Keywords: Leningrad NPP-1, life extension concept, irreplaceable components, reactor metal structures, graphite stack, component strength, main results, nuclear safety, nuclear power plants, nuclear energy, Russia
Main results of life extension concept application at LNPP Unit 1
The life extension (LE) concept for LNPP Units of the first generation was based on main technical and economic principles. The following 'irreplaceable' components have been selected at LNPP Units: for the reactor facility – reactor metal structures (RMS) and graphite stack (GS); for the unit as a whole – buildings and other civil structures. The following activities have been fulfilled at LNPP Unit 1 in 1998–2003: complex investigation of structures, systems and components; implementation of life extension programmes; development of a set of documents ensuring safety during prolonged period of Unit 1 operation. Comprehensive programmes were implemented of RMS and GS elements investigation, material studies (including testing of cut-off samples) and forecast of properties until the total life of 45 years. Justification of safe operation has also been developed for MCC components Therefore, comprehensive implementation of activities prescribed by the LE concept made it possible to ensure the safe operation of LNPP Unit 1 until 2018.