At Amentum, we're not just solving problems; we're engineering the future. Our team is driven by an unyielding commitment to innovation, integrity, and collaboration, tackling some of the most significant challenges in science, security, and sustainability. If you're passionate about making a real impact and want to be part of a community that values ethical excellence, this is the place where your ambition can thrive.

Here, we believe that success comes from continuously pushing boundaries and working together to deliver on our promises. We embrace challenges with confidence and are dedicated to creating a secure and vibrant future for all.

We’ll inspire and empower you to deliver your best work so you can evolve, grow and succeed – today and into tomorrow.  We offer an exciting range of opportunities to develop your career within a supportive team who always strive to do the right thing for our people, clients and communities.

People are our greatest asset, and we offer a competitive package to retain and attract the best talent.

In addition to the benefits you’d expect, UK employees also receive free single medical cover and digital GP service, family-friendly benefits such as enhanced parental leave pay and free membership of employee assistance and parental programmes, plus reimbursement towards relevant professional development and memberships.

Work-life balance and flexibility is a key focus area for us. We’re happy to discuss hybrid, part-time and flexible working hours, patterns and locations to suit you and our business.

Amentum is a Lot 1 key delivery partner within the Decommissioning and Nuclear Waste Partners (DNWP) Framework, a major Sellafield programme worth up to £4.6 billion and running for up to 15 years. The framework is focused on safely accelerating decommissioning, remediation and high‑hazard risk reduction across one of the most complex nuclear sites in the world.

Our nuclear team supports the front‑end design, engineering, technical leadership and delivery expertise required across the DNWP portfolio. We are looking for individuals with high‑value expertise from across regulated and comparable sectors to who can work collaboratively, embrace new challenges and contribute to the mission of safely and efficiently delivering Sellafield’s decommissioning and nuclear waste objectives.

About the Opportunity

As a Senior Project Manager you will be responsible for planning, executing, and closing projects, ensuring they are completed on time, within budget, and meet stakeholder expectations.

You will conduct work alongside Delivery Leads, Package Managers, Engineers and with support from Administrators.

Employee will be expected to contribute to the delivery of social value in line with the DNWP framework, supporting positive outcomes for local communities. Voluntary engagement is supported, with up to 16 hours per full‑time equivalent allocated.

Key Responsibilities:

• Provide strategic leadership and oversight for multiple complex or high value projects, ensuring alignment with organisational objectives and client expectations.
• Take full accountability for end-to-end project delivery performance, including cost, schedule, quality, safety, and risk across assigned portfolios.
• Lead, mentor, and develop Project Managers and other delivery staff, providing professional guidance, performance management, and succession planning support.
• Act as the primary senior interface with clients, joint venture partners, regulators, and internal senior leadership, managing key relationships and escalation matters.
• Oversee the development, approval, and governance of project execution plans, ensuring consistent application of best practice project management methodologies.
• Provide assurance that robust project controls are in place, including programme management, cost control, risk and opportunity management, and change control processes.
• Review and challenge project budgets, forecasts, and schedules, ensuring early identification of risks, trends, and recovery actions where required.
• Sponsor and lead resolution of complex project issues, claims, disputes, and contractual matters, providing direction and support to project teams.

Here’s What You’ll Need

Essential Qualifications & Experience:

• Significant, minimum 10 years of experience in Project Management within a highly regulated and quality assured system in roles dependent upon engineering judgement.
• APM Chartered Project Professional and member of the Association of Project Management (APM) or PMI.
• Degree level qualification (2:1 minimum) in a relevant STEM subject.
• Previous experience of taking full accountability for end-to-end project delivery performance, including cost, schedule, quality, safety, and risk across assigned portfolios.
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• Demonstrable experience in reviewing and challenging project budgets, forecasts, and schedules, ensuring early identification of risks, trends, and recovery actions where required.
• Superior interpersonal and leadership skills are required to enable effective interaction with clients, seniors and peers while working in a collaborative “Team” environment and able to build and maintain effective internal and external working relationships. 
• Strong organisational skills, attention to detail and quality are required along with a process improvement-oriented mindset.

Our Culture

Our values are built on a strong foundation of safety, integrity, and respect for every individual. People are at the heart of our mission, and we believe in supporting one another through a culture of care and collaboration.

We strive to create a workplace where everyone feels they belong and can thrive. Supporting mental wellbeing and fostering a sense of connection are essential to how we work.

When we embrace different perspectives and work together, we become more innovative, more agile, and more successful.

We partner with VERCIDA, for greater online accessibility please visit www.vercida.com to view and access our roles. As a Disability Confident employer, we will interview all disabled applicants who meet the minimum criteria for a vacancy. We welcome applications from candidates who are seeking flexible working and from those who may not meet all the listed requirements for a role.

If you require further support or reasonable adjustments with regards to the recruitment process (for example, you require the application form in a different format), please contact [email protected]