CERN : 20 persons on each speciality, that concern the project

Bilfinger : 4 persons (Jan, Seraphin, Anaïs, Bruno)

Place : CERN

date : november the 20th, 2025

Minutes

There were many questions asked during the meeting, i was not able to note all these interrogations !

macro calendar detail design on CE starts on february 2026

end of project Q3 2031

This is the first time something like hot cell exists in CERN
part of design is in progress on CERN side, it could change depending on the authorities. They could reject some design especialy for the subdivision of the main wastes

Jan asked: What about a spectrical analysis of the result of the cutted wastes. CERN is not sure to do that at this time.

need details to set the CE study (starting on fabruary 26.) it will be an add-on to our studies.

Bilfinger presents the current study design from the 3 main concerns : size, weight, radioactivity-emmisive

We recommand to add of a new space :

Bilfinger explain the need to add a "clean" light cell outside of the main cell to make contamination controls.
it's a 1 more cell with no radiological protection, but a sealed room anyway.
it could be removable, depending of the needs.
We precise the trolley is not into the cell when we start cutting.

Jan presents some equipment on Iceda as en example for people who do not yet know what a hot cell is.

ventilation filtring
How do we change the filter ?

with telemanipulators, put it in a waste box into the cell
no need of particular precautions, because all appens in the cell.

we recommand :

HVAC : more depression on the different parts of the installation, to garantee the safety of the cells

do be discussed, depending on the sealed level on the cells.
an ASNR or swiss organisation advise so it's acceptable or not to let burn or control the fire ? it's important to be decided

Q Cern : in case of fire what happens?

we recommand to close the dampers (and to let it burn until no oxygen)
we basically reduce the heat charge to the maximum
BE CAREFULL the coil has an epoxy coat.

propose a solution to cut fire if it starts

neutral gaz injection like Argon for example to replace oxygen

fire detection : you can't use conventional systems, because of the electronical parts, we use a fiber optic system to detect fire.
we don't need monitorings or measures because concept and calculations garantee that you will never reach the max heat
do we need water into the cell, and do we need a under tank ?

no water. No tank.

if the fire comes from outside ?

good question ! Have to consider it. But in fact, the cell is sealed, from inside, and outside ! it should not be a problem.

Q Cern : Civil Engineering ?

there is a need of integration of stainless steel structure to fix the liner.
there is another subject : the fixation plates number, size, position....
how to do the interface between CE not nuclear and us and our needs ?

The windows, the pass through, the doors, the plates, liner….

can we optimise the height of the cell

yes done. On the new 3d.

Q Cern : handling :

what is the main use of the heavy crane on the top of the batiment ?

how do we do the maintenance of it

with the maintenance area added over the airlock (we let you see it on the last 3D uptade, transmitted on monday the 24th november).
To extend the crane coverage, we have to reduce the thickness of the wall, but to extend it outside to garantee the person protection.

Q Cern : how do you ensure the sealed door is close ?

there are security measures to ensure it. It’s a airlock with two doors on monitoring. An organisation measure.
You need a physical key and a supervision.
Be careful of all the accesses even it’s small because nobody should create a security issue with seal failure.

Q Cern : possibility to have tools in the cell

Yes, specific tools developped for our cell.

Q CERN : HVAC

ducts class : it's on cern side to definit it
how much time to let the depression of the cell come to 0pa ? we don't know at this time of the study. will be define further, into a future detailed study.
damper in or out before of after radioprotection ? Out and after
how do we verify the pass through radio pro ?

we garantee the radio pro by chicanes and conception

ToDo :

Bilfinger :

Crane justification : 30T with the good size in the 3d.

DONE the new size of the structure has been updated into the new 3D transmitted on monday the 24^th november.

Add the maintenance area for the crane.

DONE with low details.

Add a cube to reserve the tools table. TBD
propose a add on to give precisions on CE interfaces, according to the level of details the CE contractor needs and the CERN's Budget.

CERN : decision on fire safety compliance to let the fire burn into the cell, so we don't need any water to stop it.