On the necessity and the role of descriptors of neutron activated structural and shielding materials of nuclear installations for future decommissioning

Existing situation in nuclear industry is characterized with simultaneous development of the following two processes: design and construction of new generation of nuclear installations and decommissioning of installations of older generations. Significant amounts of radioactive wastes generated during the decommissioning phase are determined both for the first and the second types of installations by the induced activity of neutron irradiated structural and shielding materials. Concentration of the so-called radioactivity-hazardous nuclides in primary building and construction materials is the most important characteristics determining the resulting levels of induced activity. Values of these concentrations for the same type of material extracted from different geological deposits may differ by one or two orders of magnitude. Information about concentrations of radiation-hazardous elements in radiation shielding materials is fragmented and, as a rule, unsuitable for practical application. The purpose of the present study was to substantiate the necessity of compiling and recording the data on the concentrations of radioactivity-hazardous nuclides for building and structural materials for nuclear installations during the phases of design, operation and decommissioning. Three types of shielding concrete compositions were selected for the investigation. Concentrations of radioactivity-hazardous nuclides were mainly obtained by neutron activation technique. Neutron transport calculations were performed in one-dimensional cylindrical geometry at the core mid-plane according to usual core-vessel-shielding model of modern VVER reactor unit including 2-m thick concrete shield. Both transport and activation calculations were undertaken using modules of SCALE system. The obtained results allow estimating neutron-induced activation levels in the material as the function of irradiation time, amounts and categories of radioactive waste and their evolution during the decay time from 1 to 100 years. It was established that neutron-induced activity of shielding concrete strongly depends on the actual concentrations of radioactivity-hazardous nuclides in the concrete including ‘trace’ concentrations (other factors being the same). It was also shown that failure to take such concentrations into account may lead to the underestimation of neutron-induced activation levels and amounts of radioactive wastes and their category. The obtained results confirmed the necessity of compiling and maintaining data records on the concentrations of radioactivity-hazardous nuclides for materials used in structural and shielding materials of nuclear installations. Proposals were formulated on the potential accumulation of information, composition and formatting of descriptors of chemical composition of shielding and structural materials of nuclear installations.

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Radiation Shielding Properties Prediction of Barite used as Small Aggregate in Mortar

Engineering, Technology & Applied Science Research ◽

10.48084/etasr.3880 ◽

2020 ◽

Vol 10 (6) ◽

pp. 6469-6475

Author(s):

H. Q. Vu ◽

V. H. Tran ◽

P. T. Nguyen ◽

N. T. H. Le ◽

M. T. Le

Keyword(s):

Radiation Resistance ◽

Construction Materials ◽

Cost Effective ◽

Radiation Shielding ◽

Nuclear Industry ◽

Barium Compounds ◽

Long Time ◽

Radiation Resistant ◽

Shielding Properties ◽

Materials Used

Construction materials used in the nuclear industry used to be mainly heavy materials, including lead plates, radiation-resistant heavy concrete, etc. However, these materials are either toxic after a long time of use (lead) or difficult to construct (radiation-resistant heavy concrete) and their cost is rather high. Therefore, there is a need for the manufacturing of a new kind of material with good radiation resistance, which is light, easy to use, and costs less. Barium is less toxic and more cost-effective than lead. Due to the importance of barium compounds in radiation shielding, the study of gamma radiation interactions within these compounds becomes essential, so the most important part of such a study is the experimental one, which shows the effect of the barite powder in the radiation resistance of the mortar. The research results show that the higher the thickness and percentage of barite powder, the higher is the radiation resistance.

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Study of capability of microorganisms to develop on construction materials used in space objects.

57th International Astronautical Congress ◽

10.2514/6.iac-06-a1.p.2.06 ◽

2006 ◽

Author(s):

Mrs. Yulia Svistunova

Keyword(s):

Construction Materials ◽

Space Objects ◽

Materials Used

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Double-layered fiber for lightweight flexible clothing providing shielding from low-dose natural radiation

Scientific Reports ◽

10.1038/s41598-021-83272-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Seon-Chil Kim ◽

Jun Sik Son

Keyword(s):

Low Dose ◽

Layered Composite ◽

Radiation Shielding ◽

Flight Attendants ◽

Low Dose Radiation ◽

Natural Radiation ◽

Composite Yarn ◽

Materials Used ◽

Fiber Fabric ◽

Dose Radiation

AbstractNatural and medical radiation are the most frequent sources of daily low-dose radiation exposure for the general public, but these radiation levels are generally acceptable. Among various occupations, aviation crew members and medical workers are exposed to high levels of radiation from scattered rays. This study focused on developing clothing for shielding aviation crew members from natural radiation during air travel. Materials were selected considering their radiation-shielding properties. A tungsten double-layered composite yarn and a polyethylene terephthalate (PET) fiber fabric containing BaSO4 were manufactured. The characteristics and shielding performances of the products were analyzed. Prototypes of a protective scarf (for shielding the thyroid gland) and apron (for shielding the torso) for flight attendants were produced. A lightweight fabric was produced that neither restricts the movement of the wearer nor causes them skin discomfort. The shielding performances of the tungsten composite and PET fiber fabrics containing BaSO4 were 0.018 mmPb and 0.03 mmPb, respectively, demonstrating low-dose shielding that may be useful for protecting aviation crew members from scattered rays. The characteristics of the developed fibers are comparable to those of materials used in clothing production; therefore, low-dose radiation-shielding clothing could be manufactured for use in aviation, medical, and other industries.

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AMS Dating of Potentially the Oldest Wooden Sculptures in Japan from a Shinto Shrine in Akita

Radiocarbon ◽

10.1017/rdc.2019.31 ◽

2019 ◽

Vol 61 (5) ◽

pp. 1221-1228

Author(s):

Naoto Fukuyo ◽

Yusuke Yokoyama ◽

Yosuke Miyairi ◽

Yusuke Igarashi

Keyword(s):

Tree Rings ◽

Age Determination ◽

Construction Materials ◽

Historical Documents ◽

Matching Method ◽

Historical Objects ◽

Ams Dating ◽

Akita Prefecture ◽

Materials Used ◽

Matching Techniques

ABSTRACTWe analyzed rare wooden Komainu found at Akagami Shrine in Akita prefecture, Japan. The formation of historical objects is often thoroughly recorded in documents, although the formation age of this particular Komainu sculpture is still unknown due to its antiquity. Thus, age determination exercises have been conducted using radiocarbon (14C)-wiggle-matching techniques. Although only a limited quantity was available for sampling, we have successfully measured 14C samples in the sculptures along with several sets of tree rings. We interpret the Komainu sculptures age considering the age of the trees and the result obtained from the wooden construction materials used for the Akagami shrine. The results obtained from Komainu show a range from 550 CE to 1020 CE, which is consistent with the dates of the shrine’s formation. Thus, the multiple 14C-wiggle-matching method can determine precise calendar ages of wood, as well as provide some supportive information for the periods when there are no reliable historical documents.

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Optimum Thickness of Thermal Insulation with Both Economic and Ecological Costs of Heating and Cooling

Energies ◽

10.3390/en14133835 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3835

Author(s):

Robert Dylewski ◽

Janusz Adamczyk

Keyword(s):

Thermal Insulation ◽

Construction Materials ◽

Optimum Thickness ◽

Degree Days ◽

Transfer Coefficients ◽

Cooling Period ◽

Heating And Cooling ◽

Optimum Heat ◽

Materials Used ◽

Building Walls

The energy efficiency of the construction sector should be determined by the cleanliness of the environment and, thus, the health of society. The scientific aim of this article was to develop a methodology for determining the optimum thickness of thermal insulation, taking into account both economic and ecological aspects and considering both heating and cooling costs. The method takes into account the number of degree days of the heating period, as well as the number of degree days of the cooling period. Variants in terms of different types of thermal insulation, various types of construction materials for building walls, climatic zones and heat sources, were taken into consideration. In order to find the optimum thicknesses of thermal insulation, both in economic and ecological terms, a metacriterion was used. The optimum thicknesses of thermal insulation with the use of the metacriterion were obtained in the range of 0.11–0.55 m. It was observed that the values of the optimum heat transfer coefficients for economic and ecological reasons do not depend on the type of construction materials used for vertical walls. The type of applied heat source is of the greatest importance for the size of the economic and ecological benefits. The proposed mathematical model for determining the optimum thickness of thermal insulation with the use of a metacriterion is a kind of generalization of earlier models from the literature.

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Effects of Infills in the Seismic Performance of an RC Factory Building in Pakistan

Buildings ◽

10.3390/buildings11070276 ◽

2021 ◽

Vol 11 (7) ◽

pp. 276

Author(s):

Nisar Ali Khan ◽

Giorgio Monti ◽

Camillo Nuti ◽

Marco Vailati

Keyword(s):

Numerical Model ◽

Construction Materials ◽

Building Codes ◽

Construction Technique ◽

Infill Walls ◽

Mortar Strength ◽

Materials Used ◽

Seismic Response Of Buildings

Infilled reinforced concrete (IRC) frames are a very common construction typology, not only in developing countries such as Pakistan but also in southern Europe and Western countries, due to their ease of construction and less technical skills required for the construction. Their performance during past earthquakes has been in some cases satisfactory and in other cases inadequate. Significant effort has been made among researchers to improve such performance, but few have highlighted the influence of construction materials used in the infill walls. In some building codes, infills are still considered as non-structural elements, both in the design of new buildings and, sometimes, in the assessment of existing buildings. This is mainly due to some difficulties in modeling their mechanical behavior and also the large variety of typologies, which are difficult to categorize. Some building codes, for example, Eurocode, already address the influence of infill walls in design, but there is still a lack of homogeneity among different codes. For example, the Pakistan building code (PBC) does not address infills, despite being a common construction technique in the country. Past earthquake survey records show that construction materials and infill types significantly affect the seismic response of buildings, thus highlighting the importance of investigating such parameters. This is the object of this work, where a numerical model for infill walls is introduced, which aims at predicting their failure mode, as a function of some essential parameters, such as the friction coefficient between mortar and brick surface and mortar strength, usually disregarded in previous models. A comprehensive case study is presented of a three-story IRC frame located in the city of Mirpur, Pakistan, hit by an earthquake of magnitude 5.9 on 24 September 2019. The results obtained from the numerical model show good agreement with the damage patterns observed in situ, thus highlighting the importance of correctly modeling the infill walls when seismically designing or assessing Pakistani buildings that make use of this technology.

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The electromagnetic response of composition-regulated honeycomb structural materials used for broadband microwave absorption

Journal of Material Science and Technology ◽

10.1016/j.jmst.2021.01.072 ◽

2021 ◽

Author(s):

Huifang Pang ◽

Yuping Duan ◽

Xuhao Dai ◽

Lingxi Huang ◽

Xuan Yang ◽

...

Keyword(s):

Microwave Absorption ◽

Structural Materials ◽

Electromagnetic Response ◽

Materials Used

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Gigacycle Fatigue of Welded Joints of Structural Materials (A Review)

Advanced Engineering Forum ◽

10.4028/www.scientific.net/aef.17.14 ◽

2016 ◽

Vol 17 ◽

pp. 14-30 ◽

Cited By ~ 1

Author(s):

Okechukwu P. Nwachukwu ◽

Alexander V. Gridasov ◽

Ekaterina A. Gridasova

Keyword(s):

Fatigue Testing ◽

Fatigue Behavior ◽

Testing Machine ◽

Structural Materials ◽

Fatigue Tests ◽

Material Defects ◽

Graphite Cast Iron ◽

Ultrasonic Fatigue ◽

Materials Used ◽

Fatigue Failures

This review looks into the state of gigacycle fatigue behavior of some structural materials used in engineering works. Particular attention is given to the use of ultrasonic fatigue testing machine (USF-2000) due to its important role in conducting gigacycle fatigue tests. Gigacycle fatigue behavior of most materials used for very long life engineering applications is reviewed.Gigacycle fatigue behavior of magnesium alloys, aluminum alloys, titanium alloys, spheroid graphite cast iron, steels and nickel alloys are reviewed together with the examination of the most common material defects that initiate gigacycle fatigue failures in these materials. In addition, the stage-by-stage fatigue crack developments in the gigacycle regime are reviewed. This review is concluded by suggesting the directions for future works in gigacycle fatigue.

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