GENERAL RESEARCH LINES

• radio-ecological conditions research within the regions of location of atomic industry enterprises and other facilities, which bring negative effect to ecological conditions,
• radionuclide analysis in various structure objects, using low-background gamma-ray spectrometry and alpha-ray spectrometry methods,
• research in plutonium-239, 240, cesium-137, and other radionuclide status forms in soils, bottom sediments, and surface layer of atmospheric air,
• elaboration of gamma-ray spectrometric and radiochemical techniques called to determine man-caused and natural radionuclide content in various mediums,
• "turn-key" rendering of certified radiochemical methods for environmental measuring of plutonium-239, 240, uranium-234, uranium-235, uranium-238, and americium-241,
• radionuclide measuring techniques adaptation to specific objects of examination, followed with metrological certification and rendering of techniques to a customer.

Radiochemical methods serving as the State measurement instrumentation in compliance with metrological certification licenses issued by RPA "D.I. Mendeleev VNIIM" are elaborated for measuring of plutonium-239,240, uranium-234, uranium-235, uranium-238, and americium-241 content in environmental objects. The techniques developed allow to uranium, plutonium, and americium isotope content monitoring in soils, bottom sediments, atmospheric air, vegetation, and other objects, starting with global background level.

Alpha spectrum of uranium separated from IAEA-300 certified reference material (sediment)

In 1992-1993 the laboratory rendered radiochemical technique of plutonium-239,240 content measuring in environmental objects to the Environmental Division of Siberian Chemical Combine under Minatom of Russia. Application of this technique after the accident at the Combine (April 1993) had provided for realization of examination of soil samples taken in emission "trial" and indicated an absence of plutonium background level excess in those samples, that substantially facilitated a real assessment of radiation conditions in the region of release.

On evidence of the study of forms of plutonium-239,240 status in soils, bottom sediments, and surface layer of atmospheric air it was experimentally proved for the first time that the distribution of plutonium-239,240 status forms in soils of buffer area and control area of Siberian Chemical Combine (SCC) had distinction in kind. It was concluded that no sizeable contribution had been brought by SCC to plutonium contamination of soil in control area for the period of 40-yesrs long Combine operating in comparison with global precipitations.

Since 1992 the specialists of laboratory carry out researches in plutonium-239,240 radiation conditions at the places of "Craton-3" and "Crystall" underground nuclear explosions in Yakutia. The contouring of the most contaminated areas of locality is implemented at these objects, as well as the data on contaminations of soils, lichen, and bottom sediments are compared with those published in scientific-and-technical literature.

In 1996 according to the order placed by ecological organizations from Karaganda Region of Kazakhstan Republic the Laboratory implemented the work on research in plutonium isotopic composition and content in soils and vegetations in the region of Semipalatinsk testing ground. A part of samples was studied to determine a content of "hot" particles by the method of track autoradiography and sedimentation analysis, followed with radiochemical measuring of plutonium-239,240 in soil fractions. In single samples of soil they measured the content of americium-241 with the help of certified radiochemical technique, and it was demonstrated that ²⁴¹Am/^239,240Pu ratio could be used to identify sources of plutonium emission to the environment.

In 2001 - 2002 within the frameworks of "Barents-region Ecogeochemistry" International Project under the contracts with Geological Service of Finland the Laboratory for Ecological Researches measured the content of man-caused and natural gamma-emitting radionuclides (cesium-137, cesium-134, radium-226, radium-228, etc.), as well as plutonium-239,240 and plutonium-238 in forest soils sampled within the territory of Finland and North European part of Russia.

The technique of producing of plutonium-237 preparation, which is not inferior to the best foreign patterns in isotopic and radiochemical purity, is developed at the Laboratory. The use of plutonium-237 as gamma-emitting radioactive detector suggests sizeable decrease in labor expenditures, and increases rapidness of studies of plutonium behavior in physicochemical and biological processes, and also when elaborating analytical techniques. The use of plutonium-237 to study plutonium migration, accumulation and emission within ecological systems and biological objects is especially prospective.