Error reduction in gamma-spectrometric measurements of nuclear materials enrichment

The paper provides the analysis of the uncertainty in determining the uranium samples enrichment using non-destructive methods to ensure the functioning of the nuclear materials accounting and control system. The measurements were performed by a scintillation detector based on a sodium iodide crystal and the semiconductor germanium detector. Samples containing uranium oxide of different masses were used for the measurements. Statistical analysis of the results showed that the maximum enrichment error in a scintillation detector measurement can reach 82%. The bias correction, calculated from the data obtained by the semiconductor detector, reduces the error in the determination of uranium enrichment by 47.2% in average. Thus, the use of bias correction, calculated by the statistical methods, allows the use of scintillation detectors to account and control nuclear materials

Results of studies of natural conditions and engineering-geological structure of the valley of the river Bolshaya Aleksandrovka (Sakhalin island)

The relevance of the discussed issue is caused by the need of precise ideas about the structure of the upper part of geological section, based on understanding of sediments genesis for use as engineering geological support of construction in the study area. The main aim of the study is to identify engineering-geological conditions in the valley of river Bolshaya Aleksandrovka according to the results of engineering surveys and determination of features of formation of the Neogene-Quaternary deposits of the territory. The methods used in the study: methods of engineering-geological researches: surface observation, drilling; complex laboratory methods for determining physic-mechanical properties of rocks: determination of granulometric composition of cohesive and non-cohesive sedimentary rocks, density and bulk density calculation of porosity, moisture content and the maximum molecular moisture capacity, plasticity, stickiness, swelling and other; methods for determining petrophysical properties of igneous rocks: density, bulk density, water saturation, water absorption, humidity, capillary rise, porosity, strength and elastic properties; geophysical methods of vertical electrical sounding and seismic exploration by the method of refracted waves; direct methods of correlation of ground sections, based on the study of cores and the mapping of columns in different wells; stratigraphic method. The results: As a result of geological engineering survey the authors have compiled geological section of seven kilometers to the bottom of the valley of the river Bolshaya Aleksandrovka, located in the central part of Sakhalin island. The conditions of formation of the upper part of the section were identified and engineering-geological elements and their spatial position were selected. The authors zoned the valley territory by the totality of sediments characteristics and variability of the individual parameters in different parts of the section. It was ascertained that since the Upper Pliocene time the bottom of the valley of river Bol. Aleksandrovka was subjected to sustainable lift. The authors determined the break in the alluvium between stations 31-47, which is caused by the washing of a new straightened river channel at the runoff from higher terraces, with edge level on the height of 12 m, to a lower one, with the surface level of 4-6 m above sea level. The formation of the lowest marine terraces of abrasion-accumulative genesis is associated with post-glacial transgression, occurred near 7-9 ka BP, when the sea went inward into the valley of Bol. Aleksandrovka on 5-7 km. Formation of terraces with surface level of 12-15 m can be explained by the ocean level rise at significant glacioeustatic transgressions in Late Pleistocene

Results of studies of natural conditions and engineering-geological structure of the valley of the river Bolshaya Aleksandrovka (Sakhalin island)

The relevance of the discussed issue is caused by the need of precise ideas about the structure of the upper part of geological section, based on understanding of sediments genesis for use as engineering geological support of construction in the study area. The main aim of the study is to identify engineering-geological conditions in the valley of river Bolshaya Aleksandrovka according to the results of engineering surveys and determination of features of formation of the Neogene-Quaternary deposits of the territory. The methods used in the study: methods of engineering-geological researches: surface observation, drilling; complex laboratory methods for determining physic-mechanical properties of rocks: determination of granulometric composition of cohesive and non-cohesive sedimentary rocks, density and bulk density calculation of porosity, moisture content and the maximum molecular moisture capacity, plasticity, stickiness, swelling and other; methods for determining petrophysical properties of igneous rocks: density, bulk density, water saturation, water absorption, humidity, capillary rise, porosity, strength and elastic properties; geophysical methods of vertical electrical sounding and seismic exploration by the method of refracted waves; direct methods of correlation of ground sections, based on the study of cores and the mapping of columns in different wells; stratigraphic method. The results: As a result of geological engineering survey the authors have compiled geological section of seven kilometers to the bottom of the valley of the river Bolshaya Aleksandrovka, located in the central part of Sakhalin island. The conditions of formation of the upper part of the section were identified and engineering-geological elements and their spatial position were selected. The authors zoned the valley territory by the totality of sediments characteristics and variability of the individual parameters in different parts of the section. It was ascertained that since the Upper Pliocene time the bottom of the valley of river Bol. Aleksandrovka was subjected to sustainable lift. The authors determined the break in the alluvium between stations 31-47, which is caused by the washing of a new straightened river channel at the runoff from higher terraces, with edge level on the height of 12 m, to a lower one, with the surface level of 4-6 m above sea level. The formation of the lowest marine terraces of abrasion-accumulative genesis is associated with post-glacial transgression, occurred near 7-9 ka BP, when the sea went inward into the valley of Bol. Aleksandrovka on 5-7 km. Formation of terraces with surface level of 12-15 m can be explained by the ocean level rise at significant glacioeustatic transgressions in Late Pleistocene

Results of studies of natural conditions and engineering-geological structure of the valley of the river Bolshaya Aleksandrovka (Sakhalin island)

Актуальность работы обусловлена необходимостью точного представления о строении верхней части геологического разреза, основанного на понимании генезиса отложений для использования в качестве инженерно-геологического обеспечения строительства на исследуемой территории. Цель работы: выявление инженерно-геологических условий в долине р. Бол. Александровка по результатам инженерных изысканий и космического мониторинга природных процессов, а также определение особенностей формирования неоген-четвертичных отложений территории. Методы исследования: методы инженерно-геологических исследований - наземные наблюдения, буровые работы; комплекс лабораторных методов определения физико-механических свойств пород: определение гранулометрического состава связных и несвязных осадочных пород, плотности и объемной массы, расчет пористости, влажности и максимальной молекулярной влагоемкости, пластичности, липкости, набухания, других; методы определения петрофизических свойств магматических пород: определение плотности, объемной массы, водонасыщенности, водопоглащения, влажности, капиллярного поднятия, пористости, прочностных и упругих свойств; геофизические методы: вертикальное электрическое зондирование и сейсморазведка по методу преломленных волн; прямые методы корреляции грунтовых разрезов, основанные на изучении кернов и сопоставлении колонок в разных скважинах; стратиграфический метод; космический мониторинг природных процессов. Результаты. В результате инженерно-геологических изысканий был составлен геологический разрез протяженностью семь километров для нижней части долины реки Большая Александровка, расположенной в центральной части о. Сахалин. Выявлены условия формирования верхней части разреза, выделены инженерно-геологические элементы и выявлено их пространственное положение. Выполнено районирование территории долины по совокупности характеристик отложений и изменчивости отдельных параметров в различных частях разреза. Определено, что начиная с верхнеплиоценового времени днище долины реки. Бол. Александровка было подвержено процессу устойчивого поднятия. Выявлен перерыв в аллювиальных отложениях между пикетами 31-47, который обусловлен промыванием рекой нового спрямленного русла при стоке с более высокой террасы, с уровнем бровки на высоте 12 м, на более низкую, с уровнем поверхности 4-6 м над уровнем моря. Образование низкой морской террасы абразионно-аккумулятивного генезиса связано с послеледниковой трансгрессией, произошедшей около 7-9 тыс. л. н., когда море уходило вглубь долины р. Бол. Александровка на 5-7 км. Формирование террасы с уровнем поверхности 12-15 м можно объяснить поднятием уровня океана при значительной гляциоэвстатической трансгрессии позднеплейстоценового возраста.The relevance of the discussed issue is caused by the need of precise ideas about the structure of the upper part of geological section, based on understanding of sediments genesis for use as engineering geological support of construction in the study area. The main aim of the study is to identify engineering-geological conditions in the valley of river Bolshaya Aleksandrovka according to the results of engineering surveys and determination of features of formation of the Neogene-Quaternary deposits of the territory. The methods used in the study: methods of engineering-geological researches: surface observation, drilling; complex laboratory methods for determining physic-mechanical properties of rocks: determination of granulometric composition of cohesive and non-cohesive sedimentary rocks, density and bulk density calculation of porosity, moisture content and the maximum molecular moisture capacity, plasticity, stickiness, swelling and other; methods for determining petrophysical properties of igneous rocks: density, bulk density, water saturation, water absorption, humidity, capillary rise, porosity, strength and elastic properties; geophysical methods of vertical electrical sounding and seismic exploration by the method of refracted waves; direct methods of correlation of ground sections, based on the study of cores and the mapping of columns in different wells; stratigraphic method. The results: As a result of geological engineering survey the authors have compiled geological section of seven kilometers to the bottom of the valley of the river Bolshaya Aleksandrovka, located in the central part of Sakhalin island. The conditions of formation of the upper part of the section were identified and engineering-geological elements and their spatial position were selected. The authors zoned the valley territory by the totality of sediments characteristics and variability of the individual parameters in different parts of the section. It was ascertained that since the Upper Pliocene time the bottom of the valley of river Bol. Aleksandrovka was subjected to sustainable lift. The authors determined the break in the alluvium between stations 31-47, which is caused by the washing of a new straightened river channel at the runoff from higher terraces, with edge level on the height of 12 m, to a lower one, with the surface level of 4-6 m above sea level. The formation of the lowest marine terraces of abrasion-accumulative genesis is associated with post-glacial transgression, occurred near 7-9 ka BP, when the sea went inward into the valley of Bol. Aleksandrovka on 5-7 km. Formation of terraces with surface level of 12-15 m can be explained by the ocean level rise at significant glacioeustatic transgressions in Late Pleistocene