ISLAMABAD: More than two months after a mishap that led to the complete shutdown of the 969-megawatt Neelum-Jhelum Hydro­­power Project (NJHPP), the exact cause and veracity of the problem remains unknown.

Officials privy to the development told Dawn that the problem appeared to be larger than anticipated and could keep the Rs500bn NJHPP — located near Muzaffar­ab­­ad in Azad Kashmir — off the grid for at least another 18 to 24 months.

They said the scale of the decline in headrace tunnel pressure (HRT) and dewatering of a 17km section of the tunnel indicated “some major crack or a collapse”, but the exact situation is still unclear.

Despite its installed capacity of 969MW, the project has on occasion exceeded this level, touching 1,040MW. When operational, it had been providing more than 5bn units of electricity (in kilowatt-hours) to the national grid annually at an average tariff of about Rs10 per unit, at no fuel cost.

Fault in headrace tunnel had necessitated shutdown of 969MW Neelum-Jhelum project a mere month after it achieved full capacity

The shutdown of the NJHPP means direct losses of more than Rs55bn per year, while its indirect impact would come in the shape of expensive replacement fuel, which could cost between Rs90 and Rs150bn, depending on the fuel source, an official said.

When asked by Dawn for comment, Neelum-Jhelum Hydropower Company Ltd CEO Mohammad Arfan declined, while Wapda chose not to comment after initially showing a willingness to respond.

Delayed probe

On May 2, Wapda officially confirmed the complete shutdown of the mega project for physical inspection of its HRT to locate the problem.

It had announced that a comprehensive plan would be chalked out, in coordination with the project consultants and international experts, to undertake remedial works to rectify the issue once the problem is traced.

Later, the prime minister visited the site on May 7 and announced a third-party investigation. However, it took more than two weeks after his announcement for a formal committee, led by a former bureaucrat, to be constituted.

The major fault is currently being investigated by the two-member body, which is also tasked with fixing responsibility for the mishap.

Led by former federal secretary Shahid Khan and incumbent Water Resources Secretary Syed Ali Murtaza, the committee was constituted late last month to “inquire into the flaws/shortcomings in construction of NJHPP after the incident of April 2, 2024”, according to a notification.

The committee has been asked “to ascertain the reasons for delay in submission of the findings/report of the Panel of Experts, hired in September 2022, for ascertaining the cause of blockage in the tailrace tunnel” of the project and to review the final report to be submitted by the panel.

The committee is also required to have an independent assessment of the fault in headrace tunnel (HRT) of the project through the international panel of experts hired earlier to ascertain the cause of tailrace tunnel blockage. It has been asked to recommend appropriate remedial measures to resolve the current fault in the headrace tunnel.

Responding to a question, an official said that while sabotage was a distant possibility, given the tight security arrangements and tens of kilometres of underground structures, it could not be completely ruled out in view of a recent maintenance exercise carried out at the tunnel.

The project is now under heightened security surveillance, he said, hoping that nothing would remain hidden for long.

Second shutdown in less than a year

According to Wapda, a sudden change in the HRT pressure was observed on April 2, 2024. Per the advice of project consultants, the management kept operating the plant at the restricted capacity of 530MW from April 6 onwards to monitor fluctuations in the HRT pressure and continued generating electricity until around the end of the month, without any issue.

But on April 29, further changes in the HRT pressure were observed. Subsequently, generation was gradually reduced, but the HRT pressure did not remain within safe limits, causing the plant to be shut down completely on May 1 for physical inspection.

Wapda said the project had a 51.5km tunnel system, constructed in a weak geological area prone to seismic activity. Its HRT is 48km long, while the tailrace tunnel (TRT) is 3.5km. About 90pc of the project is underground.

The project saw also complete closure earlier, in July 2022, due to major cracks in the TRT, which were repaired over 13 months. Power generation then restarted in August-September of 2023, while the plant attaining its maximum 969mw capacity on March 28.

But within a week, on April 2, the 48-km long HRT dropped pressure and power production fell to about 400MW. Earlier repairs to the 3.5-km TRT cost the exchequer about Rs6bn, in addition to about Rs37bn in energy loss during the course of repairs, maintenance and testing over the following 20 months.

Wapda has filed Rs43bn in insurance claims for the losses and is reported to have already held a series of high-level meetings on the subject.

Since its commissioning in 2018, the project has so far generated 19.83 billion units of electricity, while 1.54 billion units were generated since the resumption of generation following the rehabilitation of the TRT in August last year.

Published in Dawn, June 6th, 2024