In power grids, exactly as much electrical power must be provided at any moment as is required by the consumer. The increasing proportion of photovoltaic and wind power plants with feed-in priority means that the so-called residual load, i.e. the difference between the power fed in from photovoltaic and wind power plants and the power required in the grid, is fluctuating more and more. This fluctuating residual load must be provided by conventional and flexibly controllable energy plants in order to be able to guarantee safety of supply. This is possible, among other things, through various storage solutions, which serve to increase the degree of flexibility of conventional energy plants and to compensate for the fluctuating residual load as quickly as possible and in an environmentally friendly manner.
Aim of our work is to provide a contribution to the flexibilisation of thermal energy systems. The provision of control energy should stabilize the power grid and grant safety of supply for the economy. Subject of the project is application oriented research for novel energy technologies.
With erection of the experimental plant THERESA in the Zittauer Power Plant Laboratory the experimental infrastructure was created, to experimentally analyse component and system properties through flexibilisation measures and to derive important knowledge for future operation of energy plants. THERESA reproduces a thermodynamic cycle with pre-heaters, steam generator, superheater, heat sink and thermal storage. That way heat source and heat sink are separated temporally. Maximum water-steam parameters are 160 bar and 350 °C, depending on the configuration.
Currently, we are carrying out experimental and methodical work aimed at the development of simulation-based dimensioning and integration methods. Results can also be transferred to the integration of storage systems in production plants and process engineering facilities.
Until availability of a final disposal site in deep geological formations the necessity exists in Germany to temporarilly store used nuclear fuel elements safely using transport and storage casks (TSC) at the power plant locations. This is done that way since 2005 and it must be assumed that it stays like that for more than 50 years. The problem with it is in this context that the designated TSC (CASTOR® V/19 and V/52) only have an operational license for 40 years at the moment. Furthermore, no reliable information is currently available on the long-term behavior of spent fuel. It should be added, that extrapolative modeling of radiochemical and thermomechanical material properties is hard to do for a conclusive assessment.
As a consequence, in the sense of public service for society there is a necessity but also a guarantee for the ability of the transport of used fuel elements to the final disposal site later, to evaluate and to possibly implement means for a non-invasive condition monitoring of TSC and their content.
Extremely high activity of the stored content as well as the resulting massive structure of TSC (thick-walled spheroidal iron) restricting the spectrum of basically usable non-invasive condition monitoring methods hard. Aim of the joint project is to investigate means and methods for non-invasive condition monitoring of TSC respectively to allow for detection of changes of the cask content with its thermal and mechanical properties, without opening the TSC.
Goals of the project are experimental as well as simulative investigation and assessment of four measurement or operating principles: gamma emissions, thermografics, acustic emissions and vibration analysis.
Our task is to errect a suitable experimental infrastructure, carry out the investigation and to create together with project partner TU Dresden a procedural screening concept for condition monitoring of TSC.
In electricity grids, the exact amount of electrical power required by the consumer must be provided at all times. The increasing proportion of photovoltaic and wind power plants with feed-in priority means that the so-called residual load, i.e. the difference between the power fed in from photovoltaic and wind power plants and the power required in the grid, is fluctuating more and more. This fluctuating residual load must be provided by conventional and flexibly controllable energy systems in order to ensure security of supply. This is possible, among other things, through various storage solutions, which serve to increase the degree of flexibility of conventional energy systems and to compensate for the fluctuating residual load as quickly as possible and in an environmentally friendly manner.
The aim of our work is to contribute to the flexibilization of thermal energy plants. The provision of balancing energy is intended to stabilize the interconnected grid and ensure security of supply for the economy. The subject of the project is application-oriented research into innovative energy technologies.
With the construction of the THERESA test facility in the Zittau power plant laboratory, the experimental infrastructure has been created to experimentally analyse component and plant behaviour through flexibilization measures and to derive important findings for the future operation of energy plants. The THERESA test plant reproduces a thermodynamic cycle with preheaters, steam generator, superheater, heat sink and a thermal energy storage unit. In this way, the heat source and heat sink are decoupled from each other in terms of time. Depending on the configuration, the maximum water-steam parameters are up to 160 bar and 350 °C.
We are currently carrying out experimental and methodological work aimed at developing simulation-based design and integration methods. The results can also be transferred to the integration of storage tanks in production plants and process engineering systems.
Until a repository in deep geological formations is available, it is necessary in Germany to store spent fuel elements safely in transport and storage casks (TLB) at the power plant sites. This has been practiced in this form since 2005 and it can currently be assumed that it could remain so for long periods of more than 50 years. The problem in this context is that the TLBs (CASTOR® V/19 and V/52) and interim storage facilities intended for this purpose currently only have a maximum operating license of 40 years. Furthermore, there is currently no reliable information available on the long-term behavior of spent fuel elements. In addition, extrapolative modeling of radiochemical and thermomechanical material behavior is difficult for conclusive assessments.
In the interests of public services for society, but also to ensure the subsequent transportability of the spent fuel assemblies to a repository, this makes it necessary to evaluate and, if necessary, implement options that allow non-invasive condition monitoring of TLBs and their contents.
The extremely high activity of the cask contents and the resulting solid construction of the TLB (thick-walled spheroidal graphite cast iron) severely limit the range of non-invasive condition monitoring methods that can be used in principle. The aim of the joint project is therefore to research possibilities and methods that enable non-invasive condition monitoring of TLB and detection of changes in the thermal and mechanical properties of the container contents without opening the TLB.
The project objective is the experimental and simulation-based investigation and evaluation of the four measurement and operating principles: Gamma emissions, thermography, acoustic emissions and vibration analysis.
Our task is to set up a suitable experimental infrastructure, carry out investigations and, together with the project partner TU Dresden, develop a process engineering investigation concept for the condition monitoring of TLB.
