ISLAMABAD: The 969-megawatt Neelum-Jhelum Hydro­power Project (NJHP), completed at an estimated approved cost of more than Rs510 billion, has been partially closed once again within days of its full capacity utilisation after almost 20-month-long repair works.

The project was closed in July 2022 due to major cracks in its 3.5km tailrace tunnel (TRT), which was repaired over the next 13 months. Power generation started again in August-September 2023, attaining its maximum 969MW capacity on March 29, as announced by the Water & Power Development Authority (Wapda).

Within a week, on April 3, the 48km-long headrace tunnel (HRT) dropped pressure, and power generation fell to about 400MW “soon after the project was restored to full capacity by international contractors because of debris or cracks in HRT”, inside sources told Dawn.

They said the project authorities and contractors, in consultation with the Wapda management, tried in-house emergency measures to restore the project but the fault was bigger than anticipated, although generation had incre­ased since then.

An official said a remotely controlled vehicle would need to be arranged abroad, most probably from China, to trace and potentially address the fault, at an estimated cost of about Rs6bn. He said the prime minister had not yet been intimated about the incident. The partial project closure is resulting in a substantial daily loss of electricity units, he added.

Repair works may cost national kitty Rs6bn

The earlier repairs of 3.5km TRT cost the nation about Rs6bn, in addition to about Rs37bn in energy loss during repairs, maintenance, and testing over the following 20 months. Wapda has filed about Rs43bn insurance claims for the losses and is reported to have already held a series of high-level meetings on the subject.

When contacted, Wapda confirmed a significant reduction in power generation due to a fall in HRT pressure but remained evasive about its actual cause. “Electricity generation from Neelum-Jhelum Hydel Power Station has been restricted to 530MW due to decrease in headrace tunnel pressure on April 3,” it said in a statement, attributing this to being a “precautionary measure…to observe the behaviour of pressure fluctuation”.

The Wapda spokesperson said the generation from the power station would be increased gradually after analysis and deliberations with the project consultants.

It is important to note that all possible maintenance has been carried out during the observation, he said, adding that this maintenance included cleaning of trash racks installed at the intake gates in the reservoir, flushing of all three de-sanders, flushing of pressure gauge installed at the powerhouse and inspection of the spiral cases of the generating units.

“The project has a tunnel system comprising 51.5km. It is prudent to observe and monitor such a vast network,” the statement said.

On March 29, Wapda announced that the Neelum-Jhelum project had achieved its maximum generation capacity of 969MW. Following the resumption of its operation in early March after inspection of the TRT, the project is continuously in operation as per the availability of water and contributing electricity to the national grid.

It had said that taking advantage of the low-flow season, operation of Neelum-Jhelum project was stopped on Jan 10 for inspection of the rehabilitated tail race tunnel. Subsequently, the detailed inspection was successfully carried out prior to resumption of generation from the project“ early last month. Most importantly, International Panel of Experts also inspected the tail race tunnel, it added.

Since its commissioning in 2018, the project has generated 19.829 billion units of electricity, while 1.54bn units have been generated since the resumption of electricity generation after the rehabilitation of TRT in August last year.

Published in Dawn, April 16th, 2024