Amentum Announces Helen Simms as Vice President for International Technology and Innovation

CHANTILLY, VA., May 22, 2025 — Amentum (NYSE: AMTM), a global leader in advanced engineering and innovative technology solutions, today announced the appointment of Helen Simms as vice president for international technology and innovation.

She will leverage her experience in innovative solutions, project delivery and strategy to grow Amentum’s offerings to the energy, environment, defence, space, and large international science and research project markets.

“Helen has a proven track record of exceeding business growth targets and we are excited to welcome her aboard,” said Andy White, senior vice president of Amentum Energy & Environment International. “She will be instrumental in developing, implementing, and delivering solutions to our clients’ complex challenges with the very talented and successful team at the heart of our technology, digital and innovation strategy.”

Helen will join Amentum from global energy advisory firm Xodus, where she is chief operating officer, bringing more than 20 years of senior managerial experience in delivering technological solutions and complex programmes for the nuclear and defence industries.

Helen said: “I am deeply honoured to be joining Amentum for this irresistible opportunity to lead the truly amazing international technology and innovation team. I am excited to leverage my experience and passion for technology to drive innovation and deliver exceptional services for our clients and stakeholders. Together, we will continue to push the boundaries of what’s possible and achieve new heights of success.”

Helen takes the place of Greg Willetts, who is retiring from the business after 33 years in which he rose from graduate trainee to vice president, spending the past 16 years in senior leadership where he played a crucial part in creating and developing new business lines in analytical services, fusion and cyber security.

About Amentum

Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have more than 53,000 employees in approximately 80 countries across all 7 continents.

Visit us at www.amentum.com to learn how we advance the future together.

Amentum in the United Kingdom

With more than 6,000 people in the UK, Amentum is the delivery partner for programme, project and construction management services at Hinkley Point C; sole program and project management delivery partner at Sizewell C; and also supports the UK’s existing nuclear power stations under a Lifetime Enterprise Agreement with EDF. It is a major supplier of engineering design, safety case and project management at Sellafield and other UK nuclear decommissioning sites and operates the country’s largest private sector complex of nuclear laboratories and engineering test facilities in Warrington.

In the defence sector, Amentum has an essential role in the UK’s continuous at-sea deterrent by providing safety advice and technology services for the Royal Navy’s nuclear submarines and programme management and engineering support for AWE. Amentum’s specialist teams also assist procurement and operational delivery of goods and services across the whole of the UK Ministry of Defence.