Flow Illustration

Reactor Core, Mechanisms, Auxiliaries and Internals Architect ESP/ESPN Manager

  • Location : Aix-en-Provence technical platform
  • Contract : cdi
  • Start date : 01/12/2023

Mission :

Field: Engineering / Architecture

Attachment: Technical Department / Architecture and Integration Unit

Profile: Experienced Architectural Engineer; Engineering, Mechanical, Core, Vessel and Internals, Operation, ESP/ESPN


Calogena was created within the Gorgé industrial group to develop, market, build and operate 30 MW thermal modular heat reactors to supply carbon-free heat to urban grids.

The Calogena reactor is a water-based SMR, with a very passive and simple design, which provides it with very robust safety. Calogena is the winner of the France 2030 call for “innovative reactors” projects.

The preliminary design of the reactor is committed until 2025. This will be followed by a detailed three-year design and then the production of a prototype to prepare for the transition to the reactor series. Construction is expected to begin in 2030.

The APS team is in the process of gaining momentum. It is organized as a Project Platform, with an extended team capacity involving strategic partners. The Technical Platform is located in Aix-en-Provence.

The Project team consists of a project unit, an architecture unit, and a business unit. The cells are positioned on the Project Platform, placed under the responsibility of the Technical Department.

The architecture unit brings together the skills and abilities to carry out the development of the project in interaction with the managers of the project unit and the business unit.

Tasks assigned :

You will join the Project team of the Caligena reactor module.

You join the architecture cell.

In conjunction with the technical director, you will be responsible for the mechanical architect at heart.

You are in charge of the specification, design and studies relating to:

– reactor core processes and mechanical systems;- control mechanisms, nuclear internals and auxiliaries;- preparation of ESP/ESPN compliance files and assessments.

as well as the associated steering and coordination actions


Your main responsibilities will be as follows:

  • Responsible for the functional, mechanical, kinematic definition, responsible for defining the operating situations of the reactor core equipment, in normal and degraded conditions, during the shutdown and start-up phases and for construction;


  • Responsible for the specification, design, mechanical studies and justification files of the definition: of the reactor vessel, the fuel and the core trap, the control mechanisms, the reactor internals, the nuclear auxiliaries and the special equipment in the pool;
  • Responsible for defining the modularization of the reactor core (fabrication and assembly of vessel, core, mechanisms and internals);


  • Responsible for the evaluation and justification of the Project’s pressure equipment and ESPN files; ESP/ESPN referent vis-à-vis notified bodies;
  • Responsible for the documentation of the inspectability of mechanical equipment classified for licensing;


  • Interface with the Operation/IofC Architect: determination and integration of physical reactor core requirements, including control, hydraulics, instrumentation, low and high currents;
  • Interface with the Operation and Integration Architects: determination and integration of core reload scenarios and kinematics and periodic inspections;
  • Interface with the integration architect: determination of strategies and methods for modular installation from the reactor core to construction;


  • In interface with the integration architect and the digital model manager: development and control of system data / reactor core and installation model;
  • Interface with the safety engineer: development and control of security data for licensing;
  • Interface with the PMO manager: elaboration and control of planning data and associated costs

Candidate profile :

You have a Bac+5, a graduate of an engineering school or equivalent foreign training, at least M.Sc.Eng.

You have an experienced and proven profile in the nuclear sector, in the fields of design and industrial construction of nuclear reactors.

You have demonstrated experience in project management, technical decision-making and complex business management.

Your experience has enabled you to strengthen a strong reactor core design culture, a very robust safety culture, and a strong focus on operations.

Your experience includes at least 10 years in a position of responsibility related to the reactor process core in a new reactor project team, including the acceptance or commissioning of major nuclear components.

Responsible experience in the industrialization and manufacture of heavy equipment with a status equal to ESPN N2 or higher, or equivalent under another regulation, is required. Experience in industrialization, manufacturing, conformity assessment on different types of reactors is an asset.

You have an approach that is both very rigorous and very agile, pro-active. You have a demonstrated ability to coordinate and manage teams and external studies.

You have strong organisational, structuring and synthesis skills, combined with solid technical and practical knowledge in the fields of mechanics, qualification, manufacturing monitoring and mechanical installation.

You have extensive experience in nuclear mechanical coding (RCC or equivalent), particularly in design, materials, fabrication, welding and control, as well as in nuclear technical regulations. You have good writing skills.

You have a good command of computer tools in project design, in particular relating to study activities, calculations, diagrams/plans/isos/BOM/BOQ necessary for engineering files.

You know how to effectively combine the control of quality, safety, cost and planning objectives with a capacity for proposals, advice and resolution within the Plateau team.

You have very good listening and communication skills, a strong aptitude for a wide variety of internal and external contacts, a strong team spirit.

You have a very good level of English, reading, writing, speaking. Proficiency in a second European language is a plus.

Share the job offer
Illustration icon
Illustration icon