* EDF says no operational impact

* Was notified by Areva of the flaws

* Quality control shortcomings found related to 14 rods

* EDF cut 2018 earnings forecast last week (Adds detail, background)

PARIS, Nov 21 (Reuters) - EDF said on Tuesday it had been informed about shortcomings found in quality controls on a small number of rods installed at its French nuclear sites.

EDF said the discovery was made by nuclear equipment manufacturer Areva on 14 of 2,600,000 rods installed at its reactors across France.

“Areva notified the EDF Group of quality control deviations on certain rods used to manufacture fuel assemblies. The supplier is not able to demonstrate that quality control substantiating leak tightness of these rods has been properly performed,” EDF said in a statement.

The rods involved are in use at the Golfech 2, Flamanville 1 and Cattenom 3 reactors, while 11 others were not installed. EDF said the findings would have no operational impact.

France depends on nuclear power for more than 75 percent of its electricity, and EDF union members have warned of a risk of blackouts this winter due to nuclear reactor outages.

Last week, EDF said future nuclear reactor maintenance outages could be longer than expected and that these could weigh on its 2018 core earnings.

EDF lowered its 2018 core earnings forecast to a range of 14.6-15.3 billion euros ($17.2-$18 billion) from at least 15.2 billion.