The peculiarities of cross-correlation between two secondary precursors - radon and magnetic field variations, induced by stress transfer changes

A model of precursor manifestation mechanisms, stimulated by tectonic activity and some peculiarities of observer strategy, whose main task is the effective measurement of precursors in the spatial area of their occurrence on the Earth's daylight, are considered. In particular, the applicability of Dobrovolsky's approximation is analyzed, when an unperturbed medium (characterized by the simple shear state) and the area of tectonic activity (local inhomogeneity caused by the change only of shear modulus) are linearly elastic, and perturbation, in particular, surface displacement is calculated as a difference of the solutions of two independent static problems of the theory of elasticity with the same boundary condition on the surface. Within the framework of this approximation a formula for the spatial distribution (of first component) of magnetic field variations caused by piezomagnetic effect in the case of perturbed regular medium, which is in simple shear state is derived. Cogent arguments in favor of linear dependence between the radon spatial distribution and conditional deformation are obtained. Changes in magnetic field strength and radon concentrations were measured along a tectonomagnetic profile of the total length of 11 km in the surroundings of the "Academician Vernadsky" Station on the Antarctic Peninsula (W 64{\deg}16', S 65{\deg}15'). Results showed a positive correlation between the annual surface radon concentration and annual changes of magnetic field relative to a base point, and also the good coincidence with theoretical calculation.Comment: 27 pages, 11 figures, 3 tables (a substantially revised and extended edition; v3 -- some analysis of recent publications added

On the possibility of the self-sustaining nuclear chain reaction inside the "Shelter" object at the present time

Based on new modern data regarding the state of the fuel-containing masses (FCM) of the "Shelter", as well as taking into account the neutron incident of 1990 and the physical properties of the FCM of the "Shelter", the possibility of the occurrence and development of a self-sustaining chain nuclear fission reaction was considered in the FCM. It is shown that the drying of the FCM can lead to the occurrence of a single neutron burst with an amplitude comparable to the amplitude of neutron oscillations in 1990. It is also shown that the amplitude of the burst can be reduced if the rate of drying of the FCM is increased. The evaluations show that such a burst would have no impact on the environment

On accuracy of the parameter of deep subcriticality determination by the Feynman method

This paper considers the application of the Feynman method of neutron noise analysis for determination of the deep subcriticality parameters for multiplying systems. In particular, it is shown that the selection of the width of the timeslots, for which the mean and variance of the number of the neutron detector counts should be determined, can significantly affect the accuracy of determination of prompt neutron decay constant (), espe-cially in case of deep subcriticality. Analysis is based on the Monte Carlo method of calculation (code MCNP) of the simple multiplying systems with different neutron multiplication factors. Simple method of determination of the optimum width of the timeslot, from the standpoint of calculation increasing accuracy, near which it is ad-visable to build the experimental dependence of the dispersion to mean ratio for the determination of . It is also shown that bias estimates of is determined not only by the finite sampling data, but also by the overlapping of neutron chains. That is, the intensity of the external neutron source must not exceed a certain value, which de-pends on the neutron multiplication factor

Detector of reactor antineutrinos with plastic stintillation bars

Project of a segmented antineutrino detector is developed with the use of plastic scintillator rectangular bars 10 x 10 x 100 cm, wrapped in Gd foils and assembled into an array of 1 m3 active volume. The scintillation array is sandwiched at both sides by the continuous light guides of 100 x 100 x 10 cm size, from which the scintillation light is spreading simultaneously through continuous light guides between all photomultipliers, forming the specific Light Response Function (LRF), which is character to a certain nuclear event in detector. Analysis of LRF allows one to effectively reject background events, providing high efficiency detection of antineutrino capture in the detector. Monte Carlo simulations with the help of MCNP and ZEMAX software show that with the use of selection criteria the neutrino events are well separated from the background

Reactivity in the theory of the stationary nuclear fission wave

We studied axial motion of the stationary nuclear fission wave in the cylindrical core of the traveling wave reactor (known also as CANDLE) using an effective one-dimensional model of the fast spectrum reactor with uranium plutonium fuel. The model includes one-group diffusion equation for the neutron flux and kinetic equations for nuclear densities. The so-called velocity characteristic has been studied in our previous works. It is the dependence of the wave velocity on the effective concentration of the absorber. Due to instability of long-living 241Pu it has two branches, and the solutions of the lower branch are unstable. In this paper, reactivity was introduced into the diffusion equation as an additional parameter of the model, and the generalized equation of the velocity characteristic connecting the wave velocity with the effective concentration of the absorber and reactivity is obtained. Since the equation includes both parameters linearly and additively, their variations are interchangeable, in the appropriate scale. Obtained results open the way to study the velocity characteristic of the reactor with powerful reactor codes (outside one-group diffusion approximation), calculating the effective multiplication factor in the stationary wave mode for a series of fixed values of the reactor power

Physical principles of nuclear burning wave reactor. II. The models

In this paper the reactor based on a nuclear burning wave propagation under the presence of the absorber which does not burn out is studied. The possibility to regulate the wave velocity and thus the power of the reactor by means of a small deviation of the absorber concentration is demonstrated. Starting from the general equilibrium conditions of the wave obtained in the previous paper [1] the perturbation approach is developed providing possibility to determine the wave velocity (reactor power) and the final fluence (fuel burn out) at a given absorber concentration. Dimensionless velocity of the wave which turns out to be small for any real reactor is proved to be the expansion parameter in this perturbation theory. The effect of higher isotopes of plutonium and of fission products (for the U-Pu cycle) on the wave properties is also considered

Two-zone Sub-critical Reactor Driven by a Highintensity Neutron Generator as a Research Facility for the Nuclear Waste Transmutation //

ABSTRACT In regard to intensive development of accelerator driven system (ADS) in the past 20 years and a promising possibility of radioactive waste transmutation in such systems, we have proposed the physical project of a sub-critical research reactor driven by an external neutron source. The basis of such a research reactor is a good optimized two zone sub-critical assembly. The results of calculations of the simple homogeneous models of such assemblies are presented in the paper, and the two zone (fast and thermal) heterogeneous model has been designed on the base of these calculations. The main details of design and physical characteristics of such a model are also presented. Special attention is paid to the choice of effective external neutron source. The disadvantages and advantages of different types of accelerators and power neutron generators are considered

The Transmutation of Nuclear Waste in the Two-Zone Subcritical System Driven by High- Intensity Neutron Generator -12098

ABSTRACT The main problems of transmutation of high-level radioactive waste (minor actinides and long-lived fission products) are considered in our work. The range of radioactive waste of nuclear power is analyzed. The conditions under which the transmutation of radioactive waste will be most effective are analyzed too. The modeling results of a transmutation of the main radioactive isotopes are presented and discussed. The transmutation of minor actinides and long-lived fission products are modeled in our work (minor actinides -Np-237, Am-241, Am-242, Am-243, Cm-244, Cm-245; longlived fission products -I-129, Tc-99). The two-zone subcritical system is calculated with help of different neutron-physical codes (MCNP, Scale, Montebarn, Origen). The ENDF/B-VI nuclear data library used in above calculations

Modelling of two-zone accelerator-driven systems

Neutron-physical modelings of two-zone subcritical reactor driven by high-intensity neutron generator are considered. The cascade principle in subcritical reactors, the use of which can hypothetically substantially amplify the neutron flux from the external source is discussed in this article. The theoretical preconditions of the cascade principle are discussed, and the directions of practical realization of the cascade subcritical system are considered, namely the possible methods of neutron feedback between reactor sections elimination. The results of Monte Carlo neutron-physical modeling of the cascade subcritical systems are presented and discussed

Галоаерозольтерапія в реабілітації хворих на негоспітальні пневмонії: клінічно-функціональні аспекти

Reasonability of haloaerosoltherapy use for medical rehabilitation of the convalescents after community acquired pneumonia has been substantiated. The effectiveness of different regimes of haloaerosoltherapy in relation to the bronchial obstruction was studied.На основе клинико-функциональных исследований обоснована целесообразность использования галоаэрозольтерапии в восстановительном лечении реконвалесцентов после внебольничных пневмоний. Изучена эффективность различных режимов галоаэрозольтерапии во взаимосвязи с наличием обструкции бронхов.На основі клінічно-функціональних досліджень обґрунтовано доцільність використання галоаерозольтерапії у відновлювальному лікуванні реконвалесцентів після негоспітальних пневмоній. Вивчена ефективність різних режимів галоаерозольтерапії у взаємозв'язку з наявністю обструкції бронхів