The knowledge of mechanical properties for structural reactor materials is among the key points for producing reliable integrity assessments and accurate residual life predictions. The evaluation of mechanical properties, with the sole exception of hardness measurements, is by definition a destructive technique. In the nuclear field, the space available inside irradiation facilities is quite small and the exploitation of material has to be optimized. The optimum use of very limited irradiated materials becomes very critical in the perspective of long term operation (LTO). Thus the use of very small specimens becomes then very appealing, although they usually do not comply with existing requirements of the test standards. This triggered worldwide research efforts for developing miniature specimens that can be used for fracture mechanics testing with particular insight on the master curve application, where SCK.CEN has been very often at the fore-front of the developments [1, 2, 3, 4, 5].
Fracture toughness can be more or less directly transferred without any empirical correlation procedures such as used for the Charpy impact properties of reactor pressure vessel materials. SCK.CEN was the first one that selected the mini-CT specimen as such that 4 mini-CT specimens can be fabricated out of a half broken Charpy specimen [6, 7]. The additional advantage of the mini-Charpy is that specimen re-orientation is also possible. However, the geometry does not fully satisfy the ASTM requirements with respect to the various ratios of the specimen dimensions. In addition miniaturization induces a loss of constraint effect [7, 8] as was already assessed by 3D finite element simulations.
 E. Lucon and M. Scibetta, "Fracture toughness measurements in the transition region using miniature PCCv and CRB specimens", SCK.CEN report R-3400 (2000)
 E. Lucon and M. Scibetta, "Fracture toughness measurements in the transition region using sub-size pre-cracked Charpy and cylindrical bar specimens", SCK.CEN report BLG-863 (2001)
 E. Lucon, M. Scibetta, R. Chaouadi and E. van Walle, "Fracture toughness measurements in the transition region using sub-size pre-cracked Charpy and cylindrical bar specimens, small specimen test techniques: 4th volume, ASTM STP 1418, M.A. Sokolov, J.D. Landes, and G.E. Lucas, Eds., ASTM International (2002) 3-17
 J.L. Puzzolante and M. Scibetta, "Machining and fracture toughness testing of miniature compact tension specimens in hot cell", Hot laboratories and Remote Handling, HOTLAB-2003, September 22-24, Saclay (France)
 M. Scibetta, E. Lucon, R. Chaouadi, E. van Walle and R. Gérard, "Use of broken Charpy V-notch specimens from a surveillance program for fracture toughness determination", Journal of ASTM International 3 (2006)
 M. Scibetta, E. Lucon and E. van Walle, "Optimal use of broken Charpy specimens from surveillance programs for the application of the master curve approach", International Journal of fracture 116 (2002) 231-244
 M. Scibetta, "Constraint assessment in miniature C(T) specimens using 3D finite element simulations", SCK.CEN Report BLG-923 (2002)
 R. Chaouadi et al., "On the use of miniaturized CT specimens for fracture toughness characterization of RPV materials", Proceedings of the ASME 2016 Pressure Vessel and Piping conference (2016), Vancouver