Russian Research Centre Kurchatov Institute Research Articles

Обследование содержимого ячеек хранилища высоко- и среднеактивных отходов реактора МР

The article presents the results of a survey carried out at a storage facility for intermediate- and high-level waste established during the operation of MP and RFT research reactors at the site of the Russian Research Center Kurchatov Institute. Relevant survey methods were selected based on the personnel safety requirements for measurements, permissible individual and collective annual exposure of personnel and the population, standards for contaminated environmental objects. All RW containers held in the storage cells were certified and handled properly to ship them from the site of the RRC Kurchatov Institute. The decommissioning designs for this storage facility will be developed based on the data obtained.

Shock Loading of Advanced Materials from Macro-, Micro- to Nanoscale

Some of the activities of the Project Center for Nanotechnology and Advanced Engineering (PC-NAE), a joint initiative of the Greek National Center for Scientific Research Demokritos and the Russian Research Center Kurchatov Institute, in advanced manufacturing engineering are briefly outlined, focusing onto some recent trends and developments in manufacturing from macro-, micro-, to nanoscale of advanced materials in the important engineering topics nowadays from industrial, research and academic point of view: nanotechnology/ultraprecision engineering and advanced materials under shock loading, with industrial applications to net-shape manufacturing, bioengineering, energy and transport.

Measurements of control rod worth by modified inverse kinetic method

Results of control rod worth measurements on the Astra critical assembly at the Russian Research Centre Kurchatov Institute are presented. The measurements were carried out by the modified inverse kinetics method, which is based on the use of experimental information about the variation of neutron detector readings only after introducing a reactivity perturbation. Calculated corrections are not required. The results of measurements do not depend on the neutron detector position.

An investigation of some models and approximations used in calculating fuel assemblies of a high-temperature gas-cooled reactor of the GT-MHR type

The paper describes basic neutron-physics models developed in the Division of Advanced Nuclear Power Systems of the Institute of Nuclear Reactors, Russian Research Center Kurchatov Institute, as design models intended for calculating the characteristics of block fuel assemblies of a high-temperature gas-cooled reactor GT-MHR, namely, models for calculating burnup of fuel and isotopes of burnable neutron absorbers and calculating fuel assemblies at fixed points with respect to burnup with preparation of the neutron constants in a preassigned number of energy groups for full-scale design of a reactor. A model problem for investigation of calculated approximations is proposed. The outcome of this investigation is a developed stage-by-stage procedure of preparing group homogeneous cross sections of a fuel assembly and its parts that has been introduced into the practice of design calculations of a GT-MHR reactor.

Influence of feedbacks in the RF accelerating system and feeders between RF power generators and accelerating resonators on the in-phase dipole oscillations of bunches in cyclic accelerators

In cyclic accelerators, interaction of the beam with the RF accelerating system may generate inphase dipole oscillations of bunches, which govern the limiting current of charged particles in the accelerator. A method of calculating the influence of the parameters of the RF system on the limit current is suggested. It is shown that feedbacks stabilizing the performance of the RF system considerably influence the limiting current in the accelerator. Moreover, the length of feeders through which the power of RF generators is applied to accelerating resonators also has an effect on the limiting current. The efficiency of the method is demonstrated by calculating the limiting electron current in a Sibir’-2 storage ring installed at the Russian Research Centre Kurchatov Institute.

Theoretical and experimental physical methods of neutron-capture therapy

This review is based to a substantial degree on our priority developments and research at the IR-8 reactor of the Russian Research Centre Kurchatov Institute. New theoretical and experimental methods of neutron-capture therapy are developed and applied in practice; these are: A general analytical and semi-empiric theory of neutron-capture therapy (NCT) based on classical neutron physics and its main sections (elementary theories of moderation, diffuse, reflection, and absorption of neutrons) rather than on methods of mathematical simulation. The theory is, first of all, intended for practical application by physicists, engineers, biologists, and physicians. This theory can be mastered by anyone with a higher education of almost any kind and minimal experience in operating a personal computer. Methods of phantom experimental studies for the semi-empiric theory of NCT using epithermal neutrons. Experimental methods for measuring and monitoring the spectral composition of therapeutic, research, and analytical neutron beams for NCT and other investigations with neutrons. Experimental methods of remote neutron dosimetry of biological objects with intentional modification of the element composition of tissues in NCT. Methods of mass investigations in pharmacokinetics and biologic efficiency of novel dose-forming preparations. Methods for tailoring of therapeutic, research, and analytical neutron beams for NCT and other investigations with neutrons. Methods of capillary neutron optics application for NCT and other fundamental and applied studies with neutrons.

Decontamination of sandy soils from 137Cs by reagent treatment with agitation leaching

The simplest and the most efficient method for decontamination of sandy soils is separation of the finely dispersed fraction (<0.1 mm), with which ∼90% of the contaminating radionuclides are associated, by gravity sedimentation in water. However, for sandy soils from the Russian Research Centre Kurchatov Institute, the decontamination factor in this case is as low as 4–5. The decontamination factor can be further increased by using reagent treatment. The main parameters of the process are reagent composition and concentration, temperature, and liquid to solid ratio. The decontamination factor of 10–14 can be attained by reagent treatment with 2 M H2SO4 + 1 M H3PO4 or 3–4 M H2SO4 solutions for 7 h at 80°C, at the liquid to solid ratio of no less than 2 : 1. Two times higher decontamination factor can be attained by treatment with a 2 M H2SO4 + 0.6 M NH4F solution, but high toxicity of fluorides restricts the possibility of using this reagent.

An automatic control system of the synchrotron station and special features of the experiment automation at the LANGMUIR station of the synchrotron radiation source of the RRC Kurchatov Institute

A universal software-hardware architecture of the automatic control system (ACS) of the X-ray experiment for synchrotron stations is designed. The designed ACS ensures the reliable long-time control of the station equipment from remote terminals located in safety zones. A hierarchical three-level architecture of the control system based on personal industrial computers and specialized microcontrollers is selected to realize the hardware part. Data channels are based on Ethernet, RS-485, and RS-232 interfaces. The ACS software embodies the functional-modular principle and contains monitor modules with parametric adjustment, group control modules of functional station blocks, and modules for individual control of mechanisms. Data exchange between the modules is supported by TCP/IP, DCON, and other standard communication protocols. When the control system was being designed, the possibility of expanding the system by embedding bought articles from leading manufacturers was without fail taken into account. The designed system allows its integration with automated experiment control systems. The work presents details of the designed ACS realization on the LANGMUIR multipurpose research technological system of the synchrotron radiation source of the Russian Research Centre (RRC) Kurchatov Institute, the Russian synchrotron station intended for studying interfaces of various nature by using a wide spectrum of precision surface-sensitive and spectrum-selective X-ray technologies, in particular, for studying organic and bioorganic nanosystems on liquid surfaces and various planar nanostructures on solid substrates. The specific character of the LANGMUIR station invited development of a unique software-hardware module for controlling optical elements deflecting the beam from the horizontal line (beam control module), and creation of a special software unit for integrating the fluorescence signal recording section into the ACS and synchronization of the X-ray and fluorescence sections.

Information communication platform for the NBIC center at the Russian Research Center Kurchatov Institute

The problems of developing a unified information communication platform for the Nano-, Bio-, Info-, and Cognitive (NBIC) Technology Center at the Russian Research Center (RRC) Kurchatov Institute are considered. The distributed resources of the NBIC center are used based on grid technologies, which allow one to construct a distributed infrastructure on the basis of existing data transfer networks and computer equipment in accordance with the user’s requirements. This infrastructure makes it possible to uniformly offer combined computational resources for various scientific calculations and allows distant users to visually operate with very large amounts of data, high-resolution video streams, experimental equipment, and archival data sets.

Shaft cryostat for cooling of high-pressure chambers with diamond and sapphire anvils

A vertically loaded shaft cryostat based on a closed-cycle cryocooler built around a Sumitomo SRP-062B pulse tube has been developed. The cryostat is intended for investigating the structure and phase transformations of materials via neutron diffraction experiments on samples at pressures up to 10 GPa created in high-pressure chambers with sapphire and diamond an vils in the temperature range of 6—300 K. The cryostat has been tested with the help of the DISK diffractometer of the Russian Research Centre Kurchatov Institute. A high-pressure chamber is loaded into the cryostat through its shaft with the help of an insert. The chamber is cooled by heat-exchange gas (helium-4) an d a heat exchanger that is thermally connected with the cryocooler’s second stage. The minimum attained temperature of a sample is 6 K. The drift diameter of the shaft is 120 mm, making it possible to cool chambers with lengths up to 200 mm (in the vertical orientation) and 110 mm (in the horizontal orientation). The cryostat has been designed and manufactured at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research.

Structural studies of the lipid membranes at the Siberia-2 synchrotron radiation source

Lipid membranes are a subject of contemporary interdisciplinary studies at the junction of biology, biophysics, pharmacology, and bionanotechnology. The results of the structural studies of several types of lipid membranes by the lamellar and lateral diffraction of X-ray synchrotron radiation are presented. The experiments were performed at the Mediana and DICSI stations of the Siberia-2 synchrotron radiation source at the Russian Research Center Kurchatov Institute. The data obtained are compared with the results of studying lipid membranes at the small-angle scattering beamlines D22 and D24 at LURE (France) and at the A2 beamline at DESY (Germany). The parameters of the DICSI station are shown to meet the basic requirements for the structural study of lipid systems, which are of fundamental and applied interest.

Preface: Contrib. Plasma Phys. 3–5/2010

AbstractThe crucial importance of edge properties of fusion plasmas has been increasingly appreciated over the last decades. The development of plasma edge theory, i.e. of quantitative understanding, is monitored, critically discussed, and stimulated through the bi‐annual series of international workshops on Plasma Edge Theory in Fusion Devices (PET). The 12th PET (PET‐12) was held at the State Museum and Reserve Rostov Kremlin in Rostov Veliky, Yaroslavsky region, Russia, from 2nd to 4th of September 2009. It was carefully organized by the Russian Research Centre Kurchatov Institute. The event was generously co‐sponsored by this Research Centre. Additional financial support came from RFBR, Russia.The Director‐General of the State Museum and Reserve Rostov Kremlin, Prof. A.E. Leontiev, kindly agreed to open the conference with a welcoming address. The participants greatly appreciated the keen backing of PET‐12 by Prof. V.P. Smirnov of the Russian Research Centre. Much of the success of this meeting was based on the enormous load of diligent work carried by the Secretary of the Local Organizing Committee (LOC), Prof. Dmitry Morozov. The great supporting efforts of Dr. L.K. Kuznezova, Dr. M.L. Subbotin and Mr. L.N. Kimchenko of the LOC are particularly appreciated.In six invited summary lectures this time the subjects of ITER divertor design, tokamak edge nonlinear dynamics, pedestal physics, self‐similarity of edge plasma turbulence, theoretical aspects of dust in fusion devices, and non‐diffusive transport in detached plasma conditions have been reviewed. In the distribution according to topic, the number of papers on kinetic and fluid edge plasma simulation, followed by those on neutrals and impurities, and those on SOL turbulence were in the lead. Altogether 57 contributions were brought forward, including 9 as oral presentations, most as posters in three sessions. In addition to being discussed during the workshop, all papers have been screened by peer review. The results have been composed to these Proceedings. Given the importance of the subject for fusion and the ongoing strong international research efforts in this field, it has been decided to organize a next workshop, PET‐13, in USA, during the year 2011.January 2010

A model of radionuclide transfer by groundwater on the territory of the Russian Research Centre Kurchatov Institute

The convective transfer of 137Cs and 90Sr by groundwater on the territory of the Russian Research Centre Kurchatov Institute (RRCKI) was modeled. Geological data on the RRCKI site and possible sources of radionuclides show that the uppermost aquifer, composed of Quaternary sediments, is the most probable region of spreading of radioactive contamination. Since the lateral migration of radionuclides is predominant, a 2D horizontal model was used for the forecasting of spreading of radioactive contaminants in the subsurface medium. Transient or long-term repositories of radioactive materials at the RRCKI site (concentrated sources) and aquifer rocks contaminated in the course of removal of radionuclides from these repositories (distributed source) are responsible for groundwater pollution. The initial 137Cs and 90Sr distributions used in the forecasting of radionuclide migration were determined from their contents in core samples taken from wells drilled in contaminated areas of the RRCKI site. The zone of radionuclide migration is limited by poorly permeable moraine loam from below and by the water table from above. To determine the upper and lower boundaries, these surfaces were mapped in plan view. The data of meteorological observations over a long period were used to map the intensity of precipitation in the studied territory. The density of rocks in the uppermost aquifer and partition coefficients of radionuclides between rocks and groundwater were estimated from the data of laboratory examination of the core samples. The available data on the permeability of rock samples and the results of test pumping out of some wells were involved in the consideration. The results obtained and the data on the water table allowed us to define a gauge problem for determining the distribution of the filtration coefficient in the uppermost aquifer. This problem was solved taking the intensity of precipitation into account. The properties of the uppermost aquifer and the initial radionuclide distribution therein were used as initial data for modeling 137Cs and 90Sr migration on the territory of the RRCKI over 50 years.

Remediation of the high-level radwaste repositories at Russian Research Center “Kurchatov Institute”

The paper presents peculiarities of organization and performance of activities on disposition of the high level activity radwaste repository located at the radwaste disposal site of the Russian Research Center Kurchatov Institute in Moscow. The process of the radwaste extraction from the repository is described in comparison with similar activities in other old repositories. Tools and equipment used for the radwaste extraction from the repository are listed. Conventional construction machines equipped with a hydraulic hammer or a clamshell were used for destruction of the concrete-encased radwaste mass and extraction of low-level radwaste. Intermediate- and high-level radwaste was extracted by remotely controlled robots operating inside the shielding structure. Gamma visor was used for detection of high- level radwaste or fragments in the mass concrete being destroyed and for pointing remotely controlled robots accordingly. The paper describes peculiarities of radiation monitoring in the course of operations on disposition of the repository. For rapid detection of changes in radiation conditions in the working areas, there was used a gamma locator with on-line transmission of its data to a PC and their processing. The same measuring and extraction equipment were used for remediation of high-level radwaste repository at the Gas Plant complexes.

Formation and spread of Chernobyl lavas

The results of implementation of the ISTC Project “Development of a Model of the Behavior of Nuclear Fuel in the Active Stage of the Chernobyl Accident” are summarized. The project work was jointly undertaken by the Russian Research Centre Kurchatov Institute (RNTs KI) and Nuclear Safety Institute, Russian Academy of Sciences (IBRAE RAN). The aim of the project was to systematize a huge amount of data on lava-like fuel-containing materials (LFCM), collected over the 20 years of research work at the Shelter, into database and to develop a model of LFCM formation and spread during early post-accident days. The model will be helpful in producing recommendations on accident prevention and promote development of the best technologies for lava removal, thereby reducing the financial expenses and dose burden. Also, with the model developed, the results of the virtually unique “experiment” with the nuclear fuel of the Unit 4 reactor, organized on a huge scale, can be used for finding solutions to the general nuclear safety problems.

Study of the dynamics of a plasma current sheath in the KPF-4 Phoenix plasma-focus facility

The engineering characteristics of the KPF-4 Phoenix megajoule Mather-type plasma focus facility constructed at the Sukhumi Physicotechnical Institute are described. Results from preliminary studies of the plasma dynamics at a capacitive-storage energy of up to 700 kJ are discussed. Future experiments in KPF-4 will be oriented at technological applications and will complement the studies carried out in the 2.8-MJ Filippovtype PF-3 plasma focus facility at the Nuclear Fusion Institute of the Russian Research Centre Kurchatov Institute.

ICONE15-10194 ASSESSMENT OF THE CHF MODELS IN TRACE CODE AGAINST ROD BUNDLE EXPERIMENTAL DATA

This paper presents the assessment of the critical heat flux (CHF) models of TRACE (version 5.00RC2) with data from four sets of experiments carried out on rod bundles in the KS-1 facility at the Russian Research Center-Kurchatov Institute in Moscow, Russia, in the V-200 facility at the Institute of Physics and Power Engineering in Obninsk, Russia, and in the SKODA large Water Loop in Plzen, Czech Republic. All the experiments used for this paper were carried out for VVER-type reactor rod bundles. The test sections had different number of heated rods: 7, 19 and 37, different heated lengths of 0.8 m, 2.5 m and 3.48 m. The experimental pressures ranged from 8 to 18.5 MPa, coolant mass fluxes in the test sections were between 200 and 5000 kg/m^2s and the test section inlet subcooling varied from 1 to 200℃. Experiments with uniform axial power distributions were simulated in this work. The large size of the experimental database has enabled us to perform the assessment of the TRACE CHF models in rod bundles for a wide range of thermal-hydraulic conditions and various geometries.

Production of the Hg-199 isotope by the photochemical method

Researchers at the Russian Research Center Kurchatov Institute are developing a photochemical method of mercury isotope extraction. The method is based on oxidation of selectively excited mercury atoms in the presence of 1,3-butadiene. Along with the Hg-198, Hg-196, Hg-200, and Hg-202 isotopes, a Hg-199 isotope with a concentration as high as 90% has been produced for the first time.

Production of the Hg-196 isotope by a photochemical method

An experimental setup and photochemical approaches used for extracting highly enriched mercury isotopes at the Russian Research Center Kurchatov Institute are described. In the extraction process, selectively excited mercury atoms are oxidized in the presence of 1,3-butadiene. Along with the Hg-198, Hg-199, Hg-200, and Hg-202 isotopes, the least abundant mercury isotope, Hg-196, has been produced for the first time with a concentration as high as 97%.

Review of experimental studies of the dynamics of light liners at the Russian Research Centre Kurchatov Institute

The results of experimental studies on the implosion of liners by megaampere currents that were carried out in the Department of Relativistic Beams of the Russian Research Centre Kurchatov Institute are reviewed. The main line of research was to study the possibility of realizing the liner-converter (or liner-target) scheme proposed by L.I. Rudakov.