Generation IV Reactors have the potential for utilisation in a wide range of applications in addition to high efficiency electricity generation. The design goals include improved sustainability, safety and reliability, economics, proliferation resistance, waste management practices and most importantly take full advantage of previous experience. The technologies include Very High Temperature Reactors (VHTRs), see e.g. Figure 1, which are High Temperature Gas-cooled Reactors (HTGRs) that are amenable in principle to many applications in cogeneration.
Prototype HTGRs have already been built and operated in the UK, Germany and the US. In regard to cogeneration, High Temperature Gas-cooled Reactors (HTGRs) are capable of providing high temperature process heat for various applications. The latest designs under development may be able to provide temperatures that reach the levels required for the glass industry. Much of the R&D work for cogeneration, which involves coupling of two existing mature technologies (nuclear and conventional power plant), is being carried out at the international level to maximise gearing of investment and knowledge development.
In electrical power generation, a large fraction of the energy produced is dissipated and so cogeneration is clearly economically desirable. A considerable amount of work has been carried out within the European Nuclear Cogeneration Industrial Initiative (NC2I) and the US Next Generation Nuclear Plant (NGNP) Industrial Alliance to develop modern commercial HTGR technology for cogeneration. Figure 2 demonstrates the flexibility of a system that could serve a variety of process heat markets with different levels of temperature requirements.
In 2014, an alliance (called GEMINI), was formed comprising the European NC2I and the US NGNP Industrial Alliance to develop modern commercial HTGR technology for cogeneration. In September 2017, the EC set up the Euratom GEMINI+ project to look at the requirement for HTGR cogeneration plant in Europe and to develop an overall system that would meet these requirements. It would take account of significant earlier experience from the HTGRs that operated in Europe and the US.
Figure 3 illustrates possible cogeneration options; some are currently in operation, others are longer term. The specific aim of GEMINI+ is to develop a reactor design and associated power conversion systems to generate power and high temperature steam for industry. A demonstration industrial application for the technology is to develop it and assess it as a potential technology for replacing power generation and steam production, currently supplied by coal fire plant. The project comprises an international consortium led by NCBJ in Poland. Such a technology would provide carbon free generation and thus make a positive contribution to global warming.
The GEMINI+ project will complete on 31 August 2020. The project therefore is about two-thirds way through. Good progress has been made in defining core design options and associated power conversion systems that would meet all performance, end-user, flexibility and safety requirements. The project will consider the cost, innovative approaches to reduce cost, improve safety etc., perform demonstration simulations and finally disseminate the project outcomes to stakeholders. The project also looks at through-life issues from design, commissioning, operation and then final decommissioning. The presentation to the Cambridge SGT would cover a brief survey of work carried out to date on GEMINI+ as a demonstration and example of the potential use of nuclear energy for high temperature cogeneration.
The presentation will also touch on other HTGR work in progress internationally e.g. in China in developing modular HTGR designs for multiple unit carbon free generation.
It is recognized that very high temperatures in excess of 1000oC are required in the glass industry. HTGRs are envisaged that in principle could meet this requirement but at the present would still require extensive R&D in materials development etc. While reaching sufficiently high temperatures to meet the requirements of its current intended application, this project should be regarded a step on the way from the point of view of using HTGRs for very high temperature applications.