Key legal question
Whether removal-detention cells may remain locked during the day for operational reasons without relocating detainees.
Extracted holding
If daytime opening of cells is impossible for operational reasons, the affected detainees must be transferred; if transfer is not possible, they must be released.
Extracted reasoning
The detention regime must be organized so that daytime cell confinement caused by operational constraints does not result in unlawful detention conditions. Transfer is the required remedy; release is the fallback if transfer cannot be arranged.