Are nuclear power plants safe?

Are nuclear power plants safe?

Yes, nuclear power plants are safe – and increasingly so.

The concept of nuclear safety encompasses elements of technology, engineering, training, continuous learning, supervision, and plant operation reporting. Moreover, it is a concept that evolves to include new elements as the plants age.

Nuclear plants are safe even before they are built, because every decision focuses on ensuring the safety of workers, the public, and the environment.

At a nuclear power plant, every decision focuses on the safety of the workers, the public, and the environment.

Who oversees nuclear safety in Spain?

The highest authority in Spain is the Nuclear Safety Council (Consejo de Seguridad Nuclear, CSN), an advisory body that operates independently independent from the Government and acts as the sole authority on safety matters. They establish the principles, criteria, and regulations that govern nuclear safety throughout all stages of the plants' lifecycle.

The CSN monitors the operation of Spanish nuclear power plants through two mechanisms:

1. Resident inspectors. These are CSN personnel who are permanently stationed at each Spanish nuclear power plant. Their role is to report anything that falls outside the safety conditions established by the CSN for plant operations.
2. The Integrated Plant Supervision System (SISC). This system monitors a set of performance indicators for each plant, covering all aspects critical to safety. It includes an Inspection Programme known as the Base Inspection Plan, which oversees operational aspects of the plant not covered by the indicators. The results are published quarterly on the CSN’s website.

The Nuclear Safety Council establishes the principles, criteria, and regulations that govern plant safety during all phases of its lifecycle.

Defence in depth and safety culture

There are two main pillars that underpin nuclear power plant safety. From a technological perspective, the first is the concept of defence in depth, which defines different levels of safety. This includes consecutive barriers intended to compensate for mechanical failures or human error.

The second pillar is the safety culture, which seeks to involve all workers in recognising the importance of safety in their daily tasks. It is a concept that cuts across the entire organisation and applies to all hierarchical levels. Its mission is to ensure that employees act safely and prioritise the safety of the plant above all else.

The two pillars underpinning nuclear power plant safety are defence in depth and a strong safety culture.

What are the key elements of nuclear safety?

Safety considerations begin with the selection of the reactor technology and the systems that will make up the plant. These systems may include passive safety, redundant, or digital technology systems, with specific characteristics depending on the reactor type.

The selection of the site for a nuclear power plant also plays a critical role in its safety. Factors such as seismic activity, groundwater presence, and potential risks from external agents (floods, fires, droughts, sabotage, communication routes, etc.) are all studied carefully.

Moreover, to obtain an operating licence for a nuclear power plant – which establishes the conditions under which the facility may function – operating companies must have official operating documents approved by the Nuclear Safety Council. Compliance with these documents is mandatory in order to operate the plant, including the establishment of safe reactor shutdown conditions.

The continuous monitoring and analysis of operational experience, both internal and external, is one of the primary sources of information and feedback for improving the safety and reliability of each facility.

Additionally, information generated during all phases of a facility’s lifecycle – from construction to operation, shutdown, and decommissioning – is collected and analysed. The operator must analyse what happens at the facility itself and all other relevant locations. The goal? To maintain and improve the safety of the facility.

Another key element for safety is Periodic Safety Reviews (PSR). These reviews are conducted every 10 years, with the aim of performing additional checks that complement ongoing assessments to provide a comprehensive view of safety.

Emergency plans in nuclear power plants

Nuclear facilities are designed to ensure that the likelihood of accidents that could affect people and the environment is extremely low.

However, emergency plans are established to address potential incidents or accidents in nuclear plants. The goal is to control the accident, return the plant to a safe condition, and protect the population and the environment from potential radioactive releases.

Each nuclear plant has an internal emergency plan detailing the activities, measures, and responsibilities for preparing for and responding to accident conditions, with the goal of mitigating and minimising the potential consequences for workers, the public, and the environment.

Each plant’s internal emergency plan is regulated by the nuclear and radioactive facility regulations. They comply with the self-protection obligations defined in civil protection regulations, with the facility operator being responsible for their implementation.

To ensure preparedness for such situations, each plant’s internal emergency plan is regularly practised, both partially and in full. Annually, each plant conducts a full-scale emergency drill to test the organisation’s emergency response capabilities.

In addition to these annual full-scale drills, partial exercises are also scheduled to assess specific aspects of the emergency response.

Nuclear facilities are designed to ensure that the likelihood of accidents that could affect people and the environment is extremely low.

Furthermore, as part of the annual ongoing training programme, plant personnel receive specific training on the internal emergency plan, including both theoretical and practical sessions. In addition to verifying the effectiveness of the plan, emergency drills serve as a source of training for the organisation.

Emergency drills are observed by the regulatory authority, as well as by plant personnel, and any deficiencies are reported in the Corrective Action Programme (PAC), as part of the continuous improvement model.

In addition to the internal emergency plans, emergency response planning includes:

1. The Basic Nuclear Emergency Plan (PLABEN): this sets the basic rules for nuclear emergency planning and includes radiological protection criteria.
2. The External Nuclear Emergency Plans (PEN): their aim is to prevent, or at least mitigate, the adverse effects of ionising radiation on the population and the environment. The responsibility for implementing these plans rests with the Central Government, with the cooperation of other public administrations.

Nuclear plants in Spain are safe due to a combination of advanced technology, strict regulation, ongoing training, and a strong safety culture, all of which ensure the protection of people and the environment.