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Everyone has a part to play in nuclear safety culture

Author: Sailesh Patel, Programme Engineering Manager

Nuclear safety is more than a regulatory requirement. It is a mindset that influences every decision we make. In this article, I explore the importance of a strong nuclear safety culture, the role of leadership in setting standards and why everyone across the supply chain has a responsibility to maintain the highest levels of safety.

The UK nuclear industry is one of the most highly regulated and safety-conscious sectors in the world. Organisations such as AWE, Nuclear Restoration Services, Sellafield Ltd, Urenco and Rolls-Royce operate licensed nuclear sites where safety is always the overriding priority.

As a company delivering infrastructure projects to these organisations, we may not operate reactors, manage fissile materials or hold a nuclear site licence ourselves, but our work still contributes to the safe delivery of their nuclear mission.

A strong nuclear safety culture is essential to the success of every nuclear programme, but safety is not solely the responsibility of operators, regulators, safety specialists or senior leaders. It depends on thousands of individual decisions made every day by designers, project managers, engineers, planners, commercial teams, procurement specialists, construction professionals and contractors across the nuclear supply chain.

Every design review, procurement decision, assurance activity and construction task has the potential to influence safety outcomes. This is why nuclear safety culture matters.

A positive safety culture helps ensure that safety remains the highest priority regardless of programme pressures, commercial challenges or operational demands. It creates an environment where people feel confident to challenge assumptions, raise concerns, learn from experience and make informed decisions that support safe project delivery.

For organisations operating within the UK nuclear sector, maintaining a strong safety culture is not just a regulatory expectation. It is fundamental to protecting people, safeguarding the environment, maintaining national capability and delivering successful outcomes for clients and stakeholders.

Nuclear safety is a collective responsibility. A strong safety culture ensures that responsibility is understood, valued and acted upon by everyone. No one in the organisation is exempt from the responsibility of ensuring safety remains the highest priority.

What is nuclear safety culture?

The term “safety culture” emerged following investigations into major nuclear accidents and has since become a cornerstone of international nuclear regulation.

The International Atomic Energy Agency (IAEA) describes a strong safety culture as a combination of characteristics, values, attitudes and behaviours that ensure safety receives the attention warranted by its significance. Safety culture influences how people think, how they make decisions and how they behave when faced with competing priorities.

Put simply: Nuclear safety culture is “the way we think, behave and make decisions when safety matters”.

It is not a procedure, policy or training course, it is the collective mindset that shapes everyday actions.

Safety culture is like an iceberg

When organisations experience safety problems, the issue is often not the visible behaviour itself but the underlying assumptions driving that behaviour.

Assumptions like:

• “We’ve always done it this way.”
• “The deadline is more important.”
• “Someone else will spot the problem.”
• “Nothing bad has happened before.”

These seemingly harmless assumptions can gradually erode safety margins over time. The IAEA highlights that organisations can slowly drift towards prioritising competing concerns over safety, often without recognising it until a significant event occurs.

Why nuclear safety culture matters

Unlike many industries, nuclear safety often relies on barriers that cannot be directly observed, meaning a weld may appear acceptable while containing hidden defects, a calculation may seem correct while relying on an incorrect assumption, a document revision may contain a minor error that only becomes significant years later, or a procurement decision may ultimately affect the long-term reliability of a safety-important system.

The consequences of getting these things wrong can be severe. Nuclear facilities are designed with extensive layers of protection, often referred to as “defence in depth”. However, those layers depend on people consistently making sound decisions.

This is why nuclear safety culture is so important. It provides the attitudes, behaviours and decision-making framework that help individuals recognise risks, challenge assumptions, raise concerns and maintain the integrity of these safety barriers, even when they cannot be directly seen. A strong safety culture underpins every aspect of safe nuclear operations and supports:

Protection of people: Workers, communities and future generations depend on nuclear organisations maintaining the highest standards of safety.

Protection of the environment: Strong safety culture helps prevent events that could result in radioactive releases or environmental harm.

Protection of national capability: The UK’s nuclear sector underpins defence, energy security, scientific research and industrial capability.

Regulatory confidence: The Office for Nuclear Regulation (ONR) places significant emphasis on leadership, management for safety and organisational culture as indicators of a healthy nuclear enterprise. The UK’s Nuclear Industry Safety Culture Inventory (NISCI) identifies leadership, accountability, challenge and reporting as critical elements of safety culture.

What happens when safety culture goes bad?

Rarely does a nuclear safety culture deteriorate overnight; instead, it often declines gradually as small shortcuts become normal, questions stop being asked, concerns go unreported, deadlines begin to dominate conversations, people assume someone else is responsible, and the organisation becomes increasingly comfortable with greater levels of risk. This phenomenon is sometimes referred to as the “normalisation of deviance” and it works like a downward spiral.

Investigations into major incidents across many high-hazard industries repeatedly identify cultural weaknesses such as:

• Poor leadership behaviours.
• Weak challenge.
• Inadequate reporting.
• Lack of learning.
• Overconfidence.
• Production pressure overriding safety.
• Failure to listen to concerns.

The IAEA specifically identifies weaknesses in safety culture as a recurring root cause in nuclear and radiological accidents.
Importantly, these are not purely technical failures. They are human and organisational failures.

What does a healthy nuclear safety culture look like?

Healthy cultures are not characterised by perfection, they are characterised by vigilance and challenge. People recognise that despite robust systems, mistakes remain possible and therefore actively look for early warning signs.

NISCI identifies six key dimensions.

These characteristics align strongly with both international guidance and emerging UK regulatory expectations.

At NSG, we reinforce these behaviours through The NSG Feel, our whole system approach to culture, leadership, engagement and continuous improvement.

The NSG Feel is not a safety programme or a set of rules. It is the framework through which we create the conditions for people to succeed, ensuring that safety, quality, learning and performance are connected rather than treated as separate objectives.

While originally developed to strengthen organisational performance and employee engagement, many of its principles closely align with those required to sustain a healthy nuclear safety culture.

A strong safety culture depends on individuals feeling confident to speak up when something does not look right, ask difficult questions, share lessons learned and support colleagues in making the right decisions. Through our whole system approach, we seek to create an environment where these behaviours are encouraged and reinforced at every level of the organisation.

Many of the characteristics fostered through The NSG Feel mirror the dimensions identified by NISCI:

• Accountability for our actions and decisions.
• Constructive challenge and a questioning attitude.
• Open communication and reporting.
• Continuous learning and improvement.
• Leadership that prioritises doing the right thing.
• Collaboration across disciplines and teams.

The NSG Feel brings together leadership visibility, engagement, open communication, learning, performance insight and continuous improvement to create a culture where accountability, challenge and collaboration become part of everyday working life rather than standalone initiatives.

We reinforce these behaviours through engagement sessions, learning briefs, trend analysis, knowledge sharing and open communication. Importantly, we encourage respectful challenge and recognise that questioning assumptions is a sign of professionalism, not criticism.

Leadership also plays a critical role in demonstrating these values in practice. On one occasion, we paused work across the business following a serious accident on a competitor’s construction site to reflect on the lessons learned and reinforce the importance of safety, vigilance and continuous learning.

By creating an environment where people feel trusted, supported and empowered to do the right thing, we help strengthen the conditions that enable safe project delivery across the nuclear supply chain.

Ultimately, healthy safety cultures are not built through procedures alone. They are built through the everyday behaviours, decisions and conversations that influence how people work together and respond when safety matters most.

Why safety culture matters for infrastructure projects

At first glance, someone working on a design, procurement package or construction programme may think: “I don’t work directly with nuclear material.”

However, nuclear safety depends upon a long chain of activities extending far beyond the operating facility. Every nuclear asset begins with:

• Requirements definition.
• Design decisions.
• Supplier selection.
• Construction activities.
• Installation works.
• Configuration management.
• Verification and assurance.
• Handover.

An error introduced at any stage can propagate through the lifecycle of a facility. These so called “latent errors” are mistakes that don’t cause immediate problems, but may, through the effects of time, or in conjunction with another.

The nuclear sector increasingly recognises that safety culture must extend throughout the supply chain, not just on licensed sites. Reviews of major nuclear projects consistently highlight leadership commitment, competent personnel, effective communication and strong front-line supervision as essential to successful delivery.

In our role as infrastructure delivery professionals, whether we are:

• Project managers.
• Engineers.
• Cost consultants.
• Commercial managers.
• Construction managers.
• Business support professionals.

We influence outcomes, and our work directly affects quality, reliability, compliance and ultimately nuclear safety.

How everyone can play their part

The good news is that strengthening safety culture does not require everyone to be a nuclear safety specialist. It just requires everyone to display the right behaviours.

(The Nuclear Institutes ‘Nuclear Professionalism Standard’)

Leadership matters, but safety culture belongs to everyone

One of the greatest misconceptions about culture is that leaders own it. Leaders certainly influence culture, but culture is ultimately created and sustained through the collective behaviours of everyone within an organisation.

Every interaction sends a signal about what is truly valued, whether it is someone respectfully challenging a decision in a meeting, a concern being openly discussed during a project review, a manager thanking an individual for reporting a problem, or a designer asking one additional question to better understand a risk. These everyday moments do far more to shape organisational culture than posters or slogans ever can. As such, culture should be viewed as a strategic asset that influences performance, safety and long-term success and, when misaligned, can become a significant strategic risk.

Key safety culture lessons from Fukushima

The Fukushima Daiichi accident remains one of the most important learning events for the global nuclear industry.

While the earthquake and tsunami were the initiating events, many subsequent reviews highlighted the importance of organisational, leadership and cultural factors in determining how resilient an organisation is when faced with extreme and unexpected challenges.

Image source: Tokyo Electric Power Company Holdings, Inc. https://photo.tepco.co.jp/en/date/2020-e/202012-e/201222_01e.html

The IAEA’s post-accident reports and ONR guidance both emphasise the importance of learning from Fukushima when developing safety culture and leadership arrangements.

Lesson 1: Challenge assumptions

One of the strongest lessons is the need to continually challenge long-held assumptions.

Organisations must ask:

• What if our assumptions are wrong?
• What if the hazard is larger than expected?
• What if multiple barriers fail at the same time?

A questioning attitude is one of the core characteristics of a strong nuclear safety culture.

Lesson 2: Pay attention to weak signals

Major events are often preceded by smaller warning signs.

Healthy organisations actively search for:

• Emerging trends.
• Recurring errors.
• Near misses.
• Repeated challenges from staff.
• External operating experience.

ONR specifically identifies sensitivity to weak signals as a key feature of an effective safety culture.

Lesson 3: Avoid complacency

Past success can create a false sense of security. Just because something has never happened before does not mean it cannot happen in the future.

Nuclear safety requires continual vigilance and a willingness to revisit previous decisions and assumptions.

Lesson 4: Leadership matters during pressure

Safety culture is truly tested when organisations face competing priorities.

Leaders must demonstrate that safety remains the overriding priority even when cost, programme or operational pressures increase.

ONR guidance highlights leadership behaviour as a critical contributor to nuclear safety outcomes.

Lesson 5: Listen to people closest to the work

People carrying out work often recognise emerging problems first.

Strong safety cultures:

• Encourage reporting.
• Welcome challenge.
• Act on concerns.
• Provide feedback.

When people stop speaking up, organisations lose one of their most important safety defences.

Lesson 6: Build resilience rather than minimum compliance

Compliance is essential, but high-performing organisations go beyond simple compliance. They continually ask whether their arrangements would remain effective during unusual, unexpected or extreme conditions.

Resilience is created through preparation, learning, leadership and organisational adaptability.

What this means for infrastructure project teams

For companies supporting AWE, Sellafield Ltd, Nuclear Restoration Services, Urenco, Rolls-Royce and other nuclear operators, the Fukushima lessons remain highly relevant.

Every design review, procurement decision, construction activity, assurance check and management decision presents an opportunity either to strengthen or weaken safety culture.

The most important lesson may be this:

• Never assume somebody else is responsible for safety culture.
• Culture is shaped by thousands of everyday choices made across the entire supply chain.

Final thoughts

Nuclear safety culture is often described as what people do when nobody is watching. It is the shared commitment to doing the right thing, even when it is difficult, inconvenient or unpopular.

For those of us delivering infrastructure projects into the UK nuclear industry, safety culture is not somebody else’s responsibility. It is part of our professional responsibility. We may never handle nuclear material. We may never operate a licensed facility. But through our decisions, behaviours and standards, we contribute to systems that must remain safe for decades.

Every question asked.

Every concern raised.

Every lesson learned.

Every procedure followed.

Every improvement made.

These actions strengthen the culture that protects people, the environment and the long-term success of the UK nuclear sector.

At NSG, we believe technical excellence and safety culture go hand in hand. Through The NSG Feel, our whole system approach to culture, leadership and continuous improvement, we create an environment that encourages accountability, challenge, collaboration and learning. These behaviours help us deliver projects safely, support our clients’ objectives and continually improve the way we work.

Because in nuclear, safety is not simply a department.

It is a mindset.

And every one of us has a part to play.

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