The goal of the presented work is the detection and evaluation of cracks, in the VeRCoRs mock-up which constitutes the double-wall containment building of a Nuclear Power Plant in scale 1/3. The experiments are conducted in situ, on the inner wall of the VeRCoRs mock-up. The detection is performed by means of two automated scanners designed for the non-destructive non-contact control of concrete using surface waves (SW). The SW signal assures the penetration in a concrete wall between 1 to 60 cm. The scanners provide the non-contact measure which permits to avoid a modification of the concrete surface by a coupling agent and a time consuming coupling procedure. The results, obtained during pressure test in the VeRCoRs mock-up, prove that the scanner can be successfully used in the detection of micro-cracking, of cracks location, the evaluation of their opening and for in the progressive aging of the mock-up.