Rehabilitation of TAPS reactor recirculation pump motor unit -inspection, testing, evaluation and import substitution of components

Tarapur Atomic Power Station, having twin Boiling Water Reactors (BWRs), is now into its twenty fifth year of commercial operation, each generating 160 MWe. These reactors use the reactor recirculation pumps in the recirculation system for forced circulation of primary coolant in the core. This gives the necessary flow in the core which increases the power density and assists in maintaining the minimum critical heat flux ratio during normal operation. This paper deals with the systematic approach followed for the rehabilitation of reactor recirculation pump motor unit by carrying out inspection, testing, evaluation, reviews, safety margin calculation, administrative controls for continued operation with the available margins and later on, replacement of components by import substitution with effective planning during the unit's scheduled refuelling outage. The rehabilitated pump motor unit was test run and all its parameters were found to be within the acceptable limits. (author). 5 refs., 3 figs