Onet Technologies Logo

Onet Technologies

Support our customers in the complete lifecycle of their nuclear and conventional plants

Offices in France
countries of activities

Onet Technologies has been supporting major players in the nuclear energy sector as well as other complex industrial environments for 40 years, with three strategic areas of activity.

With locations in seven countries, Onet Technologies assists clients with project development, operations, safety maintenance and the dismantling of their nuclear facilities.

Through its various services, Onet Technologies aims to promote a culture of safety and security, skills management and operational performance at all of its client sites.

Onet Technologies in Japan
Corporate Profile

Corporate Name

Onet Technologies K.K.





Office Address


Nihonbashi Honcho YS Building

2-2-2 Nihonbashi Honcho 2F, Chuo-ku, 103-0023 Tokyo

Representative Director


Committed to the excellence of the French and international nuclear industry

Nuclear Power Station At Night

Nuclear power for energy production

Rendering of a submarine surfacing at the sea

Defense-related nuclear power

3D Render fusion reactor nuclear fusion, tokamak inside heated plasma, toroidal shape, clean energy. Copy space.

Research centers


Medical and industrial applications

More info on Onet Technologies

Organization for Japan
Efficient and Ready for Development  

Alain Gauvin

Since 40 years, we accompany the major players of the nuclear energy sector, amongst other complex industrial environments, around 3 strategical businesses : Engineering and maintenance of nuclear reactors, decommissioning and radioactive waste management as well as services to plant operators.

Safety culture, competences management and operational performance are at the heart of the services, which we deliver to each of our Clients. Today, the company employs over 2 900 collaborators, engineers or technicians and has overseas offices and partnerships set for the long term.


We are one the worldwide pioneers of the implementation of the laser technology for cutting and decontamination in nuclear environment. This cutting-edge technology enables us to offer services, which are more performant, safer and suited to complex environments. Moreover, these laser processes contribute to limiting the environmental impact by reducing the generation of waste.

Onet Technologies


President and CEO
Engineering Planning and Management (EPM), Inc.

Robert Kalantari


Business Development Director
Onet Technologies

Christophe ASTIER

D&D and Waste Management Director
Onet Technologies

Christophe Astier

Engineering & Projects


Japan Activities Head

Nuclear decommissioning is a challenge, which we have to overcome to fulfil our responsibility as a nuclear company with large experience in France and Europe. Our teams are devoted to support the Japanese nuclear industry with the best know-how and European technologies, by delivering engineering studies, R&D, equipment and expertise with the highest level of quality.

Our 10 years history in Japan has demonstrated our capabilities to understand our customer needs, to deliver on-time and quality work and to support the Japanese Industry on the long term basis.

We are committed to continue this support to Japanese stakeholders and partners in order to accomplish together great achievements in our domain of expertise.

As an engineering and services company, we have always been working near our Clients. The main purpose of our Japanese subsidiary is to stay close to our contacts and to communicate well with all market stakeholders. By establishing a durable presence in Japan, we aim at further supporting our Clients : Being able to provide knowhow in a collaborative way and participating to the demonstration of technologies in Japan. We seek partnerships and integration into the Japanese supply chain, with a view to joining the efforts for the safe restart of the Japanese nuclear power plants and for the demonstration of the effectiveness of nuclear decommissioning and radioactive waste management.


Japan Area Business Development Manager

Julien Masaru HIRATA

Japan Sales Area Manager

A center of engineering expertise
of 400 persons

Capacity of
more than
2000 on-site workers

We are involved at every stage of the life cycle of your projects

As engineering and services company, our main mission is to support the players in the nuclear industry in the development of projects, operation, maintenance in safe conditions and dismantling of nuclear installations.


The Onet Group, the family company from France
a major international player in the field of engineering and related services

0 Bn
Years of history

Our mission is to support our clients in building healthier, safer and more reliable work environments.

This means providing professional support for all key business ecosystems, including workspace management, production, energy, transport, healthcare, leisure and education.

We aim to create close relationships with clients and stakeholders through our various service providers.

Together, we are stronger. We firmly believe that effective collaboration strategies can help us face societal challenges, both today and tomorrow.

From the time of its creation in 1860, Onet has been driven by a set of strong core values.

Today, our business units around the world share the same vision.

Onet has continued to develop in connection with the nuclear industry.

The business created by Mr. Hippolyte FORMAT

The arrival of the first train at Marseille’s St Charles station dates back to 1848 in France. At this time, Marseille is experiencing one of its most important periods of economic prosperity, due, in particular to the trade of exotic products. The hills are scattered with grist mills. Semolina and flour milling activities are developing rapidly. Marseille is increasingly turning towards importation and exportation and goods are transported in sacks requiring handling services.

This is the very first known activity of the business created by Mr. Hippolyte FORMAT in 1860, which would also rapidly begin to propose cleaning services in the grist mills. Years later this company would become the Onet Group.


Acquisition of  ONECTRA

Engineering specialized in sanitation, dismantling


Acquisition of Techman Industrie

Nuclear logistics, radiation protection and training


Acquisition of Comex Nucléaire

The Group also takes over Comex Nucléaire which develops innovative engineering solutions and complex industrial interventions.


Beginning of a long-lasting collaboration between MHI and Onet Technologies

Beginning of a long-lasting collaboration between MHI and Onet Technologies (back then its subsidiary called Comex Nucléaire - CxN), for the offer of nuclear equipment and services to French nuclear power plants. In 2019, the partners received a new order form EDF (the French NPP operator) to deliver 9 Replacement Steam Generators : Manufactured in Japan, compliant with France's stringent regulations.


Onet acquires EPM Inc and expands its operations into the US market

Through its newly created subsidiary Onet North America (ONA), the group continues to grow internationally with the acquisition of EPM nuclear engineering, a company from Boston, Massachusetts.

EPM is a leader in risk prevention, technical audits and fire safety inspection for the nuclear sector.
With more than 90 employees, EPM provides services for all North American nuclear facilities as well as certain plants in Asia.

Visit EPM inc Website2015

Onet Technologies

All the subsidiaries of the company (such as Comex Nucléaire) took the name of Onet Technologies


Opening of a Representative Office in Tokyo

A cornerstone was laid for the establishment of a lasting presence in Japan.

By setting-up a Representative Office at the French Chamber of Commerce and Industry in Japan, in central Tokyo, we progressed towards our goal to further support our Clients locally.



Registration of Onet Technologies Kabushiki Kaisha

Onet Technologies K.K. was created in September 2022 as a wholly owned subsidiary of Onet.

Your contact
Julien Guillemin
Japan Area Business Development Manager

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