[en] KANUPP during its 23 years of operation has experienced multiple challenges in keeping the plant operating and supplying safe and economical power to the Karachi grid. The biggest challenge was faced in 1976, when the original vendor imposed unilateral embargo leading to the stoppage of supplies of essential spare-parts, nuclear fuel, heavy water and technical support. This forced KANUPP to a net, way of operating the plant which necessarily had to be based on indigenous support. Obsolescence of C and I components became evident soon after plant went into commercial operation because of explosive development and advancement in the electronic and computer technology. KANUPP was, however, able to cope with the normal maintenance and improvement of its process, mechanical and electrical equipment till 80's. However, many of the critical components are now reaching the end of their designed life and developing chronic problems due to ageing. The only technically suitable and commercially viable alternative is the complete replacement of CC and I components. KANUPP has already undertaken this job alongwith other related work under ''Technological Upgradation Project''. In order to manage ageing related degradation and carry out full scale assessment of the health of reactor fuel channels KANUPP prepared an ''Integrated Safety Master Action Plan'' and submitted it to IAEA for arranging international assistance. After intense negotiations and with the IAEA's cooperation in May 1990, Canadian policy towards KANUPP was revised allowing it to provide assistance for Safe Operation of KANUPP (SOK) through the IAEA and only for the IAEA suggested remedial actions. Work under SOK is being carried out to: Combat ageing and obsolence Problems; Modernize Operational Safety practices; Improve safety systems design. This paper describes KANUPP's efforts in overcoming different problems mentioned above