Karachi Nuclear Power Complex

Stand-alone 132 kV current transformers have been provided for protection and metering functions as substitute for the bushing current transformers in the bulk oil circuit breakers. KNPC and NESPAK engineers worked closely in devising a discriminative protection scheme and its integration into the complex systems of the nuclear power plant. Both circuits of KANUPP-Baldia double circuit lines have been re-energised with the new equipment. Performance indicators have since validated the intended objectives of the project vis-a-vis discriminative functioning of the protection system against disturbances in KESC power system for stable operation of KANUPP.

Since independence from United Kingdom in 1947, Pakistan had repeatedly suffered energy crises that have contributed to the country's economic slowdown. In 1960, President Field Marshal Ayub Khan appointed Abdus Salam as his Science Advisor.[1] Soon after, Abdus Salam became the head of Pakistan's IAEA delegation.[1] In that capacity, Abdus Salam advocated the UN General Assembly for the support of nuclear energy in Pakistan.[1] Due to Abdus Salam's influence on President Ayub Khan, Salam had the commercial nuclear plant near Karachi personally approved, in spite of opposition to the project from the military establishment.[1] In 1965, Abdus Salam traveled to United States, where in a ceremony, Canada and Pakistan signed a nuclear energy pact with Canadian General Electric (now GE Canada) establishing the country's first nuclear plant.[1] Per agreement, the Pakistan Atomic Energy Commission's engineers and scientists led the construction of the project, while GE Canada provided funds and natural uranium fuel. Parvez Butt, a nuclear engineer, was the chief designer of the plant at the GE Canada's designing office. In 1966, construction started, and it was completed in 1971. On 28 November 1972 then-President Zulfiqar Ali Bhutto, accompanied by Abdus Salam and the PAEC's newly appointed Chairman Munir Ahmad Khan, inaugurated the first unit of the Karachi Nuclear Plant.[2]

The technology of the nuclear power plant is similar to Canada's Nuclear Power Demonstration reactor (22 MWe, 1962-1985, also built by CGE); NPD was the prototype for the pressurized heavy water reactors that became the CANDU design. Munir Ahmad Khan, now as chairman, indigenously developed and established the nuclear fuel cycle programme. In 1972, Pakistan, under Bhutto, refused to sign the NPT. Because the reactor-grade plutonium was extremely dangerous to be open in public, the PAEC transferred it to the New Laboratories (known as The New Labs), and produced the first batch of fresh weapons-grade plutonium. In 1976, Canada stopped the supply of fuel and spare parts for the plant. The highly radioactive material was also left openly in Karachi as Canadian technicians departed from Pakistan. Pakistan media then speculated that in the absence of Canadian officials, the city would suffer a major power blackout. Canadian officials later stated that the reactor would be shut down in six months. However, the PAEC, using indigenous resources, produced sufficient feed for KANUPP. In 1978, the PAEC developed its own nuclear fuel and began loading the feedstock into KANUPP-I. As of 31 December 2017 KANUPP-I has generated 14.2 billion kWhr of electricity (net to grid, IAEA PRIS data) and been fueled by thousands of Pakistani-made fuel bundles without any failure.

The KANUPP reactor site is on the Arabian Sea coast, about 11 miles (17.7 km) west of Karachi. The Karachi Nuclear Power Plant (KANUPP) has a heavy water moderated and cooled natural uranium-fueled, horizontal pressure tube reactor. Other distinguishing features are once-through, on-power bidirectional fueling, reactor shutdown by moderator dump, and a reactor building designed for total containment of any pressure resulting from an accident.

The gross plant rating is 137 MWe and the corresponding net output is 125 MWe. The Nuclear Reactor Building contains the entire reactor system and auxiliaries, and consists of a pre-stressed concrete cylindrical wall, a hemispherical segmental dome of pre-stressed concrete, and a concrete base slab. The Turbine Building houses the turbine-generator and auxiliaries, water processing equipment, electrical distribution equipment, and the control room. The building is a reinforced concrete frame and block structure.

The reactor consists of a tubed calandria vessel of austenitic stainless steel, which contains the heavy water moderator/reflector and 208 coolant tube assemblies. The moderator system consists of the calandria, coolers, pumps and purification system in the heavy water circuit, and control valves, dump valves and helium blowers in the helium circuit. The fuel is natural uranium in the form of sintered uranium dioxide pellets sheathed in thin zirconium alloy tubes to form solid fuel elements about 19.1 inches (48.53 cm) long by 0.6 inches (1.4 cm) diameter.

KANUPP came into commercial operation in 1972 and after completing its 30 years of design life was shut down on 6 December 2002. The plant resumed operations in 2006. At present the plant is undergoing several safety upgrades for operation beyond design life. On the request of KANUPP, the Pakistan Nuclear Regulatory Authority allowed the plant to operate at 80 MW for the interim period. The PAEC has denied any media reports of shutting down the nuclear power plant, however, on 30 June 2009, a senior official of PAEC stated that the KANUPP would be decommissioned in 2012; the reactor was operating as of December 2018. The KANUPP-II, an indigenous nuclear power plant build by PAEC, will be taking the place of the KANUPP-I. In November 2013, Pakistan and China confirmed that two ACP1000 Nuclear reactors, KANUPP-2 and KANUPP-3, will be built at Karachi.[3]

On 18 October 2011 the KANUPP Karachi nuclear power plant imposed a seven-hour emergency after heavy water leaked from a feeder pipe to the reactor.[4] The leakage started around midnight on Tuesday during a routine maintenance shut down.[4] After the leakage was detected a state of emergency was imposed at the plant and the affected area was isolated. The emergency was lifted seven hours later, after the leak was reportedly brought under control.[4]