LEARNING FROM FISSION | SPECIAL REPORT
“This will feed into the INPRO study – maybe looking at that proportionality and perhaps mixing between a nuclear framework and a radiological framework for regulating fusion.” It is about “learning the positive lessons from nuclear on how to have a very structured approach to safety and security and environmental protection but also learning where that might perhaps lead to over-engineering or extended time frames that are unnecessary for the level of hazard for fusion”.
Fusion-fission collaboration In June, the IAEA hosted a week-long wide-ranging “Technical Meeting on Synergies Between Nuclear Fusion Technology Developments and Advanced Nuclear Fission Technologies”.
The purpose of the event was to provide a forum for
exchange of information as well as present up-to-date review of activities on synergies in technology development between nuclear fission and fusion for energy production at national and international levels. The discussions will feed into an IAEA Nuclear Energy Series publication which aims to provide insight on the areas covered as well as provide examples of good practices and lessons learned and offer suggestions to accelerate the transfer of technology, knowledge, and know-how from fission to fusion. Areas where there were deemed to be strong synergies
and communalities between fusion and nuclear fission included development of fusion materials to withstand harsh service conditions and minimisation of radioactive waste hazards to reasonably achievable levels. Areas with moderate synergies and communalities
between fusion and fission included: ● Fusion materials irradiation facilities under reactor- relevant conditions;
● Development of high temperature energy conversion systems;
● Computational tools, design and safety analyses codes; ● Regulatory sized for fusion energy facilities licensing; ● Reliable and feasible fuel cycle breeder material supply (lithium and lead);
● Remote handling and in-service inspection; ● Remote controllability, radiation hardened electronics and CAD-supported operations.
In general, the meeting concluded that fusion could benefit from many relevant synergies with nuclear fission experience as well as commonalities in materials development, activated metals management, remote handling, and liquid metal. There are also development parallels between Generation IV advanced fission plants and commercial fusion facilities such as DEMO. While plant licensing and decommissioning and radwaste management for fusion may require a slightly different regulatory approach – due to the reduced hazard/risk potential – elements such as design, construction, operation and parts of the fuel cycle and plasma control for fusion facilities have many synergies with fission experience. Luigi di Pace, a consultant who worked on Fusion at Italy’s
ENEA, told NEI that he believed there were good prospects for fusion and fission to work together. He noted that the fusion community was learning from the experience of nuclear in terms of design codes, safety codes and materials. “And I think in the future there will be synergies the other way round. Not only will fission help fusion but
there will be some areas of expertise in which fusion can improve and advance technology in fission, in particular with respect to Generation IV reactors that are based on advanced technologies.” He added: “I’m not sure of the timeline – who will arrive first to a commercial technology. Probably it will be fission, but in the meantime there will be a bridge as both work towards a demonstrator plant. We really do not know when this will happen, but I think it will be in the middle of this century.” He believes the big issues and main commonalities between fusion and fission are materials and waste management as well as design codes, safety analysis codes and in service inspection. “Both fusion reactors and advanced fission reactors need to operate at high temperature. This means that materials and commercial system should be designed to operate at those high temperatures.”
Learning to manage waste As to waste management, fission reactors will soon have to handle much more decommissioning as NPPs reach the end of their operating lives. “The real problem is not the high- level waste or used fuel but the huge amount of mildly- activated metals, and fusion may face the same problem. Unless they find some other solution, every five years the entire internals of the tokamak have to be replaced because of neutron damage, which means thousands of tonnes of material. Developing new materials can be helpful not only for fusion but also for advanced reactors, many of which will also face a large neutron flux. So there is a common interest to develop materials which are resistant to neutrons.” Tritium can also cause damage to materials. However, another commonality is that fission is needed to produce tritium. “For example, to start DEMO we will need a few kilograms of tritium. At the moment, this can only be produced by Candu reactors. The problem is that tritium decays, so you cannot store it for 20 years – it decays every 12 years”. Di Pace expressed some concern about the new enthusiasm for fusion sparked by the growing number of private companies in the field. “They have a lot of money and really they promise to have energy- electricity by 2030 while the governmental programmes are saying we will not have electricity before 2050. There are some doubts. They are developing new concepts for a fusion machine mainly focusing on concepts and on experiments.” At the same time, the larger government-backed projects are trying to solve the problems related to materials, fuel inventory and legal and regulatory issues. Di Pace noted that “when there is a strong driving force
and also money, that is what drives these things. So really, I am quite confident that something will happen in the next two decades.” However, he added that it was important that the ITER experiment should be successful, “otherwise we have to reconsider everything”. He added: “I hope we will have a commercial reactor no later than 2070. If all goes well DEMO will begin construction in 2040. I hope the experience of JET and ITER will also produce something.” He said he expected to see some progress by the end of the decade. “This is my hope. I spent most of my career working on this, but I am getting older and probably will not survive to see the big event. But I am happy that our younger colleagues are also very enthusiastic. It is important to engage the new generation working in nuclear in both fusion and fission.” ■
www.neimagazine.com | April 2023 | 27
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47
