AlQa'dah 22, 1432, Oct 20, 2011, SPA -- A Pakistani nuclear power plant imposed a seven-hour emergency after heavy water leaked from a feeder pipe to the reactor, but no radiation or damage has been reported, Reuters cited an official as saying on Thursday. The leakage at the Karachi Nuclear Power Plant, commonly known as KANUPP, started around midnight on Tuesday during a routine maintenance shut down, said Tariq Rashid, a plant spokesman. The 137-megawatt power plant, which started commercial operations in 1972, is located about 24 km (15 miles) to the west of Karachi, Pakistan's biggest city and commercial capital, on the Arabian Sea coast. "The plant was already shut down since Oct. 5 and the leakage started during maintenance checks," said Rashid. He said the emergency was imposed at the plant immediately after the leak and the affected area was isolated. The emergency was lifted seven hours later, after the leak was brought under control. "The situation is completely under control and no damage or radiation has been reported, though it will slightly delay the reopening of the plant," Rashid said. He said the plant will be operational again in 4-5 weeks. KANUPP supplies 80 megawatts of power to the Karachi Electric Supply Co, the city's main power utility. The plant completed its 30-year design life in 2002 and underwent upgrades to extend operations. "Currently it is well designed to work till at least 2015," said Rashid. Karachi's peak power demand is up to 2,500 megawatts. Pakistan has two commercial nuclear complexes. The other is located at Chashma in the Punjab province. Nuclear power accounts for only about 2 percent of total power supplies. China, which helped build the Chasma complex, plans to help Pakistan expand there by building two more reactors in addition to the two already operating there. Safety is a major concern in Pakistan's existing and future nuclear power plants, which analysts say are derived from designs dating back to the 1970s.