• Mining

The promise of nuclear power

- 2023-08-29 00:00:00

The world view regarding nuclear power generation is shifting as the need to decarbonise industry intensifies due to the escalating impact of climate change.
Already, nuclear energy supplies 10.3% of the world’s electricity – 31 countries use 436 nuclear plants to produce up to 75% of their electricity. In addition, 50 countries utilise nuclear energy in about 220 research reactors, which are also used for the production of medical isotopes.
According to the UN Intergovernmental Panel on Climate Change (IPCC), 80% of all electricity must be low-carbon by 2050 to meet the 2°C target. Nuclear is the world's second-largest source of low-carbon power after hydropower and produces about 28% of all low-carbon power.
Sixty-six reactors are under construction, equivalent to approximately 15% of existing capacity; another 100 are on order, and more than 300 are proposed. During the Covid-19 pandemic, only nuclear power had the flexibility to respond to changes in electricity demand.
In February of this year, Saudi Arabia approved the building of its first nuclear power plant. Turkey will commission its first nuclear power plant this year. Sweden recently changed its energy policy from 100% renewable to 100% fossil-free to allow for new nuclear power plants. India has announced that it will triple its nuclear capacity by 2047.

Nuclear waste
Nuclear power is the only large-scale energy-producing technology that takes full responsibility for all its waste and fully costs this into the product, according to the executive director of the Namibian Uranium Institute and functionary of the Namibian Uranium Association, Dr Gabi Schneider.
According to her, the amount of waste generated by nuclear power is very small relative to other thermal electricity generation technologies.
"Used nuclear fuel may be treated as a resource or simply as waste. Nuclear waste is neither particularly hazardous nor hard to manage relative to other toxic industrial waste," she said.
Safe methods for the final disposal of high-level radioactive waste are technically proven; the international consensus is that deep geological disposal is the best option, she added.

Safeguards
Through the institute, the association takes a leading role in uranium stewardship.
She explained that it engenders the cooperation of all exploration and mining companies because cumulative impacts cannot be addressed in isolation and to avoid unsustainable practices by individual companies. Such practices could have a negative impact on the entire industry.
Ongoing development and implementation of ‘best practise guidelines’ focus on health, environment, radiation, safety, security and community issues. Sustainable development in mining is achieved through an emphasis on mines’ social licence to operate.
Making sure projects are technically appropriate, environmentally sound and socially responsible is key.
"From exploration through construction, operation, and mine closure. We also advocate the avoidance of pollution and for commitment to the responsible management of ores, concentrates, chemicals, fuels, lubricants, and any other process substances," she added.
In managing uranium for beneficial use, the Namibian industry adheres to nuclear safeguards and non-proliferation standards set out by the International Atomic Energy Agency (IAEA) (1957), the Non-Proliferation Treaty of 1970, the Physical Safeguards Convention of 1979, the Comprehensive Safeguards Agreement, and the Additional Protocol for expanded access and monitoring for the Comprehensive Test Ban Treaty Organisation (CTBTO). Additionally, the African Nuclear Weapon-Free Zone, established by the Treaty of Pelindaba in 1996, is strictly enforced.

Using uranium
Uranium is the heaviest naturally occurring element. It was discovered in 1789 by German chemist Martin Klaproth and named after the planet Uranus, which had been discovered eight years earlier. Uranium has three naturally occurring isotopes: U238 (99.3%), U235 (0.7%), and U234 (0.005%).
All isotopes have 92 protons and 92 electrons, but different numbers of neutrons: U238 has 146, U235 has 143 and U234 has 42 neutrons.
Large atomic nuclei may be unstable and emit particles and electromagnetic waves, a phenomenon known as nuclear radiation.
When the nucleus of the U235 atom is bombarded with a neutron, it splits (fissions) and releases energy in the form of heat, along with additional neutrons. These released neutrons cause the nuclei of other U235 atoms to split, releasing further neutrons, thereby initiating a fission 'chain reaction.' When this process occurs repeatedly, millions of times, a significant amount of heat is generated from a relatively small amount of uranium. This process is utilised in a nuclear reactor, where the heat is used to produce steam for generating electricity.
Nuclear fission takes place within a reactor, and nuclear power plants use U235 as fuel. As U235 makes up only 0.7% of the mined uranium, it needs to be enriched by 3 to 5%. The chain reaction is moderated by control rods, which can slow or stop the reaction by absorbing neutrons.
Electricity was first generated by a nuclear reactor on 20 December 1951 when the EBR-1 test reactor in the USA lit up four light bulbs. One tonne of uranium generates 44 million kWh of electricity, equivalent to the energy produced by 20 000 tonnes of coal or 8.5 million m³ of gas. Approximately 27 tonnes of fuel are required annually for a 1000 MW nuclear reactor.

World uranium participation
Namibia participates as a member of the International Atomic Energy Agency (IAEA) on a government level, while the Namibian Uranium Association (NUA) also works with the IAEA.
Namibia has a dedicated representative to the IAEA at the embassy in Vienna, where the agency is located. According to Schneider, Namibia is a signatory to relevant instruments dealing with the peaceful usage of uranium and nuclear energy, as well as the non-proliferation of nuclear weapons.
Schneider is also an advisor for the African Regional Cooperative Agreement for Research, Development and Training Related to Nuclear Science and Technology of the IAEA as a representative of the NAU.
She was also part of the scientific committee that organised this year’s URAM23 (Uranium Raw Material for the Nuclear Fuel Cycle) Conference, and she contributed to an IAEA publication on ‘Milestones in the Development of National Infrastructure for the Uranium Production Cycle’. The mining ministry’s Geological Survey of Namibia (GSN) supports the Comprehensive Test Ban Treaty Organisation (CTBTO), which monitors and identifies illegal nuclear tests. The GSN monitors infrasound and seismic signals at its geophysical station near Tsumeb on behalf of the CTBTO.
Furthermore, the NUA is a member of the World Nuclear Association (WNA), and Schneider represents the NUA on a number of WNA working groups, namely the ESG Working Group, the Decommissioning Working Group, the Radiological Protection Working Group, the Fuel Report Working Group and the Supply Chain Working Group.
"With all these involvements, Namibia takes the stance that Namibian uranium is explored for and produced according to international best practice, and Namibian uranium is only used for peaceful purposes. The formation of a Namibian Uranium Association in order to address the cumulative impacts of the industry is another indication of Namibia’s striving for environmental and social sustainability," she said.