on 14 September 2000. After the first reactor unit, the Pakistan Nuclear Regulatory Authority (PNRA) refrained the PAEC to start working on the second unit right away because the agency wanted to monitor the nuclear reactor for its safety and performances for at least 3-years— first year and half for nominal power and rest of the time at full power as this is the most critical phase. In May 2004, the Nuclear Regulatory Authority allowed the Pakistan Atomic Energy Commission to sign the contract with the China National Nuclear Corporation (CNNC) to start the work on the second reactor, CHASNUPP-II, which would be modeled as similar to CHASNUPP-I design. The construction of the second unit start on 27 December 2005 and achieved its critical phase on 21 February 2011. The CHASNUPP-IIjoined the nation's electricity grid system on 13 March 2011 and commenced its official operations on 17 May 2011. The second unit, C2, is also a CNP-300 reactor with nominal difference of generating a gross electrical capacity of 325 MWe with a net output of about 300 MW. The reactor was designed and built in Pakistan with local industry's participation. Pakistani administration eventually financed the commercial nuclear power plant for industrial usage and reportedly contracted Chinese National Nuclear Corp. for overseeing the second unit to be installed, which was officially inaugurated on 10 May 2011 by former Prime Minister Yousaf Raza Gillani. The Pakistani government provided finance of US$860 Mn, with Chinese banks loaning the nation US$350 Mn. C3 and C4 On 28 April 2009, a general engineering and design contract for third and fourth units were signed with Shanghai Nuclear Engineering Research and Design Institute at the cost of US$2.37 Bn. Construction of CHASNUPP-III begin on 28 May 2011 and it went on its critical phase on 1 August 2016. The CHASNUPP-III joined the nation's electricity grid system on 15 October 2016 and commenced its operations on 6 December 2016. The CHASNUPP-III is a 315-MW two-loop pressurized water reactor (PWR), using between 2.4—3.0% low-enriched uranium (LEU) fuel with a gross capacity of 340 MW. The CHASNUPP-IV is also a CNP-300 type and is a 315-MW two-loop pressurized reactor with a gross capacity of 340 MW. Construction of the fourth reactor started on 18 December 2011 and it went critical on 15 March 2017. The CHASNUPP-IV was connected to nation's grid system on 25 June 2017, and commenced its operations