Development of Nuclear Facilities Piping Cleaning System Using Microbubble

2011 ◽  
Author(s):  
Jongseon Jeon ◽  
Sangchul Lee ◽  
Haksoo Kim ◽  
Byoungsub Han ◽  
Wisoo Kim
Keyword(s):  
Nuclear Power ◽  
Life Time ◽  
Radioactive Wastes ◽  
Nuclear Facilities ◽  
Experimental Conditions ◽  
Legal Standards ◽  
Cavitation Phenomenon ◽  
Cleaning Solution ◽  
Micro Bubble

It removes radioactive sludge and corrosion products deposited on the inner walls of the pipes and valves in replacement or decommission, upon termination of life time, of nuclear power plant or nuclear facility. It lowers a cost of waste treatments taking advantage of a reduction of quantity of radioactive wastes by treating in classification of the radioactive wastes whose activities are lower than legal standards. The cleaning or decontamination methods developed until now have induced a damage on systems while being operated. A decontamination has been restrained if it was difficult to access physically. We are in development of the cleaning technique for pipelines by utilizing micro-bubbles in order to improve an efficiency and to prevent from any damage of systems. It aims to conduct a decontamination for spaces difficult to access there by applying cavitation phenomenon that is generated in collapse of micro-bubbles. In order to improve an efficiency of the micro-bubble device, the experimental conditions suitable to decontamination have been established and the auxiliary equipments have been added. The generation conditions and characteristics of micro-bubbles have been demonstrated by adjusting pHs and temperatures of cleaning solution. A decontamination effect has been confirmed by adding up an electrolytic method and ozone into micro-bubbles.

scholarly journals Quality assurance program of a nuclear facility

2019 ◽  
Vol 97 ◽  
pp. 03015
Author(s):  
Dmitriy Leybman ◽  
Tatiana Khripko
Keyword(s):  
Quality Assurance ◽  
Nuclear Power ◽  
Atomic Energy ◽  
Nuclear Power Engineering ◽  
Quality Assurance Program ◽  
Nuclear Facility ◽  
Nuclear Facilities ◽  
Regular Control ◽  
Construction Works

Quality Assurance Program (QAP, Program) is a standard, which regulates and coordinates activity, as well as determines quality assurance policy regarding services rendered and construction works conducted on nuclear infrastructure facilities. The Program must comply with the requirements of federal rules and regulations in the field of nuclear power engineering. The present QAP is available to all organisation employees carrying out works and rendering services during construction, reconstruction and major repairs of nuclear facilities as well as to experts conducting works and rendering services on a contract basis. The QAP implementation analysis and the evaluation of its results is conducted through internal audits. The implementation of the quality assurance program is provided through the following principles: – the responsibility for quality assurance when conducting actual works and rendering services is imposed upon the task performer; – precise segregation of duties and responsibilities between all contractors; – regular control of compliance with regulations and developer’s requirements, as well as accurate documentation of the monitoring results; – systematic update tracking for all official regulations and norms; – the quality assurance methods incorporate the classification of equipment, systems and installation in terms of their impact on safety of nuclear facilities approved by official rules and regulations in the atomic energy sector.

ISO Standardization of the Scaling Factor Method for Low- and Intermediate Level Radioactive Wastes Generated at Nuclear Power Plants

2007 ◽  
Author(s):  
Makoto Kashiwagi ◽  
Hideki Masui ◽  
Yasutaka Denda ◽  
David James ◽  
Bertrand Lante`s ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Scaling Factor ◽  
Project Team ◽  
Radioactive Wastes ◽  
Intermediate Level ◽  
International Standard ◽  
Factor Method ◽  
International Standardization

Low- and intermediate-level radioactive wastes (L-ILW) generated at nuclear power plants are disposed of in various countries. In the disposal of such wastes, it is required that the radioactivity concentrations of waste packages should be declared with respect to difficult-to-measure nuclides (DTM nuclides), such as C-14, Ni-63 and α-emitting nuclides, which are often limited to maximum values in disposal licenses, safety cases and/or regulations for maximum radioactive concentrations. To fulfill this requirement, the Scaling Factor method (SF method) has been applied in various countries as a principal method for determining the concentrations of DTM nuclides. In the SF method, the concentrations of DTM nuclides are determined by multiplying the concentrations of certain key nuclides by SF values (the determined ratios of radioactive concentration between DTM nuclides and those key nuclides). The SF values used as conversion factors are determined from the correlation between DTM nuclides and key nuclides such as Co-60. The concentrations of key nuclides are determined by γ ray measurements which can be made comparatively easily from outside the waste package. The SF values are calculated based on the data obtained from the radiochemical analysis of waste samples. The use of SFs, which are empirically based on analytical data, has become established as a widely recognized “de facto standard”. A number of countries have independently collected nuclide data by analysis over many years and each has developed its own SF method, but all the SF methods that have been adopted are similar. The project team for standardization had been organized for establishing this SF method as a “de jure standard” in the international standardization system of the International Organization for Standardization (ISO). The project team for standardization has advanced the standardization through technical studies, based upon each country’s study results and analysis data. The conclusions reached by the project team was published as ISO International Standard 21238:2007 “The Scaling Factor method to determine the radioactivity of low- and intermediate-level radioactive waste packages generated at nuclear power plants” [1]. This paper gives an introduction to the international standardization process for the SF method and the contents of the recently published International Standard.

scholarly journals Radiochemical Methodologies Applied to Analytical Characterization of Low and Intermediate Level Wastes from Nuclear Power Plants

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Roberto Pellacani Monteiro ◽  
Aluísio Souza Reis Junior ◽  
Geraldo Frederico Kastner ◽  
Eliane Silvia Codo Temba ◽  
Thiago César De Oliveira ◽  
...  
Keyword(s):  
Radiochemical Separation ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Radioactive Wastes ◽  
Intermediate Level ◽  
Analytical Characterization ◽  
Low Level ◽  
Nuclear Techniques

The aim of this work is to present radiochemical methodologies developed at CDTN/CNEN in order to answer a program for isotopic inventory of radioactive wastes from Brazilian Nuclear Power Plants.  In this program  some radionuclides, 3H, 14C, 55Fe, 59Ni, 63Ni, 90Sr, 93Zr, 94Nb, 99Tc, 129I, 235U, 238U, 238Pu, 239+240Pu, 241Pu, 242Pu, 241Am, 242Cm e 243+244Cm, were determined  in Low Level Wastes (LLW) and Intermediate Level Wastes (ILW) and a protocol of analytical methodologies based on radiochemical separation steps and spectrometric and nuclear techniques was stablished.

Research on Electric and I&C Equipment Safety Function Classification of Nuclear Power Plant

2021 ◽  
Author(s):  
Wang Yuqi ◽  
Sun Qian
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Function Analysis ◽  
System Component ◽  
Design Work ◽  
Equipment Safety ◽  
Safety Function

Abstract Classification of System, Component and Structure (SSC) is the base as well as high level demand of nuclear power plant. Equipment classification including electric and Instrument and Control (I&C) equipment is the precondition of correct design regulation and standard. Safety function classification is key pass of electric and I&C equipment classification. This paper researches the method of nuclear power plant electric and I&C equipment safety function classification. Firstly from view of function, it explains the importance of function classification. Then function analysis and classification of equipment is implemented by design order. Lastly from view of accident analysis, function classification is validated, and a complete approach of function classification is formed. The purpose of this paper is the NPP electric and I&C equipment safety function classification as an example, to study and summarize the method of the electric and I&C equipment safety function classification, and to provide the basis for specific items design work according to design requirements. At the same time, a practical method is provided for other similar NPP electric and I&C equipment classification work. The electric and I&C equipment function classification of nuclear power plant satisfy the basic principles requirement of relative nuclear power rules and codes. It provides an important basis of equipment classification for next nuclear power plants.

SYMPOSIUM: BEHAVIOR MODIFICATION BY DRUGS

PEDIATRICS ◽  
1972 ◽  
Vol 49 (5) ◽  
pp. 702-708 ◽  
Author(s):  
C. Keith Conners
Keyword(s):  
Task Force ◽  
Neurological Diseases ◽  
Brain Dysfunction ◽  
Magnesium Pemoline ◽  
Experimental Conditions ◽  
Drug Study ◽  
Stimulant Medications ◽  
Hyperkinetic Child ◽  
Historical Accident

A number of myths have grown up regarding the behavioral effects and use of stimulant medications with children. The first is that there is a type of child uniquely responsive to stimulant compounds, namely, the hyperkinetic child. The second is that the hyperkinetic child is any child who is sufficiently overactive to be considered a menace by adults. The third is that the stimulant medications act primarily to reduce motor activity in a paradoxical "sedative" fashion; and finally, that the drugs do not influence cognitive and perceptual functioning in these children. I believe that these myths are due partly to the historical accident of the manner in which they were first studied, partly to the imprecision in diagnosis and terminology of classification of patients, and partly to the paucity of systematic data on sufficiently large samples under sufficiently varied experimental conditions. I would like to present the results of studies which bear on these issues, and try to draw some general conclusions regarding the present state of knowledge with regard to the use of the various psychostimulants. In this paper I will deal with dextroamphetamine, methylphenidate, and magnesium pemoline. I. METHYLPHENIDATE AND DEXTROAMPHETAMINE The children for this study were referred from schools, pediatricians, and social agencies for either academic or behavioral difficulties, or both. The subjects retained for the drug study comprised about ⅔ of the original referral sample. They were selected to fit the description of the child with "minimal brain dysfunction" as defined by the National Institute of Neurological Diseases and Stroke (NINDS) Task Force I report.

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