Tritium supply and use: a key issue for the development of nuclear fusion energy

Full power operation of the International Thermonuclear Experimental Reactor (ITER) has been delayed and will now begin in 2035. Delays to the ITER schedule may affect the availability of tritium for subsequent fusion devices, as the global CANDU-type fission reactor fleet begins to phase out over the coming decades. This study provides an up to date account of future tritium availability by incorporating recent uncertainties over the life extension of the global CANDU fleet, as well as considering the potential impact of tritium demand by other fusion efforts. Despite the delays, our projections suggest that CANDU tritium remains sufficient to support the full operation of ITER. However, whether there is tritium available for a DEMO reactor following ITER is largely uncertain, and is subject to numerous uncontrollable externalities. Further tritium demand may come from any number of private sector “compact fusion” start-ups which have emerged in recent years, all of which aim to accelerate the development of fusion energy. If the associated technical challenges can be overcome, compact fusion programmes have the opportunity to use tritium over the next two decades whilst it is readily available, and before full power DT operation on ITER starts in 2035. Assuming a similar level of performance is achievable, a compact fusion development programme, using smaller reactors operating at lower fusion power, would require smaller quantities of tritium than the ITER programme, leaving sufficient tritium available for multiple concepts to be developed concurrently. The development of concurrent fusion concepts increases the chances of success, as it spreads the risk of failure. Additionally, if full tritium breeding capability is not expected to be demonstrated in DEMO until after 2050, an opportunity exists for compact fusion programmes to incorporate tritium breeding technology in nearer-term devices. DD start-up, which avoids the need for external tritium for reactor start-up, is dependent upon full tritium breeding capability, and may be essential for large-scale commercial roll-out of fusion energy. As such, from the standpoint of availability and use of external tritium, a compact route to fusion energy may be more advantageous, as it avoids longer-term complications and uncertainties in the future supply of tritium

Chapter 20 Assessment of radiation pollution from nuclear power plants

Nuclear power plants split uranium atoms in a process called fission. In a nuclear power plant, heat is generated to produce steam that spins a turbine to generate electricity. Nuclear energy has been proposed in response to the need for a clean energy source compared to CO2 production plants. However, nuclear energy is not necessarily a source of clean energy as nuclear power plants release small amounts of greenhouse emissions in activities related to building and running the plant. Moreover, even if all safety measures are followed, there is no guarantee that an accident will not occur in a nuclear power plant. In the case of an accident involving a nuclear power plant, the environment and the people around it may be exposed to high levels of radiation. Another important environmental problem related to nuclear energy is the generation of radioactive waste that can remain radioactive and dangerous to human health for thousands of years. There are also several issues with burying the radioactive waste. Here, we describe different types of radioactive waste pollution from nuclear power plants, their environmental effects, nuclear regulations, and nuclear power plant incidents. Moreover, two case studies on nuclear power plant accidents and their consequences are discussed