Two 1,100MW reactor units are being added to the Karachi nuclear power plant in Pakistan. Credit: CNCC. Construction of new reactor units for the Karachi nuclear power plant started in 2015. Credit: CNCC. Karachi nuclear power plant will be the first nuclear power facility outside China to use the HPR1000 reactor design. Credit: CNCC.

Pakistan’s first nuclear plant in Karachi is undergoing a 2.2GW capacity extension with two 1.1GW pressurised water reactor (PWR) units of Chinese design.

The $10bn project is being built with financial assistance from China, the biggest energy and infrastructure investor in Pakistan.

Karachi nuclear power plant is located on the Arabian Sea coast, approximately 18km east of Karachi, and has been in service with a single 137MW reactor unit (Kanupp-1) since 1972. It is owned and operated by Pakistan Atomic Energy Commission (PAEC).

The construction of the Kanupp-2 and Kanupp-3 reactor units started in August 2015 and May 2016, with the start of commercial operations scheduled for 2021 and 2022 respectively.

Reactor units will have a design life of 60 years and account for approximately 10% of the country’s total generation capacity.

Karachi nuclear power plant’s new units and reactor design details

Kanupp-2 and Kanupp-3 will each consist of a nuclear island, conventional island and balance of plant.

Each nuclear island will house a Hualong One or HPR1000 (formerly ACP-1000) reactor from China.

“Reactor units will have a design life of 60 years and account for approximately 10% of the country’s total generation capacity.”

HPR1000 is a generation III+ three-loop PWR based on the design improvements over the China General Nuclear Power Group (CGN)’s ACPR-1000 and China National Nuclear Corporation (CNNC)’s ACP-1000 reactor models. All the six main pumps of the nuclear reactors were approved by March 2020.

The Hualong One advanced reactor design has a single stack layout, 177 nuclear fuel assemblies, a double containment structure and a combination of active and passive safety systems.

Each new reactor unit at Kanupp will have 1,100MWe gross electrical output and 3,060MWt gross thermal output.

Kanupp-2 unit will have two main circulating water pumps at the pump room, weighing 123t each with a motor power of 9000KW. The pumps will provide cooling water to the conventional islands of the power plant.

The reactors are designed to provide emergency cooling for 72 hours in the absence of electricity supply.

Kanupp-2 nuclear island details

The last concrete layer for the outer containment dome of Kanupp-2 reactor’s nuclear island was poured in April 2020. The height of the structure reached 73.98m.

The nuclear island has a two-layered containment. The outer layer is divided into a tube-like structure and a dome structure. Capping of the dome will provide a strong foundation for installation, debugging and operational purposes of the reactor.

Financing for Karachi nuclear power plant expansion

More than 80% of the estimated project cost is being financed through a loan from China’s state-owned Export-Import (Exim) Bank.

The remaining cost is being funded by the Public Sector Development Programme (PSDP) of the Pakistan Government.

Electricity transmission

The electricity transmission infrastructure works for the Karachi nuclear power plant expansion include the development of 220kV and 550kV transmission lines connecting to the national grid.

The National Transmission and Despatch Company (NTDC) of Pakistan will be responsible for the construction, operation and maintenance of the electricity transmission infrastructure for the project.

Contractors involved

China National Nuclear Corporation (CNNC) is the general contractor and reactor supplier for the project through its overseas nuclear project platform China Zhongyuan Engineering Corporation (CZEC).

The reactors are jointly developed by CNNC and China General Nuclear Power Corporation (CGN) using the ACP-1000 technology.

China Nuclear Engineering and Construction Group (CNECC) is engaged as a construction contractor.

Karachi nuclear power plant unit one details

Karachi nuclear power plant unit one comprises a 137MW single unit Canada Deuterium Uranium (CANDU) pressurised heavy-water reactor supplied by Canadian General Electric Company.

Fuelled by 30t of natural uranium, the reactor has a thermal output of 432.8MWt and gross electrical output of 137MWe.

Commissioned in 1972, Kanupp-1 outlived its 30-year design life in 2002. PAEC operates it at a reduced capacity with repairs and replacement.

Kanupp-1 is expected to be permanently shut down as soon as the new reactor units commence operation.