Noninvasive, In Situ Acoustic Diagnosis and Monitoring of Corrosion in Molten-Salt Systems

CORROSION ◽  
10.5006/3253 ◽  
2019 ◽  
Vol 75 (10) ◽  
pp. 1230-1236
Author(s):  
Alp T. Findikoglu ◽  
Janelle E. Droessler ◽  
Jerzy Chlistunoff ◽  
George S. Goff
Keyword(s):  
Molten Salt ◽  
High Temperatures ◽  
Nuclear Power ◽  
Power Plants ◽  
Microstructural Analysis ◽  
General Purpose ◽  
Corrosion Monitoring ◽  
Acoustic Technique ◽  
Salt Systems

Diagnosis and monitoring of corrosion at high temperatures are common challenges in many industries, such as conventional power plants and next generation molten-salt reactor (MSR) nuclear power plants. A simple, noninvasive, in situ acoustic technique was developed to monitor wall loss due to corrosion in a model molten-salt vessel, operating at 500°C to 600°C. This work demonstrated the feasibility of high-temperature corrosion monitoring experimentally, and validated the concept with physical and microstructural analysis, modeling, and numerical simulations. The results of this work could form the basis for the development of a general-purpose, extended-range acoustic monitoring and inspection technique for corrosion at high temperatures (with expected upper range of approximately 900°C), which does not currently exist. Such a technique could be critical for the safe operation of MSRs in the future, as well as for rapid, nondestructive testing of new reactor component materials.

In situ gamma spectrometry using portable HPGe detector. Radiological characterization and environmental surveillance around an operating nuclear power plant. Possibilities and limits

2021 ◽  
Author(s):  
Jose Angel Corbacho ◽  
A Baeza
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Gamma Spectrometry ◽  
Nuclear Power ◽  
Power Plants ◽  
Activity Concentration ◽  
Versatile Tool ◽  
Ge Detector ◽  
Radiological Characterization

Abstract In situ technique for measuring radionuclides in the soil using a portable Ge detector is a highly versatile tool for both the radiological characterization and for the monitoring of operating nuclear power plants. The main disadvantage of this technique is related to the lack of knowledge of the geometry of the source whose activity concentration is to be determined. However, its greatest advantage is the high spatial representability of the samples and the lower time and resource consumption than gamma spectrometry lab measurements. In this study, the possibilities and limits offered by in situ gamma spectrometry with a high resolution gamma portable detector in two common uses are shown: First, the radiological background characterization and its relationship with the geology of an area of 2700 km2 are assessed; Secondly, its potential for monitoring man-made activity concentration in soils located around an operating nuclear power plant in Spain for surveillance purposes is evaluated. Finally, high accuracy radiation maps have been prepared from the measurements carried out. These radiation maps are essential tools to know the radioactive background of an area, especially useful to assess artificial radioactive deposits produced after a nuclear accident or incident.

Development of Concretes with Resistance to High Temperatures in the Czech Republic and Surrounding European Countries

2013 ◽  
Vol 651 ◽  
pp. 120-125 ◽  
Author(s):  
Lenka Bodnárová ◽  
Jiri Zach ◽  
Jitka Hroudová ◽  
Jaroslav Válek
Keyword(s):  
Czech Republic ◽  
High Temperatures ◽  
Nuclear Power ◽  
Power Plants ◽  
Building Materials ◽  
European Countries ◽  
Terrorist Attacks ◽  
Load Bearing Capacity ◽  
The Czech Republic ◽  
The Stability

The resistance of concrete constructions to high temperatures at present is a much monitored issue for many scientific teams and experts in the stated area. This fact is mainly caused by fatal consequences originating in the case when concrete constructions are loaded by the effect of fire and consequent loss of their load-bearing capacity, for the population and the environment of our planet, in which we live in. The development of society goes hand in hand with the development of new building materials and as a consequence the requirements for building constructions increase which bring about extraordinary strict regulations in the area of fire safety. So, many high, non-traditional or specific constructions originate, e.g. nuclear power plants due to permanently higher demand for transport linkage and many tunnels have originated between European countries as a result. Unfortunately, in this relation the threat of terrorist attacks increases and unexpected natural disasters which also threaten the stability of the mentioned constructions. The objective of the article is to familiarize readers with the results of research concerning the improvement of the resistance of the concrete to high temperatures originated during fire instances.

The Influence of Chemical Composition of Liquid Radioactive Waste on the Evaporation Process

2000 ◽  
Vol 663 ◽  
Author(s):  
P.P. Poluektov ◽  
L.P. Soukhanov ◽  
M.I. Zhicharev
Keyword(s):  
Nitric Acid ◽  
Chemical Composition ◽  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Liquid Radioactive Waste ◽  
Salt Content ◽  
Evaporation Process ◽  
Simplified Models ◽  
Salt Systems

ABSTRACTA method is suggested to assess the tolerable salt content of the evaporator bottoms from the data on solubility in salt systems taken as simplified models of liquid radioactive waste (LRW) arising from nuclear power plants (NPP) with boiling reactors. It has been demonstrated that the degree of evaporation may be substantially increased by implementing the process in nitric acid. Equations have been derived that allow the calculation of the minimum needed acidity of the solution to allow maximum evaporation.

Planning of Large-Scale In-Situ Gas Generation Experiment in Korean Radioactive Waste Repository

2010 ◽  
Author(s):  
Juyoul Kim ◽  
Sukhoon Kim ◽  
Jin Beak Park ◽  
Sunjoung Lee
Keyword(s):  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Large Scale ◽  
Radioactive Waste Disposal ◽  
Gas Generation ◽  
Radioactive Waste Repository ◽  
Waste Repository

In the Korean LILW (Low- and Intermediate-Level radioactive Waste) repository at Gyeongju city, the degradation of organic wastes and the corrosion of metallic wastes and steel containers would be important processes that affect repository geochemistry, speciation and transport of radionuclides during the lifetime of a radioactive waste disposal facility. Gas is generated in association with these processes and has the potential threat to pressurize the repository, which can promote the transport of groundwater and gas, and consequently radionuclide transport. Microbial activity plays an important role in organic degradation, corrosion and gas generation through the mediation of reduction-oxidation reactions. The Korean research project on gas generation is being performed by Korea Radioactive Waste Management Corporation (hereafter referred to as “KRMC”). A full-scale in-situ experiment will form a central part of the project, where gas generation in real radioactive low-level maintenance waste from nuclear power plants will be done as an in-depth study during ten years at least. In order to examine gas generation issues from an LILW repository which is being constructed and will be completed by the end of December, 2012, two large-scale facilities for the gas generation experiment will be established, each equipped with a concrete container carrying on 16 drums of 200 L and 9 drums of 320 L of LILW from Korean nuclear power plants. Each container will be enclosed within a gas-tight and acid-proof steel tank. The experiment facility will be fully filled with ground water that provides representative geochemical conditions and microbial inoculation in the near field of repository. In the experiment, the design includes long-term monitoring and analyses for the rate and composition of gas generated, and aqueous geochemistry and microbe populations present at various locations through on-line analyzers and manual periodical sampling. A main schedule for establishing the experiment facility is as follows: Completion of the detailed design until the second quarter of the year 2010; Completion of the manufacture and on-site installation until the second quarter of the year 2011; Start of the operation and monitoring from the third quarter of the year 2011.

Lifetime Management of EDF PWR Pressure Vessels and Pipings

2004 ◽  
Author(s):  
F. Hedin ◽  
J. C. Legendre
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Pressure Vessels ◽  
Destructive Testing ◽  
Key Points ◽  
Cast Stainless Steel ◽  
Non Destructive

Lifetime management of EDF PWR vessels and pipings are one of the main technical key points of safety and competitivness. This paper describes the EDF global approach in this field, which is applied to the nuclear fleet i.e 58 nuclear power plants, and particularly to the first 34 three loops, as far as lifetime is concerned: • operating procedures and routine maintenance, special maintenance and ten years safety reassessment, • engineering analysis, based on feed back experience, scientific knowledge, degradations mechanisms, causes and consequences management, • operating loadings decrease, • complementary deterministic and cost-benefit analysis, • fit for service justifications, • anticipation strategy to prepare future, based on Non Destructive Testing investigations, ability to repair and/or to replace components, in situ expertises, ... Some examples are given: lifetime management of reactor vessels heads and bottom penetrations of pressure vessels, fit for service of cast stainless steel primary pipings, primary nozzles and auxiliary pipings special maintenance.

Advanced Signal Processing Techniques for Guided Wave Corrosion Monitoring System in Secondary Circuits of Nuclear Power Plants

2018 ◽  
Author(s):  
Andrei Gribok ◽  
Vivek Agarwal
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Signal To Noise Ratio ◽  
Guided Wave ◽  
Detection Sensitivity ◽  
Complex Geometries ◽  
Corrosion Monitoring ◽  
Coherent Noise ◽  
Induced Defects

This paper describes the application of independent component analysis (ICA) to detect corrosion-induced defects in commercial nuclear power plants. This paper analyzes the applicability and benefits of ICA when applied to guided wave (GW) technology to detect corrosion in secondary circuits, as well as studying the potential for expanding the range of GW technology to include complex geometries and piping components. The ultrasonic GWs can inspect long stretches of straight piping; however, more complex geometries that include elbows, welds, and tees are causing spurious reflections and coherent noise, which significantly decreases the sensitivity of the GW systems. The potential of ICA to improve detection sensitivity is analyzed and practical recommendations are provided. It is demonstrated on GW data collected at one of the commercial nuclear power plants that ICA, under certain conditions, is capable of separating different coherent noise components and has potential for improving signal-to-noise ratio.

scholarly journals Ground-based remote sensing profiling and numerical weather prediction model to manage nuclear power plants meteorological surveillance in Switzerland

2011 ◽  
Vol 4 (1) ◽  
pp. 789-813
Author(s):  
B. Calpini ◽  
D. Ruffieux ◽  
J.-M. Bettems ◽  
C. Hug ◽  
P. Huguenin ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Dispersion Model ◽  
Weather Prediction ◽  
Local Dispersion ◽  
Swiss Plateau ◽  
Nwp Model

Abstract. The meteorological surveillance of the four nuclear power plants in Switzerland is of first importance in a densely populated area such as the Swiss Plateau. The project "Centrales Nucléaires et Météorologie" CN-MET aimed at providing a new security tool based on one hand on the development of a high resolution numerical weather prediction (NWP) model. The latter is providing essential nowcasting information in case of a radioactive release from a nuclear power plant in Switzerland. On the other hand, the model input over the Swiss Plateau is generated by a dedicated network of surface and upper air observations including remote sensing instruments (wind profilers and temperature/humidity passive microwave radiometers). This network is built upon three main sites ideally located for measuring the inflow/outflow and central conditions of the main wind field in the planetary boundary layer over the Swiss Plateau, as well as a number of surface automatic weather stations (AWS). The network data are assimilated in real-time into the fine grid NWP model using a rapid update cycle of eight runs per day (one forecast every 3 h). This high resolution NWP model has replaced the former security tool based on in situ observations (in particular one meteorological mast at each of the power plant) and a local dispersion model. It is used to forecast the dynamics of the atmosphere in the planetary boundary layer (typically the first 4 km above ground layer) and over a time scale of 24 h. This tool provides at any time (e.g. starting at the initial time of a nuclear power plant release) the best picture of the 24-h evolution of air mass over the Swiss Plateau and furthermore generates the input data (in the form of simulated values substituting in situ observations) required for the local dispersion model used at each of the nuclear power plants locations. This paper is presenting the concept and two validation studies as well as the results of an emergency response exercise performed in winter 2009.

scholarly journals Room Classification Based on EMC Conditions in Nuclear Power Plants

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 359 ◽  
Author(s):  
Hrvoje Grganić ◽  
Davor Grgić ◽  
Siniša Šadek
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Electromagnetic Compatibility ◽  
Numerical Calculations ◽  
Operational Experience ◽  
Systematic Classification

Electromagnetic compatibility (EMC) in nuclear power plants today mostly relies on the qualification tests of the new equipment and adhering to some good installation practices. Diversity of the electromagnetic environment and different susceptibility of the plant equipment calls for a systematic classification of the EMC zones in a nuclear power plant. The paper proposes a methodology that uses a combination of the qualification tests, in situ and bench immunity tests, site survey measurements, operational experience, and numerical calculations to divide a nuclear power plant into a reasonable number of EMC zones. This would primarily help to have a better overview of the current EMC level in the plant and to unify emission and susceptibility requirements for the new equipment. In this paper, special attention is given to the preparation and performance of the in situ tests, which present the most challenging step of the methodology. In addition, the paper proposes some of the possible applications of the numerical calculations and addresses their challenges and limitations. The novel classification methodology, inspired by the equipment qualification program, is illustrated with examples from Krško Nuclear Power Plant, which recently performed a comprehensive EMC assessment.

scholarly journals In-situ eddy current monitoring of structural components in nuclear power plants

2005 ◽  
Vol 17 (1/2) ◽  
pp. 68-69
Author(s):  
Takashi KASUYA ◽  
Tetsuya UCHIMOTO ◽  
Toshiyuki TAKAGI ◽  
Tetsuo SHOJI
Keyword(s):  
Eddy Current ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Structural Components ◽  
Current Monitoring
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