The union added that the action is expected to be part of a week of strikes over wages and employment because "only the fight pays".
It did not indicate how many workers would be involved, nor what production capacity, if any, would be affected. Strikes towards the end of 2021 took several gigawatts of nuclear and hydropower offline.
Three other workers' unions have already said they will strike on Jan. 27 to call for an increase in both public and private sector wages.
Multiple outages in recent weeks have already removed several gigawatts of supply capacity as France grapples with measures to limit surging electricity prices.
French power grid operator RTE said in December that French nuclear capacity in January was expected to be at its lowest level ever for this time of year.
(Reporting by Forrest Crellin and Benjamin Mallet; Editing by Dominique Vidalon, Kirsten Donovan)
