The impact of materials selection on long-term activation in fusion power plants

2000 ◽  
Vol 283-287 ◽  
pp. 28-34 ◽  
Author(s):  
N.P Taylor ◽  
C.B.A Forty ◽  
D.A Petti ◽  
K.A McCarthy
Keyword(s):  
Power Plants ◽  
Materials Selection ◽  
Fusion Power ◽  
The Impact

Overview of JET results for optimising ITER operation

2022 ◽  
Author(s):  
Joelle Mailloux
Keyword(s):  
Particle Physics ◽  
Radiation Transport ◽  
Nuclear Data ◽  
Dust Particles ◽  
Runaway Electrons ◽  
Fusion Power ◽  
Jet Plasma ◽  
Diagnostic Capabilities ◽  
The Impact

Abstract The JET 2019-2020 scientific and technological programme exploited the results of years of concerted scientific and engineering work, including the ITER-like wall (ILW: Be wall and W divertor) installed in 2010, improved diagnostic capabilities now fully available, a major Neutral Beam Injection (NBI) upgrade providing record power in 2019-2020, and tested the technical & procedural preparation for safe operation with tritium. Research along three complementary axes yielded a wealth of new results. Firstly, the JET plasma programme delivered scenarios suitable for high fusion power and alpha particle physics in the coming D-T campaign (DTE2), with record sustained neutron rates, as well as plasmas for clarifying the impact of isotope mass on plasma core, edge and plasma-wall interactions, and for ITER pre-fusion power operation. The efficacy of the newly installed Shattered Pellet Injector for mitigating disruption forces and runaway electrons was demonstrated. Secondly, research on the consequences of long-term exposure to JET-ILW plasma was completed, with emphasis on wall damage and fuel retention, and with analyses of wall materials and dust particles that will help validate assumptions and codes for design & operation of ITER and DEMO. Thirdly, the nuclear technology programme aiming to deliver maximum technological return from operations in D, T and D-T benefited from the highest D-D neutron yield in years, securing results for validating radiation transport and activation codes, and nuclear data for ITER.

scholarly journals The Amur River Water During the Winter Low-water Period: The Many-year dynamics of the Sulfates Content and Runoff.

2020 ◽  
pp. 82-93
Author(s):  
Keyword(s):  
Power Plants ◽  
Hydroelectric Power ◽  
Amur Basin ◽  
Amur River ◽  
Economic Changes ◽  
Large Cities ◽  
The Amur River ◽  
The Many ◽  
The Impact

ulfates are the dominant ions among the major ones in the Amur region’s sewage. Therefore, the purpose of the research is to study the long-term dynamics of the content and runoff of sulfates in the Amur River in the winter low-water, based on the materials of Roshydromet for 1943-1976 and the author’s data for 1999-2019.Significant variations in the main areas were found due to both the diversity of natural conditions and anthropogenic influence in the areas of large cities and localities. The impact of the construction of hydroelectric power plants, significant economic changes in the Chinese part of the Amur basin, as well as the closure of pulp and paper and microbiological industries in the Russian part of the Amur basin on the long-term dynamics of the content and flow of sulfates is estimated. The maximum content of sulfates in the Amur River was observed after the accident at the Jilin chemical plant in China in December 2005. The influence of major floods on the increase in the flow of sulphates in the winter low-water was established.

Cluster analysis for dispersion patterns near nuclear power plants in South Korea

2020 ◽  
Author(s):  
Hyunha Lee ◽  
Chunsil Jin ◽  
Chunji Kim
Keyword(s):  
Power Plant ◽  
South Korea ◽  
Nuclear Power ◽  
Power Plants ◽  
Meteorological Data ◽  
Flow Patterns ◽  
Modeling Framework ◽  
Dispersion Patterns ◽  
The Impact

<p>  Clustering analysis using air parcel trajectories is actively used to investigate transport patterns of pollutants. To estimate the impact of nuclide dispersion from nuclear accident, comprehensive information based on long-term meteorological data is required to eatablish a complete and efficient public protection plan. Most of nuclear plants in South Korea are located in a complex terrain near coastal area that involves complicated meteorological phenomenon such as sea breezes and mountain-valley breezes. Robust approach based on long-term climatrological data is required to fully resolve the impacts near Korean nuclear power plants.</p><p>  In this study, we assessed the impacts of potential nuclear accident in South Korea by clustering dispersion patterns using 10-year meteorological data. Flow patterns are clustered using trajectory cluster analysis, and then combined with dispersion simulations to demonstrate the clustered dispersion patterns by each season and nuclear power plant.</p><p>  The long-term meteorological simulations from 2007 to 2016 were used to evaluate the potential impact of nuclear accidents in Korea, and the modeling framework was designed to show the impact map according to the flow patterns near each nuclear power plant. NOAA HYSPLIT modeling additional clustering analysis suggests that two or three cluster patterns for each power plant can be used. A total of 38 flow patterns are classified near the four nuclear plants in the previous season based on a 10-year wind field analysis. Korea has very complex terrain and coastal areas, and more sophisticated modeling efforts are needed to fully understand the more realistic dispersion characteristics of air masses. In terms of space-time resolution, updating land use information for simulation is very important for weather simulation near the surface of Korea.</p><p>  The results of this study can be used as a guideline for constructing a modeling framework for nuclide diffusion simulations, but given these complex simulation configurations, the results demonstrated in the current study are should be interpreted with caution.</p><p> </p>

Long-term safety of the extended SFR - Methodology and conclusions from the SR-PSU project

MRS Advances ◽  
2016 ◽  
Vol 1 (61) ◽  
pp. 4075-4080
Author(s):  
Fredrik Vahlund
Keyword(s):  
Radioactive Waste ◽  
Nuclear Fuel ◽  
Nuclear Power ◽  
Safety Assessment ◽  
Power Plants ◽  
Spent Nuclear Fuel ◽  
Surface System ◽  
Radiological Safety ◽  
The Impact

ABSTRACTSince 1988 the Swedish Nuclear Fuel and Waste Management Co. operates a repository for low- and intermediate-level short-lived radioactive waste, SFR, in Forsmark, Sweden. Due to decommissioning of the nuclear power plants additional storage capacity is needed. In December 2014, an application to extend the repository was therefore submitted. One key component of this application was an assessment of post-closure safety of the extended SFR. For this safety assessment, a methodology based on that developed by SKB for the spent nuclear fuel repository was used and the impact of the degradation of repository components, the evolution of the surface system and changes of future climate on the radiological safety of the repository was assessed over a period of 100,000 years. The central conclusion of the SR-PSU safety assessment is that the extended SFR repository meets requirements on protection of human health and of the environment that have been established by the Swedish radiation safety authority for the final disposal of radioactive waste. Furthermore, the design of the repository was shown suitable for the waste selected and the applied methodology suitable for the safety assessment.

Investigation of Thermal Ageing in Long Term Operated RPV Materials

2015 ◽  
Author(s):  
Charles C. Eiselt ◽  
Günter König ◽  
Hieronymus Hein ◽  
Maxim Selektor ◽  
Martin Widera
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Elevated Temperatures ◽  
Energy Levels ◽  
Thermal Ageing ◽  
Experimental Investigations ◽  
Low Alloy Steels ◽  
Term Operation ◽  
The Impact

The phenomenon of thermal ageing of low alloy steels comes more into focus in terms of long term operation of nuclear power plants (NPP). Safety-relevant components such as the RPV or the pressurizer have to bear the respective loads at elevated temperatures for longer times. However the mechanical properties of the applied materials might experience certain degradations such as a decrease of the impact energy levels and a shift in the ductile to brittle transition temperature (e.g. T41) leading to higher ductile-brittle reference temperatures and a reduction of material toughness. In terms of a safe long term operation it is important to understand in how far thermal ageing alone, meaning for the RPV without the cumulative damaging effects through neutron irradiation, has detrimental influences on the respective materials of interest. First of all an overview is provided of the current state of the art with respect to thermal ageing by describing influencing mechanisms, its implementation into different nuclear codes, standards and selected experimental investigations in this field. Following this, the test results of the thermal surveillance sets from three German PWRs are presented and discussed. The tested Charpy-V specimens, taken from representative RPV base and weld metals (22NiMoCr3-7 / NiCrMo1UP) as well as their heat affected zones, were exposed to ∼290°C for ∼30 years on the cold leg of the according plants’ main coolant loops. The obtained results are compared with the existing thermal aging data base (baseline and ∼7 years data) of the materials concerned. Finally, the role of thermal ageing particularly with respect to RPV irradiation surveillance will be assessed.

Long Term Operation of Safety Valves at Pressures Near the Set Pressure

2017 ◽  
Author(s):  
L. Ike Ezekoye ◽  
Thomas Beagen ◽  
Brian S. Gordon ◽  
John W. Boufford
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Valve Seat ◽  
Term Operation ◽  
Design Function ◽  
Fast Transients ◽  
High System ◽  
Transient Events ◽  
The Impact

Safety valves in nuclear power plants provide over pressure protection of pressurized systems. Accordingly, these valves are required to open quickly and stably (i.e., open, relieve pressure and close) during postulated transients to protect the integrity of the protected systems. Typically, postulated transients are classified as fast or slow. Fast transients have high system pressurization rates that proceed very quickly thereby requiring the safety valves to pop open. On the other hand, there are transients that proceed very slowly that are less challenging to the system but may initiate leakage across the installed safety valve seat. There is very limited knowledge on the impact of prolonged operation of safety valves during slow pressurization accident events. The integrity and functionality of these valves during such slow pressurization events are often in question. This paper examines analytically the behavior and the integrity of safety valves during slow pressurization transient events at pressures near the valve set pressure. This paper considers extended periods of valve simmering that may progress to valve cycling (popping fully open) during such events. To validate the analytical performance prediction, steam tests were performed with safety valves which confirmed that these valves can operate extensively under slow pressurization transient events while maintaining their capability to perform their intended design function.

scholarly journals The Amur River Water During the Winter Low-water Period: The Many-year dynamics of the Sulfates Content and Runoff

2020 ◽  
Author(s):  
Keyword(s):  
Power Plants ◽  
Hydroelectric Power ◽  
Amur Basin ◽  
Amur River ◽  
Economic Changes ◽  
Large Cities ◽  
The Amur River ◽  
The Many ◽  
The Impact

Sulfates are the dominant ions among the major ones in the Amur region’s sewage. Therefore, the purpose of the research is to study the long-term dynamics of the content and runoff of sulfates in the Amur River in the winter low-water, based on the materials of Roshydromet for 1943-1976 and the author’s data for 1999-2019.Significant variations in the main areas were found due to both the diversity of natural conditions and anthropogenic influence in the areas of large cities and localities. The impact of the construction of hydroelectric power plants, significant economic changes in the Chinese part of the Amur basin, as well as the closure of pulp and paper and microbiological industries in the Russian part of the Amur basin on the long-term dynamics of the content and flow of sulfates is estimated. The maximum content of sulfates in the Amur River was observed after the accident at the Jilin chemical plant in China in December 2005. The influence of major floods on the increase in the flow of sulphates in the winter low-water was established.

THE IMPACT OF LONG-TERM THREATS OF CLIMATE WARMING AND A PANDEMIC ON THE GLOBAL OIL MARKET

2021 ◽  
Vol 2 (8) ◽  
pp. 93-105
Author(s):  
O. V. EVSEEVA ◽  
Keyword(s):  
Renewable Energy ◽  
Power Plants ◽  
Fossil Fuels ◽  
Think Tanks ◽  
Oil Companies ◽  
Oil Market ◽  
Warming Climate ◽  
Effective Drugs ◽  
The Impact

The global oil market is currently being heavily impacted by the build-up of renewable energy power plants due to the threat of a warming climate. Many countries have decided to restructure the energy sector to minimize the burning of fossil fuels. This decision reduces the demand for oil and forces a revision of long-term oil market forecasts. The virulent COVID-2019 virus, which emerged in late 19, has caused a massive pandemic. The pandemic has markedly reduced human activity in all countries and, in the absence of effective drugs to deal with this virus and its many strains, poses additional long-term threats to both the global econ-omy and the oil market. This is confirmed by the forecasts of oil companies and think tanks discussed in this article.

Development of a Sea-State Database in the Northwest Pacific Ocean by Long-Term Numerical Hindcast Modelling

2017 ◽  
Author(s):  
Jian Shi ◽  
Antoine Joly ◽  
Jinhai Zheng ◽  
Jisheng Zhang ◽  
Tian Chen ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Power Plants ◽  
Wave Model ◽  
Northwest Pacific ◽  
Sea State ◽  
Northwest Pacific Ocean ◽  
North West ◽  
Typhoon Waves ◽  
The Impact

In the Northwest Pacific zone, all the active nuclear power plants are located in coastal areas. The extreme typhoon waves, which occur in summer and autumn, pose great risks on the nuclear facilities and related coastal infrastructures. To facilitate the assessment of the impact of typhoon waves over the whole Chinese coastal line, detailed data of the sea state over this region is necessary. For this reason, a numerical sea state data base, which includes the North-West Pacific Ocean is under construction. It will range over several decades, to provide long-term wave data in this area. An oceanic wave model with a triangular mesh covering the whole Pacific Ocean has been set up by using the third generation spectral wave model TOMAWAC. The model is calibrated by comparing the simulation results over the period of January 1999 and during typhoon Muifa (1109) to buoy data. The numerical result of significant wave height (SWH) shows an excellent agreement with the oceanic buoy observations. The minimum values of the average bias between prediction and measurement is around 2–3 cm. The prediction of mean period (MP), however, is less accurate than the results of SWH. The model underestimates the mean period with amplitudes of around 0.6–1.2 s. Five different configurations of the source terms in TOMAWAC were tested during the calibration to find the best results. The comparisons show that the BAJ configuration can provide most accurate results of SWH. The predictions for configurations JKD and JWD show best results of MP. However, the SWD configuration provides the worse results for both of SWH and MP.

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