ISLAMABAD:
The 969-megawatt (MW) Neelum-Jhelum Hydropower Plant was shut down on Wednesday for a physical inspection of its head race tunnel to identify the problem, which led to a decrease in its pressure a month ago, it emerged on Thursday.
Once the problem is traced, a comprehensive plan will be chalked out in coordination with the project consultants and international experts for undertaking remedial works to rectify the issue, read a news statement.
It stated that a sudden change in the head race tunnel pressure was observed on April 2 this year.
As per the advice of the project consultants for the safety of the head race tunnel, the project management kept operating the plant at a restricted generation of 530 MW since April 6. This was carried out to monitor any fluctuation in the head race tunnel pressure.
The Neelum-Jhelum Hydropower Plant continued generating about 530 MW of electricity till April 29 without any issue.
However, at 10:57pm on April 29, a change in the head race tunnel pressure was observed.
Subsequently, the generation was gradually reduced but the pressure could not sustain within the safe limits as per the advice of the project consultants.
Keeping in view the safety of the powerhouse, the plant was shut down at 6am on May 1 for a physical inspection of the head race tunnel to identify the problem of the reduced pressure.
After a detailed discussion with the consultants for dewatering of the 48-kilometre long tunnel, the intake gates at the dam site were lowered for flushing of the de-sanders.
The dewatering started from the powerhouse side on the same day. The dewatering will be executed at intervals for the safety of the tunnel.
The Neelum-Jhelum Hydropower Project has been constructed in a weak geological and seismic-prone area. It has a 51.5-km long tunnel system. Its head race tunnel is 48-km long. Similarly, it tail race tunnel is 3.5-km long. About 90% of the project is underground.
Earlier, the plant was shut down in 2022 for the repair of the tail race tunnel downstream of the powerhouse.
After the completion of the repair and rehabilitation work, the plant resumed electricity generation in August 2023.
However, the operations of the power project were suspended again on January 10 for the examination of its tail race tunnel.
A low-flow season was chosen for the inspection of the tunnel.
A comprehensive examination of the tunnel was successfully completed during the closure.
It eventually resumed power generation in March, reaching its full capacity later that month.
The project was constructed in 2018 on Neelum River in Azad Jammu and Kashmir (AJK).
It provides an average of 4.06 billion units of electricity to the national grid every year.
The Neelum–Jhelum Hydropower Plant has generated 19.05 billion units of electricity since it became operational.
