Stochastics in the Manufacture and Operation of Fuel Assemblies for Nuclear Power Plants

Statistical tools are believed to be essential for competent quality judgements in the field of nuclear technology as well as in other branches of industry. In comprehensive quality management, these tools comprise not only well-known statistical procedures of quality control for fuel assembly production, but also methods for fuel rod design. Procedures which are set out in standards or directives are generally used in practice. This seems to be appropriate as in almost all statistical textbooks and publications the impression is given that in statistics some few standard methods are sufficient in practice just like cooking recipes in the kitchen. However, standard methods cannot take into due account the diversity and complexity of situations and, thus, lead almost inevitably to inappropriate results and false interpretations. It follows that in general statistical standard methods should not be part of a strategy of continuous quality improvement. This paper describes by means of several examples the problems which occur in the field of nuclear technology and illustrates the need that the different quality assurance measures must be organized so as to complement each other, thereby increasing the total efficiency.