19/12/2023
This is the final article of our mini-series ‘Powering Tomorrow: Intellectual Property & Nuclear in the Age of Net Zero’ where our specialists delve into the role of intellectual property within the nuclear sphere, looking at developments in traditional nuclear power as the industry strives to adapt to the sustainable energy landscape of the future, and at the potentially revolutionary impact of nuclear fusion.
Nothing new under the sun: a history of nuclear innovations
The UK has a long history with nuclear power. It opened its first nuclear power station in 1956 and at its peak generated more than a quarter of its energy from this source. We’re now seeing a renewed wave of interest with government plans to raise the capacity of nuclear power stations back up to about 25% by 2050.
In recent articles (Nuclear’s Behind-the-Scenes Influence, Powering Towards the Fusion Era and Modular reactors mark renaissance for nuclear patent filings) we have explored the innovative entities, technologies and schemes that will likely dictate how nuclear energy fits into a future net-zero mix. However, in the following article, we will take the opportunity to look back at the history of nuclear innovation and patenting and consider how this has influenced today’s landscape, because the lessons and insights gleaned from the past may well be instrumental in how nuclear energy evolves into the future.
A pioneering patent application for nuclear energy – US56890444
In the early days of nuclear energy development, patents played a vital role in protecting the innovative ideas and technologies that formed the foundation of the industry. The earliest patent we could find relating to nuclear technology is US patent application no. US56890444 by Enrico Fermi and Leo Szilard, filed in the US in December 1944 and in the UK in 1945. This application relates to the first artificial nuclear reactor, or atomic pile, Chicago Pile-1 (CP-1) which initiated the first human-made self-sustaining nuclear reaction. The application was kept secret for national security reasons for over a decade until it was finally published and granted in 1955 in the US and 1959 in the UK.
This landmark patent may well have been the first publicly available enabling disclosure of nuclear technology, and thus it potentially paved the way for all other developments in the field.
The Figure above shows a uranium-graphite reactor completely enclosed in a radiation shield according to Fermi and Szilard’s invention.
Safety and regulation – FR 7408375 A
Right from the outset, safety has been a paramount concern for nuclear energy generation, and the early patent landscape suggests a strong awareness of the potential hazards of nuclear criticality (i.e. a self-sustaining nuclear reaction) and the risks associated with radioactive materials. The biggest concern is of course the potentially catastrophic consequences of a full scale nuclear reactor meltdown, and patent databases contains numerous examples of how innovation has helped to minimise the risks of such disasters occurring.
Generally speaking, there are three main factors affecting the safety of a nuclear reactor, namely:
- controlling the reactivity;
- cooling the fuel; and
- containing the radioactive substances.
Apart from the control rods which are inserted into the core of the nuclear reactor to absorb neutrons and control the rate of fission of nuclear fuel, the main safety provisions are the back-up emergency core cooling system (ECCS). The ECCS aims to remove excess heat from the reactor fuel rods.
An early example of a patent on which developments of ECCS technology were founded is French patent application FR 7408375 A from 1974 (published in the US as US 4035231 A). In the event of a failure of a pump, the ECCS in this patent application provides a backup supply of cooling fluid from one or more pumps in the reactor core. In the reactor core shown in Figure 1 of this application, each reactor module R is associated with a pump P which provides cooling liquid to the reactor module through pipe K with a backup pipe S that feeds cooling liquid from one of the other pumps in the event of a failure of one of the other pumps. This prevents excessive overheating caused by the residual power of the reactor and ensures cooling of the reactor under all circumstances.
In contrast to the invention of FR 7408375 A, previous cooling solutions utilised active systems including mechanical pumping elements such as auxiliary pumps which are liable to fail, thereby reducing the reliability and safety of the reactor. Consequently, ECCS systems like the one in FR 7408375 A have formed the basis for the ECCS systems which are used today.
Efficiency and Sustainability – US22345151A
As a proven scalable and reliable low-carbon energy source, nuclear power is expected to play a pivotal role in efforts to reduce reliance on fossil fuels to address climate change. However, with increased reliance on nuclear energy, there also comes increased production of the biproducts of this technology, such as nuclear waste. Nuclear waste is dangerous due to its high radioactivity, which if not properly managed and disposed of can be a risk to human health and the environment. We would expect to see increased innovation in this area in the years to come. However, even in the early days of nuclear technology, we can see that patents were being used to protect innovations that help to manage nuclear waste.
For instance, “Disposal of radioactive cations”, application number US22345151A, filed by William Ginell in 1951 relates to the use of clay materials for carrying out an ion exchange process in order to concentrate and store radioactive waste.
This patent application describes a process whereby montmorillonite minerals which have a high cation exchange capacity, are brought into contact with radioactive waste produced from nuclear fission. The radioactive cations of the waste material are exchanged with the cations in the mineral. The mineral is then heat treated to alter its crystal structure and form a clay, before being buried in a bed of natural clay to immobilise the radioactive clay and prevent the radioactive ions from escaping. This process has formed the basis for modern processes such as cementation in which solid radioactive waste is immobilised in a grout and allowed to set such that it can be stored or disposed of.
Nuclear Fusion- US75604458A
Up until now, nuclear fission has been the primary focus of nuclear power generation. However, the dream of nuclear fusion has long captured the imagination of scientists and innovators. Fusion, regularly touted as the holy grail of sustainable clean energy, offers the potential for nearly limitless clean energy.
As discussed in our earlier blog, ‘Powering towards the fusion era’, the number of nuclear fusion patents filed by private companies is on the rise, having more than doubled over the past 10 years. However, attempts at harnessing the power of nuclear fusion stretch back many decades, and early patents in the United States detail several attempts, which were made to create the extreme conditions required for nuclear fusion.
For example, US patent application ‘Method and apparatus for producing thermonuclear reactions’, US75604458A by Nicholas Christofilos relates to a pioneering device from the 1960s and 70s, known as the ‘Astron’. Its concept was the use of a unique confinement system, in which electrons were accelerated using magnetic fields to form a rotating layer into which a thermonuclear fuel was introduced. The fuel is then manipulated by the forces of the electron layer to create a controlled thermonuclear reaction which produces usable energy.
In the Figure of the patent reproduced below, solenoids 23 and coils 24 disposed around the cylindrical vessel 11 create the magnetic field which accelerates the electrons. Evacuation conduits 13 are provided for the plasma beams produced.
However, whilst the Astron was certainly a promising concept at the time, it was ultimately unable to meet the performance goals set for it and funding was eventually cancelled in 1972. Despite such abandonment, projects like the Astron and its associated patent filings have still played an important role in advancing nuclear fusion technology, by helping to inspire others about what might be possible in this field.
Conclusion
As the UK and potentially the wider world aims to increase nuclear power capacity, the lessons from historical patents remain invaluable. These patents not only highlight past ingenuity but they can also guide us towards a safer, more efficient, and sustainable nuclear future. Although the above patents may not seem significant on their own, the cumulative effect of these incremental advancements have led us to where we are today, and potentially even put the likes of nuclear fusion within realistic reach.
Read the previous article of Powering Tomorrow: Modular reactors mark renaissance for nuclear patent filings
This article is for general information only. Its content is not a statement of the law on any subject and does not constitute advice. Please contact Reddie & Grose LLP for advice before taking any action in reliance on it.
