The emergency was declared at the Karachi Nuclear Power Plant (KANUPP) at midnight on Tuesday after the leak in the primary heat transport system of the nuclear plant at Hawkesbay was detected.
The emergency continued till 7 am yesterday, when the situation was brought under control. The News daily quoted its sources as saying that staff at the plant were safe from the effects of radiation and it may take two to three weeks for the plant to begin functioning again.
KANUPP spokesman Tariq Rasheed said the situation was now under control and there was no cause for concern.
The plant was closed since October 5 for repairs. The News quoted its sources as saying that one of the channels for carrying heavy water for cooling had to be opened for a check as the temperature had increased after the flow of water declined.
The channel was restored to normal operations after repairs. However, when the pump was started again, heavy water leaked from the feeder pipe.
The pipe was immediately closed down and the leakage decreased. Staff in protective gear isolated the damaged part by yesterday morning.
The effects of the leakage were "wiped off" and the state of emergency was withdrawn later the same morning.
A similar incident of leakage of heavy water had occurred at the plant about 20 years ago. At that time too, the staff remained safe from radiation.