New ILL building access procedures

ZAC (Zone à accès contrôlé)

The ZAC is intended to increase security from unwanted intrusion. Most of the ILL's main buildings are located inside the zone, notable exceptions being the Science Building,  ILL1 and ILL50 (User office & offices for instruments located in the reactor building). The screening process is dealt with by the CoSSeN (commandement spécialisé pour la sécurité nucléaire/specialised authority for nuclear security). They then decide whether your access to the ZAC is granted or not. Until your ZAC access has been approved by these specialised authorities, you are unable to access these zones.

Security screening ('criblage') must be completed for all persons requiring access to  the ZAC.

The User Office will submit the application for screening based on the information in your User Club account therefore please ensure that it is accurate and up-to-date. The following information will be needed:

  • Surname
  • First name
  • Employer
  • Date and place of birth
  • Nationality
  • Passport or ID number

It takes up to 21 days to process security screening and the application for screening will only be sent once you register for the experiment. Visitor access requests must therefore be submitted as early as possible, i.e. 3 weeks before the planned visit to ensure that the process of validation can be properly completed.

Once the screening application has been validated and access granted, a green message will be added under the Personal Data tab on your User Club account. We invite you to check the outcome of your screening before your visit to the ILL. If your screening is not valid at the time of your experiment, you will be allowed on site but not inside the ZAC.


On site, access to the ZAC is possible with a badge programmed for the duration of your stay, in a very similar way to the previous badges.

However, your badge will be programmed in two steps:

Upon arrival, you must stop at the site entrance as usual to get a badge which gives access to all buildings on the campus outside the ZAC. You will be required to show proof of identity (passport, ID card) as usual. Then you must go the ZAC main entrance (ground floor reception in the new ILL50 building) where your badge will be programmed to enter the ZAC. Your dosimeter will also be issued at this stage. You will then need to go to the reactor entrance to get your badge to access the experimental areas (guide halls ILL7 or ILL22, ILL5).

Reception at the ZAC entrance is open during the week from 7 a.m. until 7 p.m., Monday to Saturday, but closed on Sundays.
It will be still possible to enter the site at night and on Sundays, and go to the Guest House, for example.

For those who need to start an experiment on a Sunday, the User Office can reimburse extra nights if needed, but this obviously only applies to those users who are entitled to reimbursement.

We have created offices in the new building, ILL50, for instruments sited the reactor building. This will provide a more comfortable working environment for visiting scientists, who can benefit from the now familiar remote access capability. These are located on the first floor of ILL50, opposite the new User Office offices.

When your screening expires, it will automatically be renewed upon your next visit. There is no action to be done on your side for the screening process besides registering for your experiment. Please ensure that this is done sufficiently in advance as the screening process can take up to three weeks.