Lights illuminate the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Employee headlamps are pictured in the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

The clay dating from the Jurassic period is pictured in the tunnel system of the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

An employee and media members are pictured in the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

An employee is pictured in the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

An employee walks within the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Lights illuminate the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Lights illuminate the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

A fire alarm is pictured in the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

An employee is pictured in the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

An employee is pictured in the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Lights illuminate a nuclear waste storage borehole at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Lights illuminate the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Lights illuminate a nuclear waste storage borehole at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Lights illuminate a nuclear waste storage borehole at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Lights illuminate the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Manometers are pictured in the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Lights illuminate a nuclear waste storage borehole at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

A nuclear waste storage borehole is pictured at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

An employee walks within the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

An employee is pictured in the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

An employee is pictured in the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

An employee walks within the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Employees walk within the tunnel system at the Cigeo project, a nuclear laboratory and underground storage facility site operated by French National Agency for Radioactive Waste Management (Andra) in Bure, France April 8, 2019. REUTERS/Benoit Tessier 

Empty metallic drums are pictured at the waste disposal facility in the Aube district (CSA) managed by the French National Agency for Radioactive Waste Management (Andra) where solid low and intermediate level short-lived radioactive waste are stored in Soulaines-Dhuys, France, March 15, 2019. REUTERS/Benoit Tessier 

Very-low-level radioactive waste are stored at the industrial centre for collection, storage and disposal (CIRES) managed by the French National Agency for Radioactive Waste Management (Andra) in Morvilliers, France, March 15, 2019. REUTERS/Benoit Tessier 

A worker opens a door of a very-low-level radioactive waste structure at the industrial centre for collection, storage and disposal (CIRES) managed by the French National Agency for Radioactive Waste Management (Andra) in Morvilliers, France, March 15, 2019. REUTERS/Benoit Tessier 

Excavators pour sand over very-low-level radioactive waste stored in a structure at the industrial centre for collection, storage and disposal (CIRES) managed by the French National Agency for Radioactive Waste Management (Andra) in Morvilliers, France, March 15, 2019. REUTERS/Benoit Tessier 

A worker is seen in front of an information board at the industrial centre for collection, storage and disposal (CIRES) managed by the French National Agency for Radioactive Waste Management (Andra) in Morvilliers, France, March 15, 2019. REUTERS/Benoit Tessier 

A nuclear warning sign which reads "controlled access" is pictured in a very-low-level radioactive waste structure at the industrial centre for collection, storage and disposal (CIRES) managed by the French National Agency for Radioactive Waste Management (Andra) in Morvilliers, France, March 15, 2019. REUTERS/Benoit Tessier 

A worker is seen in a very-low-level radioactive waste structure at the industrial centre for collection, storage and disposal (CIRES) managed by the French National Agency for Radioactive Waste Management (Andra) in Morvilliers, France, March 15, 2019. REUTERS/Benoit Tessier 

A helmet bears the logo of the French National Agency for Radioactive Waste Management (Andra) at the industrial centre for collection, storage and disposal (CIRES) where very-low-level radioactive waste are stored in Morvilliers, France, March 15, 2019. REUTERS/Benoit Tessier 

An employee looks at monitors at the control and command center at the waste disposal facility in the Aube district (CSA) managed by the French National Agency for Radioactive Waste Management (Andra), where solid low and intermediate level short-lived radioactive waste are stored, in Soulaines-Dhuys, France, March 15, 2019. REUTERS/Benoit Tessier 

A sign that reads "No access without special authorisation" is seen at the waste disposal facility in the Aube district (CSA), managed by the French National Agency for Radioactive Waste Management (Andra), where solid low and intermediate level short-lived radioactive waste are stored, in Soulaines-Dhuys, France March 15, 2019. REUTERS/Benoit Tessier 

A sign that reads "No access without special authorisation" is seen at the waste disposal facility in the Aube district (CSA), managed by the French National Agency for Radioactive Waste Management (Andra), where solid low and intermediate level short-lived radioactive waste are stored, in Soulaines-Dhuys, France March 15, 2019. REUTERS/Benoit Tessier 

Selma Tolba, PR manager of the French National Agency for Radioactive Waste Management (Andra), gives a statement to the media at the waste disposal facility in the Aube district (CSA) where solid low and intermediate level short-lived radioactive waste are stored, in Soulaines-Dhuys, France March 15, 2019. REUTERS/Benoit Tessier 

The logo of the French National Agency for Radioactive Waste Management (Andra) is seen at the waste disposal facility in the Aube district (CSA), where solid low and intermediate level short-lived radioactive waste are stored, in Soulaines-Dhuys, France March 15, 2019. REUTERS/Benoit Tessier 

A worker walks at a storage building under construction at the waste disposal facility in the Aube district (CSA), managed by the French National Agency for Radioactive Waste Management (Andra), where solid low and intermediate level short-lived radioactive waste are stored, in Soulaines-Dhuys, France March 15, 2019. REUTERS/Benoit Tessier 

A worker is seen in front of a very-low-level radioactive waste structure at the industrial centre for collection, storage and disposal (CIRES) managed by the French National Agency for Radioactive Waste Management (Andra) in Morvilliers, France, March 15, 2019. REUTERS/Benoit Tessier 

A truck is seen in a structure where very-low-level radioactive waste are stored at the industrial centre for collection, storage and disposal (CIRES) managed by the French National Agency for Radioactive Waste Management (Andra) in Morvilliers, France, March 15, 2019. REUTERS/Benoit Tessier 

Metallic drums containing solid low and intermediate level short-lived radioactive waste, identified by a bar code, are stored at the waste disposal facility in the Aube district (CSA) managed by the French National Agency for Radioactive Waste Management (Andra), in Soulaines-Dhuys, France, March 15, 2019. REUTERS/Benoit Tessier 

An employee walk past a nuclear warning sign which reads controlled access, at the waste disposal facility in the Aube district (CSA) managed by the French National Agency for Radioactive Waste Management (Andra), where solid low and intermediate level short-lived radioactive waste are stored, in Soulaines-Dhuys, France, March 15, 2019. REUTERS/Benoit Tessier 

A worker walks in a storage building under construction at the waste disposal facility in the Aube district (CSA) managed by the French National Agency for Radioactive Waste Management (Andra), where solid low and intermediate level short-lived radioactive waste are stored, in Soulaines-Dhuys, France, March 15, 2019. REUTERS/Benoit Tessier 

A sprayed portrait of Marie Curie is seen from the control and command center at the waste disposal facility in the Aube district (CSA) managed by the French National Agency for Radioactive Waste Management (Andra), where solid low and intermediate level short-lived radioactive waste are stored, in Soulaines-Dhuys, France, March 15, 2019. REUTERS/Benoit Tessier 

Media members are seen in front of a storage building containing solid low and intermediate level short-lived radioactive waste at the waste disposal facility in the Aube district (CSA) managed by the French National Agency for Radioactive Waste Management (Andra), in Soulaines-Dhuys, France March 15, 2019. REUTERS/Benoit Tessier 

Media members walk past a storage building containing solid low and intermediate level short-lived radioactive waste at the waste disposal facility in the Aube district (CSA) managed by the French National Agency for Radioactive Waste Management (Andra), in Soulaines-Dhuys, France March 15, 2019. REUTERS/Benoit Tessier 

Empty metallic drums are seen at the waste disposal facility in the Aube district (CSA) managed by the French National Agency for Radioactive Waste Management (Andra) where solid low and intermediate level short-lived radioactive waste are stored, in Soulaines-Dhuys, France March 15, 2019. REUTERS/Benoit Tessier 

An employee looks at monitors at the control and command center at the waste disposal facility in the Aube district (CSA) managed by the French National Agency for Radioactive Waste Management (Andra), where solid low and intermediate level short-lived radioactive waste are stored, in Soulaines-Dhuys, France, March 15, 2019. REUTERS/Benoit Tessier 

Claude Leonard, president of the Meuse Departemental Council, in favor of the project of an underground nuclear waste disposal of the French National Radioactive Waste Management Agency ANDRA in the village of Bure called CIGEO, talks to Reuters journalists during an interview at in his office in Bar-le-Duc, France, April 6, 2018. Picture taken April 6, 2018. REUTERS/Vincent Kessler 

Jean-Marc Fleury, opponent to the project of an underground nuclear waste disposal of the French National Radioactive Waste Management Agency ANDRA in the village of Bure called CIGEO, talks to Reuters journalists during an interview at his home in Verney, France, April 6, 2018. Picture taken April 6, 2018. REUTERS/Vincent Kessler 

Corinne Francois, opponent to the project of an underground nuclear waste disposal of the French National Radioactive Waste Management Agency ANDRA in the village of Bure called CIGEO, talks to Reuters journalists during an interview at her home in Bar-le-Duc, France, April 6, 2018. Picture taken April 6, 2018. REUTERS/Vincent Kessler 

One of the buildings of the underground research laboratory of the French National Radioactive Waste Management Agency ANDRA, is seen in Bure, France, April 5, 2018. Picture taken April 5, 2018. REUTERS/Vincent Kessler 

Mathieu Saint-Louis, spokesperson for the French National Radioactive Waste Management Agency ANDRA, walks in one of the 500 meter underground galleries of the research laboratory of the Agency, in Bure, France, April 5, 2018. Picture taken April 5, 2018. REUTERS/Vincent Kessler 

Empty nuclear waste containers are seen in a block of concrete at the underground research laboratory of the French National Radioactive Waste Management Agency ANDRA, in Bure, France, April 5, 2018. Picture taken April 5, 2018. REUTERS/Vincent Kessler 

Mathieu Saint-Louis, spokesperson for the French National Radioactive Waste Management Agency ANDRA, holds a block of clay at the underground research laboratory of the Agency, located 500 meters underground in Bure, France, April 5, 2018. Picture taken April 5, 2018. REUTERS/Vincent Kessler 

The boots of an opponent to the project of an underground nuclear waste disposal of the French National Radioactive Waste Management Agency ANDRA called CIGEO, who wanted to stay anonymous, are seen during an inverview with Reuters journalists in front of the "house of resistance" in Bure, Eastern France, April 6, 2018. Picture taken April 6, 2018. REUTERS/Vincent Kessler 

Technicians work in one of the galleries of underground research laboratory of the French National Radioactive Waste Management Agency ANDRA, located 500 meters underground, in Bure, France, April 5, 2018. Picture taken April 5, 2018. REUTERS/Vincent Kessler 

Mathieu Saint-Louis, spokesperson for the French National Radioactive Waste Management Agency ANDRA, stands in the elevator of the underground research laboratory of the Agency, as it arrives 500 meters underground, in Bure, France, April 5, 2018. Picture taken April 5, 2018. REUTERS/Vincent Kessler 

Mathieu Saint-Louis, spokesperson for the French National Radioactive Waste Management Agency ANDRA, stands besides an empty nuclear waste container at the underground research laboratory of the Agency, located 500 meters underground, in Bure, France, April 5, 2018. Picture taken April 5, 2018. REUTERS/Vincent Kessler 

Mathieu Saint-Louis, spokesperson for the French National Radioactive Waste Management Agency ANDRA, holds a block of clay at the underground research laboratory of the Agency, located 500 meters underground, in Bure, France, April 5, 2018. Picture taken April 5, 2018. REUTERS/Vincent Kessler