Long-Term Activation and Tritium Generation of Flowing Lithium-Lead under Prolonged Irradiation in Fusion Power Plants

Small-diameter tubes that are widely used in petroleum industries and power plants experience corrosion during long-term services. In this paper, a compact inserted guided-wave EMAT with a pulsed electromagnet is proposed for small-diameter tube inspection. The proposed transducer is noncontact, compact with high signal-to-noise ratio and unattractive to ferromagnetic tubes. The proposed EMAT is designed with coils-only configuration, which consists of a pulsed electromagnet and a meander pulser/receiver coil. Both the numerical simulation and experimental results validate its feasibility on generating and receiving L(0,2) mode guided wave. The parameters for driving the proposed EMAT are optimized by performance testing. Finally, feasibility on quantification evaluation for corrosion defects was verified by experiments.

Download Full-text

Nuclear fusion power: a bright long-term future

Civil Engineering Innovation ◽

10.1680/jciei.2007.14138 ◽

2007 ◽

Vol 1 (1) ◽

pp. 49-54

Author(s):

Chris Llewellyn Smith ◽

David Ward

Keyword(s):

Nuclear Fusion ◽

Fusion Power

Download Full-text

A Combined Approach for Model-Based PV Power Plant Failure Detection and Diagnostic

Energies ◽

10.3390/en14051261 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1261

Author(s):

Christopher Gradwohl ◽

Vesna Dimitrievska ◽

Federico Pittino ◽

Wolfgang Muehleisen ◽

András Montvay ◽

...

Keyword(s):

Power Plants ◽

Large Scale ◽

Failure Detection ◽

Energy Yield ◽

Combined Approach ◽

Levelized Cost Of Electricity ◽

Term Operation ◽

Model Based

Photovoltaic (PV) technology allows large-scale investments in a renewable power-generating system at a competitive levelized cost of electricity (LCOE) and with a low environmental impact. Large-scale PV installations operate in a highly competitive market environment where even small performance losses have a high impact on profit margins. Therefore, operation at maximum performance is the key for long-term profitability. This can be achieved by advanced performance monitoring and instant or gradual failure detection methodologies. We present in this paper a combined approach on model-based fault detection by means of physical and statistical models and failure diagnosis based on physics of failure. Both approaches contribute to optimized PV plant operation and maintenance based on typically available supervisory control and data acquisition (SCADA) data. The failure detection and diagnosis capabilities were demonstrated in a case study based on six years of SCADA data from a PV plant in Slovenia. In this case study, underperforming values of the inverters of the PV plant were reliably detected and possible root causes were identified. Our work has led us to conclude that the combined approach can contribute to an efficient and long-term operation of photovoltaic power plants with a maximum energy yield and can be applied to the monitoring of photovoltaic plants.

Download Full-text

Quantification of PV Power and Economic Losses Due to Soiling in Qatar

Sustainability ◽

10.3390/su13063364 ◽

2021 ◽

Vol 13 (6) ◽

pp. 3364

Author(s):

Amr Zeedan ◽

Abdulaziz Barakeh ◽

Khaled Al-Fakhroo ◽

Farid Touati ◽

Antonio S. P. Gonzales

Keyword(s):

Output Power ◽

Power Plants ◽

Economic Loss ◽

Economic Losses ◽

Energy Yield ◽

Solar Pv ◽

Financial Loss ◽

Grid Systems ◽

Dust Density

Soiling losses of photovoltaic (PV) panels due to dust lead to a significant decrease in solar energy yield and result in economic losses; this hence poses critical challenges to the viability of PV in smart grid systems. In this paper, these losses are quantified under Qatar’s harsh environment. This quantification is based on experimental data from long-term measurements of various climatic parameters and the output power of PV panels located in Qatar University’s Solar facility in Doha, Qatar, using a customized measurement and monitoring setup. A data processing algorithm was deliberately developed and applied, which aimed to correlate output power to ambient dust density in the vicinity of PV panels. It was found that, without cleaning, soiling reduced the output power by 43% after six months of exposure to an average ambient dust density of 0.7 mg/m3. The power and economic loss that would result from this power reduction for Qatar’s ongoing solar PV projects has also been estimated. For example, for the Al-Kharasaah project power plant, similar soiling loss would result in about a 10% power decrease after six months for typical ranges of dust density in Qatar’s environment; this, in turn, would result in an 11,000 QAR/h financial loss. This would pose a pressing need to mitigate soiling effects in PV power plants.

Download Full-text

Simulation of MASPn Experiments in MISTRA Test Facility with COCOSYS Code

Science and Technology of Nuclear Installations ◽

10.1155/2008/896406 ◽

2008 ◽

Vol 2008 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Mantas Povilaitis ◽

Egidijus Urbonavičius

Keyword(s):

Boundary Conditions ◽

Nuclear Power ◽

Power Plants ◽

Volume Fraction ◽

Characteristic Length ◽

Initial Conditions ◽

Test Facility ◽

Work Package ◽

Acceptable Agreement

An issue of the stratified atmospheres in the containments of nuclear power plants is still unresolved; different experiments are performed in the test facilities like TOSQAN and MISTRA. MASPn experiments belong to the spray benchmark, initiated in the containment atmosphere mixing work package of the SARNET network. The benchmark consisted of MASP0, MASP1 and MASP2 experiments. Only the measured depressurisation rates during MASPn were available for the comparison with calculations. When the analysis was performed, the boundary conditions were not clearly defined therefore most of the attention was concentrated on MASP0 simulation in order to develop the nodalisation scheme and define the initial and boundary conditions. After achieving acceptable agreement with measured depressurisation rate, simulations of MASP1 and MASP2 experiments were performed to check the influence of sprays. The paper presents developed nodalisation scheme of MISTRA for the COCOSYS code and the results of analyses. In the performed analyses, several parameters were considered: initial conditions, loss coefficient of the junctions, initial gradients of temperature and steam volume fraction, and characteristic length of structures. Parametric analysis shows that in the simulation the heat losses through the external walls behind the lower condenser installed in the MISTRA facility determine the long-term depressurisation rate.

Download Full-text