calculations is applied to a model integro-differential equation in a Banach space, and the resulting quasismatic equations are shown to be locally consistent with the original initial value problem.

TL;DR: In this paper, a review of the application of radiation chemistry research to improve the operating efficiency of nuclear reactors is presented, including the inhibition of graphite moderator corrosion and prevention of carbon deposition in gas-cooled reactors, suppression of radiolysis of the cooling water in concrete pressure vessels, hydrogen formation following a loss of coolant accident in a PWR and improving the stability of decontamination reagents for water reactors.

TL;DR: In this paper, the authors used a combination of pre-equilibrium and Hauser-Feshbach model to calculate neutron-induced reaction cross sections for 93 Nb for incident energies between 0.3 and 20 MeV.

TL;DR: In this paper, the authors compared the suitability of different orders of PN half-space expansions in analysing 2-dimensional rectangular geometrics and concluded that the four-term expansion is a suitable choice for angular current approximation in 2-D LWR lattice problems.

TL;DR: In this paper, the mean (v) and variance (σ2) of the prompt neutron multiplicity distribution for spontaneous fission of 252Cf and 242Pu have been made.

TL;DR: In this paper, a more fundamental scientific basis for the prediction of the Doppler effect in fast reactor systems demands that the usual ENDF/B and KEDAK conventions for the representation of cross-sections in the unresolved resonance region should be changed based upon the experience acquired in evaluations of statistical mean resonance parameter sets, made at RRC Kalpakkam, for use in neutronic calculations of fast reactors in the recent past for 235 U, 239 Pu, 232 Th, 233 U and 238 U.

TL;DR: In this article, a particle method was employed to determine the neutron flux produced by the 3 H(d, n) 4 He reaction and a 16% Ge(Li) detector measured the activity of the neutron-irradiated samples.

TL;DR: In this paper, a simple method is presented to modify Sauer's approximation for the lattice Dancoff factor to account for clad interactions, which has the advantages of being easy to implement into existing codes, having negligible impact on execution time, and showing good agreement with sophisticated methods.

TL;DR: In this paper, the problem of analyzing the statistical error of Monte Carlo point-flux estimators with unbounded variance is considered and the results are based on the generalization of the classical limit theorem for summands of identically-distributed random variables on the unbounded-variance case.

TL;DR: In this paper, the authors used a sodium iodide spectrometer for penetration through shields in six possible two-layer combinations of aluminium, steel and lead, and found that the exposure build-up factor was higher than predicted for aluminium only shields.

TL;DR: In this article, the feasibility of coupling two-phase liquid-metal magnetohydrodynamic generators (LMMHD) to LMFBRs was examined and the authors showed that a LMMHD cycle coupled to a gas turbine cycle yielded an overall cycle efficiency of 352% which is less than the efficiency of 362% when the turbine cycle is utilized by itself.