Lacking weapons, EDF relies on a hundred North American welders to repair French nuclear reactors
American and Canadian welders come to the rescue of the French nuclear power, which lacks weapons. EDF, which has confronted a main stress corrosion downside for a yr, at the moment relies on a hundred North American welders and pipe fitters employed by Westinghouse and Framatom Co., each of which have subsidiaries throughout the Atlantic. they” got here as reinforcements to allow us to cross the summit.”Regis Clement, EDF’s Deputy Director of Nuclear Production defined, throughout a press briefing on Tuesday, December 8.. “As lengthy as we want welders, we assemble welders”she added.
The want for EDF for welders will not be restricted to stress corrosion issues. The group, whose renationalisation is predicted by the tip of the yr, additionally has pipes to construct as a part of the fourth decennial inspection of its oldest reactors, which have handed the milestone of 40 years of operation. It represents a essential industrial load.
About 600 folks gathered to repair the circuit
To treatment the stress corrosion cracking, which precipitated micro-cracks within the auxiliary circuit instantly linked to the circuit across the reactor, EDF known as on 5 corporations: Fretome (an EDF subsidiary), Endel (an ex-subsidiary of Engie) Altrad Group), offered to the French Monteiro and Sighedi and the American Westinghouse.
“EDF has a vested function. We design and specify repair wants. Then the producer is accountable for performing the motion” Explained by Regis Clement. More than 300 new castings have already been created. ” A brand new weld is a sound weld”, assured the deputy director. ” There are only a few welds that we had to rework on,” He talked about.
In whole, together with reinforcements from North America, about 600 individuals are concerned on this welding and piping activity. In addition to the operators who perform these very delicate manipulations, many individuals work on management engineering, which entails organising management recordsdata that have to be verified earlier than an operation can start.
Objective: 46 reactors can be found on 1 January
Thanks to this consolidation, EDF is counting on the supply of 42 reactors on December 1, 2022 and 46 reactors on January 1, 2023, in contrast to 30 at the moment. ” Margins are decreased however this corresponds to a state of affairs the place RTE [le gestionnaire du réseau de transport d’électricité qui doit assurer en permanence un équilibre entre l’offre et la demande d’électricité, ndlr] ready for us”Regis Clement notes.
An upward shift would solely heighten the dangers for the French electrical energy system, which is already susceptible to a grueling winter. In addition, each unit outage turns into a actual headache for the shift electrician. “Getting a shutdown means seeing a schedule of shutdowns for greater than 10 years. Everything is linked. There are 350 unit outages which have to be checked to optimize the outage of reactors in them”., says Regis Clement. Here once more, the query of business assets is decisive.
Today, 26 nuclear reactors have shut down, 15 for suspected or confirmed corrosion issues. Some reactors had been truly shut down and had their pipes lower to examine in the event that they had been affected by this phenomenon, however they weren’t. These embody, for instance, the Tricastin 3 and Buge 4 reactors, that are each 900 MW reactors.
16 delicate reactors
And for good motive, the investigation carried out by EDF over a number of months lastly proved that microcracks had been extra probably to seem in the latest reactors, the design of which, that’s to say the geometry of the piping, is a little extra complicated. The 32 900 MW reactors, the oldest within the fleet, are subsequently not affected. Eight first-generation 1,300 MW reactors had been additionally spared.
On the opposite hand, 16 delicate or extremely delicate reactors have been recognized. These are the so-called N4 reactors (Chooz B1 and B2 and Civaux 1 and a couple of) in addition to the 12 most up-to-date 1,300 MW reactors.
Of these 16 significantly delicate reactors, ten are at the moment in course of and needs to be linked to the community once more by early 2023. On the opposite hand, monitoring of the remaining six reactors is not going to start till subsequent yr. and ” Compensation could also be required from these checks”, Regis warns Clement. Hence these six reactors may be shut down for a mean of 24 weeks i.e. about 5.5 months.
Standardization and automation
Thanks to the expertise gained this summer time, EDF now needs to industrialize the repair. Electricians particularly rely on standardization and automation. “These websites have to be copied to the utmost with a repair scheme that’s repeated from furnace to furnace, in order that the length of the websites may be step by step decreased”, stated the deputy director. “Automation is a second key issue. In these operations, we’re partially automated in the best way of welding and we’re not a lot in the best way of management. We want to automate extra.”
To pace up the inspection course of, EDF is relying on specifically developed ultrasound know-how. This makes it potential to detect any corrosion phenomena with out slicing the pipes. The electrician claimed a world-class efficiency within the nuclear business and claimed to have obtained two buy presents.” Our instruments aren’t on the market, nonetheless ». The group now owns about twenty such units and trains about sixty personnel to use them. To absolutely exploit the potential of this know-how, it should move a closing regulatory step which is qualification.