Operational safety experience at the Tarapur Atomic Power Station

The Tarapur Atomic Power Station (TAPS), consisting of twin BWR units currently rated 160 MW(e) each, has been in operation for more than 19 years. The paper attempts to bring out the salient safety related events which occurred over these 19 years and the manner in which they were analysed in order to pinpoint the causes. Also discussed are the remedial measures undertaken, such as modifications to equipment, procedures, personnel training, etc., so as to avoid a recurrence of similar events. The precautionary/preventive actions taken on the basis of events reported at similar BWRs abroad (which are reviewed regarding their applicability to TAPS, following which the modifications are implemented, if found to be necessary) are discussed. The review of the Three Mile Island accident in 1979 raised a number of issues and a committee which reviewed the additional safety requirements recommended certain measures to be adopted at TAPS, which were implemented. The incident at Chernobyl has also been reviewed by a committee and its recommendations are being reviewed for implementation. The Station Technical Specification stipulates that all safety related occurrences be reported to the regulatory authority and the incidents reviewed in order to assess the status of the reactor, clearance then being given for further operation of the reactor. TAPS has established a procedure for carrying out design modifications wherein the modifications are first conceived as a proposal and, after a review regarding their utility, are approved by the head of the unit, after which they are implemented. In the case of modifications which are safety related, they are referred to the regulatory authority for clearance and then implemented. (author). 2 figs, 2 tabs