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Onet Technologies acquires ESPN manufacturer’s status

Thursday 22 November 2018
- Onet Technologies
Onet Technologies acquires ESPN manufacturer’s status

Onet Technologies has just delivered to EDF the first heat exchanger of  the emergency plant cooldown system (Containment Spray System, EASu) completely designed and realized by its teams. A performance to celebrate, this nuclear pressure equipment (ESPN) having actually received all required agreements and having gone out of factory with six months ahead of schedule.



It was a major challenge : to entirely manufacture (for EDF) an exchanger of the EASu system, a nuclear pressure equipment(ESPN) for which the company had intervened up to now only as a partner, and to deliver it in a record time, keeping a maximum level of quality …


The challenge has been taken up. Onet Technologies has just delivered the precious exchanger in time, with all required certificates. A performance that Arnaud Bousquet, project manager within the Engineering system business unit (DSC), welcomes: « the most difficult part, he says, was to organize the project in order to be able to validate the documentation-regulations aspect and move forward on the manufacturing phase in a satisfactory way, at the same time. We had to begin the manufacturing while finalizing the regulations with, in addition, very restrictive constraints of deadlines, EDF having asked us to move forward the delivery by six months … »

  • 10 months of engineering studies
  • 8 months of procurement
  • 12 months of manufacturing


New challenge and new opportunities ahead


The organization of the project was by itself a real challenge.

« This project is one of the first to have been led within the framework of the new organization for Onet Technologies projects, with the identification of a technical architect as a duo with the project manager, continues Arnaud Bousquet. The implication of the whole team generated a lot of motivation within the project, they showed a strong team-spirit, and also created a positive connection with EDF, ACM and APAVE, the external organization approved by the Authority of Nuclear Safety and chosen by Onet Technologies to follow the manufacturing of the EASu exchanger. »


For Philippe Clergue, President of Onet Technologies, « This new way of working pays off, in terms of respect of the deadlines, as well as costs controls and customer satisfaction and with a smooth relationship with Safety Authority. We are really in a win-win approach.»,concludes the President.


A real technical performance


Technically, to build this heat exchanger, the company leaned on its own expertise in the manufacturing of steam generators and on the expertise of its subcontractor ACM, which proved very productive.


With the delivery of this first EASU exchanger, Onet Technologies joins the category of the manufacturers of level 2 ESPN.



« After an important final documentary work from our teams, the APAVE delivered us a certificate of conformity (module G), indicates Arnaud Bousquet. Our expertise acquired on the ESPN regulations is validated. We are now a member of ESPN manufacturers and are recognized as such. »


A new qualification which should open doors and new markets to the company, in particular in Great Britain with the Hinckley Point EPR and on ITER's research projects.


« This expertise is an undeniable added value for our company, points out Philippe Clergue. Previously, only the big groups were able to provide nuclear pressure equipment and to generate certificates with the French Safety Authority. The fact that we are now also  certified to do it, opens up new horizons in France and on the international stage for us. »


Avoid the accidents of type Fukushima


EASu Heat exchangerhas for function to cooldown the primary fluid of nuclear power plants in the event of a severe accident such as Fukushima. The one manufactured by Onet Technologies must be integrated by EDF into the new loop of the ultimate cooling system of the power plant of Tricastin 1 at the beginning of January, on the occasion of the 4th ten-year visit (VD4), then on all of the French 900 MWe reactors. The particularity and the complexity of this type of equipment come from the fact that the cooling fluid - the sea or river water – directly passes through the heat exchanger without intermediate loop, which supposes a maximal level of guarantee of water tightness between hot and cold circuits.


The EASU exchanger consists in a calander (big cylinder of 1m of diameter supported by two "cradles"), where the hot fluid circulates, a water chamber and a tube bundle which ensures the thermal exchange.



Data about EASU exchanger

  • length : 7m, height: 2m50
  • empty weight: 9,2 tonnes, weight with water: 13,3 tonnes
  • Material : stainless steel 316 L, except tube bundle
  • 460 U-tubes in 690 alloy
  • 12 baffles