Measuring the yields and angular distributions of g-quanta from the interaction between 14.1 MeV neutrons and sodium nuclei

A study of the reaction of inelastic scattering of 14.1 MeV neutrons by 23 Na nuclei was carried out at the TANGRA facility using the tagged neutron method. In this work, the energies of visible g-transitions are determined, the yields of g -quanta are obtained, the angular distributions of g -quanta for 23 Na are measured. The results obtained are in good agreement with the data of other published experimental works.

Application of Tagged Neutron Method for Detecting Diamonds in Kimberlite

The results of testing a prototype of a separator for detecting diamonds in kimberlite ore using tagged neutron method are discussed. Kimberlite ore was irradiated with fast tagged neutrons with an energy of 14.1 MeV. The elemental content of the tray with kimberlite ore was determined. The criterion for detecting diamond was the presence of excess carbon concentration in a certain region of a kimberlite sample.

Active Neutron Monitoring of Nuclear Fuel Cycle Fissile Materials

A decommissioning of nuclear fuel cycle facilities is inseparable from the problems of radioactive waste disposal. One of these problems is the categorization of a waste according to the content of beta- and alpha-emitters. Beta-emitters can be identified by existing technologies; however, the trouble arises when detecting alpha-emitting elements, primarily the long-lived members of the actinium chain with the specific activity of kBq/kg when they are spread inside a structural material. The report considers an application of an active neutron method-a differential die-away technology for reliable control of small quantities of FM. The essence of this method consists in sounding the interrogated item by pulsed thermal neutrons and recording the induced fission neutrons. The ratio of the number of fission neutrons to the number of source neutrons gives the normalized number of fission neutrons that is linked to the FM mass in the interrogated object. The work presents the scheme and principle of operation of an experimental device, as well as the results of measurement of concrete structures that contain internal traces of fissile materials. Analysis of the results shows that the proposed method allows the detection of ~ 6 mg of fissile material per kg of concrete with possible localization (cartogram) of the contaminated area.

Production method of environmental tracer 132Cs by accelerator-based neutron

Cesium-132 has proposed as an alternative tracer of 137Cs for environment study on radioactive cesium dynamics released by a nuclear power plant accident. In the present study, we conducted a production experiment of the 132Cs by means of accelerator-based neutron method to investigate production amount and radioactive purity. A 12-g Cs2CO3 sample was irradiated by the accelerator-based neutron via the C(d,n) reactions by 1.2 µA of 30-MeV deuterons. As a result, 102 kBq/g of 132Cs was obtained with higher than 98.5% radioactive purity. Following that, a feasibility study of cesium dynamics measurement in andosol soil was performed. We found distribution of absorption of cesium in andosol soil can be clearly measurable by the produced 132Cs tracer.

Study of the geochemical processes of radionuclides of oil and gas fields

The objects of study of the geochemical processes of radionuclides are deposits of the West Siberian Plate, the distribution of radioactive elements in the areas of the Tyumen oil and gas region. In the process of work, the chemical composition of sedimentary rocks was investigated, and the mass fractions of uranium, radium, thorium, potassium, and other chemical elements were determined. Data on the distribution of radionuclides in individual wells and areas were considered, correlation diagrams of geochemical specificity were constructed. To determine the mass fractions of uranium, radium, thorium, potassium, and other chemical elements, gamma spectrometric, neutron activation, X-ray spectral, and laser-luminescent measurements were used. In order to control the measurement results, the determination of uranium in the samples was duplicated using the delayed neutron method in a specialized facility. The accuracy of uranium determination, estimated from independent measurements, was ~ 6.4% (rel.). The radioactive equilibrium is shifted towards uranium, which indicates an increase in the mass fractions of naturally radioactive elements in the raw of sandstones -sandstone-siltstone open pits - siltstones. The increase of the level of natural radioactivity in the direction from sandstones to siltstones is explained by the difference in brittleness between quartz and grains of active accessories, which indicates a stable ratio between radium and uranium in the sandstones-siltstones in relation to the considered areas of the Tyumen region.