Evaluation and analysis of data with a view to safety-relevant problems and to the consideration of these problems in the further development of the catalogue of nuclear technical codes. 1. technical report

With the methods of elastic and plastic fracture mechanics, the behaviour of small and large samples can be precalculated precisely and safely within a wide range of material toughness. The recommendations for safety-relevant fracture-mechanical error analyses may be summed up as follows: The strength characteristic values on which the calculation is to be based must describe the case to be evaluated accurately (direction of stress, temperature). The fracture-mechanical values for crack initiation on which the calculation is to be based must be physical values, i.e. they must be transferable material parameters. The Ji value must be used for crack initiation. The calculation can only be done for initiation. At present, the calculation of stable crack growth before instability on the basis of crack resistance curves cannot be done with certainty. (orig./DG)