Correction methods for pulsed neutron source reactivity measurement in accelerator driven systems

Important issue in the perspective of nuclear energy development in the near future is the partitioning and transmutation (P&T) of spent nuclear fuel. For years the European Commission (EC) has sponsored this scientific activity through the Framework Programmes (FP). One of the milestones for P&T is the development of accelerator driven systems (ADS). Extensive research in this field was carried out within the EUROTRANS project of 6th FP of EURATOM. Part of this research was devoted to testing and development of reactivity monitoring techniques in ADS. This paper concerns the methods of the reactivity measurement using the pulsed neutron source (PNS). Due to the fact that basic methods devoted to determine the core reactivity are derived from point kinetics, while real subcritical core kinetics differs from this model, there is a need to improve these methods in order to deal with the observed spatial effects. There are several ways to make these methods work properly and finally it should be possible to achieve this. However, they still need a validation which is supposed to be done within next FP project FREYA.