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Light water reactor scientist and engineer

This apprenticeship is in development and is not yet ready to use

Why is this apprenticeship not ready for delivery?

An apprenticeship is only available for delivery when both the standard and assessment plan is approved and a funding band (core government contribution) has been assigned to the standard.

How can I get involved?

If you'd like to get involved and contribute to the development of this apprenticeship, please read about developing standards and assessment plans. You can email the trailblazer contact using the details on this page.

Key information

  1. Status: In development
  2. Ticked Proposal approved
    Ticked Occupational standard approved
    Unticked End-point assessment plan approved
  3. Reference: ST0640
  4. Level: 7
  5. Degree: non-integrated degree
  6. Typical duration to gateway: 60 months (this does not include EPA period)
  7. Route: Engineering and manufacturing
  8. Date updated: 30/11/2021
  9. Review:

    This apprenticeship standard will be reviewed after three years

Print occupational standard

Details of the standard

Occupation summary

This occupation is found in the science and engineering sectors of the Civil Nuclear and Defence Nuclear industries.

The broad purpose of the occupation is to use depth and breadth of scientific and engineering expertise in nuclear reactor technology to support all stages of the nuclear reactor lifecycle, including commissioning, operating and decommissioning. This involves independently performing technical assessment and scrutiny of designs and modifications, defining technical specifications against statements of requirement, developing innovative engineering solutions to in-service issues and providing senior leaders with technical knowledge and evidence based advice required to make informed decisions. Light Water Reactor (LWR) Scientists and Engineers are highly skilled using their knowledge and experience to understand the fundamental chemical, physical and radiological principles of nuclear reactor operations.

In their daily work, an employee in this occupation interacts with technical and academic organisations, regulatory bodies, technical and non-technical people at all levels of the organisation. The working environment will mainly be office-based with some plant inspections and reviews; in the defence sector, an employee in this occupation may also operate the submarine reactor at sea. This is a highly technical role found in large multi-national organisations and in supply chain organisations.

An employee in this occupation will be responsible for budgets, licence requirements, health & safety, nuclear safety and security. This is a highly responsible role managing the maintenance of the LWR design intent. In particular, LWR Scientists and Engineers are responsible for the safety, reliability, operability and attributes of the LWR plant, assuring compliance with regulatory, contractual and internal company requirements. They are responsible for making recommendations to address fundamental issues and complex challenges to ensure continued safe operation, whilst also in some instances considering innovative ways to improve upon current designs to make nuclear power more effective and efficient for the future.

Typical job titles include:

Design authority engineer Design authority scientist Fuel and core physics specialist Plant chemist Royal navy marine engineer submarine officer Structural integrity engineer Systems engineer

Entry requirements

Whilst any entry requirements will be a matter for individual employers, typically an apprentice might be expected to have already achieved 3 A levels including maths and science or equivalent on entry

Occupation duties



Duty 1 Provide guidance and solutions to technical issues to ensure the full operability and optimise performance of LWR plant systems

K1 K2 K3 K6 K12 K13

S1 S2 S3 S4 S5 S6 S7 S8

B1 B4 B7 B9 B10 B13

Duty 2 Analyse LWR plant system conditions eg temperature, pressures and flows, identify adverse trends and propose technical solutions

K3 K7 K9 K13

S1 S2 S3 S4 S5 S6 S7 S8

B1 B4 B8 B9 B10

Duty 3 Design and specify plant components, spare parts and other consumables for maintenance, repair and modifications eg valves, actuators, seals

K2 K3 K4 K7

S1 S2 S3 S5 S6 S7 S8

B1 B2 B4 B7

Duty 4 Create and/or maintain LWR plant system design documents and contribute to the development of LWR plant processes and procedures ensuring priority is given to Health & Safety

K2 K3 K7 K12

S1 S2 S3 S4 S5 S6 S7 S8

B1 B2 B7 B9 B10

Duty 5 Design and model the LWR plant systems under normal and abnormal operating conditions to ensure the safety requirements associated with nuclear safety case are met

K1 K2 K3 K4 K5 K6 K7

S1 S2 S3 S4 S5 S6 S7 S8

B1 B2 B3 B4 B7 B9 B10

Duty 6 Evaluate technical proposals for plant system design modifications and independently verify suitability and feasibility

K1 K9 K10 K11 K12 K13

S1 S2 S3 S4 S5 S6 S7 S8

B1 B2 B3 B4 B6 B7 B8 B9 B10

Duty 7 Mentor LWR team members, graduates and apprentices, providing technical development to increase own and team’s capability, enhancing organisational resilience

K1 K13

S1 S8 S11

B1 B2 B3 B5 B7 B8 B9 B11 B12 B13

Duty 8 Prepare and contribute to formal communications for appropriate regulatory and other agency interfaces such as Office for Nuclear Regulation LWR safety case report

K1 K8 K9 K13

S1 S2 S3 S4 S5 S6 S7 S8 S11

B1 B2 B4 B9 B11 B13

Duty 9 Provide a leading role and technical expertise in the event of an emergency response situation including beyond design basis events

K2 K4 K6 K8

S1 S2 S3 S4 S5 S6 S7 S8 S11

B1 B2 B3 B4 B7 B8 B9 B12

Duty 10 Provide effective communication to inform significant operational/technical issues that impact on LWR plant availability

K1 K4 K6 K7 K13

S1 S2 S5 S6 S7 S8 S11

B1 B2 B4 B8 B9 B13

Duty 11 Implement best practice in environmental and waste management

K1 K4 K6 K7 K13

S1 S2 S5 S6 S7 S8

B7 B8 B9 B10 B13

Duty 12 Undertake performance analysis to define operating parameters to meet nuclear safety case requirements

K2 K5 K7 K8 K9 K12 K13

S1 S2 S3 S4 S5 S6 S7 S8

B1 B2 B4 B9 B10

Duty 13 Input to technical budgetary operational requirements for lifecycle planning

K1 K4 K5 K7 K13

S1 S3 S6 S7 S8 S11

B1 B2 B4 B9 B10 B12 B13

Duty 14 Be an ambassador for nuclear safety culture and lead on safety and safe working practices

K1 K4 K6 K13

S1 S8 S11

B1 B6 B11 B12 B13

Duty 15 Routinely verify operational status of plant to ensure it is maintained within chemistry, physics and thermal hydraulics design constraints

K3 K8 K9 K11 K12

S1 S2 S4 S8 S9 S10

B2 B4 B7 B8 B9 B10 B13

Duty 16 Contribute to design and maintenance of LWR core and plant components under all operating conditions including assessing degradation of materials and taking into consideration of the harsh environment in which the materials are operating

K7 K10 K12

S1 S2 S3 S4 S6 S7 S8

B2 B4 B7 B8 B9 B10



K1: Regulatory framework applicable to the nuclear industry Back to Duty

K2: Nuclear reactor failure modes and potential consequences Back to Duty

K3: Different modes of reactor operation Back to Duty

K4: Hazard identification techniques and risk evaluation techniques; the principles ALARP (as low as reasonably practicable) and BAT (best available techniques) Back to Duty

K5: Principles and application of deterministic fault analysis and probabilistic risk analysis Back to Duty

K6: Principles and application of radiological protection and effects of exposure on human health and the environment Back to Duty

K7: Fundamental engineering mathematics and statistical methods Back to Duty

K8: Reactor physics including quantitative analysis of the neutron lifecycle and consequential design of reactor systems; capabilities of models and codes Back to Duty

K9: Thermal hydraulics including multiphase heat transfer, critical heat flux and prediction methods; feedback coefficients and the coupling between reactor physics and thermal hydraulics; capabilities of models and codes Back to Duty

K10: Reactor Materials including properties and selection criteria of reactor materials; the mechanisms of corrosion and degradation and the effects of irradiation on materials including fuel Back to Duty

K11: Chemistry including key functions of chemistry controls on a light water reactor to maintain reactivity controls to maintain the integrity of materials and minimise radioactivity in the primary circuit Back to Duty

K12: Interdependencies of reactor physics, reactor materials, chemistry and thermal hydraulics on the design and operation of reactor systems Back to Duty

K13: Effective leadership, management and mentoring techniques including oral and written communication strategies that incorporate a working knowledge of LWR and regulatory terminology used in this occupation, for example Nuclear and Health and Safety legislation and guidance Back to Duty


S1: Work competently and safely in a technical nuclear environment to meet regulatory and legislative requirements Back to Duty

S2: Select and use appropriate models, codes, both probabilistic and deterministic, and analytical techniques Back to Duty

S3: Assess and make recommendations for modifications to system and component design throughout the reactor lifecycle, demonstrating the rigour required to contribute to nuclear safety cases Back to Duty

S4: Evaluate plant conditions under all modes of LWR operation, for example shut down, and start up, critical steady state operations Back to Duty

S5: Integrate design principles, hazard identification and risk evaluation techniques into maintenance, repair and modification solutions Back to Duty

S6: Integrate radiological protection principles into technical proposals and solutions Back to Duty

S7: Apply appropriate mathematical statistical methods to enable uncertainties to be clearly expressed and explained to a technical and non-technical audience Back to Duty

S8: Communicate effectively and professionally with all levels within and across the organisation Back to Duty

S9: Carry out calculations for reactor physics and thermal hydraulics Back to Duty

S10: Carry out chemical and radio chemical analyses Back to Duty

S11: Generate and lead teams, physical or virtual, to solve cross-cutting problems; acknowledge the accomplishments of others and the importance of individual contributions to overall performance Back to Duty


B1: Demonstrate reliability, integrity and respect for confidentiality on work related and personal matters Back to Duty

B2: Work autonomously and interact effectively within a wide, multi-disciplinary project team Back to Duty

B3: Understand the impact of work on others, supporting an inclusive environment Back to Duty

B4: Manage time effectively, being able to plan and complete work to schedule Back to Duty

B5: Supportive attitude to change and responds positively to change management processes Back to Duty

B6: Take responsibility for personal development, demonstrating commitment to learning and self- improvement and provide and receive feedback constructively Back to Duty

B7: A strong commitment to personal safety and understanding of the consequences as set out in the nuclear industry requirements Back to Duty

B8: Take responsibility for behaviours and conditions in the workplace to reinforce nuclear, radiological and conventional safety over competing goals to ensure the protection of people and the environment, including challenging unsafe behaviours and practices Back to Duty

B9: Compliance by following rules, procedures and principles to ensure work completed is fit for purpose, sufficiently detailed and is reviewed for accuracy and completeness Back to Duty

B10: Commitment to sustainability in work design and application Back to Duty

B11: An enthusiastic advocate for the nuclear industry with the ability to represent this industry to a variety of audiences Back to Duty

B12: Demonstrates appropriate leadership and management styles dependent on situation, circumstances and environment Back to Duty

B13: Demonstrates a strong commitment to nuclear safety and security, role modelling and sharing good practice Back to Duty


English & Maths

Apprentices without level 2 English and maths will need to achieve this level prior to taking the End-Point Assessment. For those with an education, health and care plan or a legacy statement, the apprenticeship’s English and maths minimum requirement is Entry Level 3. A British Sign Language (BSL) qualification is an alternative to the English qualification for those whose primary language is BSL.

Professional recognition

This standard aligns with the following professional recognition:

  • Institute of Physics for CPhys, CEng
  • Royal Society of Chemistry for CChem

Contact us about this apprenticeship

Employers involved in creating the standard: Ministry of Defence, EDF Energy, Horizon Nuclear Power, NuGen, Rolls Royce

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