3 Performance Assessment jobs in the United Kingdom

We'll inspire and empower you to deliver your best work so you can evolve, grow and succeed - today and into tomorrow. With more than 55,000 people in 40+ countries, working with us offers an exciting range of opportunities to develop your career within a supportive and diverse 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. We also give back to our communities through our Collectively program which incorporates matched-funding, paid volunteering time and charitable donations.
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.
**About The Opportunity**
Amentum is currently recruiting a **Safety and Performance Assessment Consultant** to join our Waste Management and Disposal (WM&D) business. This position can be based at one of our key office locations-Harwell, London, Birchwood-or other locations may be considered, subject to business needs.
The successful candidate will work within a respected, multi-disciplinary team comprising chemists, physicists, geologists, engineers, safety case specialists, and mathematicians. Together, we deliver a broad portfolio of technical projects for clients in the UK and internationally.
Our Waste Management, Disposal and Safety Case teams have played a leading role in research and assessment related to the safe management and disposal of radioactive waste for over three decades. We offer nationally and internationally recognised expertise in consultancy, modelling, and laboratory work that supports the scientific and engineering foundations necessary for the safe and effective disposal of radioactive materials.
In this role, you will contribute to the delivery of a wide range of consultancy projects, with a particular focus on the development and application of models to support safety assessments for radioactive waste disposal facilities. These may include numerical models related to radiological and non-radiological risk assessment, contaminant transport, and the performance of engineered and natural barriers. You will also have the opportunity to support other decommissioning-related projects across the business.
This position offers a unique opportunity to apply technical skills to meaningful and high-impact challenges. It is well suited to individuals seeking to develop their careers in a technically complex and commercially dynamic environment, working collaboratively with clients and colleagues on projects of national and international significance.
As a **Safety and Performance Assessment Consultant** , you will play an integral role in delivering a wide range of desk-based consultancy projects for clients in the UK and internationally. Working within a collaborative and multidisciplinary team, you will contribute to both the technical delivery and ongoing development of our waste management and disposal capability. This role offers the opportunity to work on technically challenging and meaningful projects, contributing to national and international programmes aimed at the safe management and long-term disposal of radioactive waste.
Your responsibilities will include:
+ Interpreting client requirements and developing solutions that meet their objectives.
+ Contributing to the successful delivery of consultancy projects for clients such as radioactive waste producers, waste management organisations, and regulators.
+ Providing technical input across a variety of disciplines relevant to radioactive waste management and disposal, including:
+ Numerical and other types of complex modelling to support the safety case for future and existing disposal facilities in the UK and abroad. This could include groundwater flow and solute transport modelling; probabilistic and deterministic assessments of radionuclide release and contaminant migration; and assessment of engineered and natural barrier systems and their performance over long timescales.
+ Scenario development, FEP (Feature, Event, and Process) analysis, and uncertainty management.
+ Environmental Safety Case production and Environmental Impact Assessments.
+ Developing and checking calculations, technical analyses, and safety case documentation.
+ Producing high-quality technical reports and presentations, communicating complex scientific information clearly to both specialist and non-specialist audiences.
+ Business development activities, including proposal writing and client engagement.
**Here's What You'll Need:**
The successful candidate will demonstrate strong technical expertise, excellent communication skills, and a collaborative mindset, with a proven ability to deliver high-quality work in a multi-disciplinary and fast-paced environment.
**Essential Criteria:**
+ A postgraduate degree in Earth sciences, physical sciences (e.g., chemistry), engineering, or mathematics (or equivalent)
+ Experience in the development and application of numerical and/or other types of complex models.
+ Ability to evaluate complex systems and models, extract key safety insights, and present findings effectively.
+ Excellent written and verbal communication skills, with the ability to produce clear, accurate, and well-structured technical documentation for diverse audiences.
+ High level of computer literacy, including proficiency in the Microsoft Office suite.
+ Proven problem-solving ability and a creative, solutions-focused mindset.
+ Strong organisational skills, including the ability to manage time effectively, prioritise tasks, deliver work on time and within budget, capacity to work autonomously, take initiative, and respond flexibly to changing priorities and project demands.
+ A commitment to continuous learning and professional development.
+ Desire to contribute to the development of the company's radioactive waste management and decommissioning strategy capability.
Experience in one or more of the following areas would be advantageous, but is not essential:
+ Environmental safety case development and risk assessments for radioactive waste disposal facilities, including:
+ Radiological and non-radiological risk assessment methods and regulatory frameworks
+ Concept development, design, and performance assessment
+ Wasteforms, waste conditioning and packaging
+ Engineered barrier systems and host rock performance
+ Environmental safety functions
+ Use of GoldSim (or similar software) to simulate contaminant transport in complex geological settings.
+ Scientific programming or scripting (e.g., Python, MATLAB).
+ Coupled process modelling tools (e.g., COMSOL, PFLOTRAN).
+ UK nuclear industry or radioactive waste management sector.
**Our Culture**
Our values stand on a foundation of safety, integrity, inclusion and diversity. We put people at the heart of our business and we truly believe that by supporting one another through our culture of caring, we all succeed. We value positive mental health and a sense of belonging for all employees. Find out more .
We aim to embed inclusion and diversity in everything we do. We know that if we are inclusive, we're more connected, and if we are diverse, we're more creative. We accept people for who they are, regardless of age, disability, gender identity, gender expression, marital status, mental health, race, faith or belief, sexual orientation, socioeconomic background, and whether you're pregnant or on family leave. This is reflected in our wide range of Global Employee Networks centred on inclusion and diversity - ACE, Careers, Enlace, Harambee, OneWorld, Prism, Vetnet, and Women's - find out more about our employee networks here .
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