From this article:

The Pakistan Atomic Energy Commission started operation of the first nuclear power plant of the country at Karachi in 1971. The Indian nuclear explosion in 1974 forced the PAEC authorities to strengthen its efforts for indigenous manufacture of spare parts, components and equipment. Scientific and Engineering Services Directorate (SES) was established at Islamabad in 1984 with a mandate to establish infrastructure facilities in design and engineering, fabrication and welding, machining, testing, quality assurance and control, and non-destructive testing to gear up the indigenous manufacturing of mechanical equipment and parts.