Stockholm (NordSIP) – Nuclear proliferation, environmental and public health concerns create a need for the establishment of well-regulated nuclear waste management processes, particularly when discussing nuclear energy as a potential green alternative.
As is the case with the topics previously covered in this nuclear Energy series, even a cursory review of the issues affecting and affected by radioactive waste management shows that the topic is complex. The dangers are real, but technological solutions appear promising, particularly with regards to nuclear waste recycling.
Nuclear Waste Management
Depending on the level of radiation, nuclear waste can be categorized as Low-Level Waste (LLW), Intermediate-Level Waste (ILW) or High-Level Waste (HLW). According to the US Nuclear Regulatory Commission (USNRC), LLW includes items contaminated with radioactive material including protective shoe covers and clothing, wiping rags, mops, filters, reactor water treatment residues, among others. ILW is distinguished from LLW by the longer – several hundred years – isolation and containment time periods required. According to the World Nuclear Association (WNA), ILW and LLW, which are significantly less radioactive and safer to dispose of than HLW, make up 97% of all nuclear waste.
Spent (used) reactor fuel that cannot be recycled and waste materials remaining after spent fuel is reprocessed are the two main forms of HLW. Highly radioactive, they are potentially very harmful to humans and the environment. According to a report by the International Atomic Energy Agency (IAEA), spent fuel can be kept in wet- (containers submerged in water) or dry-storage (casks), to ensure the confinement of radionuclides, radiation shielding, heat reduction/cooling, and retrievability.
According to the Stimson Center, a nonprofit, nonpartisan US-based think tank, there were 442 operational nuclear power reactors in 30 countries and 220 research reactors operating across 53 countries in 2020. 400,000 tons of spent fuel have been generated, worldwide since the 1950s. This much spent fuel is clearly difficult to manage.
The Duration of Nuclear Waste Storage
Due to its inherently dangerous nature, HLW storage is a difficult issue to manage. The firstly and most problematic issue is the lack of storage facilities. According to the IAEA, “the desired isolation period (…) extends to about 1000 years for the fission products and on the order of a 100,000 years for the transuranium actinides in the high-level waste.” One of these transuranium materials is Plutonium-239, high amounts of which can be used to make nuclear weapons.
HLW storage facilities need to be 5,000 meters underground and be built to very specific requirements. Although old mines have been used for storage, they lack the necessary infrastructure. At the moment, the Posiva Oy facility in Finland, scheduled to become operational in 2025, is the one site in the world is capable of handling the most high-level waste.
Secondly, storing nuclear waste for so long in static repositories may make it an easy target for terrorist attacks or to be stolen and sold into the black market. Thirdly, if stored incorrectly (through leaks or poor handling) HLW could cause major health and environmental damage. Finally, nuclear waste storage is itself a controversial political topic. As was the case the Yucca Mountain repository controversy, the prevailing NIMBY (Not in My Backyard) attitude has traditionally stood in the way of investments in storage facilities.
Sweden has also recently struggled with this issue for many months. Following almost half a year of delays the country’s Minister of Climate and Environment, Annika Strandhäll, greenlighted the final storage facilities for used nuclear fuel in Forsmark and the associated fuel encapsulation plant in Oskarshamn yesterday, Thursday, January 27th.
“Sweden and Finland are the first countries in the world to take responsibility for nuclear waste. This will be a secure spent fuel repository that will provide safety for both the environment and people. In addition, it provides long-term conditions for the Swedish electricity supply and Swedish jobs,” Strandhäll commented on this occasion.
Nuclear Waste Recycling
However, not all nuclear waste needs to be wasted. France, the country most reliant on nuclear energy, is a leading practitioner of recycling spent nuclear fuel. In 2018 it possessed 58 power reactors which produced 72% of the electricity consumed in France that year. Inevitably, the country produces large amounts of spent fuel (HLW) every year.
To manage this output, France has a ‘closed nuclear fuel cycle’, whereby spent uranium and plutonium is reused as fuel. The reprocessed fuel, referred to as ‘Mixed Oxide’ (MOX), is used by nuclear power plants (NPPs) as fuel to produce more electricity, thereby closing the cycle. Through recycling processes, up to 96% of reusable material in the spent fuel can be recovered and put back into the nuclear cycle which addresses the issues of storing high-level waste and proliferation. MOX fuel is not new. France began using MOX in the 1960s, and has since recycled approximately 23,000 tons of fuel, enough to power its NPPs for 14 years, according to the IAEA.
OF the 400,000 tons of spent fuel have been generated since the 1950s, 120,000 tons were recycled. This is equivalent to 22,000m3, which corresponds to the area of a football pitch with waste stacked 3 metres high. Despite its technical feasibility and popularity in Europe, MOX technologies are not permitted everywhere in the world, including in the USA. Finally, total costs of a reprocessing-recycling system may not be as efficient as those of an open fuel cycle with direct disposal system.
This article belongs to a five-part series on nuclear considerations relevant for climate change. Click here to read the other contributions to this series.