The level of radioactivity in the Loire observed in January and reported by associations Tuesday, "is not a usual level and its origin should be sought," said Thursday the Institute for Radiation Protection and Nuclear Safety (IRSN).
In its press release, the institute mentions several "lines of investigation" that it will examine "in the coming weeks", among which an "exceptional / non concerted rejection between different EDF installations". Five nuclear power plants are located upstream of the measurement zone. IRSN also mentions the possibility of a measurement problem, recalling the differences in methodology between its continuous water sampling (over a week) and the point samples taken by the association for the control of radioactivity in the laboratory. West (ACRO) causing the alert, which provide "more variable results".
Radioactive hydrogen in the river and drinking water
Finally, the possibility of "another source of tritium" (radioactive hydrogen) between the measurement sites of IRSN and EDF and those of ACRO is advanced. The presence of tritium "is almost systematic, both in the river and in drinking water.In January 2019, the concentration in the water of the Loire reached 310 Bq / L" (becquerel per liter), had alerted Tuesday the laboratory based in Hérouville-Saint-Clair, near Caen in a joint communique with the Réseau Sortir du nucléaire. "ACRO's tritium levels in drinking water from its study do not exceed" the quality standard of 100 Bq / L and "remain well below the guideline value recommended by WHO ( 10,000 Bq / L) "reminds IRSN.