To reduce our reliance on fossil fuel, the global community needs to boost the presence of sustainable energy significantly. In the lineup of renewable energy sources, there are solar, wind, tidal, and geothermal energy. Then there’s nuclear power, an overlooked competitor with massive potential and a mixed reputation.
Born during World War II (Chicago Pile-1 the world’s first nuclear fission reactor went critical in 1942) and flourishing in the post-war era, nuclear reactors slowly fell out of favor in power generation after a handful of high-profile accidents caused by human errors, negligence, and natural crisis.
To revitalize this industry, scientists and engineers have been focusing on building nuclear fission reactors that have a bigger safe margin, better thermal efficiency, longer life-span, and the tendency to produce less radioactive wastes, all of which require innovations in nuclear fuel.
A long-time leader in nuclear science and research, Canadian Nuclear Laboratories (CNL) is leading the charge in Canada to bring atomic energy into the twenty-first century. During a visit to CNL's Chalk River Laboratories in eastern Ontario, LabRoots spoke with CNL’s senior scientists about the organization’s legacy, as well as the challenges they have taken up in modernizing the industry.
Between the 1950s and 1960s, the renowned CANDU (Canada Deuterium Uranium) reactor was developed at the Chalk River Laboratories by Atomic Energy of Canada Limited (AECL).
As the main workhorse in electric power generation in Canada (Canada's most populous province Ontario alone has 18 active CANDU reactors, which helped the province phase out coal-fired power generation), as well as other regions of the world, the design of CANDU reactor is unique. It uses deuterium water (heavy water) instead of normal water as neutron moderator so that fewer neutrons, emitted by reactor fuel, get trapped in water and more can participate in the fission chain reaction. This results in a second advantage. Natural uranium, which has about 0.7% uranium-235—the necessity to sustain a fission chain reaction, can be directly used in the reactor without any enrichment.
The distinctive design not only eliminates the cost of uranium enrichment but also lowers the possibility of nuclear proliferation.
Little known to the outsiders of the nuclear community, the nuclear fuel has a complicated life cycle that involved many processes. Its starts with ore mining, followed by refinement, purification and fabrication. Once the fuel is spent, the reusable components are reprocessed and recycled, and the rest are disposed.
The Nuclear Fuel Cycle (video credit: IAEA)
For over 60 years, CNL has been providing research institutes and commercial clients services in fuel fabrication, performance and testing, as well as advice and research in support of fuel cycle management.
"From a holistic point of view, our fuel development department focuses on improving all processes involved in the life cycle of nuclear fuel so that we can reduce cost and environmental impact, and improve efficiency," said Rosaura Ham-Su, the manager of CNL’s Fuel Development team in an interview with LabRoots.
While Canadian Nuclear Laboratories continue to support the current fleet of reactors, they also have their eyes on the future of nuclear technologies. Advanced reactor designs such as Small Modular Reactor can bring advantages such as better economics and increased safety margins to the table, but they also create challenges to the fabrication of nuclear fuel.
[This article contains LabRoots original contents]