Status of seismic re-evaluation and upgrading of KANUPP

The seismic upgrading activities at Karachi Nuclear Power Plant (KANUPP) began in 1992 after a preliminary plan was chalked out with IAEA to conduct the seismic walkdown of the plant and initiate site studies to reconfirm geotechnical parameters and determine new seismic input. Consequently, the seismic walkdown was arranged in May 1993. The site geotechnical parameters were re-evaluated by performing the geotechnical investigations and cross hole seismic survey. This was followed by collection of data for seismic studies, geological surveys, surface fault studies and development of a seismotectonic model for determining the new seismic parameters as per IAEA safety guide no. 50-SG-SI. In parallel with the seismic studies, the short term fixes work was also initiated with iRLE value but gained momentum during the last six months. Dynamic analyses of some structures/equipments identified by the IAEA mission with a fabricated spectra and cross checked with simplified techniques have been completed and retrofitting/anchoring details provided to the implementation division while analyses/fixes design of other structures are in progress. (author)