Keeping critical communications online when the network is off

Solutions in Nuclear Power Environments

Nuclear power stations must isolate communication systems from external networks for security. This article explains how Multitone’s modern radio-based paging and lone worker protection deliver resilient, two-way critical communications at UK nuclear sites such as ​​Torness.

The UK’s Nuclear Power Industry: A Snapshot

Nuclear power generates up to 15% of the UK’s electricity supply, making it a key source of energy. The nuclear industry has a long heritage in the UK, with the first commercial power station, Calder Hall, generating electricity for domestic use from its opening in 1956. Today, EDF Energy is responsible for managing the fleet of five operational nuclear power stations: Heysham 1 & 2, Hartlepool, Sizewell B and Torness.

As many nuclear plants age and reach the end of their working lives, the industry is commissioning new plants including Hinkley Point C in Somerset, the UK’s first new nuclear station in over 30 years. The UK government similarly approved a second new plant – Sizewell C – in July 2025.

When Isolation from External Networks is the Safest Option

In this period of generational transition, the need for instant, reliable communication across every corner of a nuclear site remains constant. In an environment where security is paramount, the most dependable systems are nearly always those that operate entirely independently of external networks.

As part of the ​​UK’s Critical National Infrastructure (CNI), nuclear power operators must isolate their communication systems from external networks to minimise security risks. With hostile actors increasingly targeting CNI, any system connected to external networks presents a potential attack route. A system with no connection removes this threat.

For specialists in critical communications such as Multitone, this obligation shapes the solutions it creates for clients working in this industry. Multitone delivers bespoke integration, automation, and communication systems that make workplaces safer, more efficient, and more resilient; and nuclear power stations such as Torness, are amongst the industries where the best solutions are modern paging systems and dedicated lone worker protection devices.

Radio-based modern pagers answer the system isolation challenge directly: they are resilient, operate on dedicated frequencies and work entirely independently of IP networks, phone lines and mobile coverage.

Outlined below are some of the challenges faced by nuclear plants such as Torness and Heysham, the factors prompting operators to review or upgrade their communication systems as well as the operational and safety benefits that modern critical communications deliver.

The Challenges Facing the Sector

Delayed communication in a nuclear environment is not an inconvenience; it’s a safety incident if it inhibits maintaining operations, protecting staff and ultimately safeguarding the interests of the wider public.

Two-way communication is of critical importance, especially when in emergencies every second counts and it’s important to understand the difference between legacy systems such as traditional pagers, and modern paging systems which are the future. Legacy systems provide only one-way communication. The operator sends an alert; the recipient receives it. The sender does not know whether the pager received it, whether the recipient saw it, or whether they are responding.

In an emergency, that uncertainty forces a choice: assume the message got through – which is inherently dangerous – or spend precious time chasing confirmation through other channels, which is ultimately slow.

As well as the absence of two-way communication, legacy systems present limitations.

As these systems age, operators face mounting challenges: sourcing replacement parts becomes ever harder as obsolescence creeps in, the technology’s limited functionality falls further behind operational needs, and any fault means waiting for an engineer to attend site in person.

Beyond the hardware, legacy systems create wider risks: when the senior engineers who understand them leave, a knowledge gap follows; when sites upgrade their alarm or fire panels, older systems may be unable to integrate with them; and equipment that no longer receives security updates becomes a vulnerability in itself.

Which Factors Prompt Organisations to Review or Upgrade their Communication Systems?

• Ageing infrastructure: If organisations cannot get parts to repair, systems are effectively defunct. If senior individuals leave, there is a knowledge gap in managing systems.
• Cyber/security concerns: If systems are out of date, security concerns arise. Using the latest versions of anti-cyber-attack software is essential.
• Integration limitations: E.g. a new alarm panel. If suppliers refresh the fire panel and use a more modern version, it may not be possible to integrate it.
• Compliance changes: Legacy equipment will not have the latest features and data governance.
• Reliability concerns: The older it is, the more prone it is to breaking down.
• Business continuity requirements: For a critical system like paging, it is recommended that equipment is powered via a UPS in case of an electricity outage.

The Solution: Bespoke and Complementary Systems

No two sites are the same, and in an environment as demanding as a nuclear power station, it is unlikely that off-the-shelf technology will provide a solution. That is why bespoke solutions matter: maximising efficiency, reducing risk and extending the working life of the systems that operators depend on.

For power plants such as Torness, Multitone believes that two complementary solutions are the answer:

• Modern radio-based paging systems – operating on dedicated frequencies and entirely independent of IP networks, phone lines and mobile phones.
• Multitone’s EkoTek Staff Safety solution enables individuals working alone or in high-risk areas to summon help instantly.

In every project Multitone manages, the company’s overriding objective is to engineer resilience into every level of the critical communication system. As an example, customers frequently commission an additional set of transmitters, so that if the primary transmitters go offline for any reason, communications continue – uninterrupted. Alarm integration is also incredibly useful for many clients, saving time and reducing the potential for human error.

Critically, Multitone builds devices for the environment they work in: they are durable, have the ability to page from any landline phone on site and are ATEX rated for use in potentially explosive atmospheres. Furthermore, Multitone understands that as shifts change, it must be simple to hand over without complication – so devices pass seamlessly from one team to the next.

Deploying the Project: Guaranteeing Business Continuity

Maintaining business continuity is the first consideration in all projects. Whenever possible, Multitone recommends a phased deployment, with all the installation work handled by the company’s engineers who are specially trained and fully security vetted.

Typically, the new system runs in parallel with the old, letting the project team identify and resolve any issues before the migration completes. Disruption stays minimal – normally just four hours of planned downtime – and both parties agree a contingency plan in advance. This gives both the project team and the operator complete confidence throughout.

Faster Incident Escalation and Response Times

There are numerous benefits from introducing new communication systems. Nuclear power operators can typically expect faster incident escalation and response times, reduced downtime as well as improved reliability. Furthermore, managers have access to better stock availability from suppliers should parts need replacing. There is similarly an enhanced ability to link with third-party systems such as fire panels and security alarms.

There are other advantages too. In a highly regulated industry such as this, it is necessary to provide an effective audit trail for compliance. For example, through a dedicated console, administrators can audit both incoming alarms and outgoing paging calls.

Future-proofing the Sector

Dominic Matthews is Multitone’s Major Account Manager, managing accounts in the North of England and North Wales, including Heysham and Torness Nuclear Power Stations. Dominic said:

“When every second counts, you can’t just hope a message gets through. You need to know for certain. That is why at Multitone we carefully design and create solutions which do precisely that – solutions which are innovative, reliable and effective. People are sometimes surprised that pagers still matter. But paging has survived in critical environments for a reason: it works when everything else does not. A combination of modern pagers and our EkoTek Staff Safety solution provides precisely what a nuclear power plant needs: instant, two-way communication across the whole site and protection for employees.”