What is the project about?

Objectives

The “supercritical CO2 heat removal system”, sCO2-HeRo, safely, reliably and efficiently removes residual heat from nuclear fuel without the requirement of external power sources. This system therefore can be considered as an excellent backup cooling system for the reactor core or the spent fuel storage in the case of a station blackout and loss of ultimate heat sink. sCO2-HeRo is a very innovative reactor safety concept and provides breakthrough options with scientific and practical maturity, which will be finally demonstrated and experimentally proven by reactor simulation studies in the unique glass model of the Gesellschaft für Simulatorschulung GfS.

Our main objective is to show the proof of the concept of the sCO2-HeRo system by:

  • Designing a compact heat exchanger to transport the decay heat to the supercritical CO2 cycle which energy is also used for driving the self-propellant cycle
  • Designing a turbo-machine set which is self-propellant and self-launching
  • Evaluating a sink heat exchanger to transport the decay heat from the supercritical CO2 cycle to the alternative ultimate heat sink (ambient air)
  • Ensuring quality assurance by individual component reviewing and testing the individual components in a supercritical CO2 loop to demonstrate the fulfilment of industrial standards

Proofing the sCO2-HeRo system regarding safety, reliability and the possibilities for retrofitting by implementing the system into a unique glass model run by the Gesellschaft für Simulatorschulung (GfS)

Work packages

The project is in total divided into six work packages (WPs) as illustrated in the figure below.

The thermodynamic and mechanical interfaces between the glass model and the single components of the sCO2-HeRo system will be defined in WP1 System integration & simulation. Within this WP the integration of the sCO2-HeRo in the European LWR (Light Water Reactor) fleet will be demonstrated. The requirements regarding the position of the single components in the reactor building will be defined and the demands to achieve the quality assurance will be specified.

In WP2 Heat exchanger, we aim at designing, investigating and testing the compact heat exchanger and the sink heat exchanger with regard to the stringent space limitations, the applied conditions and the corresponding working fluids. Ultimately, the compact heat exchanger for the glass model will be manufactured and delivered to GfS (Gesellschaft für Simulatorforschung). The experimental work on the compact heat exchanger will be carried out in the supercritical CO2 test loop SCARLETT at IKE University of Stuttgart. More information on SCARLETT…

In WP3 Turbo-machine set, the University of Duisburg-Essen (UDE) will develop a turbo-machine under consideration of its reachable performance under the yet unknown boundary conditions for supercritical CO2 applications. Before the turbo-machine set is shipped to GfS for installation, a component test is conducted in the SUSEN CO2 loop at CV Rez (Research Centre Rez) that proofs the calculated performance map. More information on SUSEN…

WP4 Integration into the glass model brings together the single components that will be installed at the glass model at GfS. The developed test scenarios from WP1 are then implemented to test the feasibility of the device as a self-propellant passive cooling system even in very unlikely scenarios.

In WP5 Exploitation and Dissemination, the scientific aspects and project results will be made available to the wider public but also specifically to the scientific community and the business and industrial community.

WP6 Management deals with the general management of the project.

Benefit

With its autarkic operation, the sCO2-HeRo opens new avenues towards reactor safety and will considerably influence future safety concepts in the field of nuclear energy. The sCO2-HeRo system is completely independent of external supply of resources, such as electricity or water, for an almost unlimited period. The period of a reliable and safe decay-heat removal during a station blackout, combined with the loss of the ultimate heat sink, will be considerably extended by applying the proposed system. Furthermore, the sCO2-HeRo system is able to generate excess electricity, which is extremely valuable during a long-term station blackout.

Once being proven as reliable system, already existing nuclear power plants could be easily upgraded in the future by the very compact and self-launching device.

The sCO2-HeRo concept is independent of the type of light water reactor and provides the option to enhance the safety of the entire European fleet of LWRs. The sCO2-HeRo system is capable to be coupled to almost all nuclear plants in Europe, which underlines the European dimension of the idea.