The Pulse
PA Consulting joins Cosine coalition for UK nuclear AI model
PA Consulting is joining Cosine’s coalition to co-design Lumen Sovereign, a UK frontier AI model for regulated industries. The first planned application is a nuclear-trained large language model for Britain’s civil and defence nuclear secto
AI.info Team ·
“AI sovereignty is becoming increasingly important for organizations operating in critical national infrastructure.”
Alwin Magimay, Global Head of AI, PA Consulting
PA Consulting is joining a coalition led by British AI lab Cosine to co-design Lumen Sovereign, a planned frontier model for regulated and nationally important industries. The first application under the partnership is a nuclear-trained large language model for the United Kingdom’s civil and defence nuclear sectors.
Jacobs, which owns PA Consulting, announced the collaboration on September 21, 2026. The companies say the nuclear model is intended to address skills shortages, preserve specialist knowledge and make decades of technical information easier to access.
A nuclear model before a general-purpose rollout
Lumen Sovereign is not being presented as a finished product. Cosine and its partners are defining the model’s uses, security requirements and governance standards before deployment, with the nuclear sector serving as the first target.
Alistair Pullen, Cosine’s chief executive, said civil nuclear organisations need systems that understand sector-specific terminology and specialised workflows. He identified knowledge management, engineering support and operational delivery as early areas for investigation.
That focus separates the project from a broad consumer chatbot launch. The proposed system is being designed around organisations that must control where models run, how data is handled and which operational environments can access them.
Sellafield work supplies the starting point
PA and Jacobs are bringing experience from work with Sellafield and the Nuclear Decommissioning Authority. Their previous project, DANI, is described by Jacobs as the nuclear decommissioning industry’s first AI assistant.
According to Jacobs, DANI helps nuclear organisations manage complex knowledge, support safety-critical activities and give engineers faster access to technical information. The new coalition aims to apply that experience to a model built specifically for nuclear-sector language and processes.
Carl Dalby, Group Head of AI and Digital at the Nuclear Decommissioning Authority, said the industry’s specialist information sits in experienced staff, technical records and complex systems. He said sovereign AI could help preserve and access that knowledge while supporting decisions across the nuclear enterprise.
Isambard-AI anchors the UK strategy
Cosine says Lumen Sovereign is being developed with compute awarded through the UK government’s Sovereign AI programme and trained on Isambard-AI. The government-backed AI Research Resource includes Isambard-AI at the University of Bristol and other national computing systems.
The UK’s Sovereign AI programme is also intended to keep strategically important AI companies anchored in Britain. Government material describes a £500 million fund that combines investment with access to public compute, research support, procurement opportunities and other assistance for UK AI companies.
Cosine’s own description says Lumen Sovereign is intended for secure settings where sensitive code, data and operational context must stay within controlled infrastructure. Its model page says the system is being developed for deployment with customer control over model location, data governance and system operation.
From nuclear to other regulated sectors
The coalition’s proposed scope extends beyond nuclear operations. Jacobs says the partners want to support sovereign AI applications in government, defence, financial services, healthcare and other critical national infrastructure.
PA’s role gives Cosine access to sector knowledge from a consultancy already working across energy, defence and public services. Cosine supplies the model-development effort, while the nuclear partnership provides a defined domain in which data handling, operational controls and specialist terminology matter as much as general language performance.
Neither company has disclosed the model’s size, training timetable, evaluation results or planned release date in the announcement. The immediate commitment is to co-design the nuclear use case and determine how a UK-controlled model could operate inside one of the country’s most tightly governed industries.