The design (study) and delivery of a sampling system for airborne radioactive material from the stack at BR2. The assignment consists of: a fixed part; Design( study) and a contingent part (purchasing, delivery and installation). Although the conclusion of the contract covers the entire contract, it binds the contracting authority only for the fixed portions. The execution of the conditional part is subject to a decision of the contracting authority communicated to the contractor (Article 57 of the Law of June 17, 2016),), after approval of Phase 1, confirmation of the budget within the requested implementation period, and provided that the study has been approved by BEL-V. . In the absence of such approval, the conditional part shall not be executed. The installation and validation will take place under the supervision of SCK CEN. A quote for the maintenance should be provided and is considered as an permitted option