Showing papers by "National Nuclear Energy Commission published in 1980"
TL;DR: In this article, the theoretical background of four independent calibration methods and their application to the silver activated Geiger counter used to determine the neutron yield of the Frascati 1 MJ plasma focus machine are described.
33 citations
26 citations
22 citations
TL;DR: The results of total deposition measurements as a function of particle size taken on 6 volunteers are presented and a wide variability has been found among the subjects; it is discussed and, in contrast with some literature data, there is no apparent correlation with normal expiratory reserve volumes, ERVN.
Abstract: A technique for the assessment of the total deposition efficiency, DE, in the human respiratory tract is described. It is based on the use of non-wettable solid spherical monodisperse particles in the 0.3 to 1.5 µm range and on the measurement of particle concentrations in the inhaled and exhaled air. The results of total deposition measurements as a function of particle size taken on 6 volunteers are presented. A wide variability has been found among the subjects; it is discussed and, in contrast with some literature data, there is no apparent correlation with normal expiratory reserve volumes, ERVN. Therefore at 0.6 µm the deposition has been measured at various ERV. The scatter of data is considerable, but it can be greatly reduced if the relative deposition (ratio of the effective DE to DEN, the deposition at “normal” volumes) is expressed as a function of the relative ERV, (the ratio of the effective ERV to the normal ERVN). Measurements have been performed with monodisperse and unipolarly charged pa...
21 citations
TL;DR: Very low levels of plutonium ( 239,240 Pu and 238 Pu) in marine samples (sea water,sediments, marine organisms) are determined by extraction on columns of tri-n-octyl phosphine oxide supported on microporous polyethylene (Micro thene-710), electrode position, and α-spectrometry.
20 citations
TL;DR: In this article, a thin-film-capacitor counter provides real-time detection of fission fragments, which induce breakdowns at fields lower than the dielectric strength of the insulating film.
19 citations
TL;DR: In this article, a microscopic formalism is proposed for the calculation of the thermodynamic functions, the level densities in particular, for deformed nuclei with an odd number of neutrons and/or protons, on the basis of the singleparticle level blocking due to unpaired nucleons.
Abstract: Within the framework of the BCS approximation, a microscopic formalism is proposed for the calculation of the thermodynamic functions, the level densities in particular, for deformed nuclei with an odd number of neutrons and/or protons, on the basis of the single-particle level blocking due to unpaired nucleons.
16 citations
01 Jan 1980
TL;DR: The reliability evaluation of a multiphase system has been described in a number of papers, but if components were assumed to be non repairable, only an upper bound can be found using the fault-tree approach.
Abstract: The reliability evaluation of a multiphase system has been described in a number of papers, if components were assumed to be non repairable. If a system is composed of repairable components, only an upper bound can be found using the fault-tree approach. In order to find an exact solution to the problem, the Markov approach can successfully be used. The purpose of this paper is to present both above-mentioned approaches.
16 citations
TL;DR: An interferometric method is discussed which enables changes in refractive index of irradiated optical fibers to be determined and changes of step-index fibers irradiated with 1 krad of gamma rays from a (60)Co source are determined.
Abstract: An interferometric method is discussed which enables changes in refractive index of irradiated optical fibers to be determined. The method was used to determine the changes of step-index fibers irradiated with 1 krad of γ rays from a 60Co source. In one case, relative changes in the core and cladding radii of 3.9‰ and 1.8%, respectively, and in the core and cladding refractive indices of 2.8‰ and 2.26‰, respectively, have been determined.
13 citations
11 citations
TL;DR: In this article, absolute (e, 2e) five times differential cross sections measured for the outermost 5p and 5s orbitals of xenon were reported, and data were taken by varying the incident energy from 200 to 4500 eV.
TL;DR: In this article, a mathematical model of steady turbulent flow in wide-angled conical diffusers is presented, which is more flattened than the experimental data, due to the underestimation of normal turbulent stresses.
Abstract: The mathematical model of steady turbulent flow in wide-angled conical diffusers is presented. Static pressure distribution resulting from the numerical solutions is more flattened than the experimental data, due to the underestimation of normal turbulent stresses. On the contrary, the shear stresses are generally overestimated: The opposing effects of the stresses counterbalance in the mean kinetic energy and momentum analysis. The spatial distribution of stream lines is well predicted as well as the detailed characteristics of recirculating region, as a result of the choice of the wall function. The discrepancies in the predictions of some quantities confirm the need to refine the turbulence modeling when recirculating regions are present, as in wide-angled diffusers.
TL;DR: In this paper, a parallel derivation of the forward Kolmogorov equation (FKE) and of the backward KG equation (BKE) from detailed probability balance equations for a population of neutrons, precursors and detected neutrons living in a multiplying medium where processes of capture and leakage, fission, precursor decay, detection and source emission occur.
TL;DR: An extremity dosimetry system, developed by TNO and CNEN in cooperation, is described and its application in nanofiltration and X-ray diffraction is described.
TL;DR: In this paper, a critical rate of energy loss for track registration of (0.85 ± 0.05) MeV cm 2 mg −1 has been derived, which corresponds to a critical alpha-particle energy of (4.6 ± 0 4.4) MEV.
01 Jan 1980
TL;DR: In this paper, a phenomenological approach is described in which relevant parameters are derived from known experimental quantities and parameter systematics have been determined which may be used for interpolation where experimental information is not available.
Abstract: The topic of nuclear level densities is considered from the standpoint of applications. A phenomenological approach is described in which relevant parameters are derived from known experimental quantities. Parameter systematics have been determined which may be used for interpolation where experimental information is not available.
TL;DR: In this article, an analysis of wind and current data collected in the Ligurian Sea (North Tyrrhenian Sea) during Autumn 1978 is made, and it is shown that the dominant low-frequency fluctuations in current are not strongly correlated to wind fluctuations.
Abstract: An analysis of wind and current data collected in the Ligurian Sea (North Tyrrhenian Sea) during Autumn 1978 is made. It results that the dominant low-frequency fluctuations in current are not strongly correlated to wind fluctuations. Conclusions about the motion dynamics are reached by means of empirical orthogonal functions and other indicators.
TL;DR: In this paper, a safety study on a particular plant (Tapiro Research Reactor in service at C.N.S. Casaccia) allows one to reach more general conclusions about the reliability of computerized protection systems.
TL;DR: In this article, the number of counts tallied when the activity of a gamma-emitting thick foil is measured by means of a sodium iodide crystal is calculated using the Fortran IV program.
TL;DR: In this paper, the authors describe the work of two working groups which are preparing international standards on thermoluminescence dosimeters (TLD) and TLD readers, respectively.
TL;DR: In this article, a semi-empirical model was derived from in-pile temperature measurements at low burnup and BWR Garigliano rods PIE at high burn-up.
01 Jan 1980
TL;DR: Human lymphocytes from peripheral blood are considered to be among the most radiosensitive cells in vivo as well as in vitro.
Abstract: Human lymphocytes from peripheral blood are considered to be among the most radiosensitive cells in vivo (1) as well as in vitro (2–3).
01 Jan 1980
TL;DR: In this paper, a mathematical diffusion model of the wreckage area (the Otranto Channel) was developed; simulation tests were performed and potential pollution of marine and coastal waters was evaluated assuming conservative boundary conditions.
Abstract: The Cavtat accident can be considered as one of the worst cases of potential localized pollution in the Mediterranean Sea in the last decade. The strategies followed in order to evaluate and monitor the effects on the marine and the coastal environment by alkyl lead releases due to corrosion and/ or recovery operations are described. A mathematical diffusion model of the wreckage area (the Otranto Channel) was developed; simulation tests were performed and potential pollution of marine and coastal waters was evaluated assuming conservative boundary conditions. Analytical procedures for rapid field determination of alkyl lead concentration and for more precise determination of organic and inorganic lead concentrations in sea water were developed in order to permit a reliable monitoring of the diver's environment and of the wreck area. Lead in sea water, in sediments and in biota was monitored before, during and after the recovery operations which were successfully completed with negligible marine pollution.
TL;DR: In this article, the forward stochastic method equations have been applied to a two-zone fuel-coolant system characterized by a heat-generating fuel and a one-phase heat-removing coolant.
TL;DR: In this article, the authors describe the full experience gained in the design, implementation and validation of the computerized protection system for the TAPIRO fast reactor at the Casaccia Center - Rome.
Abstract: The paper describes the full experience gained in the design, implementation and validation of the computerized protection system for the TAPIRO fast reactor at the Casaccia Center - Rome. The TAPIRO fast reactor is a 5 Kw research reactor, cooled by He.
01 Jan 1980
TL;DR: In this paper, the authors describe the full life cycle process of design, development and validation, which has been followed for the production of software for an experimental computerized reactor protection system at Casaccia Center.
Abstract: The paper describes the full life cycle process of design, development and validation, which has been followed for the production of software for an experimental computerized reactor protection system at Casaccia Center. The aim of the paper is to put in emphasis phase- by-phase the criteria which have been followed, the verification procedures adopted and the errors discovered. Additionally the system testing activity is described.