The Board

David joined UKNNL’s board as interim Chair in January 2026, bringing over 30 years of infrastructure and financial advisory experience across government and the private sector. 

After qualifying as a Chartered Accountant, David went on to become a Partner at Deloitte, where he led their infrastructure advisory team. His expertise spans a broad range of sectors including energy, airports, ports, roads, water and telecommunications.

David's expertise lies in complex infrastructure transactions and strategic advice in challenging, high-profile environments. During his career he has advised the largest investors in infrastructure on some of the largest transactions including Gatwick airport, the Green Investment Bank and HS1 and led major restructurings including Schaeffler and Waterford Wedgwood.  

Since leaving Deloitte, David has taken on several board roles, including the Department of Energy Security and Net Zero's Audit and Risk Assurance Committee, Water and Sanitation for the Urban Poor and the Royal Geographical Society. In addition to advising several businesses, he has also founded an innovative tidal turbine business, combining his infrastructure expertise with his commitment to the clean energy transition.

David holds a BA (Hons) in Economics from Durham University.

Married to Helen and with four grown up children, in his spare time David enjoys captaining his local village cricket team and hiking fells, mountains and downlands.

Julianne became Chief Executive Officer of UKNNL in April 2025, bringing over 25 years of nuclear sector experience to the role. 

After beginning her career as a Graduate Radiation Protection Advisor with British Nuclear Fuels Ltd, UKNNL's predecessor organisation, Julianne went on to hold strategic leadership positions at Nuvia, Atkins and PA Consulting before returning as our CEO. 

Julianne’s expertise lies in strategic implementation and operational excellence. During her career she has led and implemented transformational growth strategies, established strategic joint ventures between UK, European and international organisations and secured long term strategic frameworks with Government and commercial entities. As Global Head of Nuclear at PA Consulting, Julianne established and grew an innovative nuclear practice, working with clients across the entire nuclear fuel cycle from new build to decommissioning. 

Passionate about diversity and inclusion, Julianne has been a driving force for women in STEM. Her contributions to the nuclear sector were recognised with an Honorary Fellowship from the Nuclear Institute in 2023 and the National STEM Ambassador Award from Forward Ladies. 

Julianne holds an MSc in Pollution and Environmental Control from the University of Manchester and a BSc (Hons) in Environmental Science from Manchester Metropolitan University. 

In her spare time Julianne enjoys being in the great outdoors with her family, from skiing and cycling to running and walking, with most big days out finishing with a refreshing glass of something cold and fizzy! 

Brian joined UKNNL as Chief Financial Officer in 2026, bringing over 30 years of finance, strategy and operational leadership experience across the energy, nuclear and technology sectors.

He began his career as an accountant and consultant with PwC in London and Auckland, specialising in energy sector advisory work in the UK and during a secondment with Shell in Ukraine. On leaving practice, he held Head of Investor Relations and Finance Director roles across telecoms businesses in France and the UK, before spending four years as Finance Director for British Nuclear Group — responsible for Sellafield, the low-level waste repository, and the UK's Magnox reactors — while also chairing the Audit Committee at AWE. He subsequently served in senior executive positions across several UK publicly listed companies, including Scapa Group, Renold, NCC Group and Nanoco Group.

Brian's expertise lies in developing and implementing major strategic transformation programmes with a focus on purpose, accountability and a forward-looking culture. The change programmes he has created have proven consistently self-sustaining, delivering lasting improvements in financial control, governance and reporting, health and safety culture and risk management, all alongside significant gains in stakeholder value.

Brian holds an LLB (Hons) from the University of Edinburgh. He qualified as a charted accountant in 1994 and has completed the Advanced Management Programme at the European Institute of Business Administration, Fontainebleau.

Outside of work, Brian chairs a National League Hockey Club and can still be found playing or umpiring across the Northwest most weekends. He is also a keen beekeeper, tending his hives and jarring up honey for family and friends.

Sam Wheeler is Company Secretary to our UKNNL Board, having held the position as Deputy Company Secretary since 2021. Prior to joining UKNNL Sam was Company Secretary within the NHS, advising senior colleagues on governance matters throughout the Covid-19 pandemic and helping to develop the Green Plan for County Durham and Darlington NHS Foundation Trust.

During Sam’s career she has provided both legal and governance advice across several industry sectors, after beginning her career as a corporate lawyer for PwC Legal. Sam has a breadth of knowledge of the public sector, with expertise in rail, nuclear and health.  Since qualifying as a chartered company secretary Sam has strengthened her knowledge of corporate governance and is keen to introduce it to the sector. Sam is both an Associate of Chartered Governance Institute and a qualified solicitor.

Dr Neil Smart joined UKNNL as Non-Executive Director in 2025. He Chairs both the Environment, Health, Safety and Security Committee and the Technical Advisory Board.

With over three decades of experience in the nuclear sector, Neil brings exceptional technical expertise and a proven track record in driving innovation. His career spans leadership roles at several prominent organisations, including Head of Technical Assurance, Chief Scientist, and Head of Research and Development at Sellafield Ltd, Director of Research and Innovation at the Nuclear Innovation and Research Office, and Science Director at Radioactive Waste Management Ltd.

Throughout his career, Neil has demonstrated a commitment to advancing nuclear science and technology. As a named inventor on 15 patents in fields including radionuclide separation and radioactive waste management, and author of 30 peer-reviewed publications, he has made significant contributions to nuclear research and development. His expertise in technical assurance and programme delivery has been instrumental in shaping major nuclear initiatives across the UK.

Neil serves as the UK Representative on the European Nuclear Society Higher Scientific Council and is a visiting professor at the University of Manchester. He holds a BSc in Applied Chemistry, a PhD in Corrosion Science and an MSc in Technology Management, combining deep technical knowledge with strategic business acumen.

Iain joined UKNNL’s board in October 2019, having previously served as Chief Financial Officer of WYG plc, an international consulting, engineering and project management business. Prior to that, Iain was Finance Director for Amec Foster Wheeler’s Clean Energy business, and before that he held various finance director positions in Westinghouse Electric Company, a global nuclear technology provider, including two periods spent working in the United States.

Iain started his career with Coopers & Lybrand where he qualified as an ACA before moving into corporate finance to work on mergers and acquisitions. He moved into industry in 1996 and now has over 20 years’ financial leadership experience in international consulting and engineering businesses, with a particular specialism in the international energy sector.

In addition to his non-executive director role, Iain chairs our Audit Committee.

When Mandy Clarke joined the UKNNL Board as a Non-Executive Director in 2026, she brought with her a career spanning over 25 years of senior HR executive leadership, and over 15 years of board-level governance experience.

Mandy started her professional life as a commissioned officer in the Royal Air Force, serving as a fighter controller and specialising in weapons, radar and electronic warfare. She was among the first women to serve operationally in the field, before women were permitted to undertake roles such as pilot or navigator — a milestone she reflects on with pride.

Following her military career, Mandy built a substantial executive track record across multiple industries and countries, with senior leadership responsibility for people strategy, culture, governance and change management. In 2010, she established her own consulting business, advising UK and international clients on HR strategy, organisational development and learning and development.

Mandy has more than 15 years of experience as a non-executive board member. She currently serves as a Non-Executive Director at The Pensions Regulator, chairing its Remuneration and People Committee; as a board member at Platform Housing Group, chairing its People and Governance Committee; and as independent chair and trustee of Engage Technical Solutions, an employee-owned technical services business.

Mandy is a Chartered Fellow of the Chartered Institute of Personnel and Development, a Fellow of the Institute of Directors and a Fellow of the Royal Society of Arts. She holds a Master's degree in Human Resource Management and is an MSP (Managing Successful Programmes) and PRINCE2 (Projects In Controlled Environments) Practitioner.

Outside of work, Mandy is a season ticket holder at Bath Rugby, enjoys travel and exploring new places, and can often be found reading or watching drama and science fiction.

Hannah was appointed to UKNNL's board in 2025, bringing over 25 years of corporate finance and governance experience across government and the private sector.

After qualifying as a Chartered Accountant with PricewaterhouseCoopers, Hannah went on to hold senior positions at NM Rothschild & Sons, UBS and Deloitte before joining UK Government Investments in 2017, where she continues to serve today.

Hannah's expertise lies in complex transactions and strategic interventions in challenging, high-profile environments. During her career she has led major restructuring and governance programmes, advised Ministers and Permanent Secretaries on critical corporate interventions including Carillion, British Steel and COVID-related support schemes, and built high-performing teams that deliver significant value for taxpayers. As a Director at UK Government Investments, Hannah leads shareholder teams for Government Property Agency and Ordnance Survey, and heads the Special Situations team – a recognised centre of excellence providing specialist advice on government's most complex corporate challenges.

Passionate about diversity, inclusion and public service, Hannah has been a committed advocate for maintaining strong organisational culture and the highest standards of professional conduct. She currently serves as Shareholder Non-Executive Director for the Government Property Agency and as a member of HM Treasury's Advisory Credit Committee.

Hannah holds a BA (Hons) in Economics from Durham University and is a Fellow of the Institute of Chartered Accountants in England and Wales.

In her spare time Hannah enjoys running, splicing and reading.