ISLAMABAD: On Thursday, the Water and Power Development Authority (Wapda) declared that the Neelum-Jhelum Hydropower Project, which has a value of about Rs500 billion and is 969 megawatts, has been shut down entirely for inspection.
According to a statement from Wapda, the decision was made in response to a serious operational problem that was discovered a month ago and caused notable pressure variations in the project’s headrace tunnel.
It stated that after the issue is identified, a thorough strategy will be developed in collaboration with project consultants and foreign specialists to carry out corrective actions to resolve the problem.
On April 2, an abrupt shift in the headrace tunnel pressure was noted. On April 6, the project management began operating the plant at a restricted generation of 530MW in order to monitor fluctuations in the headrace tunnel pressure, per the consultants’ advice regarding the safety of the tunnel.
Move comes after a significant operational problem that was discovered a month ago and caused a pressure reduction in the Neelum-Jhelum project tunnel
The Azad Jammu and Kashmir plant kept running smoothly at this lower capacity until April 29, when more instability in the tunnel pressure forced a step-by-step decrease in electricity output.
On April 29, “further change in the headrace tunnel pressure was observed” at approximately 11 p.m. The generation was then progressively decreased, however Wapda stated that despite the project consultants’ advise, the pressure could not be maintained within safe bounds.
Consequently, on May 1, at 6 a.m., the plant was closed in order to conduct a physical examination of the headrace tunnel and determine the cause of the decreased pressure, all while maintaining the safety of both the tunnel and the powerhouse.
Following a thorough consultation with consultants about the dewatering of the 48-kilometer tunnel, the intake gates at the dam site were lowered to facilitate the de-sander flushing process. To guarantee the safety of the tunnel, dewatering began from the powerplant side on the same day and will continue intermittently.
According to Wapda, the project features a 51.5 kilometer tunnel system built in a region prone to earthquakes and poor geology. There is a 48km headrace tunnel and a 3.5km tailrace tunnel. Ninety percent of the project is subterranean.
Due to significant cracks in its 3.5 km tailrace tunnel, the project was previously shut down entirely in July 2022. These flaws were filled over the course of the following 13 months. According to Wapda, power generating resumed in August–September 2023 and reached its maximum capacity of 969MW on March 28.
A week later, on April 2, “soon after the project was restored to full capacity by international contractors because of debris or cracks in the headrace tunnel,” inside sources informed Dawn, the headrace tunnel’s pressure dropped and power output reduced to roughly 400MW.
They said that although internal emergency procedures were attempted to restart the project by the project authorities, contractors, and Wapda management, the task proved more difficult than expected.
The tailrace tunnel pressure dropped when Dawn requested confirmation of the occurrence, which was not disclosed by the authorities to the government either. On April 14, however, it was verified that the plant’s generation had been curtained off as a precaution to monitor pressure fluctuation behavior because of lower tailrace tunnel pressure.
In addition to the approximately Rs37 billion in energy lost during repairs, maintenance, and testing over the next 20 months, the previous repairs of the tailrace tunnel cost the country almost Rs6 billion. Wapda is said to have already convened a number of high-level meetings on the matter and has submitted insurance claims totaling approximately Rs43 billion for the damages.
The Neelum-Jhelum Hydropower Project was put into service in 2018 and has produced 19.83 billion units of electricity so far. Of that amount, 1.54 billion units have been produced since the tailrace tunnel’s restoration in August of last year.
After a 21-year delay, the project’s construction started in 2002 and was finished in April 2018 despite numerous cost overruns and missed deadlines.
Hired in December 2007, the China Gezhouba Group Corporation (CGGC) handled the principal construction work, which included building around 58 km of tunnels.
After a 21-year delay, the project’s construction started in 2002 and was finished in April 2018 despite numerous cost overruns and missed deadlines.
Hired in December 2007, the China Gezhouba Group Corporation (CGGC) handled the principal construction work, which included building around 58 km of tunnels.
