Features of adsorbed chemical elements and their isotopes distribution in iodine air filters FU-1500 of nuclear power plant

The main aim of research is to investigate the physical features of spatial distribution of the adsorbed chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU-1500 in the forced-exhaust ventilation at the nuclear power plant. The γ-activati...

Full description

Saved in:
Bibliographic Details
Published in:Вопросы атомной науки и техники
Date:2013
Main Authors: Neklyudov, I.M., Dovbnya, A.N., Dikiy, N.P., Ledenyov, O.P., Lyashko, Yu.V.
Format: Article
Language:English
Published: Національний науковий центр «Харківський фізико-технічний інститут» НАН України 2013
Subjects:
Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/111848
Tags: Add Tag
No Tags, Be the first to tag this record!
Journal Title:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Cite this:Features of adsorbed chemical elements and their isotopes distribution in iodine air filters FU-1500 of nuclear power plant / I.M. Neklyudov, A.N. Dovbnya, N.P. Dikiy, O.P. Ledenyov, Yu.V. Lyashko // Вопросы атомной науки и техники. — 2013. — № 3. — С. 192-200. — Бібліогр.: 16 назв. — англ.

Institution

Digital Library of Periodicals of National Academy of Sciences of Ukraine
id nasplib_isofts_kiev_ua-123456789-111848
record_format dspace
spelling Neklyudov, I.M.
Dovbnya, A.N.
Dikiy, N.P.
Ledenyov, O.P.
Lyashko, Yu.V.
2017-01-15T11:28:45Z
2017-01-15T11:28:45Z
2013
Features of adsorbed chemical elements and their isotopes distribution in iodine air filters FU-1500 of nuclear power plant / I.M. Neklyudov, A.N. Dovbnya, N.P. Dikiy, O.P. Ledenyov, Yu.V. Lyashko // Вопросы атомной науки и техники. — 2013. — № 3. — С. 192-200. — Бібліогр.: 16 назв. — англ.
1562-6016
PACS: 28.41.Te; 43.20.Ks; 43.25.Uv; 43.28.+h; 45.70.-n; 45.70.Mg; 87.16.dp; 83.80.Fg
https://nasplib.isofts.kiev.ua/handle/123456789/111848
The main aim of research is to investigate the physical features of spatial distribution of the adsorbed chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU-1500 in the forced-exhaust ventilation at the nuclear power plant. The γ-activation analysis method is applied to accurately characterize the distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the AU-1500 iodine air filter after its long term operation at the nuclear power plant. The typical spectrum of the detected chemical elements and their isotopes in the AU-1500 iodine air filter, which was exposed by the irradiation of bremsstrahlung γ-quantum producing by the accelerating electrons in the tantalum target, are obtained. The spatial distributions of the detected chemical element ¹²⁷I and some other chemical elements and their isotopes in the layer of absorber, which was made of the cylindrical coal granules of the type of SKT-3, in the AU-1500 iodine air filter are also researched. The possible influences by the standing wave of air pressure in the iodine air filter on the spatial distribution of the chemical elements and their isotopes in the iodine air filter are discussed. The comprehensive analysis of obtained research results on the distribution of the adsorbed chemical elements and their isotopes in the absorber of iodine air filter is performed.
Головною метою було дослiдження особливостей розподiлення поглинених хiмiчних елементiв та їхнiх iзотопiв у гранульованому середовищi у йодному повiтряному фiльтрi типу AУ-1500 у притоковитягових системах на атомнiй електростанцiї. Метод γ-активацiйного аналiзу застосовано щоб охарактеризувати розподiлення поглинених хiмiчних елементiв та їхнiх iзотопiв у гранульованому фiльтовальному середовищi йодних повiтряних фiльтрiв типу AУ-1500 пiсля їх довгоготермiну роботи на атомнiй електростанцiї. Отриманi типовi спектри виявлених хiмiчних елементiв та їхнiх iзотопiв у повiтряному фiльтрi AУ-1500, зразки з якого опромiнювалися гальмовими γ-квантами, якi виникали при проходженнi прискорених електронiв через танталову мiшень. Просторове розподiлення йоду та деяких iнших хiмiчних елементiв та їхнiх iзотопiв у абсорберi, котрий був заповнений цилiндричними гранулами вугiлля типу СKT-3, у повiтряному фiльтрi AU-1500 було дослiджено. Можливий вплив стоячих коливань повiтряного тиску в йодному повiтряному фiльтру на просторове розпредiлення радiоактивних хiмiчних елементiв та їхнiх iзотопiв у йодному повiтряному фiльтрi було обговорено авторами. Зроблено всебiчний аналiз отриманих результатiв дослiдження просторового розподiлення хiмiчних елементiв та їхнiх iзотопiв у повiтряному фiльтрi.
Главной целью работы было исследование особенностей, распределения адсорбированных химических элементов и их изотопов в гранулированной фильтрующей среде в йодных воздушных фильтрах типа АУ-1500 в системах приточно-вытяжной вентиляции на атомной электростанции. Использован метод γ-активационного анализа для точного изучения распределения адсорбированных химических элементов и их изотопов в гранулированной адсорбирующей среде в йодных воздушных фильтрах АУ-1500 после их долгосрочной работы на атомной электростанции. Получены типичные спектры обнаруженных химических элементов и их изотопов в йодном воздушном фильтре АУ-1500, образцы из которого облучались тормозными γ-квантами, возникавшими при прохождении ускоренных электронов через танталовую мишень. Найдено пространственное распределение йода и ряда других химических элементов и их изотопов в слое адсорбента, который состоял из цилиндрических угольных гранул СKT-3. Детально обсужден возможный механизм влияния стоячих колебаний давления воздуха в йодном воздушном фильтре на пространственное распределение поглощенных химических элементов и их изотопов. Выполнен всесторонний анализ полученных результатов исследования пространственного распределения адсорбированных радиоактивных химических элементов и их изотопов в адсорбенте йодного воздушного фильтра.
en
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
Вопросы атомной науки и техники
Ядернo-физические методы и обработка данных
Features of adsorbed chemical elements and their isotopes distribution in iodine air filters FU-1500 of nuclear power plant
Особливостi розподiлення радiоактивних хiмiчних елементiв та їх iзотопiв у йодних повiтряних фiльтрах АУ-1500 атомної електростанцiї
Особенности распределения радиоактивных химических элементов и их изотопов в йодных воздушных фильтрах АУ-1500 атомной электростанции
Article
published earlier
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
title Features of adsorbed chemical elements and their isotopes distribution in iodine air filters FU-1500 of nuclear power plant
spellingShingle Features of adsorbed chemical elements and their isotopes distribution in iodine air filters FU-1500 of nuclear power plant
Neklyudov, I.M.
Dovbnya, A.N.
Dikiy, N.P.
Ledenyov, O.P.
Lyashko, Yu.V.
Ядернo-физические методы и обработка данных
title_short Features of adsorbed chemical elements and their isotopes distribution in iodine air filters FU-1500 of nuclear power plant
title_full Features of adsorbed chemical elements and their isotopes distribution in iodine air filters FU-1500 of nuclear power plant
title_fullStr Features of adsorbed chemical elements and their isotopes distribution in iodine air filters FU-1500 of nuclear power plant
title_full_unstemmed Features of adsorbed chemical elements and their isotopes distribution in iodine air filters FU-1500 of nuclear power plant
title_sort features of adsorbed chemical elements and their isotopes distribution in iodine air filters fu-1500 of nuclear power plant
author Neklyudov, I.M.
Dovbnya, A.N.
Dikiy, N.P.
Ledenyov, O.P.
Lyashko, Yu.V.
author_facet Neklyudov, I.M.
Dovbnya, A.N.
Dikiy, N.P.
Ledenyov, O.P.
Lyashko, Yu.V.
topic Ядернo-физические методы и обработка данных
topic_facet Ядернo-физические методы и обработка данных
publishDate 2013
language English
container_title Вопросы атомной науки и техники
publisher Національний науковий центр «Харківський фізико-технічний інститут» НАН України
format Article
title_alt Особливостi розподiлення радiоактивних хiмiчних елементiв та їх iзотопiв у йодних повiтряних фiльтрах АУ-1500 атомної електростанцiї
Особенности распределения радиоактивных химических элементов и их изотопов в йодных воздушных фильтрах АУ-1500 атомной электростанции
description The main aim of research is to investigate the physical features of spatial distribution of the adsorbed chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU-1500 in the forced-exhaust ventilation at the nuclear power plant. The γ-activation analysis method is applied to accurately characterize the distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the AU-1500 iodine air filter after its long term operation at the nuclear power plant. The typical spectrum of the detected chemical elements and their isotopes in the AU-1500 iodine air filter, which was exposed by the irradiation of bremsstrahlung γ-quantum producing by the accelerating electrons in the tantalum target, are obtained. The spatial distributions of the detected chemical element ¹²⁷I and some other chemical elements and their isotopes in the layer of absorber, which was made of the cylindrical coal granules of the type of SKT-3, in the AU-1500 iodine air filter are also researched. The possible influences by the standing wave of air pressure in the iodine air filter on the spatial distribution of the chemical elements and their isotopes in the iodine air filter are discussed. The comprehensive analysis of obtained research results on the distribution of the adsorbed chemical elements and their isotopes in the absorber of iodine air filter is performed. Головною метою було дослiдження особливостей розподiлення поглинених хiмiчних елементiв та їхнiх iзотопiв у гранульованому середовищi у йодному повiтряному фiльтрi типу AУ-1500 у притоковитягових системах на атомнiй електростанцiї. Метод γ-активацiйного аналiзу застосовано щоб охарактеризувати розподiлення поглинених хiмiчних елементiв та їхнiх iзотопiв у гранульованому фiльтовальному середовищi йодних повiтряних фiльтрiв типу AУ-1500 пiсля їх довгоготермiну роботи на атомнiй електростанцiї. Отриманi типовi спектри виявлених хiмiчних елементiв та їхнiх iзотопiв у повiтряному фiльтрi AУ-1500, зразки з якого опромiнювалися гальмовими γ-квантами, якi виникали при проходженнi прискорених електронiв через танталову мiшень. Просторове розподiлення йоду та деяких iнших хiмiчних елементiв та їхнiх iзотопiв у абсорберi, котрий був заповнений цилiндричними гранулами вугiлля типу СKT-3, у повiтряному фiльтрi AU-1500 було дослiджено. Можливий вплив стоячих коливань повiтряного тиску в йодному повiтряному фiльтру на просторове розпредiлення радiоактивних хiмiчних елементiв та їхнiх iзотопiв у йодному повiтряному фiльтрi було обговорено авторами. Зроблено всебiчний аналiз отриманих результатiв дослiдження просторового розподiлення хiмiчних елементiв та їхнiх iзотопiв у повiтряному фiльтрi. Главной целью работы было исследование особенностей, распределения адсорбированных химических элементов и их изотопов в гранулированной фильтрующей среде в йодных воздушных фильтрах типа АУ-1500 в системах приточно-вытяжной вентиляции на атомной электростанции. Использован метод γ-активационного анализа для точного изучения распределения адсорбированных химических элементов и их изотопов в гранулированной адсорбирующей среде в йодных воздушных фильтрах АУ-1500 после их долгосрочной работы на атомной электростанции. Получены типичные спектры обнаруженных химических элементов и их изотопов в йодном воздушном фильтре АУ-1500, образцы из которого облучались тормозными γ-квантами, возникавшими при прохождении ускоренных электронов через танталовую мишень. Найдено пространственное распределение йода и ряда других химических элементов и их изотопов в слое адсорбента, который состоял из цилиндрических угольных гранул СKT-3. Детально обсужден возможный механизм влияния стоячих колебаний давления воздуха в йодном воздушном фильтре на пространственное распределение поглощенных химических элементов и их изотопов. Выполнен всесторонний анализ полученных результатов исследования пространственного распределения адсорбированных радиоактивных химических элементов и их изотопов в адсорбенте йодного воздушного фильтра.
issn 1562-6016
url https://nasplib.isofts.kiev.ua/handle/123456789/111848
citation_txt Features of adsorbed chemical elements and their isotopes distribution in iodine air filters FU-1500 of nuclear power plant / I.M. Neklyudov, A.N. Dovbnya, N.P. Dikiy, O.P. Ledenyov, Yu.V. Lyashko // Вопросы атомной науки и техники. — 2013. — № 3. — С. 192-200. — Бібліогр.: 16 назв. — англ.
work_keys_str_mv AT neklyudovim featuresofadsorbedchemicalelementsandtheirisotopesdistributioniniodineairfiltersfu1500ofnuclearpowerplant
AT dovbnyaan featuresofadsorbedchemicalelementsandtheirisotopesdistributioniniodineairfiltersfu1500ofnuclearpowerplant
AT dikiynp featuresofadsorbedchemicalelementsandtheirisotopesdistributioniniodineairfiltersfu1500ofnuclearpowerplant
AT ledenyovop featuresofadsorbedchemicalelementsandtheirisotopesdistributioniniodineairfiltersfu1500ofnuclearpowerplant
AT lyashkoyuv featuresofadsorbedchemicalelementsandtheirisotopesdistributioniniodineairfiltersfu1500ofnuclearpowerplant
AT neklyudovim osoblivostirozpodilennâradioaktivnihhimičnihelementivtaíhizotopivuiodnihpovitrânihfilʹtrahau1500atomnoíelektrostancií
AT dovbnyaan osoblivostirozpodilennâradioaktivnihhimičnihelementivtaíhizotopivuiodnihpovitrânihfilʹtrahau1500atomnoíelektrostancií
AT dikiynp osoblivostirozpodilennâradioaktivnihhimičnihelementivtaíhizotopivuiodnihpovitrânihfilʹtrahau1500atomnoíelektrostancií
AT ledenyovop osoblivostirozpodilennâradioaktivnihhimičnihelementivtaíhizotopivuiodnihpovitrânihfilʹtrahau1500atomnoíelektrostancií
AT lyashkoyuv osoblivostirozpodilennâradioaktivnihhimičnihelementivtaíhizotopivuiodnihpovitrânihfilʹtrahau1500atomnoíelektrostancií
AT neklyudovim osobennostiraspredeleniâradioaktivnyhhimičeskihélementoviihizotopovviodnyhvozdušnyhfilʹtrahau1500atomnoiélektrostancii
AT dovbnyaan osobennostiraspredeleniâradioaktivnyhhimičeskihélementoviihizotopovviodnyhvozdušnyhfilʹtrahau1500atomnoiélektrostancii
AT dikiynp osobennostiraspredeleniâradioaktivnyhhimičeskihélementoviihizotopovviodnyhvozdušnyhfilʹtrahau1500atomnoiélektrostancii
AT ledenyovop osobennostiraspredeleniâradioaktivnyhhimičeskihélementoviihizotopovviodnyhvozdušnyhfilʹtrahau1500atomnoiélektrostancii
AT lyashkoyuv osobennostiraspredeleniâradioaktivnyhhimičeskihélementoviihizotopovviodnyhvozdušnyhfilʹtrahau1500atomnoiélektrostancii
first_indexed 2025-11-25T04:22:06Z
last_indexed 2025-11-25T04:22:06Z
_version_ 1850506136928649216
fulltext NUCLEAR-PHYSICAL METHODS AND PROCESSING OF DATA FEATURES OF ADSORBED CHEMICAL ELEMENTS AND THEIR ISOTOPES DISTRIBUTION IN IODINE AIR FILTERS AU-1500 OF NUCLEAR POWER PLANT I.M.Neklyudov, A.N.Dovbnya, N.P.Dikiy, O.P.Ledenyov∗, Yu.V.Lyashko National Science Center ”Kharkov Institute of Physics and Technology”, 61108, Kharkov, Ukraine (Received April 11, 2013) The main aim of research is to investigate the physical features of spatial distribution of the adsorbed chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU-1500 in the forced-exhaust ventilation at the nuclear power plant. The γ-activation analysis method is applied to accurately characterize the distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the AU-1500 iodine air filter after its long term operation at the nuclear power plant. The typical spectrum of the detected chemical elements and their isotopes in the AU-1500 iodine air filter, which was exposed by the irradiation of bremsstrahlung γ-quantum producing by the accelerating electrons in the tantalum target, are obtained. The spatial distributions of the detected chemical element 127I and some other chemical elements and their isotopes in the layer of absorber, which was made of the cylindrical coal granules of the type of SKT-3, in the AU-1500 iodine air filter are also researched. The possible influences by the standing wave of air pressure in the iodine air filter on the spatial distribution of the chemical elements and their isotopes in the iodine air filter are discussed. The comprehensive analysis of obtained research results on the distribution of the adsorbed chemical elements and their isotopes in the absorber of iodine air filter is performed. PACS: 28.41.Te; 43.20.Ks; 43.25.Uv; 43.28.+h; 45.70.-n; 45.70.Mg; 87.16.dp; 83.80.Fg 1. INTRODUCTION The latest concept of the development of energy in the world make use of as many new sources of clean energy and the further development of already existing technologies currently, the most important of them for their contribution to the economy of leading countries is the nuclear power. The new strategy of nuclear energy industry development in Ukraine, in- cludes a wide range of research and development pro- grams toward the 4-th generation nuclear reactors de- signs, including the sodium cooled fast reactor, lead cooled fast reactor, gas cooled fast reactor, very high temperature reactor, molten salt reactor, supercrit- ical water-cooled reactor, which can be used in the various technological applications [1]. In this con- nection, the ecological aspects of the nuclear energy industry operation will require a significant attention, including the appearance of increasing necessity for the improved designs of the iodine air filters (IAF) in the air filtering applications at the nuclear power plants [1]. The air filtering with the application of the iodine air filter of the type of AU-1500 prevents a possible radioactive contamination of environment due to the introduction of the process of air filtering from the chemical elements and their isotopes, which are usually generated during the nuclear reactors op- eration at the nuclear power plants. In this research article, we report the research results on the physical features of distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium (GFM) in the iodine air filters (IAF) of the type of AU-1500 in the purge ventilation and systems at the nuclear power plant (NPP). The research on the interaction of the aerosol streams, which transfer the radioactive chemical ele- ments together with the small dispersive coal dust particles masses in the granular filtering medium, possessing the adsorption properties, represents a considerable interest for the branches of the physics, studying the properties of the granular substance [2], soft condensed matter [3, 4], transport and structur- ing of the small dispersive coal dust particles pre- cipitations [5], and features of the chemical elements adsorption processes [6]. In the case of such com- plex systems as the air filters at the nuclear power stations, there is a big number of physical phenom- ena, connected with the aerodynamic and diffusion movement of the radioactive chemical elements and their isotopes together with the small dispersive coal dust particles masses. These effects frequently in- clude both the self-interactions as well as the interac- tions with the adsorbing granular filtering medium. As it has been found in our previous research, the distribution of chemical elements, detected by the ∗Corresponding author E-mail address: ledenyov@kipt.kharkov.ua 192 ISSN 1562-6016. PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY, 2013, N3(85). Series: Nuclear Physics Investigations (60), p.192-200. gamma activation method [7]. The allocation of dust masses, measured by the gamma activation method [7] and the gravimetric method [8-13], are character- ized by the presence of the correlated maximums in the granular filtering medium in the adsorber in the IAF. It is difficult to explain this fact, going only from the diffusion representations about the physical mechanism of the chemical elements transportation and/or considering its similarity to the process, which occurs in the chromatographic columns, where the concentration maximums appearance in the distribu- tion of the transported chemical compounds with the various molecular masses is observed. Considering other physical mechanisms, which can influence both the distribution of the small dispersive coal dust par- ticles and the adsorption process of the radioactive chemical elements and their isotopes in the granu- lar filtering medium with the cylindrical coal gran- ules, we paid some attention to the fact that the air stream can generate the forced acoustic oscillations of the pressure P(r,t) and the air movement veloc- ity [14]. The layer of granular adsorbent, in which there may be such oscillatory processes, plays a role of the acoustic resonator, whereas the propagating acoustic wave, which is multiple to its thickness, cre- ates the standing wave oscillations. The pressure os- cillations in the air can have a certain influence on the transportation of the small dispersive coal dust particles masses, causing their accumulation in the regions, corresponding to the anti-nodes of the stand- ing acoustic waves [14]. On the other hand, the same oscillations of air density in the regions of the anti- nodes of the standing acoustic waves will lead to the increase or decrease of the external (in relation to the adsorbent granules) pressure of air, thereby mak- ing possible the forced ventilation of the internal air volumes between the cylindrical coal granules. This process should result in the excessive accumulation of the absorbed radioactive chemical elements and their isotopes in these regions. The oscillatory processes can make an influence on the diffusion flows inside the cylindrical coal granules, resulting in an increase of the content of the adsorbed radioactive chemi- cal compounds in the regions of the granular filter- ing medium in the IAF, where the acoustic oscilla- tions reach their maximum amplitudes. The same action by the acoustic oscillations must have place in the adsorption processes, which originate in the small dispersive coal dust particles masses, concen- trated in the described parts of an absorber in the IAF. Thus, the penetration of the radioactive chem- ical elements and their isotopes inside the small dis- persive coal dust particles becomes relatively easy, because of their small sizes in comparison with the dust particles [14]. These acoustic mechanisms could significantly influence the processes of accumulation of the adsorbed radioactive chemical elements and their isotopes, leading to their re-distribution inside the IAF’s absorber in the form of the concentration maximums, which correlate with the anti-nodes of the air pressure oscillations. In the previous research [7] with the gamma activation method application, it was found that there are the concentration max- imums in the distribution of the adsorbed chemical elements and their isotopes in the IAF. In the present research, the more detailed improved research data on the distribution of the adsorbed chemical elements and their isotopes in the IAF at the NPP during its long term operation are presented. The possi- ble physical mechanisms, resulting in a non-uniform distribution of the adsorbed chemical elements in the IAF at the NPP, are also discussed. The presented highly innovative researches are important, because they can improve our understanding on the nature of the physical-chemical processes in the granular filter- ing mediums at the air-dust aerosol streams action, and they help us to improve the advanced IAF’s de- sign for the air filtering applications at the NPP. 2. MATERIALS AND METHODS The gamma activation method was applied to re- search the distribution of the adsorbed chemical el- ements and their isotopes in the granular filtering medium of an absorber in the AU-1500 IAF after many years of the IAF’s operation at the Zaporozh- skaya nuclear power plant (NPP) in Ukraine. The researched IAF has the following technical character- istics: the diameter of the IAF is about 1 m; the thickness of layer with the cylindrical coal granules is equal to 0.3 m. The IAF’s absorber is made of the cylindrical coal granules of the type of SKT-3 with the granule’s diameter of 2 mm and the gran- ule’s length of 3.2 mm. During the experimental research, the absorbers were opened with the spe- cial automatic experimental setup, then the probes were taken in the three places (at the center place and at the two places on the periphery) in the re- searched IAF’s. The obtained probes were extracted at the various depths in the absorber and divided on the samples with the weights of 5, 6, 7 g with the purpose to perform the chemical composition analy- sis. It is necessary to point out that the macro- and micro- element composition analysis of the adsorbent of the type of SKT-3 together with its small disper- sive coal dust particles fraction was performed by the means of the gamma activation analysis at the elec- tron accelerator of scientific research complex ”Ac- celerator” at the NSC KIPT in Kharkov, Ukraine. The samples were exposed to the irradiation by the bremsstrahlung gamma quantum from the Tantalum converter with the thickness of 2 mm. The energy of electrons was 22 MeV. The current of electron beam was 700 µA. The time of exposition to the irradi- ation was 10 hours. The activity of the irradiated samples was measured by the Germanium-Lithium detector with the volume of 50 cm3 and the energy resolution of 2,8 keV at the line of 1333 keV. The ab- solute content of the adsorbed chemical elements and their isotopes were determined in relation to the stan- dards, which were exposed to the irradiation at the same time. The researches on the determination of fractional composition and the separation of the small 193 dispersive coal dust particles from the cylindrical coal granules were also conducted. It was found that the small dispersive coal dust particles mass share near the input surface of the absorber in the IAF reached 12%. In the process of measurements, it was estab- lished that the accumulated quantity of the small dis- persive coal dust particles at the distances far away from the absorber’s input surface decreased sharply. The small dispersive coal dust particles mass shares were different at the centre and on the periphery in the absorber in the IAF. It makes sense to note that the quantity of the small dispersive coal dust parti- cles was slightly smaller near to the absorber’s walls, comparing to the quantity of the small dispersive coal dust particles at the centre of the absorber in the IAF. Fig.1. Typical spectrum of detected radioactive chemical elements and their isotopes in iodine air filter, obtained at gamma activation analysis 3. RESULTS In the spectroscopy experiment, the induced activities of a number of the isotopes in the fol- lowing reactions: 55Mn(γ,n)55Mn, 127I(γ,n)126I, 35Cl(γ,γ)35mCl, 90Zr(γ,n)89Zr, 88Sr(γ,n)87mSr, 48Ca(γ,n)47Ca, 44Ca(γ,p)43K, 23Na(n,γ)24Na, 27Al(n, α)24Na, 140Ce(γ,n)139Ce, 204Pb(γ,n)203Pb, 135Ba(γ,γ)135mBa were measured. The typical spec- trum of the induced activity for the probe, taken in the core of the IAF, is presented in Fig. 1. The re- searched IAFs are mainly intended for the chemical adsorption of the radioactive Iodine (I) at the NPP. Therefore, it was in the scope of our research interest to find out the quantitative content of the Iodine per a mass unit of the adsorbent; and its distribution, depending on the depth of the extracted probe. The measured distribution of 127I is shown in Fig. 2. The probes were extracted on the periphery of the IAF, and the direction of filtrated air flow as well as the exact position of probe extraction are shown in Fig. 2. The average specific content of small dispersive coal dust particles fraction at the depth of an adsorbent did not exceed 0,5%. The fission of Uranium atoms in a nuclear re- actor is accompanied by the accumulation of ra- dioactive isotopes of the Iodine (131,132,133,134,135I). It is a well known fact that the half-decay pe- riod for the isotopes of Iodine is 8.1 days; in the case of 131I; it is 20.9 hours in the case of 133I; it is 6.7 hours in the case of 135I. Getting to the IAF, the Iodine isotopes are captured in the IAF, where the physical process of their decay takes place. Fig.2. Distribution of specific content of Iodine ( 127I ) in absorber of iodine air filter at NPP The stable isotope 127I is accumulated and pre- served in the IAF at the moment of experimental measurements. As it can be seen in Fig. 2, the 127I is mainly accumulated in the frontal region of the IAF, i.e. there is the intensive adsorption of 127I as soon as it comes to the IAF. The specific content of Iodine in close proximity to the input surface of absorber in the 194 IAF is 43 µg/g. Let us note that, according to our measurements results, the initial specific content of Iodine in the cylindrical coal granules in an absorber doesn’t exceed 5 µg/g. Some part of decay products of the Iodine isotopes could be detected in the re- actions 135Ba(γ,γ)135mBa and 133Cs(γ,n)132Cs. The Figs. 3 and 4 present a relative distribution of the light-weight alkaline chemical elements such as the Sodium and Potassium (the 1-st group of a periodic table of the chemical elements), which were obtained in our measurements. It is visible that the chemical elements such as the Sodium and Potassium are non-homogeneously dis- tributed in the absorber in the IAF and their depen- dences are well correlated along the length of the IAF. Fig.3. Distribution of specific content of Sodium in absorber of iodine air filter at NPP Fig.4. Distribution of specific content of Potassium in absorber of iodine air filter at NPP The distributions of radioactive chemical elements from the 2nd group from a periodic table of the chemical elements such as the light-weight Strontium and heavy-weight Barium are shown in Figs. 5 and 6. These distributions have a high degree of similarity. The easiest chemical element from the 3rd group such as the Scandium is distributed a little differently, but there is a main maximum in the center of absorber in the IAF as shown in Fig. 7. Fig.5. Distribution of specific content of Strontium in absorber of iodine air filter at NPP Fig.6. Distribution of specific content of Barium in absorber of iodine air filter at NPP Fig.7. Distribution of specific content of Scandium in absorber of iodine air filter at NPP The distributions of radioactive chemical elements from the 4-th group of a periodic table of the chemi- cal elements such as the Zirconium is given in Fig. 8. The most light-weighted radioactive chemical el- ement from the 7-th group of a periodic table of 195 the chemical elements such as the Manganese has the distribution with the three maximums in Fig. 9. Fig.8. Distribution of specific content of Zirconium in absorber of iodine air filter at NPP Fig.9. Distribution of specific content of radioactive Manganese in absorber of iodine air filter at NPP Fig.10. Distribution of specific content of Chlorine in absorber of iodine air filter at NPP In Fig. 10, the distribution of the Chlorine with the smaller mass, comparing to the Iodine mass, from the 17-th group of a periodic table of the chemical elements is depicted. It is necessary to comment that the distribution of the Chlorine in Fig. 10 is ab- solutely different from the distribution of the Iodine in Fig. 2. We would like to show the distribution of the rel- ative content of the Strontium at other places in the absorber in the IAF. In fig. 11, the distribution of the Strontium in the probe, extracted at the periph- ery region of absorber in the IAF is shown. In Fig. 12, the distribution of the Stron- tium in the probe, extracted at the cen- ter of absorber in the IAF is shown. Fig.11. Distribution of specific content of Strontium at periphery of absorber in IAF at NPP Fig.12. Distribution of specific content of Strontium at center of absorber in IAF at NPP On the upper net of the IAF, the thick and dense layer of the small dispersive coal dust particles layer, which was not captured by the aerosol filters, was registered. It was found that the direct inflow of aerosols into the IAF from the space, which is in close proximity to the nuclear reactor, worsens the IAF’s aerodynamic performances. As it was shown during the research with the application of a model of the IAF, the presence of the small dispersive dust particles layer on the upper grid increases the ab- sorber’s aerodynamic resistance at the rate of 20 196 %. The typical spectrum of the detected radioactive chemical elements and their isotopes, which were pre- cipitated at the grid of the AU-1500 iodine air filter, is presented in Fig. 13. As it can be seen, the presence of 137Cs, 60Co, 110mAg, 54Mn isotopes corresponds to a typical composition of the isotopes, which can be normally detected in the radioactive aerosols at the operating nuclear reactor. The small dispersive dust particles layer on the upper grid of the IAF rep- resents the densely packed atmospheric dust, which is mixed with the operating nuclear reactor dust at the NPP. The dust layer was indissoluble, because of presence of the oils and moisture. The moisture mass fraction was 5 %. The particles with the size of about 1 µm represented a biggest share of particles in the small dispersive dust particles layer, according to the completed microscopy analysis. Fig.13. Typical spectrum of detected radioactive chemical elements and their isotopes in the IAF on the grid of iodine air filter 4. DISCUSSION As we explained in the introduction, the distribu- tion and accumulation processes of the adsorbed ra- dioactive chemical elements and their isotopes in the granular filtering medium of absorber in the AU-1500 IAF strongly depends on both the physical features of the transportation processes of the small dispersive coal dust particles of the micro- and sub micro-sizes [8-14], as well as the action by the acoustic oscilla- tory processes, connected with the acoustic oscilla- tions generation and propagation in the air in the granular filtering medium of absorber in the AU-1500 IAF [14]. The generating standing wave oscillations of the sound frequencies of the first harmonics, which represent the half-wave standing wave oscillations, described by the dependence between the wavelength and the thickness of granular filtering medium layer: λ1 = 2L and by the next harmonic’s dependence: λ2 = 2L/3, have the biggest amplitudes. These stand- ing wave oscillations are important for the process of excessive accumulation of the small dispersive coal dust particles, penetrating deeply into the adsorber, which takes place in the anti-nodes positions along the length of the IAF [14-16]. The pressure max- imums in the standing wave oscillations are posi- tioned: 1) in the case of the first harmonic, it is positioned on the distance of 15 cm, and 2) in the case of the second odd harmonic, they are located on the distances of 5, 15, 25 cm from the input sur- face of absorber in the IAF. The presence of maxi- mums in the distribution of the small dispersive coal dust particles masses has been detected in the exper- iments with the vertical model of the IAF in [8] and the horizontal model of the IAF in [12]. According to the research in [9], the maximums of accumula- tion of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium of absorber in the AU-1500 IAF must be observed in these positions. On the one side, the alternating-sign pressure appearing in the positions of the anti-nodes of standing wave oscillations, results in an origina- tion of the processes of accelerating penetration of the radioactive chemical elements and their isotopes together with the air into the cylindrical coal gran- ules. From other side, it is a well known fact that such oscillations can intensify the diffusion processes, occurring in the cylindrical coal granules [14]. As it is shown in the experimental data in Fig. 2, the Iodine is well adsorbed in the IAF at the initial moment of its penetration into the IAF. The main share of 127I is absorbed by the granular filtering layer with the thickness of 10 cm. The spatial distribution of Iodine has a decreasing diffusion-type dependence [8] on the distance from the source. However, nev- ertheless, the concentration maximum is clearly vis- ible on the curve of characteristic dependence. This maximum is positioned in the point, where there are 197 the anti-nodes for the two harmonics of the pressure waves in the air in the IAF. Therefore, the additional absorption is connected with either: the excessive ac- cumulation of the small dispersive coal dust particles or the influence by the acoustic waves on the adsorp- tion of chemical elements and their isotopes in the granular filtering medium of absorber in the AU-1500 IAF. In Fig. 2, there is also a small next maximum in the position near to the absorber’s output, which can be related to the action by the acoustic oscillations of second harmonic, which is slightly shifted by the air stream. The Alkaline metals such as the Sodium and Potassium have the clearly expressed distributions with the maximums, which are located at the forward fronts of anti-nodes, i.e. they are promptly absorbed at the initial stage of filtering process at the moment of entrance to the region of anti-nodes, generated by the acoustic waves. Therefore, their maximums are shifted to the position of source, i.e. to the absorber’s input region in the IAF. Moreover, it is necessary to consider the two pos- sibilities: 1) the cross replacement by the chemical elements and their isotopes in the course of the ab- sorption or 2) the presence of co-operative absorp- tion in the IAF. Thus, for example, the distributions of the radioactive Strontium and Barium from the 2-nd group of chemical elements, are characterized by the maximums of absorption (see Figs. 5 and 6), which are similar to the maximum of absorption of Iodine (see Fig. 2). Of course, we don’t take to the consideration the giant absorption maximum of Io- dine near to the absorber’s input surface in the IAF in Fig. 2. Whereas, for example, the Potassium (see Fig. 4) was forced to move deeply into the absorber out of absorber’s sub-surface region in the IAF. It is a well known fact that the Barium can easily cre- ate the oxides and nitrides. Also, the Barium can easily form the Ba(IO3)2 and the BaI2 chemical com- pounds, which can have the influences on its distrib- ution in the absorber in the IAF. The radiation ac- tivity results in the creation of the Acetic acid from the Methane, containing in the air (the oxidizing of CH3 by the Hydroxyl OH): → CH4 + O2 → CH3O + OH → CH3OOH. The acetic acid can intensively react with the chemical elements of the 2-nd group. The Scandium, which is a chemical element from the 3-rd group, has a central maximum of distribu- tion in the region of joint maximums of the both har- monics at the distance L = 15 cm from the absorbers input surface in the IAF. The Sc is accumulated on the forward front of the first maximum of the second harmonic of the standing wave oscillations at the ab- sorber’s input surface; and it is also accumulated on the backward front near to an absorber’s output sur- face in the IAF. The Zirconium distribution accompanies the Io- dine distribution; however in the places with the small concentration of 127I at the absorber’s output surface, it is concentrated in the region of the third maximum of the second harmonic of the standing wave oscillations at the distance L ≈ 25 cm from the absorbers input surface in the IAF. The Manganese, which is a chemical element of the 7-th group, is inclined to occupy the forward fronts of maximums of acoustic oscillations, but, at the center, it occupies the position at the distance L = 15 cm from the absorbers input surface in the IAF (see Fig. 9). The Chlorine, which is a chemical element from the 17-th group, occupies the back front of the first maximum of the second harmonic of the acoustic os- cillations and the back front of the second maximum of the second harmonic of the acoustic oscillations, i.e. there is its replacement in the region, where there are no the concentration maximums of other chemical elements (see Fig. 10). In Figs. 11 and 12, the physical features of dis- tribution of the Strontium at the different places of probes extraction are shown. It is visible that the air streams can flow non-uniformly, resulting in some non-significant changes of distributions of the ad- sorbed radioactive chemical elements in the core of the IAF. At center of the IAF, the Sr has a max- imum of accumulation near to the absorber’s input surface, whereas at the periphery it accumulates in the region at the distance L = (17...18) cm from the absorbers input surface in the IAF. In the cases of other chemical elements with the distribution dependences, which are not shown in our research paper, it is necessary to point out that the Calcium has its accumulation maximum at the dis- tance L = 15 cm. Let us stress that the Ba, Sr, Sc, Zr, Ca chemical elements can have a positive impact on the absorption capacity of the cylindrical coal granules of the type of SKT-3, forming the chemically stable compounds with the Iodine. The almost constant concentrations of the Ni, Ce, Pb absorbed chemical elements along the length of the IAF was observed. We would like to note that the PbI2 compound is one of the most stable Iodine’s compounds. Let us note that the simultaneous consideration of both the diffusion mechanism and the acoustic mech- anism in our research on the processes of the accu- mulation and distribution of the adsorbed chemical elements and their isotopes in the granular filtering medium of an absorber allows us to explain the ob- tained complex dependences of the distribution of the adsorbed chemical elements and their isotopes in the granular filtering medium of an absorber in the AU- 1500 IAF at the NPP. 5. CONCLUSIONS The main purpose of our research was to investi- gate the physical features of distribution of the ad- sorbed radioactive chemical elements and their iso- topes in the granular filtering medium in the iodine air filters of the type of AU-1500 in the heating purge ventilation systems at the nuclear power plant. In 198 our research, the γ-activation analysis method was applied to accurately characterize the distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the AU- 1500 iodine air filter after its long term operation at the nuclear power plant. We obtained the typi- cal spectrum of the detected chemical elements and their isotopes in the AU-1500 iodine air filter. The spatial distributions of the detected chemical element 127I and some other chemical elements and their iso- topes in the layer of absorber, which was made of the cylindrical coal granules of the type of SKT-3, in the AU-1500 iodine air filter were also comprehensively researched. The possible influences by the changing aerodynamic resistance of the iodine air filter on the spatial distribution of the chemical elements and their isotopes in the iodine air filter were discussed. In ad- dition, the comprehensive analysis on the obtained research results on the distribution of the adsorbed chemical elements and their isotopes in the absorber of iodine air filter was performed, the criteria of iodine air filter effective operation were formulated and the possible iodine air filter design improvements were proposed. Authors are very grateful to a group of scientists from the National Academy of Sciences in Ukraine for the numerous scientific discussions on the reported experimental research results. This innovative research is completed in the frames of the nuclear science and technology fun- damental research program, facilitating the environ- ment protection from the radioactive contamination, at the National Scientific Centre Kharkov Institute of Physics and Technology in Ukraine. The research is funded by the National Academy of Sciences in Ukraine. References 1. B.E. Paton, O.S. Bakai, V.G. Bar’yakhtar, I.M. Neklyudov. On the strategy of nuclear en- ergy industry development in Ukraine, Analytic Research Review // NAS of Ukraine. 2008, p. 1-61. 2. P.G. de Gennes. Granular matter: a tentative view // Rev. Mod. Phys. 1999, v.71, N2, p. 374- 382. 3. G.H. Ristow. Pattern formation in granular ma- terials // Springer Tracts in Mod. Phys. 2000, v. 161, p. 1-161. 4. R.A.L. Jones. Soft Condensed Matter, Oxford, U.K., Oxford University Press, 2002, 195 p. 5. N.B.Ur’ev. Physical-chemical dynamics of dis- persive systems // Uspekhi Khimii. 2004, v.79, N1, p. 39-62 (in Russian). 6. Yu.K. Tovbin. Absorption in porous systems. Moscow: ”Nauka”, 1996, p. 128-178 (in Russian). 7. N.P. Dikiy, A.N. Dovbnya, N.A. Skakun, et al. Use of accelerators in geology, medicine, iso- topes production and atomic power industry // PAST. Ser. ”Nuclear Physics Investigation”. 2001, N1(37), p. 26-35. 8. O.P. Ledenyov, I.M. Neklyudov, P.Ya. Poltinin, et al. Physical features of small disperse coal dust fraction transportation and structurization processes in iodine air filters of absorption type in ventilation systems at nuclear power plants // PAST. Ser. ”Physics of Radiation Damages and effects in solids”. 2005, N3(86), p. 115-121 (in Russian). 9. O.P. Ledenyov, I.M. Neklyudov, P.Ya. Poltinin, et al. Physical features of accumulation and dis- tribution processes of small disperse coal dust precipitations and absorbed radioactive chemical elements in iodine air filter at nuclear power plant // PAST. Ser. ”Physics of Radiation Damages and effects in solids”. 2006, N4(89), p. 164-168 (in Russian). 10. I.M. Neklyudov, L.I. Fedorova, P.Ya. Poltinin, et al. Research on physical features of small disperse coal dust particles movement dynamics at action by differently directed forces in granular filter- ing medium in iodine air filter at nuclear power plant // PAST. Ser. ”Physics of Radiation Dam- ages and effects in solids”. 2007, N6(91), p. 82-88 (in Russian). 11. I.M. Neklyudov, O.P. Ledenyov, L.I. Fedorova, et al. Influence by small dispersive coal dust parti- cles of different fractional consistence on charac- teristics of iodine air filter at nuclear power plant // PAST. Ser. ”Physics of Radiation Damages and effects in solids”. 2009, N2(93), p. 104-107 (in Russian). 12. I.M. Neklyudov, O.P. Ledenyov, L.I. Fedorova, et al. Formation of small dispersive coal dust particles maximums by air-dust aerosol in dis- persive granular filtering medium // PAST. Ser. ”Physics of Radiation Damages and effects in solids”. 2010, N5(96), p. 67-72 (in Russian). 13. I.M. Neklyudov, O.P. Ledenyov, L.I. Fedorova, et al. On the structurization of coal dust precip- itations and their influence on aerodynamic re- sistance by granulated mediums in air filters at nuclear power plants // PAST. Ser. ”Physics of Radiation Damages and effects in solids” 2012, N2(78), p. 76-82. (in Russian). 14. O.P. Ledenyov, I.M. Neklyudov. Distribution of small dispersive coal dust particles and adsorbed radioactive chemical elements in granular filter- ing medium in iodine air filter at nuclear power plant in conditions of forced acoustic resonance // PAST. Ser. ”Physics of Radiation Damages and effects in solids”. 2013, N2(84), p. 94-99. (in Russian). 199 15. D.I. Blokhintsev. Acoustics of non-homogeneous moving medium. Moscow: ”Nauka”, 1981, 208 p. (in Russian). 16. I.P. Golyamina. Ultrasound: Small Encyclope- dia. Moscow: ”Soviet Encyclopedia Publishing House”, 1979, 400 p. (in Russian). ОСОБЕННОСТИ РАСПРЕДЕЛЕНИЯ РАДИОАКТИВНЫХ ХИМИЧЕСКИХ ЭЛЕМЕНТОВ И ИХ ИЗОТОПОВ В ЙОДНЫХ ВОЗДУШНЫХ ФИЛЬТРАХ АУ-1500 АТОМНОЙ ЭЛЕКТРОСТАНЦИИ И.М. Неклюдов, А.Н. Довбня, Н.П. Дикий, О.П. Леденёв, Ю.В. Ляшко Главной целью работы было исследование особенностей, распределения адсорбированных химических элементов и их изотопов в гранулированной фильтрующей среде в йодных воздушных фильтрах типа АУ-1500 в системах приточно-вытяжной вентиляции на атомной электростанции. Использован метод γ-активационного анализа для точного изучения распределения адсорбированных химических элементов и их изотопов в гранулированной адсорбирующей среде в йодных воздушных фильтрах АУ-1500 после их долгосрочной работы на атомной электростанции. Получены типичные спектры обнаруженных химических элементов и их изотопов в йодном воздушном фильтре АУ-1500, образцы из которого облучались тормозными γ-квантами, возникавшими при прохождении ускоренных электронов через танталовую мишень. Найдено пространственное распределение йода и ряда других химических элементов и их изотопов в слое адсорбента, который состоял из цилиндрических угольных гранул СKT-3. Детально обсужден возможный механизм влияния стоячих колебаний давления воздуха в йодном воздушном фильтре на пространственное распределение поглощенных химических элементов и их изотопов. Выполнен всесторонний анализ полученных результатов исследования пространственного распределения адсорбированных радиоактивных химических элементов и их изотопов в адсорбенте йодного воздушного фильтра. ОСОБЛИВОСТI РОЗПОДIЛЕННЯ РАДIОАКТИВНИХ ХIМIЧНИХ ЕЛЕМЕНТIВ ТА ЇХ IЗОТОПIВ У ЙОДНИХ ПОВIТРЯНИХ ФIЛЬТРАХ AУ-1500 АТОМНОЇ ЕЛЕКТРОСТАНЦIЇ I.М. Неклюдов, А.М. Довбня, М.П. Дикий, О.П. Леденьов, Ю.В. Ляшко Головною метою було дослiдження особливостей розподiлення поглинених хiмiчних елементiв та їхнiх iзотопiв у гранульованому середовищi у йодному повiтряному фiльтрi типу AУ-1500 у притоко- витягових системах на атомнiй електростанцiї. Метод γ-активацiйного аналiзу застосовано щоб охарактеризувати розподiлення поглинених хiмiчних елементiв та їхнiх iзотопiв у гранульованому фiльтовальному середовищi йодних повiтряних фiльтрiв типу AУ-1500 пiсля їх довгого термiну роботи на атомнiй електростанцiї. Отриманi типовi спектри виявлених хiмiчних елементiв та їхнiх iзотопiв у повiтряному фiльтрi AУ-1500, зразки з якого опромiнювалися гальмовими γ-квантами, якi виникали при проходженнi прискорених електронiв через танталову мiшень. Просторове розподiлення йоду та деяких iнших хiмiчних елементiв та їхнiх iзотопiв у абсорберi, котрий був заповнений цилiндричними гранулами вугiлля типу СKT-3, у повiтряному фiльтрi AU-1500 було дослiджено. Можливий вплив стоячих коливань повiтряного тиску в йодному повiтряному фiльтру на просторове розпредiлення радiоактивних хiмiчних елементiв та їхнiх iзотопiв у йодному повiтряному фiльтрi було обговорено авторами. Зроблено всебiчний аналiз отриманих результатiв дослiдження просторового розподiлення хiмiчних елементiв та їхнiх iзотопiв у повiтряному фiльтрi. 200