HARIPUR, April 7: Four power generators of the Tarbela Dam were expected to start operation by April 15, sources told Dawn here on Wednesday. Electricity production, according to the sources, was recorded on Wednesday at 12.776 MKWH from the operating units No 5 to 10 out of the total designed capacity of 3,000-plus MW.

The Tarbela Dam's tunnel No 1 was closed down on April 1 when engineers spotted certain mechanical fault in the inlet valve of unit No 3 in the last week of March. They got it closed by the Wapda authorities for 15 days, suspending operations of generators No 1 to 4, having a total production capacity of 700 MW.

Wapda engineers had also detected a fault in the same unit last year, the sources said. The Wapda authorities had initially approached Japan's Hitachi company, the manufacturing firm of Tarbela's power generators, but had to seek the help of Scientific & Engineering Services, a subsidiary of Pakistan Atomic Energy Commission (PAEC), as the manufacturing firm demanded Rs5 million as examination fee.

The utility reportedly engaged PAECs experts at a much lesser cost. The experts were carrying out repair work of the affected unit under the supervision of Wapda and PAEC engineers, and were expected to complete it before April 14.