Saturday, February 24, 2024
NewsRSSTechnology

What happens after a nuclear power station is closed?

When a nuclear power station is closed, the process of decommissioning begins. This involves various tasks to ensure the safe removal of radioactive materials and the long-term storage of hazardous waste. At Hinkley Point B, for example, workers are currently defueling the reactor cores and dismantling the used fuel assemblies. The site will eventually be handed over to the Nuclear Decommissioning Authority, where the reactor buildings will be sealed and stored for another 20-40 years. However, the most dangerous waste products created by nuclear power stations still present a challenge, as there is currently no permanent solution for their storage. Despite these challenges, the construction of new nuclear power stations, such as Hinkley Point C, continues. The process of decommissioning these plants is expected to take around 20 years and will not be completed until well into the 22nd century.

What happens after a nuclear power station is closed?

This image is property of ichef.bbci.co.uk.

What happens to a decommissioned power station?

Defueling the reactor

When a nuclear power station is decommissioned, one of the first steps is defueling the reactor. This process involves removing the fuel assemblies from deep within the reactor cores and stripping them down. The fuel assemblies are highly radioactive and need to be handled with extreme care. A heavily-shielded crane known as the charging machine is used to lift the fuel assemblies, ensuring the safety of the workers involved in the process. The fuel assemblies are then placed in a steel-lined cell for dismantling, and the used fuel is removed from its casings.

Handing over to the Nuclear Decommissioning Authority

Once the defueling process is complete, the power station is handed over to the Nuclear Decommissioning Authority (NDA). The NDA is responsible for overseeing the safe decommissioning and cleanup of nuclear sites in the UK. They will take charge of the decommissioning process and ensure that all necessary steps are taken to safely manage the site and its radioactive waste.

Care and maintenance phase

During the care and maintenance phase, the reactor buildings are sealed up to protect them from the weather. This phase is necessary because radioactivity decays over time, and it is safer to wait before dismantling the reactor buildings. The NDA believes that this approach will minimize the risks associated with the decommissioning process. The site will be monitored and maintained to ensure its safety and security during this phase.

Handling of dangerous waste products

One of the major challenges in decommissioning a nuclear power station is the handling of dangerous waste products. Nuclear plants produce high and intermediate-level radioactive wastes, some of which will remain hazardous for thousands of years. Currently, there is no permanent repository for these wastes in the UK. The government plans to build a geological disposal facility (GDF) deep underground, but it will not be ready for several decades. In the meantime, these wastes need to be carefully managed and stored to minimize the risks to human health and the environment.

What happens after a nuclear power station is closed?

This image is property of ichef.bbci.co.uk.

Hinkley Point B: An example of decommissioning

History of Hinkley Point B

Hinkley Point B, located in Somerset, was the UK’s first advanced gas-cooled reactor (AGR) when it opened in 1976. It played a crucial role in the country’s energy generation for 46 years. However, cracks developed in the graphite cores of the reactors, which raised safety concerns. As a result, Hinkley Point B was shut down in August 2022.

Current activities at the site

At present, the main activity at Hinkley Point B is defueling the reactors. The fuel assemblies are being removed from the reactor cores, dismantled, and sent for storage at Sellafield. This process requires the use of a heavily-shielded crane known as the charging machine to handle the highly radioactive fuel assemblies safely. It is estimated that removing all the fuel assemblies will take up to four years and cost around £1 billion.

Plans for removing fuel assemblies

Once the defueling process is complete, EDF, the owner of the site, will hand over Hinkley Point B to the NDA. The NDA will be responsible for the next steps of the decommissioning process. These steps include the safe dismantling of the reactor buildings and the storage and disposal of the remaining radioactive waste. The complete decommissioning of Hinkley Point B is expected to take several decades.

What happens after a nuclear power station is closed?

This image is property of ichef.bbci.co.uk.

Hinkley Point A: A first-generation site

History of Hinkley Point A

Hinkley Point A is another decommissioned nuclear power station located near Hinkley Point B. It was one of the UK’s first-generation nuclear sites, with its two reactors brought online in 1965. After 35 years of operation, Hinkley Point A was shut down permanently in 2000.

Decommissioning challenges

Decommissioning Hinkley Point A comes with its own set of challenges. One major task involves the cleaning of miles of intricate pipework to remove traces of asbestos. Asbestos was used as insulation during the construction of the plant, and its removal is a meticulous process that requires laborers to wear respirators for protection. Additionally, the reactor buildings themselves will be left standing, sealed up against the weather, for another 20-40 years during the care and maintenance phase.

Cleaning of asbestos

Large quantities of asbestos were used as insulation in the construction of Hinkley Point A. As part of the decommissioning process, teams of laborers are carefully cleaning the pipework by hand to remove any traces of asbestos. Thousands of tonnes of asbestos have already been removed from the site, but this painstaking work is still ongoing.

What happens after a nuclear power station is closed?

This image is property of ichef.bbci.co.uk.

Future of decommissioning

Timeline for decommissioning

The timeline for decommissioning nuclear power stations can vary depending on various factors, including the size of the site and the complexity of the decommissioning process. In the case of Hinkley Point A and B, the decommissioning work is expected to be completed by 2039. However, the reactor buildings will be left standing for another 20-40 years during the care and maintenance phase. The final stage of decommissioning is expected to take about a decade, meaning the site won’t be fully cleared until the 2070s at the earliest.

Permanent repository for waste

One of the key challenges in the decommissioning process is the management of radioactive waste. Currently, there is no permanent repository for high or intermediate-level nuclear waste in the UK. The government plans to build a geological disposal facility (GDF) deep underground to address this issue. However, the GDF will take several decades to be ready. In the meantime, waste from decommissioned nuclear power stations needs to be carefully stored and managed.

Critics of the nuclear industry

The decommissioning challenges and the lack of a permanent solution for nuclear waste have led to criticism of the nuclear industry. Some argue that the difficulty in handling nuclear waste should deter the construction of new nuclear power stations. Environmental groups like Greenpeace UK advocate for alternative energy sources that do not produce hazardous waste.

Construction of new power station

Despite the concerns surrounding decommissioning and nuclear waste, the construction of new nuclear power stations continues. Hinkley Point C, the new power station being built near Hinkley Point A and B, is expected to begin generating electricity in four years’ time. A decommissioning plan for Hinkley Point C has already been established, ensuring that the site will be properly managed and cleaned up once it reaches the end of its operational life.

What happens after a nuclear power station is closed?

This image is property of ichef.bbci.co.uk.

Conclusion

The decommissioning of a nuclear power station involves various stages, including defueling the reactor, handing over the site to the Nuclear Decommissioning Authority, and the care and maintenance phase. The handling of dangerous waste products and the challenges associated with decommissioning pose significant tasks. However, steps are being taken to ensure the safe management and disposal of radioactive waste. The future of decommissioning includes the construction of new power stations, which will require a thorough decommissioning plan to be in place. The process of decommissioning nuclear power stations is complex and time-consuming, but it is essential for ensuring the long-term safety and security of these sites.

Source: https://www.bbc.co.uk/news/business-67087673?at_medium=RSS&at_campaign=KARANGA