Current practice of LPSA in Hungary

This paper summarises and gives an overview of the living PSA (LPSA) procedure used in Hungary to update the PSA model and its documentation of the Paks NPP units. In recent years unit-specific PSAs have been developed for the units of VVER-440/213 type NPP of Paks to assess the general level of their safety, to identify plant weaknesses, and to outline necessary safety upgrading measures. The PSAs performed have been limited to level-1 and to internal initiating events. Since completion of the original unit-specific PSAs several safety related modifications of the technological systems have been made, as well as operational changes described in related procedures have been introduced. These changes make it necessary to update the risk model of the plant on given conditions to reflect their impact on the plant safety. Therefore the use of an LPSA has become necessary. (authors)